Winter 2019No.36
http://www.valqua.co.jp● Greetings・
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・1
Representative Director, President & CEO

Toshikazu Takizawa● Greeting upon the Publication of 2019 Winter Issue・・2
Senior Executive Officer, Director of Corporate Research andDevelopment Group Mutsuo Aoki

● Customer Solutions《Joint Authorship》
Introduction of a System for Detecting Abnormal
Vibration in Shipboard Equipment〜The Potential of Abnormal Vibration Detection Systems for Preventive Maintenance〜・・3Managing Director MOL Techno-Trade, Ltd. Makoto Haneda
Corporate Research and Development Group Product Development DivisionⅠ Hisataka Sato
Corporate Research and Development Group Product Development DivisionⅠ Tetsuya Komeda
Corporate Research and Development Group Advanced Technology Reseach Division Yasushi Aburatani● Customer Solutions《Contribution》

Practical training Equipment for Flange Tightening
Force Fluctuation due to Temperature Difference ・・8Engineering Department SHOWA YOKKAICHI SEKIYU CO.,LTD Kenichi Takamura● Technical Papers

Evaluation of Mechanical Properties and Sealing Performanceof 24 Pipe Flange Connections with No.GF300 Gasket・・・・12
Corporate Research and Development Group Product Development Division Kouji Satou
China Research Institute Seal Engineering Development Group Xing Zheng
Hiroshima University, Professor Emeritus Toshiyuki Sawa

● Technical Papers

Lining Tank（Application）
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・20
Assistant To High Performance Plastics Product Manager

Takeshi Yokoyama● Product Introductions

Long-Lifetime FEPM TOUGHUORO™・
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・28
Corporate Research and Development Group
Product Development Division Hirofumi Zushi● Product Introductions

Low Torque & Long-Lifetime Swivel Joint LFR JOINT ™・・32
Research and Development Headquarters
Product Development Division 1 Ryosuke Nishi● Recent Technology News Back Issues・
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・36

Greetings
Toshikazu Takisawa
Representative Director,
President & CEO
VALQUA, LTD.

I wish you a year filled with peace and happiness in the beginning of
2019.
Thank you for regularly reading the Valqua Technology News.
Looking back on last year, reflecting the depreciation of the yen, increased corporate profits, and therecovery of personal consumption, etc., Japan’s economy steadily grew in the first half, but in thesecond half, with the effect of economic friction between the USA and China and the employment
environment where there is a lack of workforce, the company outlook was not always positive. In suchbusiness environment, private companies strongly need to break out of the fixed mold that hascontinued from the past and create new innovation to provide added-value to their customers while
being fully compliant and continuously striving towards improvement of quality.

Winter 2019

As we have already announced through various media, our company’s name has changed to
VALQUA,LTD from October 1 of last year. Our company group has continued to work towards“Value”and“Quality”for over 90 years starting from the establishment until now, and supported theindustrial foundations throughout the world as a pioneer of sealing engineering. We would like ourreaders to reconfirm that our new company name reflects our commitment to push towads developing
No.36 our business globally with this“Sealing Engineering”as its main axis.
Our company group defines this name change as a chance for having a second chance forestablishment and is highly committed to be reborn as a H&S company, develop total solutions
consisting of products and services that consider the customer’s viewpoint, and deliver these to ourcustomers.
The“New Valqua Stage Eight（NV・S8）”management plan that started from last year is as alreadydescribed in the previous paragraph, and it positions the“Sealing Engineering Service”solutions thatwere developed from our history in creative technology as its main axis and H&S activities aiming toprovide new value for customers is positioned as the core for our group business’s growth. To achievethis, we will try to avoid traditional ways of considering things, and try not to be trapped into abstractand uniform ways of thinking. We will understand the true needs of our customers by going back tothe basics and conducting analysis and discussions regarding the challenges that surround ourcustomers. We have a strong commitment to achieve healthy and continuous growth together with you
by conducting technological development that creates“Creative Destruction”.
We look forward to your continued support this year and wish all our readers the best in the comingyear.
1Greeting upon the Publication of 2019
Winter Issue

