Toray RO
Handling
ManualLast updated March 2024
06-G-MB1-240305

Toray Reverse Osmosis Membrane Element

NoticePlease use our products in compliance with the laws and regulations applicablein each country and region.
The data and information contained in this document are based upon rigorous
technical testing by Toray and is to the best of our knowledge reliable. Toray
cannot control design and operating conditions, and consequently Toray does
not assume any liability for results obtained or damage incurred through theapplication of the information provided herein. No liability, warranty or guaranteeof final product performance by Toray is implied by the information provided inthis document.
This manual supersedes all previous versions. Technical modification of
products or production technology may necessitate changes to information inthis manual without prior notice. Please verify that your version of the manualis the latest version available by either contacting Toray, or checking online athttps://www.water.toray.
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When using this document, please read the Terms and Conditions of Use below thoroughly and agree tothem before using this document. By using this document, you agree to all of the Terms and Conditions of Use
outlined here. The Terms and Conditions of Use are subject to change without prior notice, so please checkwith Toray for the latest Terms and Conditions of Use before using the document.
1.

Intellectual Property Rights
The content in this document is protected by copyright laws in respective countries and relevant
treaties. Accordingly, the document's information may not be reproduced, altered, or distributed without
permission in writing from Toray. We permit downloading this document through Toray's website as a
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prohibit transferring this document to any other websites or printed media. The material contained inthis document may not be used without permission from the copyright holder for any other purpose thatexceeds the scope permitted under copyright law.

2.

Trademarks
The "TORAY" company name used in this document is a trade name, and the names of products
manufactured by Toray are trademarks or registered trademarks. Toray's trade names and trademarks
are protected under the Japanese Trademark Law, the Unfair Competition Prevention Law, and otherlegislation. The trade name and trademarks may not be used or reproduced without express permission
from Toray.

3.

Disclaimer
Toray takes all reasonable care in updating the information in this document. However, Toray makes
no representation and warranty of any kind, either express or implied, including without limitation, any
implied warranties concerning the accuracy, usefulness, suitability, or fitness for a particular purpose of
the information in the document.
Toray shall not be responsible or liable for any losses or damage incurred due to the use of theinformation in this document. The information in this document is subject to change without prior notice,and Toray reserves the right to suspend or discontinue the publication of this document.

4.

Availability of Goods and Services
The goods and services contained in this document are not available in all countries and regions. Goods
and services may also be supplied under different trademarks in different countries. We ask that you
contact your nearest Toray representative's office if you wish to use the goods and services shown or
implied in this document.

5.

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This Terms and Conditions of Use shall be governed by and construed according to the laws of Japan.
Any and all disputes arising out of or relating to this document shall be brought to the Tokyo District
Court Tokyo, Japan.

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Contact Information
Toray Industries, Inc. — RO Membrane Products Department Global Headquarters
Nihonbashi Mitsui Tower, 1-1, Nihonbashi-Muromachi 2 chome, Chuo-ku, Tokyo, 103-8666 Japan
Tel: +81-3-3245-4540 Fax: +81-3-3245-4913
Toray Membrane USA, Inc. (TMUS)
13435 Danielson Street, Poway, California 92064 USA
Tel: +1-858-218-2360 Fax: +1-858-218-2380
Toray Membrane Europe AG (TMEU)
Grabenackerstrasse 8b, Muenchenstein 1 CH-4142, Switzerland
Tel: +41-61-415-8710 Fax: +41-61-415-8720 E-mail: info.tmeu.mb@mail.toray
Toray Asia Pte. Ltd. (TAS)111 Somerset Road, #14-22-#14-27, Singapore 238164, Republic of Singapore
Tel: +65-6226-0525 Fax: +65-6226-0509
Toray BlueStar Membrane Co., Ltd. (TBMC)
Zone B, Tianzhu Airport Industrial Zone, Beijing 101318, China
Tel: +86-10-8048-5216 Fax: +86-10-8048-5217
Toray Membrane Middle East LLC (TMME)
3515, 3rd Industrial City, 8682, Dammam, 34857, Kingdom of Saudi Arabia
Tel: +966-13-568-0091 Fax: +966-13-568-0093
Toray Advanced Materials Korea Inc. (TAK)
Korea Toray R&D Center 7, Magokdonng-ro 10-gil, Gangseo-gu, Seoul 07790, Republic of Korea
Tel: +82-22-3279-7389 Fax: +82-2-3279-7088

website: https://www.water.toray

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TABLE OF CONTENTS
TMM-100
Introduction - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 6
TMM-200
Installation of RO Elements - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 7
		Before Installation - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 7
		Unpacking the Elements - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 8
		Installation of Spare Parts onto the Elements - - - - - - - - - - - - - - - - - - - - - 12		Insertion of Elements - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 13		Documentation of the Loading Process - - - - - - - - - - - - - - - - - - - - - - - - 16		Initial Start-up Checklist - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 16
TMM-210
Element Removal - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 17
TMM-220
Start-up Checklist for RO - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 18
		
Pre-Commissioning Checklist - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 18
		Regular Start-up Checklist for Daily Operations - - - - - - - - - - - - - - - - - - - 21		Parameters for Start-up Procedures - - - - - - - - - - - - - - - - - - - - - - - - - - - 22		General Start-up Procedures for Different HPP Configurations - - - - - - - 23
TMM-230
Operation Monitoring - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 26
		Monitoring - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 26
		Regular Monitoring and Checkpoints - - - - - - - - - - - - - - - - - - - - - - - - - - 26
		Logbook - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 27		Normalization of System Performance - - - - - - - - - - - - - - - - - - - - - - - - - 27		Precautions and Useful Information for Monitoring Operating Data - - - 28
		RO System Operation Parameters and Logging Intervals - - - - - - - - - - - 29		Normalization Program — TorayTrak - - - - - - - - - - - - - - - - - - - - - - - - - - - 37
TMM-240
Shutdown Considerations for RO systems - - - - - - - - - - - - - - - - - - - - - - - - 41
		Short-term Shutdown - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 42		Long-term Shutdown - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 42
TMM-250
Flushing Procedures - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 44
TMM-260
Preservation of RO Element Inside the Pressure Vessel - - - - - - - - - - - - - - 45
TMM-300
General Instructions and Conditions for RO Cleaning - - - - - - - - - - - - - - - 47
TMM-310
Guidelines for RO cleaning - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 48
		When to Clean - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 48
		Determining Foulant Type - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 48
		Selecting the Right Cleaning Method - - - - - - - - - - - - - - - - - - - - - - - - - - 49		Typical CIP Procedure - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 49
		Evaluating Cleaning effectiveness - - - - - - - - - - - - - - - - - - - - - - - - - - - - 49
TMM-320
Instructions for Chemical Cleaning - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 50
		General Guidelines - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 50
		Membrane Cleaning System Design Considerations - - - - - - - - - - - - - - 53
		Important Notes - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 54
TMM-330
Citric Acid Cleaning Procedure - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 55
		Flushing of elements - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 55
		Preparing a 2 wt% Citric Acid Solution - - - - - - - - - - - - - - - - - - - - - - - - - 55

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		Circulation of Cleaning Solution - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 		Flush Elements - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 		General Description of Citric Acid - - - - - - - - - - - - - - - - - - - - - - - - - - - - 		General Description of Ammonia Solution - - - - - - - - - - - - - - - - - - - - - - TMM-340
DSS (Dodecyl Sodium Sulfate) Detergent Cleaning Procedure - - - - - - - - 		Flushing of elements - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 		Preparing a 0.03 wt% DSS Solution - - - - - - - - - - - - - - - - - - - - - - - - - - - 		Circulate Cleaning Solution - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 		Flush Elements - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 		General Description of DSS (Dodecyl Sodium Sulfate) - - - - - - - - - - - - 		General Description of TSP (Trisodium Phosphate) - - - - - - - - - - - - - - - 		General Description of NaOH (Sodium Hydroxide) - - - - - - - - - - - - - - - TMM-350
Acidic SHMP CIP Procedure - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 		Flushing of Elements - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 		Preparing a 1 wt% SHMP Solution - - - - - - - - - - - - - - - - - - - - - - - - - - - - 		Circulate Cleaning Solution - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 		Flush Elements - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 		General Description of SHMP (Sodium Hexametaphosphate) - - - - - - - TMM-360
Reverse Flow CIP / Flushing - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - TMM-400
Sanitization Methods for RO/NF Elements - - - - - - - - - - - - - - - - - - - - - - - 		Sanitizing Solutions - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 		Biocide - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - TMM-410
Heat Sanitization of RO Elements (TMRO and TS types)- - - - - - - - - - - - - TMM-500
Storage - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 		General Guidelines - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 		Storage of New Elements - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 		Storage of Used Elements - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - TMM-600
Introduction to Troubleshooting - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 		Permeate Center Pipe Probing Method - - - - - - - - - - - - - - - - - - - - - - - TMM-610
Typical Performance Changes and Countermeasures - - - - - - - - - - - - - - - 		Case A: Normalized Permeate Flow Rate (NPFR) Decline: First Bank - - 		Case B: Normalized Permeate Flow Rate (NPFR) Decline: Last Bank - - 		Case C: Normalized Salt Passage (NSP) Increase: All Vessels - - - - - - - 		Case D: Normalized Permeate Flow Rate (NPFR) Decrease:
All Banks Simultaneously - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 		Case E: Normalized Permeate Flow Rate (NPFR) Decrease:
All Banks Simultaneously with Variations for Individual Brine Stages - - 		Case F: Differential Pressure (DP) Increase - - - - - - - - - - - - - - - - - - - - - 		Case G: Normalized Salt Passage (NSP) Increase:
Individual Vessels - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - TMM-700
Policy for Chemical Compatibility Test - - - - - - - - - - - - - - - - - - - - - - - - - - - TMM-800
RO Feed Water Guidelines - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

56
56
57
57
58
58
58
58
59
59
60
60
61
61
61
61
62
63
64
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65
66
67
68
68
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69
70
70
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74
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76
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TMM-100 INTRODUCTION
GeneralTMM-100

Section page
1 of 1

Proper operation and maintenance of reverse osmosis (RO) system are
key factors in maximizing long-term plant availability and efficiency andminimizing fault-related downtime.
This manual contains checklists and procedures for commissioning elements
at start-up as well as providing useful information relating to regular operationand maintenance procedures. Separate sections cover data recording of
membrane element performance and normalization.

Conventional Symbols
This symbol indicates either an imminent or potentiallyhazardous situation which will result in serious property
damage, injury or death when the instruction is not observed.
This symbol indicates an important action or procedure
which has to be taken without fail.

This symbol indicates a useful tip to handle Toray reverse
osmosis membrane elements properly and effectively.

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TMM-200
Section page
1 of 10

TMM-200 INSTALLATION OF RO ELEMENTS
Before Installation
1.

Before feeding pre-treated into the elements, make sure the piping systemand pressure vessels are free of dust, oil, metal residues, organic deposits,
and other debris or contaminants. Repeat this procedure when elements
are reloaded or replaced.

2. Verify that the feed water quality matches the system design values.
3. Flush the empty system with pre-treated RO feed water to completely
remove all contaminants.
4. Remove end plates from both ends of pressure vessels, check inside of thevessel and if necessary clean mechanically.
INSTRUCTION. Clean the inside of the pressure vessels if they are dirty.
Use a soft mop or swab, occasionally flushing the vessel with pre-treatedwater. Be careful not to scratch the inside surface of the pressure vessels.
5. Install the permeate adapter with o-rings into the permeate port of brine side
end plate. Lubricate both parts using glycerin. Use the thrust ring according
to the following note.
with “thrust ring”
8-inch TM type(TM, TLF, TSW, TBW-series)

without “thrust ring”
othersEnsure that the thrust ring for the absorption of axial thrust (this is a part ofthe pressure vessel) is installed for the TM Type (“TM”, “TLF”, “TSW” and“TBW” series) 8-inch elements to transmit axial forces from the brine side
element (this is the first installed element).
6. Optionally and at this stage, insert the permeate adapter with o-rings into
the permeate port of the brine side end plate. If this installation is carried out
as the last step before re-fitting piping connections, the risk of seal damage
can be minimized.
7. Attach the brine side end plate onto the brine side of the vessel and install
the retaining ring set according to the pressure vessel's instruction manual.
USEFUL TIP. Remove the head seal before insertion to facilitate the final
control of element installation. Verification of full element insertion is easier
this way since the installed head seal usually provides additional resistanceupon removing the endplate.
INSTRUCTION. Each element package shipped from Toray contains
all necessary parts except the pressure vessel permeate adaptors. The
pressure vessel manufacturer typically supplies the permeate adaptors andthrust devices. To ensure the pressure vessel manufacturer provides all of
the correct parts, please specify the type of RO element that will be installed

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TMM-200
Section page2 of 10when ordering pressure vessels.

Unpacking the Elements
Concerning the proper storage of RO elements before unpacking, please referto section TMM-500: Storage of RO Element Outside of the Pressure Vessel.
Toray recommends that new elements are stored in their original packaging
until the products are ready to be loaded into the pressure vessels just before
system start-up. Keeping the RO elements in its original packaging will help
prevent any foreign debris from coming into contact with the RO element andaffecting performance. One or two RO elements are packed in one carton box.
1.

Open element boxes and remove RO elements and accessories. The
accessories are separately packaged in small plastic bags inside theelement box. Handle the element with care to avoid damage. Place empty
boxes aside.
Packaging materials(1) Plastic bags for RO element
Inner bag: Composite film (Polyethylene / Polyamide / Ethylene-vinyl
		alcohol copolymer)
Outer bag: Polyethylene*Some types of elements are packed in the inner bags only.
(2) Plastic bags for brine seal and interconnector: Polyethylene(3) Cap: Polystyrene (Styrofoam)(4) Carton box: Cardboard paper(5) Pallet: Fumigated wood

2. Prepare the necessary parts, as shown in Table TMM-200-1.
Table TMM-200-1
Parts

Required Quantity

Brine seals

One per element

O-rings

4 pieces per element

Permeate port adaptor (open)*

One or two per pressure vessel

Permeate blind plug adaptor (solid)**

One per pressure vessel (optional)Interconnectors(qty. of elements) − (qty. of pressure
vessels)*The permeate port adaptor is not supplied by Toray. Please contact the engineering
company to inquire about or obtain the part.
**End port pressure vessel requires a permeate blind plug adaptor.

lubricateasneeded

3. If required, assemble interconnectors with supplied o-rings carefully
to avoid any scratches. Use glycerine as a lubricant. Keep assembled
interconnectors in a clean place until inserting them into permeate tubes Figure TMM-200-1(Figure TMM-200-1).
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TMM-200
Section page
3 of 10INSTALLATION OF RO ELEMENTS
4. Safety considerations before opening the packing bags and removing the
RO element:
DANGER. When shipped from Toray, new elements are packaged inapproximately 0.5–1.0 wt% sodium bisulfite solution, or sodium chloride
solution with an oxygen scavenger. Do not ingest these solutions andhandling them may irritate the eyes and skin. Personal protective equipment
is required when handling. Please refer to the safety data sheet (SDS) for
sodium bisulfite for additional handling instructions and information.
The element shell is FRP (Fiber Reinforced Plastic). Beware of glass fiber
strands and use correct safety equipment.
5. Cut open the element's shipping bag and prepare for insertion, following
illustrations provided below.
INSTRUCTION. Handle elements with care. Avoid dropping on hardsurfaces. Use clean personal protective equipment (e.g., gloves, goggles)
and avoid contamination of the element surfaces.
USEFUL TIP. Toray elements indicate a flow direction arrow on the element
label to ensure that the brine seal is oriented correctly during installation.
The arrow does not imply a mandatory installation direction – the element
can be installed either way. The important point is correctly installing thebrine seal relative to the direction of brine flow (see illustrations below).
Sample procedure A: removing the bag from an element packaged with
polystyrene foam endcaps at both side.
Cut open the polybag at
the top end.

Push the polybag down
and leave the upper
styrofoam cap in place for
Step 3.

1

2

push down

PPE Required!

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TMM-200

Flip the element onto theopen end and stand it on
the styrofoam cap.

Remove the top foam cap
together with the polybag.

3

4Section page
4 of 10USEFUL TIP. The polybags are made of unique oxygen barrier materials formaintaining the lifetime of the oxygen scavenger packaged inside the bag. If
the bags are carefully cut open at one end, they can be stored and reused later
if any RO elements need to be conserved or shipped. It is also a good idea toretain some packaging boxes if an element needs to be stored.
INSTRUCTION. Handle the element with care when standing it on the floor to
avoid breaking the oxygen scavenger sachet on the element's feed side. The best
recommendation is to lay the element on a table and cut open the polybag.