We wish you a Happy New Year 2019.
I would like to express my sincere gratitude to all of the readers of VALQUA Technology News.
We have entered the final year of the Heisei era and as we reflect back on the technologicalenvironment and trends of the past few years, the rapid changes and progress in information
technology including IoT and AI has drastically changed the core value of the IT industry. For suchtechnological innovation that brings impactful changes to the market, the keyword of“Connectivity”
comes into play in innovative technology. Collaboration among companies from various fields andtechnologies is now achieved in the digital space using IT technologies along with the concept of open

open innovation in technological development activities. We aim to combine our accumulated
technological know-how with leading-edge technologies to create authentic customer solutions fromthe customer’s perspective and to deliver them with speed. Throughout these activities, we would
also like to value the“Connectivity”with our Group’s customers and partnerships as well as ourviews for the environmental and economic sustainability when delivering products and technologicalsolutions to customers as a result of our activities as“H&S Company”.
This issue of Technology News consists of 3 parts which continues on from the previous issue: thereal-life examples from“Customer Solution”which is provided by our Group, the articles that
introduce our Group’s technologies, and the introduction of new products. In the real-life examples of“Customer Solution,” we introduce our predictive maintenance technology which detects
abnormalities in marine equipment and delivers“safety and security”with a system that combines
our proprietary sensing technology and material technology. This section also lists the contributions
from customers who have experienced our Group's on-the-job training equipment and learning
program on flange tightening. As for technical articles, we have picked up themes related to thecharacterization of large diameter flange tightening, processing technology and an evaluation methodof lining tanks, and published them to provide readers with technical reviews for reference.
In addition, we provide information on new products—for example, new materials that show excellent
characteristics even in severe environments such as high temperature steam environment—which
will be useful for you to select products in the future.
We hope you will continue to enjoy the VALQUA Technology News this year as the new era begins.
Senior Executive Officer, Director of Corporate Research and Development Group

Mutsuo Aoki
2

Winter 2019

innovation.
In a world where new waves of technological innovation are surging forward, and as this year marks
the 92th anniversary since the company’s founding, our Group will further promote globalization andNo.36

Introduction of a System for Detecting
Abnormal Vibration in Shipboard Equipment～The Potential of Abnormal Vibration Detection Systems for Preventive Maintenance～
1. Introduction

problems.

The Japanese economy is supported by import /export

Recently, with the improvement in technology for

trade and international sea transport accounts for overtemperature, pressure and vibration sensors, systems

90% of total import /export cargo. Transport bythat automatically monitor various inspection items andWinter 2019shipping is an extremely important method for

issue warning on abnormalities are installed, but the

conducting international trade.

actual situation is that not all the small behavioral

With the expanding global economy and borderless-changes and abnormal vibrations of onboard equipment

ness, it is becoming apparent that global risk is

could be automatically monitored sufficiently.

intricately interconnected. Sea transport businesses are

In this report, we would like to introduce a portable

always at the brink of danger and they aim to prevent

system which detects abnormal vibrations that wasserious accidents. To conduct safe transport whiledeveloped together by MOL Techno-Trade, Ltd. andmaintaining a transport schedule, not only maintenanceValqua as a collaboration.

management to safely operate vessels, but also various
efforts towards safe operation of the vessel and marine

No.36

five human senses were mainly relied upon to findenvironment maintenance are being taken.
The important basics for maintaining safe operation of

2. ‌Efforts toward preventive
maintenance of equipment

vessels are appropriate monitoring by the navigation

２-1）
Monitoring of status of onboard equipment

officers and selection of an optimal route taking

The operational status such as the temperature, pressure,

weather and sea conditions into consideration.

rotation rate, etc., of each part of major equipment

Important equipment for operation such as the main

onboard, such as the main engine, power generator,

engine that propels the vessel, power generator andboiler, etc., are automatically monitored at all times.

auxiliary engines such as various pumps, fans andThis is periodically recorded in the data logger

motors are located in the engine room, which isinstalled in the engine control room, and when an

monitored by the engineer who also manages preventive

abnormality is detected, a warning is issued regardlessmaintenance.

of the time, which automatically slows down or initiates

To prevent serious damages beforehand, the operationalan emergency shut-down, and for equipment with astate of the various engines and equipment in the

back-up function, the substitute equipment will startengine room are patrolled and inspected daily toautomatically to avoid any operational disruptions or

discover any abnormalities, and early actions such as

major equipment damage.

overhaul inspections are extremely important.

However, small rotating equipment and motors that

In previous times, only the bare minimum of monitoring

run fans and pumps are not equipped with sensors to

devices for equipment installed on vessels were available

monitor their operational status. Overheating, abnormal

and during the patrol to inspect the engine room, thesounds and vibrations due to wearing out of motor3

C u s t o m e r S o l u t i o n s《 J o i n t A u t h o r s h i p 》

bearings are inspected by relying upon the five senses

does not require any conversion to be used for allof the engineers during periodic patrols using touch

onboard equipment. It is an easy-to-use monitoring tooland listening rods. If the discovery of abnormalities ist hat ca n conduct w i reles s d ist a nce v ibrat ion

delayed, this may lead to the burning of the motor due

measurements of equipment installed in places that are

to damage to the bearing. The current situation is that

dangerous or in high places where access is restricted,

preventive maintenance such as periodic opening

and it has noise-cancelling features that enables it tomaintenance based on operational time is conducted for

eliminate disturbance vibrations that are generated

main equipment onboard.

from equipment other than the measurement target
and has an addition of a wireless detection feature. The

２-2）Use of big data onboard

system composition is anticipated to be used not only

Recently, the voluminous data obtained from status

for onboard equipment in vessels, but also widely used

monitoring can be monitored around-the-clock on landfor preventive maintenance of equipment used in theby using a satellite link. Efforts towards improving safe

track & field industry and industrial plant related

operation are being conducted by combining this withequipment.

weather and sea condition data, selection of an optimalroute to decrease the burden on the vessel andpropulsion engine, and utilization of optimal automaticnavigation, etc.

3-1）F unctions and characteristics of thevehicles are being vigorously pursued by automobile

vibration detection maintenance systemmanufacturers, and technical development of anThis system is currently undergoing validation on an

autonomous navigation vessel（automated ship）has also

actual vessel. As described above, it does not require

started for ships. In the beginning of 2020, a test

conversion to monitor equipment status and it isvoyage to conduct actual validation is scheduled, so incurrently undergoing validation as a system that can

addition to weather and sea condition information,measure and monitor equipment vibration without

various big data such as information on navigational

being affected by vibrations due to rocking.

meters（radar, collision prevention device, electronic

Figures1 and 2 show the external appearance of themarine maps）and status monitoring information

vibration detection maintenance system and Table1

within the engine room, etc. are becoming even moreshows the major specifications of the main section ofimportant elements to promote autonomous navigation.

the system.

However, currently, not all onboard equipment is

The sensor part for detecting vibration utilizes aautomatically monitored and a tool that can measurefluorine resin and is intended to be used for locations

the status of equipment, confirm the presence/absencewith high temperatures such as pumps and has heatof abnormalities, and make decisions is anticipated. In

resistance in 100℃ environments. To enable easy

particular, for onboard equipment, different frominstallment regardless of the shape of equipment, it canequipment installed on ground, the location itself wherebe attached by tape and magnets.

the equipment is installed may rock or be affected by

The signal from the sensor is transmitted through thevibrations from other installed equipment and in thiswireless dock and received by a tablet terminal locatedenvironment, it is very difficult to measure andaway from the equipment and whether there aremonitor abnormal vibrations of the equipment itself.

abnormalities can be confirmed as chronological changes.