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TMM-200

INSTALLATION OF RO ELEMENTS
Sample procedure B: removing the bag from an element packaged with a small
polystyrene foam endcap only at the feed side.
Push the outer polybag
down and remove theelement still inside theinner polybag.

Cut open the inner polybag
at the top end.

1

2

Push the inner polybag
down.

Remove the element from theinner polybag.

3

4

push down

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INSTALLATION OF RO ELEMENTS

TMM-200

Section page
6 of 10Installation of Spare Parts onto the Element
1.

Brine seal: Toray elements shipped from Toray Membrane USA (TMUS),
Toray Membrane Middle East (TMME), Toray Bluestar Membrane (TBMC),
Toray Membrane Foshan (TMFC) and Toray Advanced Materials Korea (TAK)comes with the brine seal pre-installed. Customers who received elementsfrom TMUS, TMME, TBMC, TMFC or TAK can skip this step and only checkthe correct position of the seal. For other regions, follow the instructions
illustrated in Figures TMM-200-2 and TMM-200-3.
Top
Brine seal

TM style element

Toray

Figure TMM-200-2
Bi-directional brine seal "TORAYSEALTM" is in some cases useful to easier loading
due to reduced friction. "TORAYSEAL" is not the standard brine seal which isincluded in the new RO elements. Please contact Toray or its representative
before using the seal.

Figure TMM-200-3 TORAYSEALTM
2. Install the interconnector. Lubricate using glycerine as needed before theinstallation.

Figure TMM-200-4
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TMM-200
Section page
7 of 10INSTALLATION OF RO ELEMENTS
Insertion of Elements
INSTRUCTION. Work with a team of more than two people.
Verify the position and direction of the v-shaped brine seal, as shown in Figure
TMM-200-5.
Brine seal

Feed flow

Brine flow

Toray

TM style element

Figure TMM-200-5: Orientation of brine seal
CAUTION. Only one brine seal per element is required. DO NOT INSTALL TWO.
The brine seal is typically fitted at the feed end of the element.
If not already done, open the feed side of the RO pressure vessel.
Prepare by removing any head locking devices before unpacking the elements(if site conditions allow this).
Lubricate the inside of the RO pressure vessel with water and glycerine tofacilitate the installation process (especially with longer pressure vessels
containing multiple elements). Consider using approximately 100 mL of glycerine
for each pressure vessel. If the glycerine's viscosity is too high, dilute it withclean water as needed to improve lubrication.
Minimize the ingress of foreign matter, dust, and dirt to the pressure vessels by
only opening and closing one vessel at a time.
Use a clean, soft mop, swab, or similar tool to lubricate the pressure vessel's
full length, as shown in Figure TMM-200-6. Take precautions not to scratch
the inner surface of the pressure vessel.

Figure TMM-200-6: Lubrication of RO vessel

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TMM-200

After lubricating the brine seals and pressure vessel's inner surface withglycerine, insert the element from the feed side into the pressure vessel.
Approximately two-thirds of its length should be in the vessel, and one-third
outside the vessel (see Figure TMM-200-7). Insert the element carefully,
especially the first element.

Section page
8 of 10

Pressure
vesselFigure TMM-200-7: Insertion of first element
CAUTION. Carefully handle the element to avoid jamming fingers between thevessel's edge and the element and preventing an injury.
Attach brine seal to the second element as same for the first element. Connect
the two elements through the inter-connector if not preinstalled already (seeFigure TMM-200-8). The partly inserted element should be held in place by asecond person. Carefully push both elements firmly into the pressure vessel,
keeping them in line to avoid damage to the inter-connector or brine seal.

Pressure
vesselFigure TMM-200-8: Insertion of subsequent elements
Repeat the above steps and insert elements one by one into the pressure vessel.
Insert the last element until only one-third of the element is outside the vessel.
Locate and install correctly brine end permeate adaptor (with o-rings) into thebrine side end plate's internal permeate port.
Note: If permeate is collected from the brine end of the pressure vessel, install
the permeate port adaptor. If permeate is not collected at the brine end, install
the solid permeate plug adaptor.
Lubricate all o-rings with glycerine. Note: this step can wait until before installingthe end plate into the pressure vessel to minimize any risk of o-ring damage.
Locate and install thrust ring into the brine side end of the pressure vessel (ifneeded).
INSTRUCTION. A Thrust Ring is typically necessary for 8-inch and larger diameter
elements. Its purpose is to help absorb axial loads transmitted through theelements in the vessel during operation. Ensure it is installed, and omitting thethrust ring may result in mechanical damage to downstream elements.

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TMM-200
Section page
9 of 10INSTALLATION OF RO ELEMENTS
Insert brine side end cap into the brine side of the pressure vessel and installretaining ring set according to the pressure vessel manufacturer's instructions.
USEFUL TIP. Check for the complete insertion of the adaptor into thedownstream element and correct positioning of the brine side end plate relative
to the retaining ring groove by first removing the end plate seal (located on thecircumference of the end plate). This reduces the resistance to movement of
the end plate. The end plate seal MUST be replaced prior to final installation of
the end plate.
Push the last element until the downstream element's permeate adaptor tube
is firmly connected, and the brine side end plate is securely located against theretaining ring set.
The elements cannot be allowed to move in the axial direction to prevent
premature wearing of the permeate seal rings. The pressure vessel manufacturer
typically supplies the permeate ports. Shim rings are also generally available
from the pressure vessel manufacturer to fill remaining gaps or tolerances (seeFigure TMM-200-9).
Feed flow

Brine flow

Feed side

Brine side

Gap

Toray

TM style elements(1 to 8 elements)

Brine flow

Plastic washers("shim rings")
Permeate adaptor
closed version

Figure TMM-200-9: Applying shim rings

Thrust ring(for TM, TLF, TSW,
TBW-series 8-inch)

After installing all membranes, check distance "A" (see Figure TMM-200-10). If
distance "A" is larger than the thickness of the shim provided by the pressure
vessel manufacturer, use the shim to fill the excess distance. The remaining
space should be smaller than the thickness of the shim. Shims must be
positioned on the upstream end of the vessel.
The risk of mechanical disconnection of permeate adapters is high if thepermeate header is connected to the pressure vessel's feed side. Installing thepermeate output connection to the pipework on the pressure vessel's brineside is recommended over the feed side.

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INSTALLATION OF RO ELEMENTS•

Free gap length: A = D − (B + C)•

Requested number of shims (t = shimthickness): N = (A − 1 mm) / t

TMM-200

Section page
10 of 10Figure TMM-200-10:
Shimming procedure

Permeate ports not used are best plugged with "closed" or "solid" type permeate
adaptors (permeate plugs) supplied by the pressure vessel manufacturer. Plugging
provides the best protection against the brine entering the permeate stream.
Attach the feed side end plate of the pressure vessel and fit the piping system to
end plates. IMPORTANT: Make sure to install head seals for all pressure vesselend plates at this time.

Documentation of the Loading Process
Toray membrane elements bear unique serial numbers, which can trace element
origin and factory test results. Toray recommends recording the serial numbersof RO elements during the loading process, indicating their exact installed
location. A successful way to do so is to create a "membrane map" or "loading
diagram" similar to the sample below. Identification of the pressure vessel andelements are essential for performance monitoring and troubleshooting.
Pressure vessel
no. (or row/column
position

Brine

Element# 123456

Anotherelement #’s

Element #123456

Feed

Pressure vessel
no. (or row/column
position

Brine

Element# 123456

Anotherelement #’s

Element #123456Feed

Use spreadsheet software to accomplish this task efficiently and effectively.

Initial Checklist for Start-up
After connecting all piping works, go through the checklist for initial start-up, as
described in section TMM-220: Start-up Checks for RO.

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TMM-210

Section page
1 of 1

TMM-210 ELEMENT REMOVAL
Due to inspection, long-term storage, shipment, or replacement purposes,
elements may have to be removed from the pressure vessels.
The procedure to remove elements is as follows:
CAUTION. Before removing the connection from the feed, brine, andpermeate piping ports on the pressure vessel, drain the water remaining in
the pressure vessel to release the inside pressure.
1.

Remove connection fittings from the feed, brine, and permeate piping portson the pressure vessel.
USEFUL TIP. For side port and multiport pressure vessel configurations,removing the permeate piping connections from the end plates is only required.

2. Remove the pressure vessel end plates from both the feed and concentrateends of the pressure vessel.
3. Push the element stack into the vessel from the feed end of the pressure
vessel. Push the element stack forward, so the brine end element sticks outof the pressure vessel far enough for the operator to grip the element andpull the remaining element out of the pressure vessel.
4. When removing the downstream element from the pressure vessel'sbrine end, pull the element straight out. Do not apply any load up, down,or side to side on the interconnector that connects the element being
removed to the upstream element(s) remaining in the pressure vessel.
Excessive load can damage the interconnector, product tube, brine seal,
or interconnector O-rings.
5. Repeat steps 3 and 4 to remove the remaining element(s) in the pressure
vessel. A section of the PVC pipe can push the elements forward towards
the vessel's brine end for removal.
6. Remove and retain all interconnectors and permeate end plate adapters
as these parts may be reused. It is good engineering practice to replace allo-ring seals and brine seals with new ones before replacement.
If you expect to re-install the elements soon, we recommend the elements are
immediately repackaged into clean plastic bags (see TMM-500: Storage).
For reloading of RO elements, follow steps outlined in TMM-200: Installationof RO Elements.
For proper disposal of removed elements as industrial waste, please checklocal regulations and discard accordingly.

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TMM-220 START-UP CHECKLIST FOR RO
Pre-commissioning Checklist
1.

TMM-220

Section page
1 of 8Before loading RO elements and allowing water to enter the RO system,
check the following:•

Feed water quality matches design values for selected RO elements.

•

Verify that the pipework installation is free of all debris such as dust,
grease, oil, metal residues.

•

Ensure the system's cleanliness and, if necessary, clean according to
TMM-200: Installation of RO Elements.

•

Slit Density Fouling Index (SDI15)•

Turbidity (NTU)•

Chlorine and any other oxidants are absent from the RO feed.

•

Sufficient bisulfite surplus can be dosed (if used for chlorine removal).

•

Verify that all instruments and components are operating correctly.
CAUTION. If chlorine dioxide is used for raw water sanitation, a
combination of bisulfite dosing and activated carbon is strongly
recommended for the total removal of oxidants. Experience has shownthat bisulfite dosing alone is insufficient for raw water sanitation.

•

Pretreatment is working correctly. Ensure the dosing of any flocculants
used in the pretreatment (particularly cationic compounds and somenonionic compounds) are optimized, so such compounds are notpresent in the RO feed water.
CAUTION. Filter Cartridges must be free of surfactants, lubricants,
and textile aides. Either ensure the filters are supplied without such
additives or, if unsure if they are present, flush the cartridges according
to cartridge manufacturer's published guidelines.
Install RO elements (refer to Section TMM-200: Installation of RO
Elements). Ensure all fittings are tight (particularly Victaulic® couplingsand pressure vessel end plate retaining rings).
CAUTION. Seal the pressure vessels as soon as possible, or a maximum of
12 hours after element installation. Conduct air purging and initial trial run
without undue delay after confirming that fittings are tight and establishingmechanical safety. Avoid storage in stagnant water. Installed elements
may remain in closed pressure vessels without contact with any water
for up to four days. The product warranty does not cover performancechanges resulting from the drying up of membrane products.

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TMM-220

Section page2 of 8START-UP CHECKLIST FOR RO
2. Following element installation, purge air from the piping system, including
all headers and RO vessels, for a minimum of one hour. Use pre-treated feedwater at low feed pressure, with the brine valve fully opened. Pay attention
not to exceed allowed ranges for flow and differential pressure in the data
sheet!
A mixture of air and water present in the piping may lead to water
hammering. We recommend venting the piping to the atmosphere to purge
any entrained air while filling the piping. Keep the initial flow rate low to
avoid unsafe conditions.
Once brine flow discharges from the brine piping, increase the flushing flowrate to expel any remaining air present in the piping through the vent ports.
Some pockets of air can be challenging to remove. We recommend startingand stopping the flush procedure several times to help move any remaining
air pockets to the venting port(s). Continuous flushing may only pressurize
the air while allowing it to remain trapped in the piping.
Suggested flush flow rates when venting air from piping depend on thepressure vessel diameter.
•

For 8-inch vessels, regulate the flush flow rate to 40 L/min (11.0 gpm)
per each vessel in parallel.

•

For 4-inch vessels, regulate the flush flow rate to 10 L/min (3.0 gpm)
per each vessel in parallel.

While flushing to remove air in the piping, keep the line pressure < 0.1 MPa(15 psi).
It is essential to open any permeate side isolating valves and minimize
permeate side back pressure during the flushing procedure. Brine pressure
should always be higher than permeate side pressure to avoid permeate backpressure problems.
For detailed instructions for flushing, see TMM-250: Flushing Procedure.
Pressure drop (feed to brine) across a pressure vessel / a single RO element
Element types TM

Per vessel

Per single element

8-inch and 4-inch

0.34 MPa (50 psi)

0.10 MPa (15 psi)

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must never exceed the following values:

TMM-220

Section page
3 of 83. After bleeding all air from the system, the initial trial run for the RO cancommence according to design operating parameters.
In particular, adjust the Permeate flow rate and Recovery ratio parameters
to design values. Also, check the Operating pressure.
If the operating pressure is much higher than expected, conducttroubleshooting exercises to determine the cause, such as:a) If energy recovery device (ERD) or booster pump is in use, is it operatingcorrectly?
b) If the design includes permeate throttling valves, are they set correctly?
c) Verify the calibration of the instrumentation. Check conductivity massbalances for flow and recovery.
d) Check individual stage differential pressures. Operation at differential
pressures above the maximum pressure drop per vessel (listed on
product specification sheets) may result in irreversible damage to the
RO elements.
e) Feed pressure always must be lower than the “maximum operatingpressure” stated in the product specification sheet. If operatingpressure exceeds the limit, the RO element may incur irreversible
damage. The maximum operating pressure would vary depending on
feed temperature. Please get in touch with a Toray membrane expert if
you require detailed information.
For the first 1 hour of the trial run, discard the permeate and brine to drain. If thesystem is designed for recirculation, do not operate any internal concentrate
recirculate during the first hour of the trial run.
The initial trial run is defined as the first exposure of the RO elements to the feedwater, followed by an operation in design conditions, which should continue for24 hours. Toray recommends 48 hours to confirm the initial performance of RO
elements and salt passage stabilization.
4. Check the quality of permeate and system performance as follows:
After the initial 1 hour of operation, check the permeate conductivity for each
vessel. If the permeate's conductivity is much higher than expected, checkO-rings, brine seals, and other parts of the affected vessel, and change
components if necessary. Log all data and record corrective measures taken.
As a minimum requirement, record data 1, 24, and 48 hours after start-up.
Use these data points for standard normalization. It is, therefore, critical to

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START-UP CHECKLIST FOR RO

Section page
4 of 8correctly calibrate all the instrumentation before the start-up. It is, therefore,
crucial to calibrate all instrumentation before the start-up.
As a minimum, consider the following data to record during the initial operation:
1.

Feed conditions:•RO feed pressure•

Water temperature•

TDS (electrical conductivity)

•

pH

•

Silt Density fouling index (SDI15)•

Turbidity (NTU)•

Chlorine (must be not detectable*)

2. Brine:
•

Flow

•

TDS (electrical conductivity)•pH

3. Permeate:•

Permeate flow of each stage (and total system)•

TDS (electrical conductivity) from each vessel and total system•

Permeate pressure (for each bank)

4. Differential pressure across each RO bank
It is recommended to take feed water, brine water and permeate water samples
to analyze individual ions.
A typical data log sheet is shown in section TMM-230 Operation Monitoring.

Regular Start-up Checklist for Daily Operation
1.

Check feed water quality is meeting recommendations for membraneelements loaded in the system.

2. Flush the RO system with pre-treated feed water at low feed pressure
before starting the high-pressure pump to remove air from the system.
NOTE: Following instructions are for a “generic” start procedure for a systemusing a centrifugal pump with feed and brine flow control valves. Refer to thesection “General Start-up procedures for different High-pressure pump (HPP)
configurations for other options.”

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The regulating valve between the high-pressure pump discharge andmembranes should be nearly closed at a high-pressure pump start-up to avoid
excessive flows and a water hammer.

TMM-220

Section page
5 of 83. Gradually increase feed pressure and feed flow rate to RO elements while
throttling the brine flow rate. Avoid excessive flow rates and differential
pressures across RO banks during start-up.
CAUTION. The maximum pressure drop across any vessel is 0.34 MPa (50psi) for TM-element types. The product specification sheets state details foreach element type.
4. Adjust RO operating parameters to design permeate and brine flow rates.
The recovery ratio is defined as the permeate flow over feed water flow. Do
not exceed the design recovery ratio during any stage of operation.
5. Discard permeate water to drain until the required water quality is achieved.