The newly developed "System to detect abnormal

It is also possible to directly connect the sensor andvibrations in marine equipment" considered suchtablet with a cable for measurements.

environment which such equipment is placed in, andOn the functional side, it has a function that analyzes
4Winter 2019Technical development on automatic operation of

3. Summary‌of vibration detection
maintenance system

No.36

Introduction of a System for Detecting Abnormal Vibration in Shipboard Equipment～ The Potential of Abnormal Vibration Detection Systems for Preventive Maintenance ～the pattern of rocking of the vessel and equipment andTable1the amplitude as vibration frequency. It reduces thevibration effect（disturbance vibrations）by rocking of ajor specifications of the main section of theMsystem

Display section 10-inch tablet（touch panel）

the vessel, and by distinguishing it from vibrations of
the equipment itself, it conducts continuous vibration

Ch No.

４ch or ２ch / amplifier
Max. 12ch（wireless connection with ４ amplifiers）

OutputSD card slot（SDHC compatible, Max. 32GB）

monitoring of the equipment.

Water resistant IP54 waterproof equivalent
Use range

Size and weight−10℃ to 50℃ , under 90% RH（with no condensation）
40（H）x275（W）x188（D）mm
1200g（includes Li-ion battery, 280g）

Radio Law approved（Europe, US, China, Japan）［Scheduled］ CE marking, WEEE directive
Chinese version of RoHS

Figure1

Winter 2019

External appearance of the vibration detection
maintenance system
Left：Tablet
Upper right：Sensor（Approximately 2cm square）
Bottom right：Wireless dock（amplifier）

3-2）Examples‌of validation experiments on
reduction of disturbance vibrations
A validation using experimental methods was tried
regarding the effects（disturbance vibrations）due tothe navigational environment of onboard measurements,
such as the wind and waves at the time of operation.
A vibrator device was used as the source for disturbancevibrations, and the motor was setup on a vibrating

No.36

platform to confirm whether it would be possible todistinguish between disturbance vibrations and motor
vibrations. The vibrator device was i2 4 0SA3M（manufactured by IMV）using 5Hz, 5mmp-p conditions
to vibrate in the z-axis direction （up and down
vibrations）. The motor was a Superline single-phasemotor（SC-KR-100W-4P-100V）under the condition of1720 rpm（28.7 Hz）and was installed and fixed so themotor rotational axis was perpendicular to thevibration direction. Measurement results are shown in
Figures3 and 4.
Figure2 hin film fluorine resin organicTpiezoelectric element

According to Figure3, motor vibrations are affected by
disturbance vibrations and compared to when thevibrator is turned off, the signal intensity at 5 Hz,
which is the additional vibration conditions, increases
and significantly changes（approximately 50 dB）invibration level. On the other hand, if disturbancevibrations are reduced, the increase in vibration

5

C u s t o m e r S o l u t i o n s《 J o i n t A u t h o r s h i p 》

No disturbance vibration reduction

Motor vibration during
vibration excitation

Motor vibration when not vibrating

Figure3 Motor vibration band affected by vibrator vibrations

With disturbance vibration reduction
Motor vibration during
vibration excitation

Motor vibration when not vibrating

Motor vibration band when effect of vibrator
vibrations is reduced

intensity at 5 Hz was confirmed to be within 5 dB
（Figure4）. Similarly, the results of the effect of

Figure5‌An example of vibration measurement results onan actual vessel（seawater cooling pump）

Winter 2019

Figure4No.36

4. Summary

disturbance vibrations were under 5 dB even if

With the developed system, it was possible to confirm

measurements were under the conditions such as whenreduction of disturbance vibrations in the validation

the additional vibration amplitude was changed（5 Hz:

study at the laboratory level. In addition, a difference in

5,7, 10mmp-p）or the additional vibration frequency

t emp or a l s ig n a l i nt ens it y wa s c on f i r med by

was changed（75 Hz: 0.03, 0.05mmp-p, 200 Hz: 0.005,

measurement on an actual vessel.

0.007 mmp-p）. This suggests the possibility of reducing

However, in actual navigation, it will be necessary to

the effect of waves during navigation.

measure the vibration status with everchanging
surroundings and environment, such as main power

3-3）
Measurement example on an actual vessel

output, loading conditions that differ between outboundFigure5 shows an example of measurement results of aand inbound trips, operational status of auxiliary

seawater cooling pump on a coastal tanker（Technostar）

equipment, etc.

owned by MOL Techno-Trade, Ltd. Temporal changes in

Aiming for the main validation study, while confirming

the signal intensity can be seen. Measurements are toand considering the effect of a wide variety of

be continued while considering the effect of disturbance

disturbance vibrations, detecting the status changes invibrations in preparation for the main validation study.

equipment vibration and setting the appropriate cut-off
value are our future challenges.
6Introduction of a System for Detecting Abnormal Vibration in Shipboard Equipment～ The Potential of Abnormal Vibration Detection Systems for Preventive Maintenance ～5. Conclusions

maintenance parts. By continuing our validation study,
we would like to produce a system that visualizes the

It is considered effective for vessels operating on sea

states that differ from the normal state and deliver aaway from land to conduct appropriate maintenancepredictive maintenance effect that would contribute to

management that includes keeping track of defects andsafety and security throughout the whole industrial

breakdown trends of individual equipment and stocking

field regardless of land or sea.

Makoto Haneda
Managing Director
MOL Techno-Trade, Ltd.

Winter 2019

Tetsuya Komeda
Corporate Research andDevelopment Group
Product Development DivisionⅠ

No.36

7

Hisataka Sato
Corporate Research andDevelopment Group
Product Development DivisionⅠ

Yasushi Aburatani
Corporate Research andDevelopment Group
Advanced Technology
Reseach DivisionC u s t o m e r S o l u t i o n s《 C o n t r i b u t i o n 》

Practical training Equipment for Flange
Tightening Force Fluctuation due toTemperature Difference
1. Introduction

internal fluid through practical training and to know
the mechanism. We asked Valqua Co., Ltd. to

A countless number of flanges are used in petroleum

manufacture practical training equipment and develop

refineries to connect pipes. Because there is littlea training program using that equipment.

leakage of internal fluid from these flange connection

In this paper, we are going to report the summary ofparts, the plants are operated with little awareness ofthe practical training program by using this equipment.

leakage of internal fluid from the flange. In addition,although we know as general knowledge that metalmaterials expand and contract due to temperature

2. Overview‌of practical training equipment
2-1）Design specification

largely determine whether or not the operation is

In examining the specifications of the practical training

performed in relation to the flange tightening force.

equipment, we adopted a fluid temperature（highAlthough veteran employees recognize that flanges

temperature, low temperature）close to our case, andleak from past failure experiences, young employees

considered safety for use as training. The equipmentwith little experience cannot imagine that leaks will

was designed based on the training program, and both

occur from the flange connecting parts.

companies discussed the design proposal, and the

It is essential a the safe operation of the plant to learn

equipment which reflected the result of the consultationthat when a piping changes in temperature, the flange

was produced.

tightening force is affected, and in some cases, theinternal fluid leaks from the decrease in the surface2-2）Outline of equipmenttpressure, and this knowledge must be learnt by the

Outline of the completed equipment is shown inpersonnel involved in the operation of a plant.