Parameters for Start-up Procedures
The following parameters must be maintained during the start-up of RO systems.
The design and control of the RO system must be suitable to ensure that thefollowing can be maintained.
1.

Pressure increase ≤ 0.07 MPa (10 psi) / sec at any time during the start-up
sequence of SWRO.

2. Pressure increase ≤ 0.034 MPa (5 psi) / sec at any time during the start-up
sequence of BWRO.
3. Feed flow increase ≤ 5% / sec of final flow.
4. Permeate pressure is lower than brine pressure at all times, especiallyduring flushing and transient conditions during the start-up sequence.
INSTRUCTION. Clean the inside of the pressure vessels if they are dirty.
Use a soft mop or swab, occasionally flushing with pre-treated water. Caremust be taken not to scratch the inside surface of the vessels.
CAUTION. The installation of check valves alone on the permeate header
may be insufficient to ensure requirement #4, especially with ultra-low
pressure element types. During flushing, ensure that the permeate line istruly at atmospheric pressure and permeate pressure is always lower thanbrine pressure. Alternatively, direct the brine and permeate flows to one
common discharge line during the flushing sequence, ensuring equal static
water column for both streams.
INSTRUCTION: Keep the ramp down period within the following ranges fornormal shutdown:
Seawater membrane: Ramp down period >60 sec
Brackish water membrane: Ramp down period >30 sec

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TMM-220

Section page
6 of 8START-UP CHECKLIST FOR RO
General Start-up Procedures for Different High-Pressure Pump
(HPP) Configurations
NOTE: The information provided here is for general reference only. Pumps,
energy recovery devices (ERDs), and associated control equipment are notsupplied by or operated by Toray. Toray accepts no liability, which may result fromincorrect usage or installation of such devices. Consult your OEM equipment
manual or the pump supplier for information regarding the safe operation of
specific pump models on your system. For detailed instructions regarding thesafe operation of energy recovery devices (ERDs), please consult your OEM
equipment manual, or contact your ERD supplier.
This section describes typical start-up procedures, sorted by type of HPP.
RO systems will usually employ one of those four different types of highpressure pumps:
1) Plunger (displacement) pump system with a constant speed motor (Figure
TMM-220-1)
1.

Open brine control valve (VB), to approx. 50%.

2. Open relief loop valve (VR).
3. Close feed pressure control valve (VF), if installed.
4. Start the high-pressure pump (HPP).
5. Slowly open VF and close VR until brine flow reaches design value.
6. Close VB until brine flow starts decreasing. Feed pressure now starts toincrease.
7. Check feed pressure, pressure drop and permeate flow.
8. Repeat procedure 5–7 until permeate and brine flow match design.
Accumulator
Permeate

Feed

VF
HPP

VR

RO

Brine

VB

Figure TMM-220-1:
Plunger (displacement) pump system with constant speed motor

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TMM-220

2) Centrifugal pump system with a constant speed motor (Figure TMM-220-2)
1.

Section page
7 of 8Open brine flow control valve (VB) to approximately 50%.

2. Open minimum flow valve (VM).
3. Close feed pressure control valve (VF). If no VM is installed, throttle tominimum flow.
4. Start the high-pressure pump (HPP).
5. Slowly open VF until brine flow reaches design value (observe note!).
6. When minimum flow for HPP is reached, close VM (if installed).
7. Close VB until brine flow starts decreasing. Feed pressure now starts toincrease.
8. Check feed pressure, pressure drop, and permeate flow.
9. Repeat procedure 5-7 step by step until permeate and brine flow match
design.
Note: If excessive brine flow is obtained at point 4 (watch ΔP), brine flow
control valve VB must be throttled from step (1).
Permeate

Feed
HPP

VF

RO

VM

Brine

VB

Figure TMM-220-2: Centrifugal pump system with constant speed motor

3) Centrifugal pump system with constant speed motor and soft start (Figure
TMM-220-3)
1.

Open brine flow control valve (VB).

2. Throttle the feed pressure control valve (VF) to approximately 10%.
3. Start the high-pressure pump (HPP) (see notes A and B).
4. Slowly open VF until design brine flow is reached.
5. Close VB until brine flow starts decreasing. Feed pressure now starts toincrease.
6. Check feed pressure, pressure drop, and permeate flow.
7. Repeat procedures 4–6 step by step until permeate and brine flow
match design.
Note (A): In case excessive brine flow is obtained (watch ΔP), set the brine
flow control valve (VB) to the throttled position in advance.
Note (B): To avoid excessive feed flow, throttle the feed valve from the beginning.

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TMM-220

START-UP CHECKLIST FOR RO

Section page
8 of 8Permeate

Feed
HPP

VF

RO

Brine

VB

Figure TMM-220-3:
Centrifugal pump system with constant speed motor and soft start4) Centrifugal pump system with a frequency-controlled motor (Figure TMM220-4)
1.

Open brine flow control valve (VB).

2. Start the high-pressure pump (HPP) at the minimum frequency (speed).
3. Increase the speed of HPP until design brine flow is reached.
4. Close VB until brine flow starts decreasing. Feed pressure now starts
to increase.
5. Check feed pressure, pressure drop, and permeate flow.
6. Repeat procedure 3–5 step by step until permeate and brine flow
match design.
Note: Figures TMM-220-1 to 220-4 are for the general explanation of highpressure pump start-up procedures only. Some of the necessary equipment
and instruments are not shown.
Permeate

Feed
HPP
with frequency
controlled motor

RO

Brine

VB

Figure TMM-220-4:
Centrifugal pump system with frequency controlled motor

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TMM-230 OPERATION MONITORING
Monitoring of a RO system’s performance is a fundamental prerequisite toensure dependable RO system performance. Regular RO system performancerecords will provide a factual basis for troubleshooting and evaluating membraneelements and system performance.

TMM-230

Section page
1 of 15

Monitoring
Tables 1.A through Table 1.C lists the operational data for logging and data
logging intervals.
Table 1.D summarizes typical water analysis items for periodic comparison toearlier (original) analytical data.
Table 1.E summarizes items for scheduled or system performance related
maintenance.

Regular Monitoring and Checkpoints
When feed water quality and operating parameters (such as pressure,temperature, differential pressure, and recovery) are constant, permeate flow
rate, and permeate quality should also remain essentially constant (±5%).
If operating parameters change, regular performance normalizations of current
data are necessary to compare normalized data to original (start-up) performancevalues. Confirm that the current normalized performance is in agreement with
the initial (start-up) system design parameters.
The frequency of normalizations required will depend on the extent andfrequency of variations in feed water quality and operating conditions.
It is also advisable to perform normalization calculations before and after anyscheduled maintenance procedures. If, after such maintenance procedures,
the normalized performance data indicate significant deviations from original
operating parameters, system adjustments may be required to return
performance to the initial RO system design parameters.

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TMM-230

Section page2 of 15OPERATION MONITORING
Logbook
A logbook should be maintained. Record all relevant operational events(however trivial they may seem to be at the time) and their date of occurrence
for future reference. Some key operational parameters to record are as follows:
Parameters

Key factors affecting performance

Permeatequality

Feed water chemical composition (total concentration of ions)Feed pH
Feed water temperature
Pressure of feed, brine and permeate for each stage
Feed water quality (total ions, colloids and suspended solids;
fouling tendency — SDI15 by Millipore Type HA)
Recovery (conversion) ratio

Permeate
flow rate

Recovery (conversion) ratio
Pressure at feed, brine and permeate of each stage
Feed water temperature
Feed water quality (total ions, colloids and suspended solids;
fouling tendency — SDI15 by Millipore Type HA)

Normalization of System Performance
To effectively evaluate current system membrane element performance, it isnecessary to compare current membrane performance data with performancedata recorded when the membranes were first placed in service.
As the current operating conditions may be different (i.e., feed salinity, temperature),
the current data must be “normalized” to the original start-up operating conditions
to allow direct and meaningful comparison. “Normalization,” therefore, refers toadjusting current data to reflect what the flows and quality parameters would be
if the plant were operating at the original (start-up) conditions.
By comparing initial membrane performance data (new elements) withcurrent “normalized” membrane performance data, we can determine if any
membrane element maintenance (such as a chemical cleaning or system
adjustments) is required.
Toray normalization software (TorayTrak) performs these calculations. It is opensource spreadsheet which is available for download on the Toray web site:
Download site: https://www.water.toray
For general information on TorayTrak, see this section “Normalization program
TorayTrak,” page 37.
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Precautions and Useful Information for Monitoring Operating Data

TMM-230

Section page
3 of 15

Daily monitoring of operating parameters provides a factual basis for theevaluation of RO system performance.
Quick recognition of undesirable trends in normalized operating data allows
the timely application of appropriate countermeasures and avoids irreversible
damage to membrane elements or other system components.
TMM-310: Guidelines for RO Cleaning describe the guidelines formaintenance, such as recommendations for cleaning.
Troubleshooting guidelines are described in the sections TMM-600:
Introduction to Troubleshooting and TMM-610: Typical Performance Changes
and Countermeasures.
Typical signs of system performance change are covered in section TMM-610:
Typical Performance Changes and Countermeasures.
A graph of normalized performance data is highly recommended to evaluate
actual system status and detect trends early (see Figure TMM-230-2).
For specific projects and special membrane element applications, please
consult the Toray warranty for particular conditions and requirements regarding
the extent and frequency of plant monitoring.

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TMM-230OPERATION MONITORING

Section page
4 of 15

RO System Operating Parameters and Logging Intervals
Table 1.A: Softened drinking or well water, SDI ≤ 2, peak 3; NTU ≤ 0.05, peak 0.1
Parameters
1.

Date and time of data logging

2.

Total operating hours

3.

Number of vessels in operation

4.

Feed water conductivity

5.

Total hardness

6.

Feed water pH

7.

Feed water FI (SDI15)

8.

Feed water temperature

9.

Feed water pressure

10. Feed water chlorine concentration
11.

Feed water ORP *)OnlineMonitoring(continuous)

Daily(datasheet)

x
x

(2)

x
x(3)
x
x(4)
x(8)

x
x
x
x
x
x
x(4)
x
x

Brine flow rate

18. Total permeate conductivity

21. Total permeate flow rate

x(7)
x
x
x

x
x
x
x

x
x

x
x
x

x
x
x

x(5)
x
x(6)

23. Permeate individual ion concentrationx

24. Total recovery ratioxxx

25. Recovery ratio for each bank
26. Normalized salt passage
27. Normalized permeate flow rate
29. Brine pressure - permeate pressure

x

x
(5)

22. Permeate flow rate for each bank

28. Brine pressure

x(3)
x
x(4)

x

19. Permeate conductivity of each vessel
20. Permeate pressurex(6)

14. Brine conductivity

17.

x

x

13. Feed water individual ion concentration

16. Pressure drop of each bank

Alarm &
SafetySystemxx

12. Brine surplus of HSO3 (≥0.5 mg/L) **)15. Brine pH

Periodically(1)

x
x

x
x

x

*)

The ORP meter reading should always be less than the value of the line shown in Figure 230-1.

**)

HSO₃- surplus in brine ≥ 0.5 mg/L if raw water is chlorinated

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Notes:(1)

TMM-230

Section page
5 of 15

Log these parameters monthly from the initial start-up operation. In case of troubleshooting
or fluctuating operating conditions, the operating party is requested to check theseparameters more frequently, depending on the particular situation.

(2) In case of significant fluctuations.
(3) In case of high fluctuations or heat exchanger systems.
(4) If chlorine is detected in the feed water, the plant must be stopped immediately and flushedwith chlorine-free water.
(5) In the case of fluctuating pressure ≥ 0.5 MPa, closed permeate loop or (automatic) valve →risk of water hammer.
(6) The recommended procedure is water analysis of individual ions, comparing results withprojected data. Table 1D lists the required typical ions.
(7) In case of high fluctuations or acid dosing.
(8) In the case of prechlorination/dechlorination only.

ORP value changes depending on pH of feed water.
The HH line with SBS is below the line without SBS due to reduction of oxidant in feed water.

Figure 230-1:
HH lines for controlling ORP value in feed water

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TMM-230

Section page
6 of 15OPERATION MONITORING
Table 1.B: Drinking or well water, SDI ≤ 3, peak 4; NTU ≤ 0.05, peak 0.1

Parameters

1.

Date and time of data logging

2.

Total operating hours

3.

Number of vessels in operation

4.

Feed water conductivity

5.

Feed water pH

6.

Feed water FI (SDI15)

7.

Feed water turbidity (NTU)

8.

Feed water temperature

9.

Feed water pressure

10. Feed water chlorine concentration
11.

Feed water ORP *)OnlineMonitoring(continuously)

Daily(datasheet)

x
x
x
x
x
x

x(2)
x(3)
x
x(4)
x
x(5)
x(9)

19. Total permeate conductivity

x(3)
x
x
x

22. Total permeate flow rate

x
x

x(7)
x
x(5)

24. Permeate individual ion concentrationx

25. Total recovery ratio

x
x
x
x

26. Recovery ratio for each bank
27. Normalized salt passage
28. Normalized permeate flow rate
30. Brine pressure - permeate pressure

x
x
x

x
x
x

(7)

23. Permeate flow rate for each bank

29. Brine pressure

x
x(5)

x

20. Permeate conductivity of each vessel
21. Permeate pressure

x(4)
x
x(5)

x
x
x
x
x

15. Brine conductivity

18. Brine flow rate

x(3)

x(5)

14. Feed water individual ion concentration

Pressure drop of each bank

x

x
x
x(5)
x
x(8)
x

13. Antiscalant concentration in feed water

17.

Alarm &
Safety Systemx

12. Brine surplus of HSO3 (≥ 0.5 mg/L) **)16. Brine pH

Periodically(1)

x
x

x
x

*)

The ORP meter reading should always be less than the value of the line shown in Figure 230-1.

**)

HSO₃- surplus in brine ≥ 0.5 mg/L if raw water is chlorinatedx

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OPERATION MONITORING
Notes:(1)

TMM-230

Section page
7 of 15

Log these parameters monthly from the initial start-up operation. In case of troubleshooting
or fluctuating operating conditions, the operating party is requested to check theseparameters more frequently, depending on the particular situation.

(2) In case of significant fluctuations.
(3) In case of high fluctuations or acid dosing.
(4) In case of high fluctuations or heat exchange system.
(5) If there is any possibility of chlorine content in the feed water.
(6) Recommended procedure is water analysis of individual ions, comparing results withprojected data. Table 1D lists the required typical ions.
(7) In the case of fluctuating pressure ≥ 0.5 MPa, closed permeate loop or (automatic) valve →risk of water hammer.
(8) Volumetric recording of daily consumption, divided by total daily feed flow and brine
flow respectively.
(9) In the case of prechlorination/dechlorination only.

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TMM-230

Section page
8 of 15OPERATION MONITORING
Table 1.C: Surface water / Tertiary effluent, SDI ≤ 4, peak 5; NTU ≤ 0.05, peak 0.1
Parameters

1.

Date and time of data logging

2.

Total operating hours

3.

Number of vessels in operation

4.

Feed water conductivity

5.

Feed water pH

6.

Feed water FI (SDI15)

7.

Feed water turbidity (NTU)

8.

Feed water temperature

9.

Feed water pressure

10. Feed water chlorine concentration
11.

Feed water ORP *)OnlineMonitoring(continuously)

Daily(datasheet)

x
x
x
x
x
x
x

12. Brine surplus of HSO3 (≥ 0.5 mg/L) **)13.

Antiscalant concentration in feed water

14.

Feed water individual ion concentration

17.

Pressure drop of each bank

18. Brine flow rate
19. Total permeate conductivity

x
x
x
x
x
x
x
x
x
x
x
x
x

22. Total permeate flow rate

x
x
x
x
x
x

x
x

x
x
x

x
x
x

x
x
x(2)

24. Permeate individual ion concentrationx

25. Total recovery ratio

x
x
x
x

26. Recovery ratio for each bank
27. Normalized salt passage
28. Normalized permeate flow rate

30. Brine pressure - permeate pressure

x
x
x
x

x

23. Permeate flow rate for each bank

29. Brine pressure

x

x
x
x
x
x

20. Permeate conductivity of each vessel
21. Permeate pressure

Alarm &
SafetySystemx(2)15. Brine conductivity
16. Brine pH

Periodically(1)

x
x

x
x

x

*)

The ORP meter reading should always be less than the value of the line shown in Figure 230-1.