Figure1. The central part is a flange for monitoring the

At this refinery, there have been past cases where

flange tightening force, and the tightening force offlushing oil（light oil）leaked from the flange fastening
part during the start-up operation. Leakage occurs
when flushing oil（about 25 ℃）is introduced, a sudden
temperature drop occurs at the connected hot pipe
flange connection（about 200 ℃）, the surface pressure
at the pipe flange connection decreases due to thechange in the pipe’s thermal strain.
From the above discussion, it is indispensable for safe
operation of the plant to learn the decrease in surfacepressure of the flange connecting part due totemperature change and the subsequent leakage of

Figure1 Educational hands-on training equipment（The left side is the high temperature part, the right side is the low temperature part）
8

Winter 2019changes, it seems that knowledge and experience

No.36

Practical training Equipment for Flange Tightening Force Fluctuation due to Temperature Differenceeach bolt is displayed on the monitor on the left handdepartment because the gasket replacement anddesk.

tightening of small-diameter pipes are carried out by
the trainees themselves.）2-3）Training procedures（see Figure2）① Set the fluid temperature on the high temperature3-1）Manufacturing Department

side to about 200 ℃ , monitor the flange tightening

Lecture program 1.5 hours（see Figure 3）

force online without the fluid on the low temperature・What is a gasket?

side（about 20 ℃）, and check the tightening status（What is a seal /allowable leakage /（balance）on the monitor.
② Introduce the low-temperature side fluid gradually,required characteristics, etc.）
・Type of gasket and Tightening

and visually check the level inside the pipe from the（Tightening method/retightening, etc.）

peephole（right flange in Figure1）.

・Failure cases③ Check how the flange tightening force（balance）（Poor tightening, selection mistakes, etc.）

changes by adding low-temperature fluid.
④ Through this experience, each person will experience a
decrease in flange tightening force that leads toleakage of internal fluid, and each person should
be careful when operating the plant equipment in

Winter 2019

charge.

Figure3No.36

Trainees attending a lecture programPractical training program 4.5 hours（see Figures4, 5
and 6）
・Flange tightening methods for gaskets（‌Compare the tightening force actually tightenedby each trainee against the target tightening
Figure2 emonstration of practical training program byDusing new equipment
（Trainee in the front and lecturer in the back）

3. Training program
We asked STC Nara to install this practical training

force, and determine their own skill.）・‌Gasket creep relaxation, sealing performance,
compression failure（‌Experience of defects due to creep phenomenon,
which are the thermal characteristic of gaskets,
excessive or insufficient tightening force.）

equipment and consider a training program that

・Influence of bolt management

combines this training with the existing equipment

・Practical training using new equipment

and training program related to flange tightening. The（mentioned above）

training program is different for the manufacturing
department and the construction department.（Themanufacturing department allocates about one hourmore for tightening flanges than the construction9

C u s t o m e r S o l u t i o n s《 C o n t r i b u t i o n 》

Practical training program 3.5 hours
・Fange tightening methods for gaskets
・Gasket creep relaxation, sealing performance
・Influence of bolt management
・Practical training using new equipment（mentioned above）
The training is conducted in small groups of four inorder to reinforce the lecture program with thepractical training program, and to enable eachparticipant to think about and experience the purpose
Figure4 emonstration of practical training programD
by using existing equipment（Torque checker）

of practical training, and to fully understand theresults. The participants are engaged in practicaltraining with a sense of tension. In addition, althoughsafety measures have been taken into consideration inadvance, it is also intended that a small number ofpeople will maintain a sense of tension and prevent
accidental injuries.
and it takes about 2 hours one way from our company
in Yokkaichi to Nara Pref.（Valqua）, and the work load
for shift workers is particularly heavy. For this reason,
lecture programs are held multiple time at Yokkaichi

Winter 2019

The standard training hours are from 9:00 to 17：00,

City（our company）, and practical training programs
Figure5 D emonstration of practical training program by using
existing equipment（Flange tightening equipment）

are performed at Nara STC（Valqua）
.

No.36

4. Results of training
At the end of the training, VALQUA, Ltd. conducts asurvey and the feedback from the participants isused in subsequent courses.
To summarize the results of our 12 participants' so far① Overall satisfaction：Average 4.7（5 levels of satisfaction high 5 ⇔ low 1）② Difference between initial expectation and actual
content：Average 4.8（5 levels of expectation as expected 5 ⇔ disappointing 1）
Figure6 D emonstration of practical training program by using
existing equipment（Seal performance equipment）

3-2）Construction Department③ Understanding of lecture program：Average 4.3（5 levels of understanding well understood 5 ⇔ notunderstood 1）

Lecture program 2.5 hours④ Understanding of practical training program：Average 4.7

・What is a gasket?