**)

HSO₃- surplus in brine ≥ 0.5 mg/L if raw water is chlorinated.

Notes:(1) Log these parameters monthly from initial start-up operation. For trouble shooting or fluctuating
operating conditions, additional check-ups are required, depending on particular situation.

33 of 93(2) Recommended procedure is water analysis of individual ions, comparing results with projected
data. Required typical ions are listed in Table 1D.

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OPERATION MONITORING

TMM-230

Section page
9 of 15

Table 1.D: Typical Water Analysis Items
Items

Unit orAbbreviation

Feed water

Permeate

x(1)
x
x
x(1)
x
x(1)
x
x
x
x
x
x
x(1)
x(1)
x
x
x
x
x
x
x(2)
x
x
x
x
x
x
x

x
x
x
x
x
x
x

1.

Conductivity (25°C)

µS/cm

2.

Total dissolved solids

TDS

3.

pH

—

4.

ChlorideCl-

5.

NitrateNO3-

6.

Bicarbonate

HCO3-

7.

SulfateSO42-

8.

Phosphate

PO₄3-

9.

FluorideF-

10. Sodium

Na+

11.

K

Potassium+

12. Ammonium

NH₄+

13. Calcium

Ca2+

14. Magnesium

Mg2

15. Strontium

Sr2+

16. Barium

Ba2+

17.

Iron as ion

Fe3+

18. Manganese

Mn2+

19. Silicate

SiO₂

20. Silicic acid

SiO₃-

21. Boron+B

22. Chemical oxygen demand

COD

23. Biochemical oxygen demand

BOD

24. Total organic carbon

TOC

25. Carbon dioxide

CO2

26. Microorganism

unit/cc

27. Hydrogen sulfide

H2S

28. Temperature

°C

x
x
x
x

x
x
x(2)

x

Note:
The above table is for reference only. The selection of required ions for analysis will also
depend on the feed water and target permeate qualities.
(1)

These values constitute the minimum information required for a qualified RO lay-out. Ions
not analyzed will not be available for calculation of scaling potentials.

(2) In case of specified data for permeate quality.

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TMM-230OPERATION MONITORING

Section page
10 of 15

Table 1.E: RO system maintenance items (to be noted in system log)
Items

Frequency & Procedure

1. Instruments
Pressure sensors & indicators
System control devices
Safety shutdown facilities

Perform regular calibration andmaintenance according to themaintenance manual supplied by the
manufacturer.

2. Cartridge filter change
Use only new pre-washed filter
cartridges free of surfactants andchemical additives introduced during
cartridge filter manufacture.

Record the differential pressures of
the cartridge filter housing before
and after installation of cartridge
filters. It is also beneficial to record
the date of installation and filter
model number.

3. RO system cleaning
As a minimum, record the following:
Type of cleaning solution, solution
concentration and conditions during
the cleaning (pressure, temperature,
flows, pH, conductivity).

Perform according to themaintenance manual supplied by thesystem manufacturer.
TORAY membrane element cleaning
guidelines and instructions arereferenced in TMM Sections 310
and 320.

4. Membrane treatment upon
shutdown
Record preservation method, theconcentration of the preservative
solution, operating conditions before
shutdown and shutdown duration.

Perform according to systemmanufacturer’s operating manual.
TORAY guidelines & instructions
for long and short term membraneelement preservation can be foundin TMM sections 240 and 260.

5. Pretreatment operating data
RO system performance depends
mainly on the proper operation of
the pretreatment systems.

Residual chlorine concentration,discharge pressure of booster
pump, consumption of all chemicals,
calibration of gauges and meters.

6. Maintenance log

Record any routine system
maintenance procedures,
mechanical failure events andchange of position or replacementof any membrane elements.

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TMM-230

Section page
11 of 15

Figure TMM-230-2: Typical monitoring charts for RO systems

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TMM-230

Section page
12 of 15OPERATION MONITORING
Daily monitoring and data normalization are recommended. Watch out for
performance change trends. As the current operating conditions may bedifferent (i.e., feed salinity, temperature), the current data must be “normalized”
to the original start-up operating conditions to allow direct and meaningfulcomparison. “Normalization,” therefore, refers to manipulating current data
to reflect what the flows and quality parameters would be if the plant wereoperating at the original (start-up) conditions.
In Figure TMM-230-2, no performance changes are indicated, which is typicalfor proper system operation.
By comparing initial membrane performance data (new elements) with current“normalized” membrane performance data, it is possible to determine if any
membrane element maintenance (such as a chemical cleaning or system
adjustments) will be required.

Normalization Program — TorayTrak
To assist in RO system performance and data normalization, TORAY developed
a RO performance data normalization program called TorayTrak. TorayTrak is
open-source spreadsheet which is available for download at the Toray web site
https://www.water.toray.
Toray provides TorayTrak as a Macro-Free Microsoft Excel program with fiveversions to handle different process system designs and varied operational
data collection points. The process schemes available are:
A. A one-stage system: TorayTrak_OneStage_PTotal.xlsx
B. A split permeate one-stage system: TorayTrak_OneStage_Split.xlsx
C. A two-stage system with first and second stage permeate flow ratemonitoring: TorayTrak_TwoStage_PF1_PF2.xlsx
D. A two-stage system with first stage and overall permeate flow ratemonitoring: TorayTrak_TwoStage_PTotal_PF1.xlsx
E. A two-stage system with second stage and overall permeate flow ratemonitoring: TorayTrak_TwoStage_PTotal_PF2.xlsx
Procedures for normalization are given in ASTM D 4516.
The following is a general introduction to TorayTrak for a one-stage system as
an example.

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OPERATION MONITORING
1) Configuration

TMM-230

Section page
13 of 15

2.

3.

1.
1.

Left-click your mouse on the "Configuration" Tab. All required system
information is in green fill.

2. From the drop-down lists, enter Toray membrane model numbers, enter
the number of pressure vessels (PV), and the number of elements perpressure vessel.
3. Next, select the desired engineering units. These units must remain
consistent for all data entries in the workbook.

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TMM-230

Section page
14 of 15OPERATION MONITORING
2) Input data

2.

3.

1.
1.

Left-click your mouse on the "Data" tab where you will enter the membrane
performance data.

2. Starting on row 6, enter membrane performance data in columns A throughK. All columns titled in the yellow colored field after the Date entry must
contain data out to column K.
3. Baseline data to establish recommended cleaning lines are generated byaveraging the data entered in rows 7–10.

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OPERATION MONITORING
3) Trend graph

TMM-230

Section page
15 of 15

"NormPerm," "NormSP," and "NormDP" tabs automatically display the trend
graphs of the normalized membrane performance data by the overall system.

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TMM-240

Section page
1 of 3

TMM-240 SHUTDOWN CONSIDERATIONS FOR RO
SYSTEMS
1.

When shutting down a RO system, the system should be thoroughly flushed
at low pressure with sufficient quality flushing water to displace all the brinefrom the pressure vessels (refer to TMM-250 Flushing Procedures).
Acceptable water for flushing is pre-treated feed water (refer to Table 2401) or RO product water.
Water used for flushing must not contain any oxidants. Maintain the flush
water solution pH between 3.0 to 8.5 at all times.

Table 240-1: Suggested flushing water for various RO feed water
treatment systems
RO feed water type

Flushing waterSea water

Pre-treated feed water

Brackish water

Pre-treated feed water

Wastewater

RO product waterHigh pH feed water (such as 2nd
pass high pH feed water)

Pre-treated feed water without
NaOH
1st pass product water without
NaOH

2. Ensure membrane elements are kept wet, properly sanitized, and protectedfrom freezing during the shutdown period.
3. Ensure guidelines for temperature and pH of the preservative solution are
observed during the shutdown period.
Take care that product back pressure never exceeds 0.03 MPa at any time.
Assess product back pressure on an individual stage basis. Product backpressure is defined as product pressure minus feed resp. brine pressure.
CAUTION. When multiple RO trains are running in parallel, and one train
requires a shutdown, assure that the train to be shutdown is properly isolated
from the common header piping using check valves or isolation valves. It
is critical that pressure relief valves be present and installed on each train
permeate line.
4. Under any circumstances, do not expose any membrane elements tochlorine or other chemical oxidants. Any such exposure may damage themembrane, possibly resulting in an irreversible increase in salt passage.

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SHUTDOWN CONSIDERATIONS FOR RO SYSTEMS
5. Take extra care to avoid chlorine exposure:•

When disinfecting piping or pre-treatment equipment upstream of themembrane•

When preparing cleaning or storage solutions•

Take extra caution to ensure that no trace of chlorine is present in thefeed water to the RO membrane elements.

•

If residual chlorine is known to be present in the RO feed, it must be
removed with sodium bisulfite (SBS) solution in stoichiometric excess,allowing sufficient contact time to accomplish complete dechlorination.

TMM-240

Section page2 of 3

Short-term Shutdown
Definition:
Short-term shutdown is for periods where an RO plant must remain out of
operation for more than one day, but fewer than four days, with the RO elements
remaining loaded in the vessels.
Prepare each RO train as follows:1.

Flush the RO section with flushing water, while simultaneously venting any
air from the system feed piping.

2. When the pressure vessels are filled with flushing water, isolate the train byclosing all isolation valves.
3. Repeat steps 1 and 2 above every 24 hours.
For detailed instructions of flushing procedures, see TMM-250: Flushing Procedure.

Long-term Shutdown
Definition:
Long-term shutdown is for periods where an RO plant must remain out of
operation for more than four days with the RO elements remaining in thepressure vessels.
Prepare each RO train as follows:
Case. A) Sufficient flushing water is available.
1.

Flush the RO system with flushing water for 0.5-1.0 hour, while simultaneously
venting any air from the system.

2. When the pressure vessels are filled with flushing water, isolate the train byclosing all isolation valves.
3. Repeat 1) and 2) above at least every two days.
For detailed instructions, see TMM-250 Flushing Procedure.

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TMM-240

Section page
3 of 3

SHUTDOWN CONSIDERATIONS FOR RO SYSTEMS
Case. B) Flushing water is not available.
1.

Circulate the permeate through the system. While circulating permeate
through the system, inject the RO system, flush line with a 500 to 1000 mg/L
(maximum) SBS solution. This solution will serve to inhibit biological growthduring the shutdown period. Circulate for 30–60 minutes.

2. Make sure the RO system is filled with the SBS solution. To prevent thesolution from draining from the system, close all system isolation valves.
3. The pH of the preservative solution should never be allowed to drop below
3.0. Regularly check the pH. If the pH drops below 3.2, drain and replace thepreservative solution as soon as possible.
4. If measuring the preservation solution's pH is not possible, repeat steps a)
and b) with fresh solution.
•

Every 30 days if the temperature is less than 27°C (80°F)•

Every 15 days if the temperature is equal to or greater than 27°C (80°F)

Note: Any contact of the SBS solution with air (atmospheric oxygen) will oxidize
SBS to sulfate, and the preservative solution pH will begin to drop. Take special
care to keep the SBS preservative solution isolated from atmospheric oxygen.
If the SBS is allowed to revert to sulfate, the potential for biological activity will
increase.

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TMM-250 FLUSHING PROCEDURES
A straightforward procedure for the removal of foulants is to flush the systemwith flushing water. Flushing scours the membrane surface by taking advantage
of high velocity at low pressure. A large volume of flush water is required.
This procedure can be an effective method for removing light organic foulingprovided it is applied before there is a significant performance decline.

TMM-250

Section page
1 of 1

General operating conditions for flushing are as follows:
Flushing water

Use pre-treated feed water (refer to Table 250-1) or RO
product water.
Flushing water should not contain any oxidants.
Maintain flushing water pH range between 3.0–8.5.
Table 250-1: Flushing water of various RO feed water
treatment systems
RO feed water type

Flushing waterSea water

Pre-treated feed water

Brackish water

Pre-treated feed water

Waste water

RO product waterHigh pH feed water (i.e.,
2nd pass high pH feedwater)

Pre-treated feed water
without NaOH
1st pass product water
without NaOH

Pressure

Low pressure (0.1–0.2 MPa [15–30 psi])

Water flow rate

High flush water flow rate is best but do not exceed therecommended vessel pressure drop.
Limit pressure drop to max 0.2 MPa [30 psi] per stage.

Maximum feedflow rate pervessel8-inch element: 200 L/min (53 gpm)
4-inch element: 50 L/min (13 gpm)

Temperature≤ 40°C (104°F)

Period

0.5–1.0 hour

It is important to keep the permeate side isolation valve(s) open to keep thepermeate back pressure to a minimum during the flushing procedure.
Feed/brine pressure should always be higher than permeate pressure to avoid
any membrane damage.
INSTRUCTION. For flushing before/after chemical cleaning, flush each stage(bank) separately to optimize the flow rate of each stage for effective cleaning,
and to prevent the foulants removed in the upstream stage contaminating
the downstream stage. Do not recirculate flushing water to prevent the spentcleaning solution from mixing with the clean flush water in the flushing watertank.
Operation, Maintenance, and Handling Manual

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TMM-260

Section page
1 of 2

TMM-260 PRESERVATION OF RO ELEMENT IN
PRESSURE VESSELThe objective is to store elements under clean conditions to maintainperformance and to prevent bacteria growth.
INSTRUCTION. After the system shutdown, displace brine in the system withflushing water.
General conditions for preservation:
Flushing water Use pre-treated feed water (refer to Table 260-1) or RO
product water.
Flushing water should not contain any oxidants.
Flushing water pH range should be maintained between
3.0–8.5.
Table 260-1: Flushing water of various RO feed water
treatment systems
RO feed water type

Flushing waterSea water

Pre-treated feed water

Brackish water

Pre-treated feed water

Waste water

RO product waterHigh pH feed water (i.e., 2nd Pre-treated feed waterpass high pH feed water)
without NaOH
1st pass product water
without NaOHCAUTION. If the potential for scaling and fouling exists, RO membranes must
be flushed on shutdown according to the procedures outlined in TMM-250
Flushing Procedures.
1.

Elements must be wet at all times to maintain performance.

2. Sanitization may be required to prevent bacterial growth in the pressure
vessels (see TMM-400: Sanitization Methods).

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PRESERVATION OF RO ELEMENT IN PRESSURE VESSEL
3. If an extended shutdown is scheduled due to contamination or foulingof the elements, chemical cleaning before preservation is recommended.
Doing so removes foulant from membranes and minimizes bacterial
growth. Please review:•

TMM-300: General Instructions and Conditions for RO Cleaning•

TMM-310: Guidelines for RO Cleaning•

TMM-320: Instructions for Chemical Cleaning

TMM-260

Section page2 of 2

4. The allowable temperature range for preservation solutions 5–35°C (41–95°F)
5. The allowable pH range during preservation in the pressure vessel is 3.0–8.5.
6. Make-up water for preservation solution must be free from residual chlorine
or other oxidizing agents.
For preserving elements, use sodium bisulfite solution. For details, see section
TMM-400: Sanitization Methods.

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TMM-300

Section page
1 of 1

TMM-300 GENERAL INSTRUCTIONS AND
CONDITIONS FOR RO CLEANINGThe surface of an RO membrane is subject to fouling by suspended solids,
colloids, and precipitation. Design the pretreatment of feed water before the
RO process to avoid contamination/fouling of the membrane surface as muchas possible.
Operation at optimum conditions (permeate flow rate, pressure, recovery, andpH-value) will result in less fouling of the membranes.
SDI15 is a measurement of particulates present in feed water. With high SDI15
values (even in allowable range), membrane fouling due to particulates cancause performance decline in long-term operation.
Fouling can also be a consequence of large variations in raw water quality or
RO operation mode errors.
Fouling of the membrane surface will result in a performance decline, i.e.,lower permeate flow rate, higher solute passage, increased differential
pressure loss from the feed side of a stage to the brine side.
Figure TMM-300-1 illustrates the decrease of flux caused by fouling andrestoration of flux achieved through cleaning. If the foulant source is unaddressedand corrected, foulant removal will only bring temporary relief, as indicated by
the “sawtooth” pattern of the permeate flow.

Figure TMM-300-1: Effect of fouling on permeate flow rate
NOTE: The best solution is to remove the foulant through improved
pretreatment rather than subject the membranes to repeated cleanings.

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TMM-310 GUIDELINES FOR RO CLEANING
When to Clean:

TMM-310

Section page
1 of 2

Cleaning the elements before the fouling has fully developed determines thebest cleaning efficiency. Delaying cleaning will render foulant removal from themembrane surface and re-establishing full performance more difficult.
INSTRUCTION. Commence cleaning when:1.

Normalized differential pressure increases more than 20%; or

2. Normalized permeate flow rate decreases by more than 10%; or
3. Normalized salt passage increases by more than 20%.
Weighing an element is an easy check for the occurrence of fouling. If theelement's weight is much higher than that of the new element, fouling has
occurred. Before weighing the element, stand it vertically on a perforated plateor drain for 60 minutes to drain fluids.
The approximate weights of new elements (drained condition) are:•4 inch diameter x 40 inch long: 4 kg,•

8 inch diameter x 40 inch long (400 ft² membrane area): 15 kg•

8 inch diameter x 40 inch long (440 ft² membrane area): 16 kg

Determining Foulant Type
Determining the type of foulants on the membrane surface before cleaning is
critical. The best approach for this is a chemical analysis of residues collectedwith a membrane filter during an SDI15 value determination for pre-treated water.
USEFUL TIP. When a chemical analysis is unavailable, it is possible to classify
foulants by color and the residue's consistency on the membrane filter. A
brownish color residue will typically indicate iron fouling. White or beige color
typically indicates silica, loam, calcium scale, or biological fouling. The crystalline
constitution is a feature of calcium scales or inorganic colloids. Bio-fouling ororganic material will, besides the smell, often show a slimy or sticky consistency.

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TMM-310

Section page2 of 2GUIDELINES FOR RO CLEANING
Selecting the Right Cleaning Procedure
Select the correct cleaning procedure upon identifying contamination of themembrane surface.
INSTRUCTIONS.
•

If suspect foulants are metal hydroxides (e.g., ferric hydroxide or calcium scale),acidic cleaning procedures may be most effective (see TMM-320: Instructions
for Chemical Cleaning and TMM-330: Citric Acid Cleaning procedure).

•If suspect foulant is organic or biological, cleaning with alkaline agents or
detergents is recommended (see TMM-320: Instructions for chemicalcleaning and TMM-340: Dodecyl Sodium Sulfate (DSS) Detergent
Cleaning Procedure).

Typical CIP Procedure
1.

Flushing with RO permeate to decrease conductivity & neutralize the pHof the feed side.

2. EDTA-4Na cleaning:•

1.0wt%, pH 11.0 adjusted with NaOH, 35°C.

•

1 hr recirculation followed by 1 hr soaking, repeat three times, then,overnight soaking.

3. Rinsing with permeate.
4. Citric acid cleaning.
•

2.0wt%, No pH adjustment; pH is more than 2.0, 35°C.

•

1 hr recirculation followed by 1 hr soaking, repeat two times.

5. Rinsing with permeate.
CAUTION. Establish the most effective cleaning regime at the site forthe specific foulants. Toray does not guarantee the efficiency of genericcleaning solutions in removing site foulants.

Evaluating Cleaning EffectivenessDescriptions of various cleaning procedures are given in TMM-320: Instructions
for Chemical Cleaning. Generally, the following recommendations yielddesirable results. The pressure drop across the modules should be reduced
to the initial value, while the permeate flow rate and solute rejection will be
restored.
If performance is not sufficiently improved after cleaning, a different cleaning
procedure may lead to a better result. Foulants will frequently adhere to themembrane surface or remain in spacer material. Final removal may take several
successive cleaning procedures. As foulants may be present as layers on themembrane surface, alternating acid and alkaline cleanings are more effective
than repeated cleans with only one type of cleaner.

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TMM-320 INSTRUCTIONS FOR CHEMICAL
CLEANING

TMM-320

Section page
1 of 5General Guidelines
Chemical maintenance cleanings remove contaminants from membranesurfaces by dissolving or separating through physical and chemical interaction
with cleaning chemicals.
INSTRUCTIONS. It is a good practice to perform a system flushing before
initiating a chemical maintenance cleaning. Perform a chemical cleaning before
introducing any chemical preservatives if the RO system is taken offline for an
extended time.
After any chemical cleaning, thoroughly flush the system with either pre-treated
raw water or permeate to completely remove any residual cleaning chemicals
dissolved or suspended solids from the RO system. See section TMM-250:
Flushing Procedures.
CIP agents

Generic cleaning chemicals are listed in Table 320-1

Make-up water

Softened water or permeate, free of heavy metals,
residual chlorine, or other oxidizing agents.

Required quantity of CIP
solution

40–80 liters (11–22 US gallons) per 8-inch element
depending on the severity of the fouling.
10–20 liters (3–6 US gallons) per 4-inch element
depending on the severity of fouling.

CIP pressure

Low pressure: 0.1–0.2 MPa (15–30 psi)

CIP flow rate
(recommended flow rate)

100–150 L/min ([25–40 gpm], [6–9 m3/h]) per 8-inch
vessel.
25–36 L/min ([6.5–-10 gpm], [1.5–2.2 m3/h]) per
4-inch vessel.
The goal is to try and achieve the recommended
cleaning flow rates above while keeping thecleaning solution pressure within the CIP pressure
range of 15–30 psi.

Min. feed flow rate

50 L/min (13.2 US gallons/min) for each 8-inch
vessel.
10 L/min (2.7 US gallons/min) for each 4-inch vessel.
CIP with further low feed flow rate is acceptable insome cases to prevent scratch of RO membraneby scale substances which are removed from themembrane surface during the CIP.

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TMM-320

Section page2 of 5

INSTRUCTIONS FOR CHEMICAL CLEANING
Temperature

The maximum temperature of the cleaning
solution depends on the pH of the cleaning
solution as below:
Temperature ≤ 35°C (pH 2–11)
Temperature > 35°C and ≤ 45°C (pH 2–10)
For other pH, please contact Toray.

Cleaning technique

Clean each bank separately. It is also helpful
to recirculate the cleaning solution then allow
the membranes to soak in the solution. This
procedure can be repeated several times toassist in the membrane cleaning process. See
below suggested recirculation time intervals.

Recirculation intervals

0.5–1 hour (repeat 2–3 times) monitor solution
temperature (see maximum temperatures
above).

Soaking period

2–24 hours including recirculation time (times
depending on type and degree of fouling).

Method of cleaning

Recirculation followed by soaking of each bank.

Final flushing period

Minimum 1–2 hours, depending on theapplication.

It is essential to keep any permeate side valves open to keep the permeateback pressure to a minimum during circulation and flushing.
Feed/brine pressure should always be higher than permeate pressure to avoid
any membrane damage. See section TMM-250: Flushing Procedures for moredetails on flushing the RO System.
INSTRUCTION. Start circulation with a slow flow increase. For the first 5
minutes, slowly throttle the flow rate to 1/3 of the target flow rate. For the second
5 minutes, increase the flow rate to 2/3 of the target flow rate, and then increase
the flow rate to the target flow rate.
INSTRUCTION. Clean each stage (bank) separately to optimize the flow rate ofeach stage for effective cleaning, and to prevent the foulants removed in the
upstream stage contaminating the downstream stage.

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INSTRUCTIONS FOR CHEMICAL CLEANING

TMM-320

Section page
3 of 5

Table 320-1: CIP chemicals
Contamination

CIP chemical

Cleaning
conditions

INSTRUCTION.
Ref. description

Calcium scale

Citric acid 1–2
wt%, adjust withammonia (NH₃),
ammoniumhydroxide (NH4OH)
or sodiumhydroxide (NaOH)

pH value: 2-4

10.TMM-330
Citric acidcleaning
procedure

Dodecyl Sodium
Sulfate (DSS,
Sodium Lauryl
Sulfate), 0.03–0.2
wt% with alkaline
solution;

pH value: 7-11,
adjust with sodiumhydroxide; or11.TMM-340 DSS
DSS (Dodecyl
Sodium Sulfate)
Detergent
Cleaning
Procedure

Metal hydroxides
Inorganic colloids

Organic matter,
bacterial matter*)or
Polyoxyethylene
Sodium Lauryl
Sulfate(PSLS),
0.1–0.5 wt% withalkaline solution;

sodium tripolyphosphate; or
trisodium phosphateorAlkaline solution
without organic
reagents
Acid insoluble
Scaling**)
CaF₂; BaSO₄;
SrSO₄; CaSO₄*)

1 wt% Sodium hexametaphosphate(SHMP)

pH value: 2
adjust withhydrochloric acid

12.TMM-350
Acidic SHMP CIP
Procedure

Alkaline solution with 1 wt% EDTA-4Na is more effective in some cases.
Combining sterilization and detergent cleaning is effective for bacterial contamination.
Sequence of sterilization and detergent cleaning depends on the type of fouling andreagents. Detergent cleaning is often performed first followed by sterilization. (see TMM400 Sanitization methods for RO/NF - elements)**)

It is recommended to start with an acid cleaning to remove any other (combined) acidsoluble fouling materials (such as e.g. CaCO₃). Acid insoluble scaling is difficult or
impossible to remove if the fouling layer is aged. Cleaning should be done within one week
after such scaling is recognized.

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TMM-320

Section page
4 of 5

INSTRUCTIONS FOR CHEMICAL CLEANING
Membrane Cleaning System Design Considerations

Upper solution level

CIP tank

Cleaning pump

C/F
RO vessels

Figure TMM-320-1: Calculation of CIP tank volume
The recommended CIP tank volume, as shown in Figure TMM-320-1, iscalculated as (A + B) x 1.2 + C, where:
A = CIP system volume (cleaning system piping and pipe headers)
B = Volume of water in elements subject to simultaneous cleaning (20 liters [6US gallons] for 8-inch element, 5 liters [1.3 US gallons] for 4-inch element)
C = Minimum required volume to run the cleaning pump (this depends on
the tank design and cleaning pump specifications such as Net Positive
Suction Head (NPSH) requirement)This CIP tank volume calculation is based on the following CIP procedure.
1)

Makeup cleaning solution in the CIP tank.

2) Feed the cleaning solution to the cleaning system piping, pipe headers andpressure vessels to replace the water inside with the cleaning solution. During
this period, the replaced water is flushed out via drain line.
3) Flush out initial 10–20% of the cleaning solution since this contains a highconcentration of foulant.
4) Start CIP solution circulation. Open CIP return valves to CIP tank, and closedrain valves.
The cleaning flow rate measured as the discharge flow rate of the cleaning
pump should be as follows:
100–150 L/min. ([25–40 gpm], [6–9 m3/h]) per 8-inch vessel.
25–36 L/min. ([6.5–10 gpm], [1.5–2.2 m3/h]) per 4-inch vessel.
The goal is to achieve the recommended maximum flow rate while
maintaining a CIP pressure range between 0.1–0.2 MPa (15–30 psi).
INSTRUCTION. Pump head is calculated from:53 of 9306-G-MB1-240305•

Max. differential pressure across RO elements (approx. 0.2 MPa) [30 psi]•

Pressure loss of piping system and pressure vessel connections•

Max. differential pressure across cleaning cartridge filter (approx. 0.2 MPa)
[30 psi]Operation, Maintenance, and Handling Manual

Toray Reverse Osmosis Membrane Element

INSTRUCTIONS FOR CHEMICAL CLEANING

TMM-320

Section page
5 of 5IMPORTANT NOTES:
1.

INSTRUCTION. Provide a separate return line for permeate. It is importantto keep any permeate side valves open to keep permeate back pressure
to a minimum during the circulation or flushing procedure. Feed/brinepressure should always be higher than permeate pressure to avoid any
membrane damage.

2. INSTRUCTION. The design of the cleaning tank must allow for complete
draining.
3. CAUTION. To avoid excess foaming of cleaning solutions the cleaning
solution and permeate return lines should be sufficient length to extend
below the solution's level in the CIP cleaning tank.
4. CAUTION. Spent cleaning solutions must be neutralized before discharge.
Consider local regulations for discharge.
5. WARNING. When working with chemicals, follow safety regulations
indicated in material safety sheets. Wear suitable protection, such as eye
protection, protective gloves, and rubber apron.

Figure TMM-320-2: Typical CIP system arrangement

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TMM-330

Section page
1 of 3

TMM-330 CITRIC ACID CLEANING PROCEDURE
Flushing of Elements
Before cleaning with a citric acid solution, it is advisable (although notmandatory) to flush elements with softened water or RO permeate (see TMM250. Flushing procedures).

Preparing a 2 wt% Citric Acid Solution
1.

Fill the cleaning tank with water.
Fill the cleaning tank with RO permeate or softened water, free of oxidizing
agents. Determine the amount of cleaning water by the RO system's size andthe extent of fouling (see TMM-320 Instructions for chemical cleaning).

2. Dissolve citric acid.
Add citric acid (white powder) in small increments to the cleaning water toobtain a 2 wt% (by weight) — solution. Continuous agitation (or recirculationof the cleaning solution directly from the cleaning pump into the cleaningtank) will dissolve the citric acid wholly and quickly. Break up any large
chunks or lumps of citric acid before adding to the tank to avoid damaging
the agitator or circulation pump parts.
Example: 20 kg (44 lbs) of citric acid is required to prepare 1,000 liters(264.2 US gallons) of 2 wt% (by weight) solution.
The solution pH should be adjusted with ammonia (NH3), ammoniumhydroxide (NH4OH) or sodium hydroxide (NaOH) to the specified value (seeTMM-320 Instructions for Chemical Cleaning).
3. Adjusting the solution's pH with ammonium hydroxide should be performed
with the agitator or recirculation pump in operation. Use an exhaust system
if necessary to draw off ammonia gas that has been released. The use of anelectric drum transfer pump or manual drum transfer pump helps minimize
ammonia gas release.
The amount of ammonium hydroxide (NH4OH), required to adjust the pH
to 3.5 can be calculated approximately in proportion to the amount of citricacid by the following formula:Amount of NH4OH (100%) = 0.1 x Amount of citric acid (100%) in kg
For example, if the calculated amount of citric acid is 20.4 kg, the required
amount of ammonium hydroxide (30 wt% by weight) is 6.8 kg = (0.1 x 20.4)/ 0.3.

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CITRIC ACID CLEANING PROCEDURE
Circulation of Cleaning Solution

TMM-330

Section page2 of 3Circulate the cleaning solution at low pressure — less than 0.2 MPa (30 psi) is
recommended. Elevated solution temperature will improve cleaning results.
CAUTION. Recirculating the cleaning solution for extended periods improvescleaning efficiency. Monitor the cleaning solution's temperature to ensure
it does not exceed the recommended maximum allowable cleaning solution
temperature (refer to TMM-320 Instructions for Chemical cleaning).
INSTRUCTION. Soaking elements in the cleaning solution can be an effective
procedure to dissolve metal foulants. Alternating soaking intervals withrecirculation of the cleaning solution can also be beneficial.
Use citric acid cleanings when the suspected foulant(s) are metal compounds.
If the element experiences severe fouling, the citric acid cleaning solution may
become less effective as the cleaner reacts with the metal foulant(s). The initialcleaning solution will have a greenish-yellow color. As the metals react with thecleaning solution during the recirculation phase, the color may begin to turndark yellow, progressing to a darker red-brown. This color shift indicates theimpairment of the cleaning solution's effectiveness due to chemical interaction
with the foulant(s). Discard the solution when the color of the solution color turns
darker. Prepare a fresh citric acid solution and repeat the cleaning procedure toensure complete and effective cleaning.

Flush Elements
Once the chemical cleaning circulation is finished, completely drain and rinse
the cleaning solution tank. Next, fill the cleaning solution tank with permeateor oxidant free feed water. Fill the tank with sufficient flush water to displace all
cleaning solution remaining in the cleaning system piping, RO system headers,and pressure vessels. Direct all flush water to drain for proper disposal. Refer to
TMM-250: Flushing Procedures.
INSTRUCTION. Flush each stage (bank) separately to optimize the flow rateof each stage for effective cleaning, and to prevent the foulants removed in
the upstream stage contaminating the downstream stage. Do not recirculate
flushing water to prevent the spent cleaning solution from mixing with the clean
flush water in the flushing water tank.

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TMM-330

Section page
3 of 3

CITRIC ACID CLEANING PROCEDURE
General Description of Citric Acid
DANGERIUPAC name:2-hydroxypropane-1,2,3-tricarboxylic acidAppearance

white crystalline powder

Density

1665 g/cm³ (18°C)

Solubility in water

59 g/100mL (20°C)

pH~ 1.7 (100 g/L, 20°C)

Chemical formula

C₆H₈O₇Structural formula

CAS number:

77-92-9

Safety precautions low hazard potential, irritant
INSTRUCTION. Please consult the Safety Data Sheet available from thechemical supplier for full safety details BEFORE handling this chemical. Use allrecommended safety equipment.

General Description of Ammonia Solution
DANGER

Appearance

Colorless solution

Density

0.9 g/cm³

pH

~ 11

Molecular formula

NH₃

CAS number:

1336-21-6

Safety precautions

Corrosive

INSTRUCTION. Please consult the Safety Data Sheet available from thechemical supplier for full safety details BEFORE handling this chemical. Use allrecommended safety equipment.