（5 levels of understanding well understood 5 ⇔ not・Gasket types, selection, and tightening

understood 1）
10Practical training Equipment for Flange Tightening Force Fluctuation due to Temperature Difference

The average understanding level of the practicalsurface pressure at the pipe flange connection may

training program is 4.7, which is a high level ofcause a leakage of the internal fluid which may lead tounderstanding.

a major accident. On the other hand, even if you are in

Comments from the participants

charge of the operation and maintenance of a refinery,“I was surprised at the faster change in tightening

you rarely have the opportunity to actually experience

force due to flange quenching than expected.”

the mechanism of surface pressure reduction, and in“It was easy to understand because we were able tomany cases when trouble occurs you are reminded ofconfirm the decrease in tightening force due to coolingits importance.

in real time.”

In this study, VALQUA, Ltd. developed practical“By experiencing equipment that simulated an actual

training equipment and by developing a practicalcase it reinforced the dangers in me for the next 10, 20

training program with the equipment it teaches theyears or more.”mechanism of reduction of surface pressure at the pipe

It seems that they had a favorable impression of theflange connection part due to temperature-change

practical training equipment.

which causes leakage of internal fluid and this is

Most participants have the impression that they would

essential to the safe operation of the plant.

Winter 2019like to introduce this training to their colleagues

As a result of conducting employee education using（especially junior colleagues） in the workplace.

the practical training equipment, its effectiveness could

Because of the high level of satisfaction andbe verified, so we will continue to educate employees

understanding mentioned above, it is consideredon the importance of managing flange tightening force

effective in strengthening management of flange

utilising this equipment and the practical training

tightening force by participating in this training, andprogram. In addition, we hope that many otherthe participation of those who have not yet participatedcompanies will take this program to prevent similarin this training is planned as part of our educational

trouble at their factories.

program in the future.

Finally, we would like to thank Valqua, Ltd. and Toyo
Sangyo Co., Ltd., for manufacturing this equipment and

No.36

5. Conclusion

for giving us the opportunity to publish our findings
and experience.

We have installed piping and valve facilities on our
premises, and as part of our training for new
employees, we have taught them about the importanceof gasket replacement and flange tightening by basic
operations training such as flange tightening as
voluntary maintenance activities. A decrease in

Kenichi Takamura
Engineering Department
SHOWA YOKKAICHISEKIYU CO.,LTD11

6. Reference1）Akira Muramatsu：Valqua Technology News No. 33,
15-18（2017）

Technical Papers

Evaluation of Mechanical Properties andSealing Performance of 24” Pipe Flange
Connections with No.GF300 Gasket
track record as asbestos gaskets do until now, and for

1. Introduction

this theoretical property study or research is required.
We have been investigating the mechanical behavior of

petrochemical plants, power, steel plants, etc.

connection flange joints incorporating our PTFE

Asbestos gaskets are widely used because of theircompound gasket No. GF300 under normal and highhigh heat resistance, sealing properties, high strength,

temperature environments and under pipe bending6）-8）.

easy handling properties, and economical with

It is known that gasketed connection flange connections

numerous studies having been conducted1）-3）. There

have various nominal dimensions, and their characteristics

have been numerous reports of human health hazards

change when the nominal diameters are different. In

with asbestos gaskets published and regulations haveparticular, it is said that the sealing property of the

been established in Japan since around the year 2000.

connections deteriorate as the nominal diameter

However, this trend has been advancing in Europe

increases. However, due to cost and time issues, mostand the United States for some time. Since 2008,of the research on connection flange connections with4）

asbestos gaskets cannot be used in Japan .