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TMM-340 DSS (DODECYL SODIUM SULFATE)
DETERGENT CLEANING PROCEDURE

TMM-340

Section page
1 of 3

Flushing of Elements
Before cleaning with DSS solution, it is advisable (although not mandatory) toflush elements with softened water or RO permeate (see TMM-250: Flushing
Procedures).

Preparing a 0.03 wt% DSS Solution
1.

Fill the cleaning tank with water
Fill the cleaning tank with RO permeate or softened water, free of any
oxidizing agents. The size of the RO system and the extent of foulingdetermine the amount of cleaning solution (see TMM-320: Instructions for
Chemical Cleaning).

2. Dissolve DSS
Add sufficient DSS to the cleaning water to obtain a 0.03 wt% (by weight)
solution.
CAUTION. This chemical can form a film on the cleaning water surface,capable of trapping gases. Take precautions to minimize the potential
mixing of air with the DSS when making up the cleaning solution to avoid
excessive foam formation. It is recommended to dissolve the DSS in a small
volume of cleaning water and then add to the bulk solution in the cleaningtank; a continuous and slow agitation of the solution is required to disperse
the DSS evenly. To minimize the potential of the formation of foam, use thelowest speed setting on the mixer.
Example: 0.3 kg (0.66 lbs) of DSS is required to produce 1,000 liters (264.2
US gallons) of the solution.
3. Monitor pH value
Maintain the pH of the detergent solution within the recommended pH
range (see TMM-320: Instructions for Chemical Cleaning). If the pH falls
outside the recommended range, solution pH adjustment will be required.
The expected pH of the DSS solution is 7.

Circulate Cleaning Solution
INSTRUCTION. The initial flow of cleaning solution within the cleaning returnline may contain a high concentration of contaminants. Discard the initial 10-15%
of the cleaning solution volume to drain before circulating the cleaning solution
to the cleaning tank.
Increasing the cleaning solution temperature will improve the efficiency ofthe cleaning. Do not exceed the recommended temperature guidelines.
Additionally, it is beneficial to perform the cleaning at low pressures. Do not
exceed (approximately 0.2 MPa [30 psi]) during the cleaning solution's circulation.

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TMM-340

Section page2 of 3

DSS (DODECYL SODIUM SULFATE) DETERGENT CLEANING PROCEDURE
CAUTION. Extending the circulation time is beneficial to maximize the efficiencyof the cleaning. The cleaning solution temperature should be monitored closely
during the circulation of the cleaning solution. Take care not to exceed therecommended maximum temperature value (refer to TMM-320 Instructions
for Chemical Cleaning).
To minimize the potential for foam formation within the CIP solution tank, makesure the cleaning solution return line and permeate lines extend below thecleaning solution level.
INSTRUCTION. The efficiency of chemical cleanings can be improved if theelements are allowed to soak in the cleaning solution for an extended time.
Repeated intervals of soaking, followed by the cleaning solution's circulation,
can also improve cleaning results.

Flush Elements
Once the chemical cleaning circulation is finished, completely drain and rinse
the cleaning solution tank. Next, fill the cleaning solution tank with permeateor oxidant free feed water. Fill the tank with sufficient flush water to displace all
cleaning solution remaining in the cleaning system piping, RO system headers,and pressure vessels. Direct all flush water to drain for proper disposal. Refer tosection TMM-250: Flushing Procedures.
INSTRUCTION. Flush each stage (bank) separately to optimize the flow rateof each stage for effective cleaning, and to prevent the foulants removed in
the upstream stage contaminating the downstream stage. Do not recirculate
flushing water to prevent the spent cleaning solution from mixing with the clean
flush water in the flushing water tank.

General Description of DSS (Dodecyl Sodium Sulfate)
DANGER

Appearance

Powder or aqueous solution

Solubility in water

10 g/100 mLpH

7–8 (1 wt% solution based on powder)

Charge in solution

Anionic

Molecular formula

CH3(CH2)11SO3Na

CAS number

151-21-3

INSTRUCTION. Please consult the Safety Data Sheet available from thechemical supplier for full safety details BEFORE handling this chemical. Use allrecommended safety equipment.

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DSS (DODECYL SODIUM SULFATE) DETERGENT CLEANING PROCEDURE
General Description of TSP (Trisodium Phosphate)
DANGER

Appearance

White crystalline powder, granular or chunks

Density

1.630 g/cm3 (18°C)

TMM-340

Section page
3 of 3

Solubility in water 28.3 g/100 mL
pHStrong alkalinity in solution

Chemical formula Na3PO4
CAS number

7601-54-9

INSTRUCTION. Please consult the Safety Data Sheet available from thechemical supplier for full safety details BEFORE handling this chemical. Use allrecommended safety equipment.

General Description of NaOH (Sodium Hydroxide)
DANGER

Appearance

White crystalline powder, granular or chunks

Density

2.130 g/cm3 (18°C)

Solubility in water Soluble in random ratio
pH

Strong alkalinity in solution

Chemical formula NaOH
CAS number

1310-73-2

INSTRUCTION. Please consult the Safety Data Sheet available from thechemical supplier for full safety details BEFORE handling this chemical. Use allrecommended safety equipment.

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TMM-350

Section page
1 of 3

TMM-350 ACIDIC SHMP CIP PROCEDURE
Flushing of Elements
Before performing this cleaning procedure, it is advisable, especially if operatingon raw water having a high total hardness concentration, to flush elements
using softened water or RO permeate (see TMM-250: Flushing Procedures).

Preparing a 1 wt% SHMP solution
1.

Fill the cleaning tank with water.
Fill the cleaning tank with RO permeate or softened water, free of oxidizing
agents. Determine the amount of cleaning water by the RO system's size andthe extent of fouling (see TMM-320 Instructions for chemical cleaning).

2. Dissolve SHMP.
Add SHMP (white powder) to water to obtain a 1% (by weight) solution.
Continuous agitation of the solution by a motorized mixer or re-circulation
pump will be needed to dissolve the chemical entirely. SHMP should be
added to the cleaning tank in small batches to avoid clogging.
Example: 10 kg (22 lbs) of SHMP is needed.
Add hydrochloric acid to prepare 1,000 liters (264.2 US gallons) of thecleaning solution.
3. Add hydrochloric acid.
Slowly add HCl to the SHMP solution until you reach a pH value of 2.
WARNING. HCl is an aggressive inorganic acid, pay attention to safety
precautions when handling HCl.
4. Check pH value.
The pH of the cleaning solution should remain just above 2. If the pH
increases above 3.5 during circulation of the cleaning solution, add HCl until
the pH is again just above pH 2. Should the pH go below 2, adjust the pH toslightly above pH 2 by adding caustic soda (NaOH).
WARNING. Caustic soda is an aggressive inorganic base; pay attention toapplicable safety rules when handling it. The expected pH of a 1 wt% SHMP
solution is neutral.

Circulate Cleaning Solution
INSTRUCTION. The first 10–15% of the original cleaning solution volume
returned from the RO system may contain contaminants in high concentrations.
Therefore, it is recommended to dispose of this portion of the cleaning solution
to drain and not recycle it back into the solution tank. Once this initial volume
has been discarded, direct all the returned cleaning solution to the solution tankfor re-circulation.
Apply low feed water pressure during re-circulation (approximately 0.2 MPa [30psi]). Higher cleaning solution temperature can improve the cleaning efficiency.

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ACIDIC SHMP CIP PROCEDURE
CAUTION. Longer periods of circulation are beneficial for chemical cleaning.
However, prolonged circulation will increase the cleaning solution's
temperature. Monitor the solution temperature to ensure it does not exceed
the recommended maximum allowable temperature (refer to TMM-320:
Instructions for Chemical Cleaning).

TMM-350

Section page2 of 3

When mixing the SHMP, there is a potential for excessive foaming. To reduce
this foaming potential, make sure the permeate and cleaning solution returnlines are extended below the liquid level in the cleaning solution tank.
INSTRUCTION. Soaking the elements in the cleaning solution can help to breakup and remove contaminants. Alternating periods of soaking and circulation of
the cleaning solution can improve the chemical cleaning efficiency.
INSTRUCTION. If the pH value during circulation increases above pH 3.5, add
more HCl until pH value drops to just above pH 2. If the pH of the returned
cleaning solution increases rapidly, the solution's effectiveness has been
reduced due to reaction with contaminants. Should a rapid rise in pH be noted,
discard the spent cleaning solution and mix up a fresh batch and proceed as
before with the cleaning process.

Flush Elements
Once the chemical cleaning circulation is finished, completely drain and rinse
the cleaning solution tank. Next, fill the cleaning solution tank with permeateor oxidant free feed water. Fill the tank with sufficient flush water to displace all
cleaning solution remaining in the cleaning system piping, RO system headers,and pressure vessels. Direct all flush water to drain for proper disposal. Refer to
TMM-250: Flushing procedures.
INSTRUCTION. Flush each stage (bank) separately to optimize the flow rateof each stage for effective cleaning, and to prevent the foulants removed in
the upstream stage contaminating the downstream stage. Do not recirculate
flushing water to prevent the spent cleaning solution from mixing with the clean
flush water in the flushing water tank.

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TMM-350

Section page
3 of 3ACIDIC SHMP CIP PROCEDURE
General Description of SHMP (Sodium Hexametaphosphate)
Appearance

White powder, odorlessConcentration

Approx. 67 wt% as P2O5

Density

0.95–1.05 g/cm3 (20°C)

Solubility in water

Almost unlimitedpH

Approx. pH 7 (1 wt% solution)

Chemical formula(NaPO3)nCAS number

10124-56-8

INSTRUCTION. Please consult the Safety Data Sheet available from thechemical supplier for full safety details BEFORE handling this chemical. Use allrecommended safety equipment.

Safety precautions•

Consult safety data sheet (SDS) of suppliers of SHMP before use.
DANGER. Wear standard safety equipment like gloves and eye protection
during the handling of SHMP.

•

In case of eye contact, flush the eye immediately with a large amount ofwater and consult a physician.

•

Avoid prolonged contact with the skin. Avoid breathing dust.

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TMM-360 REVERSE FLOW CIP/FLUSHING
During normal operation, the higher operating flux and foulants from upstream
expose the front side RO elements to higher fouling potential.

TMM-360

Section page
1 of 1

If CIP or flushing of the RO elements is carried out in the flow direction fromthe feed side to the brine side, foulant will pass through the downstream RO
elements to be discharged from the brine side. This event has potential risks tostack foulant on downstream RO elements.

Figure TMM-360-1: Water flow image at normal operation
Reverse flow CIP/Flushing is an efficient cleaning method that helps avoid thestacking of foulants and increase RO elements' lifetime.

Figure TMM-360-2: Water flow at reverse flow CIP/Flushing
CAUTION. Maximum allowable DP: 2.0 bars/pressure vessel (at reverse flow
CIP/Flushing).
Proper shimming is required to avoid thedamage of RO element and interconnector
O-rings with its movement during reverse
flow CIP/Flushing.
The diameter of "E" in the special permeate
adapter should be equal or larger than "G."Note: if attempting reverse flow CIP without
the special permeate adapter, there is arisk of damaging the elements.
Bi-directional brine seal "TORAYSEALTM" isin some cases useful to increase cleaning
efficiency of reverse flow CIP/flushing.
Please contact Toray or its representative
before using the seal.

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TMM-400

Section page
1 of 2

TMM-400 SANITIZATION METHODS FOR
RO/NF ELEMENTS
Sanitizing Solutions
Formaldehyde
One effective method to prevent the propagation of bacteria is to soak themembrane elements in a sanitizing solution of 0.2–0.3 wt% formaldehyde(HCHO) at pH 6–8. Adding sodium bicarbonate (NaHCO3) adjusts the sanitizing
solution's pH.
This sanitization method is a satisfactory and effective method to control
biological activity for short- or long-term shutdowns.
Immersion of membrane elements in a formaldehyde sanitization solution does
not apply to new elements. Elements must have been in full operation at design
conditions for at least 72 hours before any formaldehyde sanitization procedures.
Exposure of elements to formaldehyde before 72 hours of operation may resultin irreversible flux loss.
Alternate Sanitizing Solutions
If formaldehyde sanitization is not permitted, the following alternative solutions
can be employed (see chart below). Membrane elements can be soaked inthese alternate solutions during system shutdowns. Please note that membrane
exposure time to these alternate solutions is limited. Refer to the chart below forrecommended soak intervals.
Table TMM-440-1: Alternate sanitizing solutions
Sanitizing solution

Concentrate(ppm)

Duration oftreatment *) (hour)

Applicable tomembrane typeHydrogen peroxide

2,000–10,000

1 ***)

Other than 800
series and TSW

500–1,000

No limit ***)All types

H2O2 **)
Sodium bisulfite
CAUTION.
1.

The water used to prepare all sanitizing solutions must be free of residual
chlorine or other equivalent oxidizing agents.

2. Be sure that the selected chemicals are appropriate and chemicallycompatible with the membrane type to be sanitized. Refer to the chart above.

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SANITIZATION METHODS FOR RO/NF ELEMENTS*)

Contact time with sterilizing solutions must not exceed recommended durations to avoid
membrane performance decline.

**)

The use of hydrogen peroxide in the presence of heavy metal residues will quickly lead toirreversible damage of composite membranes.

TMM-400

Section page2 of 2

Hydrogen peroxide for this application must be prepared with de-ionized feed water withless than 0.2 ppb iron. If the concentration of iron is above 0.2 ppb in the solution's makeup
water, the membrane elements can be irreversibly damaged, increasing salt passage.
Any presence or indication of heavy metal precipitates (i.e., iron, manganese) on themembrane surface requires mandatory cleaning of the membranes with an acid solution
before exposure to hydrogen peroxide. For details of the citric acid cleaning procedure,see TMM-330: CIP — Citric Acid. Failure to do so may result in catalyzed oxidation of themembrane surface by the hydrogen peroxide resulting in irreversible salt passage increase.
***) After sterilization, thoroughly flush the system with permeate or pre-treated raw water
before placing the system back online. If the preservation of membranes is required as partof an extended shutdown, the system must be thoroughly flushed before introducing any
preservative solutions.

BiocideDBNPA (2,2-dibromo-3-nitrilopropionamide) is a highly effective non-oxidizing
broad-spectrum biocide used to control algae, bacteria, and fungi in reverse
osmosis systems and other industrial water applications.
This product is typically applied as a shock treatment to control biological activity
within membrane elements. Dosing frequency depends on the microbiologicalactivity of the RO feed water and the condition of the membranes.
There are several DBNPA-based products available. For more information
about DBNPA, refer to DBNPA supplier technical data and Safety Data Sheet or
contact your chemical supplier for recommendations.

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TMM-410

Section page
1 of 1

TMM-410 HEAT SANITIZATION OF RO ELEMENTS(TMRO AND TS TYPES)
Periodic hot water sanitization (pasteurization) is a preventive measure to
reduce bacteria and fungus growth. The following recommendations apply to
TORAY hot water-resistant elements (TMRO and TS types).
CAUTION.
•

Temperature slope during heating & cool down period: maximum 2.0°C / minute.

•

It is preferable to use permeate, or at least softened water, for this procedure.

•

Do not apply heat sanitization to standard RO products, as it will cause
irreversible damage.

INSTRUCTION. For effective sanitization, the water temperature can beincreased up to 85°C (temperature required depends on bacteria strainspresent). Increasing the temperature to above 85°C can lead to irreversible
damage to the elements.
CAUTION.
•Net feed pressure (= Feed pressure - Permeate pressure) during hot water
treatment must always be less than 0.17 MPa (25 psi).

•

Feed pressure during hot water treatment must always be ≤ 0.30 MPa (45psi).
- Acceptable case : Feed pressure = 0.30 MPa, Permeate pressure = 0.16
MPa, Net feed pressure = 0.14 MPa- Not acceptable case : Feed pressure = 0.30 MPa, Permeate pressure =0.13 MPa, Net feed pressure = 0.17 MPa•

Feed and brine side pressure should be always higher than permeateside pressure during heat sanitization treatment. Extra permeate side backpressure might cause a trouble of membrane destruction.

•

The maximum differential pressure should be 0.10 MPa (15 psi) per element.

The frequency of hot water treatment depends on feed water quality and theuse of product water. The average frequency of treatment should, however, notexceed one treatment per week.
INSTRUCTION. Microbiological testing of the feed, brine, and permeate
streams determines the need for and effectiveness of heat sanitization.
It is important to open the permeate side valve and maintain no permeate sidebackpressure condition during high-temperature treatment. Feed and brinepressure should be higher than permeate side pressure at all times to avoid
permeate back pressure problems.

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TMM-500 STORAGE OF RO ELEMENT OUTSIDE OF
PRESSURE VESSEL

TMM-500

Section page
1 of 2

General Guidelines

TORAY RO elements must be preserved in a solution to prevent biological
growth on membrane surfaces during storage and performance loss in a
subsequent operation.
Element preservation is necessary for:•Long-term storage of new and used elements•

RO system shutdown ≥ 24 hours

If the RO elements have been in service, see TMM-240 Shutdown considerations
for RO systems.

Storage of New Elements
Store new elements in its original packaging until installing membrane elements
into the pressure vessels for system startup. Recommended storage conditions
are listed below:
1.

Store elements in a cool and dry place inside a closed building. Keepelements away from exposure to direct sunlight.
Note: New elements are packaged with a preservative solution made of
0.5–1.0% sodium bisulfite or sodium chloride, and a deoxidizer packet.

2. Elements must be stored within a temperature range from freezing point to
35°C (95°F).
3. Oxygen impermeable plastic bags under a slight vacuum are used for
packaging new elements. The elements are shipped in durable carton
boxes. Store the elements in the original shipping cartons until they are
installed in the RO system's pressure vessels. Dispose of used bags anddeoxidizers as regular municipal solid waste.
4. Do not stack more than five rows of carton boxes when re-stacking fromoriginally delivered packing (export packing).
5. Please keep the original element packaging dry at all times to preserve
structural integrity.

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TMM-500
Section page2 of 2

STORAGE OF RO ELEMENT OUTSIDE OF PRESSURE VESSELStorage of Used Elements
1.

For storing elements that have been in service, refer to TMM-240:
Shutdown Consideration for RO Systems. Using RO permeate or softenedwater, prepare a 500–1,000 ppm sodium bisulfite solution. To prepare thesolution, use food-grade sodium metabisulfite (SMBS). SMBS reacts withwater to form sodium bisulfite (SBS) according to this reaction:
Na2S2O5 + H2O ==> 2 NaHSO3

2. After soaking the elements for about 1 hour in the bisulfite solution, remove
the elements and place them in a plastic oxygen barrier bag. Obtain oxygen
barrier bags from Toray. Seal and label the bag(s), indicating the packaging
date.
3. Storage conditions for used/repackaged elements are the same as for new
RO elements. See page 1 of this section.
4. When sending back used elements to Toray, please contact Toray or its
representative before unloading elements.

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TMM-600 INTRODUCTION TO TROUBLESHOOTING

TMM-600

Section page
1 of 3The RO system's potential problems can be recognized early by monitoring thechanges of permeate flow rate*, salt passage (salt rejection)*, and differential
pressure* of the RO pressure vessels. Therefore, it is recommended thatthe system operator(s) record and review operational data frequently. Early
detection of system performance decline will alert the operators to potential
operational problems and initiate appropriate countermeasures to restore
membrane element performance.
Typical performance changes and their countermeasures are explained in
section TMM-610: Typical Performance Changes and Countermeasures.
The basic steps of troubleshooting are summarized below:
ActionItem concerned

Check

Calibration of Instruments: Pressure, Temperature,
Conductivity, pH, Flow etc.

Review

Daily operational data, normalized data, maintenancelogs, and comparison of current performance to design
specifications.

Investigate

Reasons for performance changes and their possible
causes. Refer to TMM-610 Typical Performance Changes
and Countermeasures.

TroubleshootInitiate corrective measures; perform countermeasuresin a timely fashion e.g. chemical cleaning, sterilization,
replacement of defective parts, system adjustments.

Permeate Center Pipe Probing Method
If measuring permeate conductivity from a specific pressure vessel indicatesa sudden and significant increase in permeate conductivity, a faulty o-ring(mechanical leak) or loss of rejection in the membrane may cause the high saltpassage. Probing the elements will help determine the cause of the increase in thesalt passage. Figures TMM-600-1 and TMM-600-2 shows the probing apparatus.
Water quality (conductivity) can be easily measured at different positions within thepressure vessel by sampling the water using the center pipe probing technique.
*)

Normalization of values marked with * is required to understand the operation data properly.
Procedures for normalization are described in section TMM-230: Operation Monitoring.

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TMM-600
Section page2 of 3INTRODUCTION TO TROUBLESHOOTING

Figure TMM-600-1: Center pipe probing method 1

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INTRODUCTION TO TROUBLESHOOTING

TMM-600

Section page
3 of 3Figure TMM-600-2: Center pipe probing method 2

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TMM-610

Section page
1 of 8

TMM-610 TYPICAL PERFORMANCE CHANGES AND
COUNTERMEASURES
Record reliable operational data daily to evaluate the performance of a RO
system properly. Implement a regular instrument calibration to ensure thecollected performance data is accurate. Logging of collected data and all
maintenance procedures are important for proper system evaluation. Analysisof the recorded historical system data will help determine what remedy is best
suited to recover any lost system performance.
This section is about problems and countermeasures regarding salt passage
and permeate flow rate. Section TMM-230: Operation Monitoring discusses theimpact of feed water conditions such as pressure, temperature, concentration,
pH, and recovery ratio in the system performance.
The following abbreviations are used in this section:
NPFR= Normalized permeate flow rate

NSP

= Normalized salt passage

DP 		= Differential pressure

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TYPICAL PERFORMANCE CHANGES AND COUNTERMEASURES

TMM-610

Case A: Normalized Permeate Flow Rate (NPFR) Decline:
First Bank

Section page2 of 8Decreasing
trend

Increasing

Potential causesCountermeasures

Change in feed water quality

Check operating parameters(recovery, flux). Optimize pretreatment, check pre-filtration(perform any required adjustments).

Fouling by metal hydroxides,
inorganic colloids, organic orbacterial matter

Optimize pre-treatment, followed byappropriate CIP and / or sterilization.

Fouling by suspended particles

Chemical cleaning.
Optimize pre-treatment, check prefiltration equipment.

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TMM-610

Section page
3 of 8TYPICAL PERFORMANCE CHANGES AND COUNTERMEASURES
Case B: Normalized Permeate Flow Rate (NPFR) Decline:
Last Bank

Decreasing trend(major symptom)

Increasing trend

Potential causesCountermeasures

Change in feed water quality

Check operating parameters(recovery, flux). Optimize pretreatment, especially the scale
inhibitor injection system anddosage rate.

Scaling in bank 2 (precipitation of
sparingly soluble salts

Check feed analysis for changes.
Check scale inhibitor injection
system and inhibitor dosage rate.

Fouling by metal hydroxides,
inorganic colloids, organic orbacterial matter

Optimize pre-treatment, analyze thefoulant followed by an appropriate
CIP and / or sterilization procedure.

Fouling by suspended particles

Analyze precipitate, followed byappropriate chemical cleaning.

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TYPICAL PERFORMANCE CHANGES AND COUNTERMEASURES
Case C: Normalized Salt Passage (NSP) Increase: All Vessels

TMM-610

Section page
4 of 8NSP
OR
Increasing trend(major symptom)
Shutdown ormaintenance period

NPFR
OR
Increasing trend

Operating time

Operating time

Potential causesCountermeasures

Membrane affected by exposure tooxidants,

Check, modify and/or optimize
chemicals that come in contact withthe membrane elements.

Use of non-compatible chemicals,
System operation outside
recommended design values.

Mechanical damage due to scratch
by particles such as precipitation of
sparingly soluble salts.

Check oxidant removal apparatus(if any).
Check and adjust operating
conditions according torecommendations of the membrane
manufacturer.
Check pre-treatment, in particularregarding pH adjustment and / ordosing rate of scale inhibitors.
Adjust system recovery withattention to limits given by feedwater chemistry.

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TMM-610

Section page
5 of 8TYPICAL PERFORMANCE CHANGES AND COUNTERMEASURES
Case D: Normalized Permeate Flow Rate (NPFR) Decrease:
All Banks Simultaneously
NSP

Decrease

OR

NPFR

Shutdown ormaintenance period

Rapid decrease

OR

Operating time

Operating time

Potential causesCountermeasures

Initial stages of damage causedby exposure of non-compatible
chemicals.

Check, modify and/or optimize
chemicals coming in contact with themembranes. Check to make sure all
chemicals are compatible with the
installed membrane.
Check and adjust operating
conditions according torecommendations of the membrane
manufacturer.

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TYPICAL PERFORMANCE CHANGES AND COUNTERMEASURES
Case E: Normalized Permeate Flow Rate (NPFR) Decrease: All
Banks Simultaneously with Variations for Individual Brine stages

TMM-610

Section page
6 of 8NSP
OR
Increasing trend
Shutdown ormaintenance period

Decreasing trend

NPFR

OR

Operating time

Operating time

Potential causesCountermeasures

Excessive concentration polarization

Check and adjust operating
conditions according torecommended guidelines. Make
sure the minimum brine flow
requirement has been maintained.
Check the system’s recovery rate
to make sure it is within the systemdesign specifications- if needed
reduce the recovery.
Check pre-treatment chemical
dosage and addition.
Check and replace brine seals ifnecessary.

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TMM-610

Section page
7 of 8TYPICAL PERFORMANCE CHANGES AND COUNTERMEASURES
Case F: Differential Pressure (DP) Increase
Shutdown ormaintenance period

DP
OR
Increasing trend

Operating time

Operating time

Potential causesCountermeasures

Contamination by particulate matteror bio-growth

Refer to Case A and B.

Excessive feed flow

Check feed flow rates forcompliance with recommendations
and latest trends.

Check and improve pre-treatment,in particular for particle removal
and carbon feed to system (TOC/
DOC ratio).

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TYPICAL PERFORMANCE CHANGES AND COUNTERMEASURES
Case G: Normalized Salt Passage (NSP) Increase:
Individual Vessels

TMM-610

Section page
8 of 8

Shutdown ormaintenance period

NSP
OR
Quick increase

Operating time

Operating time

Potential causesCountermeasures

Mechanical leakage due toDetect location of the leak in aparticular vessel by probing thepressure vessel in question.

O-ring seal damage
Excessive feed flow / pressure drop
Excessive permeate backpressure

Make sure permeate back pressure(permeate pressure minus feed/brine pressure) is less than 0.03 MPa[5 psi] at all times especially during
start-up and shutdown.

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TMM-700

Section page
1 of 1

TMM-700 POLICY FOR CHEMICAL COMPATIBILITY
TEST
1.

Toray will not accept any compatibility test inquiries as it is not RO membrane
manufacturer’s scope.

2. Toray can provide information on the compatibility of RPI antiscalants tocustomers, as promoted by Toray.
3. Toray will disclose the recommended method for testing only as a reference
for the compatibility of chemicals supplied by other chemical manufacturers.
It is the customer's responsibility to make and draw their evaluations andconclusions. Toray does not take any responsibility for test results andfindings made by customers.
4. Please contact Toray for the validity of the test results previously reported
by Toray because compatibility will change due to the composition ofchemicals or membrane specifications.

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TMM-800 RO FEED WATER GUIDELINES

TMM-800
Section page
1 of 4

1. Iron & Manganese

Iron and manganese are present in naturally occurring waters. They are generally
present in higher concentrations in well water. They exist in soluble forms (Fe(II)and Mn(II)) and insoluble forms (Fe(III), Mn(III) and Mn(IV)). The soluble form canbe oxidized to the insoluble form by contact with oxygen and/or oxidizing agentsin water. The rate of oxidation at natural water pH (typically 6 - 8) is very fast. The
insoluble ions precipitate in RO systems as hydroxides or oxides.
Guideline feed concentration. The recommended concentration in the RO feedis ≤ 0.05 mg/L (as insoluble Fe or Mn). Fe/Mn precipitate on the membrane must
be removed by CIP for stable plant operation. CIP frequency increases withincreasing Fe/Mn concentration in the RO feed.
Please note that even if their concentration is below 0.05 mg/L, care must still
be taken. The metals can act as catalysts and accelerate membrane oxidation if
they are present on the RO membrane surface with even small concentrationsof oxidants. In such cases, sufficient sodium metabisulfite (SMBS) must be dosed
to inactivate oxidants (e.g. NaOCl) before feed to RO systems. In such cases,
adequate measures must be taken to inactivate oxidant.

2. Aluminum

Aluminum is usually present in trace amounts in natural waters at around neutral
pH. It is also used as a coagulant (e.g. polyaluminum chloride) for RO pretreatment.
Aluminum forms the highly insoluble hydroxide Al(OH)₃ in the neutral pH range.
Together with silica it also forms aluminium silicate fouling on the RO membrane.
To avoid these issues, it is recommended to keep the aluminum in the RO feed
to 0.05 mg/L or less.
Aluminum causes not only fouling but also scaling as well. Anti-scaling agentsshould be properly used to solve scaling problems.

3. Aluminum coagulants
Aluminum coagulants such as polyaluminum chloride or Aluminum sulfate arewidely used for pretreatment in RO system. Aluminum coagulants neutralize thenegative charge of suspended particles and facilitate the coagulation due to its
cationic charge.

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TMM-800

RO FEED WATER GUIDELINES

Section page2 of 4

If it comes in contact with a negatively charged polyamide RO membrane there
is a strong possibility of attachment, and it may prove difficult or impossible to“unattach” it without risking membrane damage. There is therefore risk associatedwith the use of such compounds. The key to using them safely lies entirely in theoperation of the pretreatment. The optimum dose is determined by jar test, orother laboratory scale test procedure. Only sufficient chemical to maximize thefloc formation should be added. More is NOT better. If excess is added, there
are no additional particles present in the pre-treatment for them to attach to, andthey remain in the solution. As such, they are too small to be rejected by even
MF/UF pretreatment, and will therefore pass through the pretreatment and enter
the RO membrane system, with the strong probability of attachment to the RO
membrane.
As previously stated, irreversible fouling of the RO membrane is not covered by
Toray warranty.

4. Cationic substances
Cationic substances have risks of fouling due to interactions between positive
charge of the substances and negative charge of RO membranes. Cationiccoagulants, textile aids, defoaming agents, wetting agents, cationic surfactants
are examples of the cationic substances.
As such, cationic coagulants are designed to be electrochemically “sticky”.
Particular types of functional groups are used to create areas on the molecule ofnet positive charge. This facilitates the agglomeration of small/colloidal particles
into larger size groups of particles which can be removed through downstream
filtration (conventional of membrane based).
All comments made above regarding the use of aluminum coagulants apply tosuch compounds. If the dosage is too high, and unattached cationic substances
reach the RO membrane, there is a high probability of chemical bonding to themembrane surface which will result in irreversible fouling.

5. Nonionic substances
Nonionic substances represent also risk of fouling due to hydrophobic interactions
between the lipophilic areas of the substances and hydrocarbon portion of RO
membranes. Oil, grease, nonionic coagulants, nonionic surfactants are examplesof nonionic substances. These substances may cause irreversible fouling of RO
membranes if present in feed water.

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RO FEED WATER GUIDELINES

TMM-800
Section page
3 of 4

6. TOC

Total Organic Carbon (TOC) is the total amount of oxidizable organic matter inwater expressed as concentration of carbon.
TOC analysis does not yield information regarding:
I. The organic compounds which are included in the TOC measurement. (Size/
shape/ molecular weight/ surface charge)
II. The fouling tendency of the organic compounds comprised the TOC value(any tendency to bond with/ foul the membrane surface to increase resistanceto water flow (resulting in flux loss)).
It is not possible to determine the fouling potential of a water on the basis of a
TOC value alone. Neither is it possible to estimate the rejection of the organics
present on the basis of a TOC value alone. Higher concentration of TOC may
indicate higher potential for fouling from the source. A pilot trial is normallyrequired to establish organic rejection and fouling potential.

7. COD

Chemical Oxygen Demand (COD) is defined as the quantity of a specified oxidantthat reacts with a sample under controlled conditions. The quantity of oxidant
consumed is expressed in terms of its oxygen equivalence. COD is expressed in
mg/L-O₂.
COD is therefore a measure of the oxidizable content of the sample. It includes:
Organics
Some inorganic compounds
COD value is typically higher than the TOC value.
COD is often used as a measurement of pollutants in natural and waste waters,
and to assess the strength of waste such as sewage and industrial effluent waters.
As for TOC, it is not possible to determine the fouling potential of a water on thebasis of a COD value alone. Neither is it possible to estimate the rejection of theorganics present on the basis of a COD value alone. As the concentration of
COD increases, the potential for irreversible fouling also increases depending on
the organic compounds in the RO feed water. An elevated COD value suggests
the need of a closer analysis. A pilot trial is normally required to establish organic
rejection and fouling potential.

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TMM-800

RO FEED WATER GUIDELINES

Section page
4 of 4

8. BOD
Biochemical Oxygen Demand (BOD) is a measure of the potential of the sample
as a food source for bacteria – how much organic carbon is there available forany bacteria present to be used as food.
Higher BOD content shows a higher risk of biofouling of RO membranes. However,
it is difficult to determine a guideline value of BOD because the risk of foulingdepends on which kinds of bacteria and substances exist.
Elevated BOD values indicate a need for closer inspection of the feed water,
including typically determination of the assimilable organic content (AOC).
Ultimately, qualified piloting under real site conditions will show the extent of
performance changes caused by the elevated BOD values.

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INDEX

A

Accessories — 8
Acid dosing — 30, 32
Acid insoluble scaling — 52
Acidic cleaning — 49
Acidic SHMP — 61
Activated carbon — 18
Agitation — 55, 58, 61
Agitator — 55
Air — 19, 20, 21, 43, 58
Algae — 66
Alkaline solution — 52
Aluminum — 82
Aluminum coagulants — 82
Ammonia (NH3) — 52, 55, 57
Ammonia gas — 55
Ammonium — 34
Ammonium hydroxide (NH4OH) — 52, 55
Antiscalant — 31, 33, 81
ASTM D 4516 — 37
Atmospheric oxygen — 43
Atmospheric pressure — 22

B

Bacteria — 65, 66, 67, 85
Bacterial contamination — 52
Bacterial growth — 45, 46
Bacterial matter — 52, 74, 75
Barium — 34
BaSO4 — 52
Bicarbonate — 34
Biochemical Oxygen Demand (BOD)— 34, 85
Biocide — 66
Bio-fouling — 48

Biogrowth — 79
Biological activity — 43, 65, 66
Biological fouling — 48
Biological growth — 43, 68
Bisulfite surplus — 18
Boron — 34
Brine — 16, 17, 20, 21, 27, 41, 45
Brine flow — 9, 19, 21, 22, 23, 24, 25, 78
Brine seal — 8, 9, 12, 17, 20, 64, 78
Brine surplus of HSO3- — 29, 31, 33
Brownish color residue — 48

C

CaF2 — 52
Calcium — 34
Calcium scale — 48, 49, 52
Calibration — 20, 35, 70, 73
Carbon dioxide — 34
Carton box — 8, 68
Cartridge filter change — 35
Cartridge manufacturer — 18
CaSO4 — 52
Cationic compounds — 18, 83
Caustic soda (NaOH) — see Sodium hydroxide
Centrifugal pump — 21, 24, 25
Checkpoints — 26
Check valves — 22, 41
Chemical additives — 35
Chemical analysis — 48
Chemical cleaning — 46, 49, 50, 55, 58, 61
Chemical cleaning circulation — 56, 59, 62
Chemical composition — 27
Chemical dosage — 78
Chemical oxidants — 41

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Chemical oxygen demand (COD) — 34, 84

Daily operational data — 70

Chloride — 34

Data log sheet — 21

Chlorine dioxide — 18

Data logging intervals — 26

Chlorine exposure — 42

DBNPA — 66

Chlorine removal — 18

Dechlorination — 30, 32, 42

CIP flow rate — 50

De-ionized feed water — 66

CIP pressure — 50, 53

Deoxidizer — 68

CIP solution — 50, 53, 59

Deoxidizer packets — 68

CIP system — 53, 54

Detergent — 52, 58

Circulation — 51, 54, 56, 58, 61

Detergent cleaning — 52, 58

Circulation pump — 55, 61

Differential pressure (DP) — 19, 21, 26, 47, 48,
53, 67, 70, 73, 79

Circulation time — 59
Citric acid — 49, 52, 55, 66
Cleaning chemicals — 50
Cleaning flow rate — 50, 53
Cleaning procedure — 49, 52, 55, 58, 61, 66
Cleaning pump — 53, 55
Cleaning solution — 35, 44, 50, 55, 58, 61
Cleaning solution tank — 56, 59, 62
Cleaning solution volume — 58, 61
Cleaning tank — 54, 55, 58, 61
Cleaning technique — 51
Cleaning water — 55, 58, 61
Clogging — 61
Colloids — 27, 47, 48, 52, 74, 75
Concentration polarization — 78
Conductivity — 20, 21, 70
Contamination — 9, 46, 47, 49, 52, 79
Conversion — 27
Countermeasures — 28, 70, 73, 74, 76

D

Daily monitoring — 28, 37
Daily operation — 21

Direct sunlight — 68
Dirt — 13
Discharge — 22, 35, 53, 54
Dispose — 61, 68
Distance "A" — 15
Documentation — 16
Dodecyl Sodium Sulfate — see DSS
Dosing frequency — 66
Dosing rate — 76
Downstream element — 14, 15, 17, 64
Drain — 53
DSS (Dodecyl Sodium Sulfate) — 49, 52, 58
Dust — 7, 13, 18, 63

E

EDTA — 49, 52
Element box — 8
Element preservation — 35, 68
Element removal — 17
Element stack — 17, 68
End plate — 7, 14, 15, 16, 17, 18
End plate seal — 15
Energy recovery devices (ERDs) — 23

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Excel — 37

Foulants — 44, 48, 64

Excessive feed flow — 24, 79, 80

Fouling — 44, 47, 48, 50, 55, 74, 82

Excessive flow rates — 22

Fouling Index —see Slit Density Fouling Index

Eye contact — 63

Fouling tendency — 27, 84

FFreezing — 41

Factory test result — 16

Frequency (speed) — 25

Feed condition — 21

Frequency — 26, 28, 35, 66, 67, 82

Feed pH — 27

Frequency controlled motor — 25

Feed water chlorine concentration — 29, 31,
33

FRP (Fiber Reinforced Plastic) — 9

Feed water conductivity — 29, 31, 33
Feed water FI (SDI15) — 29, 31, 33
Feed water ORP — 29, 31, 33
Feed water pH — 29, 31, 33
Feed water pressure — 29, 31, 33, 61
Feed water quality — 7, 18, 21, 26, 74, 75
Feed water temperature — 27, 29, 31, 33
Feed water turbidity (NTU) — 31, 33
Feed/brine pressure — 44, 51, 54, 80
Ferric hydroxide — 49
Filter cartridge — 18, 35
Flocculants — 18
Flow direction arrow — 9
Fluctuating operating conditions — 30, 32, 33
Fluctuating pressure — 30, 32
Fluoride — 34
Flushing flow rate — 19
Flushing procedure — 44
Flushing water — 41, 42, 44, 45, 56, 59, 62
Foam formation — 58, 59
Foaming — 54, 62
Food grade — 69
Formaldehyde (HCHO) — 65
Foulant type — 48

Freezing point — 68

Fungus — 67

G

Gaps — 15
Glycerine — 8, 12, 13, 14
Grease — 18, 83
Guidelines — 48, 50, 68, 82

HHardness concentration — 61
HCl — see Hydrochloric acidHeat exchange system — 32
Heat sanitization — 67
Heavy metal residue — 66
Heavy metals — 50, 66
High pH feed water — 41, 44, 45
Hot water sanitization — 67
Hot water treatment — 67
Hydrochloric acid (HCl aq.) — 52, 61, 62
Hydrogen peroxide (H2O2) — 65, 66
Hydrogen sulfide (H2S) — 34

I

Individual ions — 21, 30, 32, 33

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Individual stage — 20, 41

Lubricant — 8, 18

Industrial waste — 17

Lubrication — 13

Initial membrane performance — 27, 37

M

Initial operation — 21
Initial start-up — 16, 30, 32, 33

Magnesium — 34

Initial trial run — 18, 20

Maintenance items — 35

Inner surface — 13, 14

Maintenance log — 35

Inorganic colloids — 48, 52, 74, 75

Maintenance procedures — 26, 35, 73

Inspection — 17, 85

Make-up water — 46, 50

Installation — 7, 18, 35

Manganese — 34, 64, 82

Installation direction — 9

Maximum temperature of cleaning solution— 51

Installed location — 16
Instrumentation — 20, 21
Interconnector — 8, 12, 17, 64
Interconnector O-rings — 17, 64
Iron — 48, 66, 82
Iron as ion — 34
Iron fouling — 48
Irreversible damage — 20, 28, 66, 67
Irreversible flux loss — 65
Isolation valve — 41, 42, 43, 44

K

Key factors — 6, 27

LLine pressure — 19
Loading process — 16
Loam — 48
Local regulations — 17, 54
Logbook — 27
Logging intervals — 29
Long-term storage — 17, 68
Long-term shutdown — 42

Mechanical damage — 14, 76
Mechanical leak — 70
Mechanical leakage — 80
Membrane damage — 44, 51, 54, 83
Membrane surface — 44, 47, 48, 50, 82
Metal compounds — 56
Metal foulant(s) — 56
Metal hydroxides — 49, 52, 74, 75
Metal residues — 7, 18, 66
Microbiological activity — 66
Microbiological testing — 67
Microorganism — 34
Millipore Type HA — 27
Minimum brine flow — 78
Mixer — 58
Monitoring — 21, 26, 70
Motorized mixer — 61
Multiple RO trains — 41
Multiport pressure vessel — 17
Municipal solid waste — 68

N

NaHSO3 — see Sodium bisulfite

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NaOH — see Sodium hydroxide

O-ring seals — 17

Net positive suction head (NPSH) — 53

O-rings — 7, 8, 14, 17, 20, 64

New elements — 8, 9, 27, 37, 48, 65, 68

ORP meter — 76, 77

Nitrate — 34

Oxidant free feed water — 56, 59, 62

Non-compatible chemicals — 76, 77

Oxidant removal — 76

Nonionic compounds — 18, 83

Oxidants — 18, 41, 44, 45, 76, 82

Non-oxidizing broad-spectrum biocide — 66

Oxidizing agent — 46, 50, 55, 58, 61, 65, 82

Normalization — 26, 27, 37, 70

Oxygen barrier bag — 10, 69

Normalization program — 37

Oxygen impermeable plastic bag — 68

Normalization software — 37

P

Normalized data — 26, 70
Normalized differential pressure — 48
Normalized permeate flow rate — 29, 31, 33,
48, 73, 74, 75, 77, 78
Normalized salt passage — 29, 31, 33, 48, 73,
74, 76, 80
NPFR — see Normalized permeate flow rate
NSP — see Normalized salt passage
NTU — see Turbidity

O

Oil — 7, 18, 83
Operating data — 28, 35
Operating pressure — 20
Operation parameters — 20, 22, 26, 29, 74,75

Particulate matter — 79
Pasteurization — 67
Performance change — 28, 37, 70, 73
Permeate — 21, 27
Permeate adapter — 7, 15, 64
Permeate adaptor tube — 15
Permeate back pressure — 44, 51, 54, 80
Permeate back pressure problems — 19
Permeate center pipe probing method — 70
Permeate conductivity — 20, 29, 31, 33, 70
Permeate flow — 21, 22, 23
Permeate flow rate — 20, 26, 27, 37, 47, 48
Permeate header — 15, 22
Permeate blind plug adaptor (solid) — 8

Operational events — 27

Permeate plugs — 16

Organic deposits — 7

Permeate port — 7, 14, 15, 16

Organic fouling — 44

Permeate port adaptor (open) — 8, 14

Organic material — 48

Permeate pressure — 21, 22, 29, 31, 33, 44,
51, 54, 80

Organic matter — 52, 84
Original conditions — 27, 37
Original operating parameters — 26
Original packaging — 8, 68
O-ring seal damage — 80

Permeate quality — 26, 27, 34
Permeate side valve — 51, 54, 67
Permeate tubes — 8
Permeate water — 21, 22
pH adjustment — 49, 58, 76
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Phosphate — 34

Regular monitoring — 26

Pipe headers — 53

Regular performance normalizations — 26

Piping ports — 17

Regulating valve — 22

Piping system — 7, 16, 19, 53

Repeated cleanings — 47

Plastic bag — 8, 17, 68

Replacement — 17, 35, 70

Plunger (displacement) pump — 23

Residual chlorine — 42, 46, 50, 65

Polyoxyethylene(PSLS) — 52

SodiumLaurylSulfatePotassium — 34
Potential problems — 70
Prechlorination — 30, 32
Precipitation — 47, 75, 76
Preservation procedure — 35, 45, 68
Preservation solution — 43, 46
Pressure drop — 19, 22, 23, 24, 25, 29, 31, 33,
44, 80Pressure vessel — 7, 8, 13, 14, 16, 17, 45, 68
Pressure vessel manufacturer — 7, 15, 16, 18
Pre-treated feed water — 19, 21, 41, 44, 45
Pre-treated raw water — 50, 66
Pretreatment — 18, 35, 74, 75, 82, 83
Product back pressure — 41
Product tube — 17
Proper disposal — 17, 56, 59, 62
Published guidelines — 18
Pump head — 53
Purge air — 19
PVC pipe — 17

R

Raw water — 61
Raw water quality — 47
Recirculation pump — 55
Recovery (conversion) ratio — 20, 22, 27
Regular calibration — 35

Residual chlorine conc. — 35
Residual cleaning chemicals — 50
Retaining ring — 7, 15
Rinse — 59, 62
RO cleaning — 47, 48
RO feed pressure — 21
RO operating parameters — 22
RO permeate — 49, 55, 58, 61, 69
RO pressure vessels — 70
RO product water — 41, 44, 45
RO system cleaning — 35
RO system headers — 56, 59, 62

S

Salinity — 27, 37
Salt passage — 20, 41, 66, 70, 73
Salt rejection — 70
Sanitization — 65, 67
Sanitization methods — 65
Sanitizing solutions — 65
SBS — see Sodium bisulfite
Scale inhibitor — 75, 76
Scaling — 34, 45, 52, 75, 82
Scratch — 7, 8, 13, 22, 50, 76
SDI15 — see Slit density fouling index
Serial numbers — 16
Shim rings — 15
Shimming procedure — 16, 64

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Shipment — 17

Storage — 68

Shipping bag — 9

Storage solutions — 42

SHMP — see Sodium hexametaphosphate

Strontium — 34

Shock treatment — 66

Strontium sulfate (SrSO4) — 52

Short-term shutdown — 42

Sulfate — 34, 43

Shutdown — 41, 45

Surfactants — 18, 35, 83

Side port — 17

Suspended particles — 74, 75, 82

Silica — 48, 82

Suspended solids — 27, 47, 50

Silicate — 34, 82

Swab — 7, 13, 22

Silicic acid — 34

System adjustments — 26, 37, 70

Silt Density fouling index (SDI15) — 18, 21, 27,
29, 31, 33, 47, 48

System log — 35

Slimy — 55
Smell — 55
Sodium — 39
Sodium bicarbonate (NaHCO3) — 65
Sodium bisulfite (SBS) — 9, 42, 43, 46, 65, 68,
69
Sodium chloride solution — 9
Sodium hexameta phosphate (SHMP) — 52,
61
Sodium hydroxide (NaOH) — 49, 52, 55, 60
Sodium metabisulfite (SMBS) — 69, 82
Sodium tripolyphosphate — 52
Soft mop — 7, 13, 22Softened drinking — 29
Softened water — 50, 55, 58, 61, 67, 69
Spacer material — 49
SrSO4 — see Strontium sulfate
Start-up — 16, 18, 21, 22, 23
Start-up sequence — 22
Start-up procedures — 22, 23
Sterilization — 52, 70, 74
Sterilization procedure — 75
Sticky — 48, 83

System performance — 20, 26, 37, 70, 73
System piping — 53, 56, 59, 62
System recovery — 76
System volume — 53

T

TDS (conductivity) — see Total dissolved
solidsTemperature slope — 67
Textile aides — 18
Thrust device — 7
Thrust ring — 7, 14
TOC/DOC ratio — 79
Tolerance — 15
Toray web site — 27, 37
TorayTrak — 32, 42
Total dissolved solids (TDS) — 21, 34
Total hardness — 29, 61
Total ions — 27
Total organic carbon (TOC) — 34, 84
Total system — 21
Trace element origin — 16
Trisodium phosphate (Na3PO4, TSP) — 52, 60
Troubleshooting — 70
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TS types — 67
TSP — see Trisodium phosphate
Turbidity (NTU) — 18, 21, 31, 33
Type HA — 27
Typical signs — 28

U

Unpack — 8
Upstream end — 15
Used elements — 68, 69

V

Velocity — 44
Vent port — 19
Venting air — 19
Vessel manufacturer — 7, 15, 16
Vessel permeate adaptors — 7
Victaulic couplings — 18
Viscosity — 13
V-shaped brine seal — 13

W

Water hammer — 19, 22, 30, 32
Water temperature — 21, 27, 29, 31, 33
Weight — 48, 84
Well water — 29, 31, 82
Wet — 41, 45

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