gaskets has targeted relatively small diameter

There are two types of asbestos gaskets which are

dimensions of 2 to 6 inches, and the characteristics ofasbestos filled spiral wound gaskets and asbestos joint

large diameter flange connections are yet to be clarified.

sheet gaskets. There were no major problems in

Sawa et al. used a 20 inch sized pipe flange connection

replacing asbestos filler with expanded graphite filler ofto characterize a spiral wound gasket connection,spiral wound gaskets. On the other hand, as alternatives

demonstrating that it differs from the characteristics

for asbestos joint sheet gaskets, a non-asbestos jointof a small diameter pipe flange connection and that it

sheet gasket containing aramid fibers, an expanded

is less sealable9）-13）. However, the ASME standard

graphite sheet gaskets, and a PTFE compound sheet

stipulates a 24 inch flange size with a larger nominal

5）

gaskets were developed and evaluated . Since thediameter, in addition, the mechanical properties andaramid joint sheet gasket contains a large amount ofsealing properties of a large-diameter connection

rubber, it hardens and cracks in a high temperature

flange fastening body incorporating a widely usedenvironment, and the bolts cannot be tightened. The

PTFE compounded gasket hanve not yet been

expanded graphite sheet gasket is easily damaged andinvestigated. Therefore, study of a pipe flange connection

has poor handling properties. From this background,using such a gasket is necessary.

PTFE compound gaskets have become widely used in

The purpose of this study is to evaluate the mechanicalJapan. PTFE is excellent in heat resistance, chemical

properties of the 24 inch tube flange fastener withresistance, and sealing properties, and the problem of

No.GF300 by FEM analysis and experimentally. First,

large creep has been greatly improved by improving thethe basic characteristics of No.GF300 gasket arecompounding formulation and manufacturing method.

investigated in accordance with JIS B 249014）. These

However, the PTFE compound gasket do not have abasic data are to be used in the FEM-analysis to12

Winter 2019

Gasketed pipe flange connections are used in many

No.36

Evaluation of Mechanical Properties and Sealing Performance of 24”Pipe Flange Connections with No.GF300 Gasket

calculate the axial bolt force variations and gasket
contact-stress distributions. In addition, the amount ofleakage from the pipe flange connection is estimatedusing the gasket contact stress distribution calculated
from the FEM analysis and the leakage gasket stressrelationship obtained from the experiment. Experiments
will be conducted to show the validity of the FEM
analysis, and the experimental results and the FEM
analysis results will be compared and examined.
In the experiment, the amount of leakage from thepipe flange connection and the fluctuation of the axial
bolt force are measured. The pipe flange connections
used in this study were ASME class 300 24 inch-sized
connections.
Our high-performance sheet gaskets containing PTFE,
such as No.GF300 used in this research, are widelyused because of their excellent heat resistance,
chemical resistance, sealing properties, and handling

Winter 2019

property. In addition, since it does not contain any
rubber, material deterioration does not occur attemperatures below 300 ℃ or over time and it isconsidered that mechanical properties can beevaluated with high accuracy in this study.

Figure1 Experimental equipment of 24-inch pipe flange connection

2. Experimental method

No.36

⑴

Figure1 shows the No.GF300 gasketed pipe flange
connection equipment for measuring axial bolt force
fluctuations and leaks. The pipe flange connection size

Here, L：leakage amount, M：molar mass, V：internal

is ASME class 300 24 inches, and the material isvolume of the apparatus, t：measurement time, R：gas. It is known that the characteristics of theconstant, T1：temperature at the start of measurement,

pipe connector change greatly depending on the

T 2：temperature at the end of measurement, P 1：

presence or absence of a pipe, and this device has ainternal pressure at the start of measurement, andlong pipe like the actual pipe connection. The size of

P2：internal pressure at the end of measurement.

the gasket is ASME class 300 24 inches, the thickness

The initial internal pressure P1 is set to 2 MPa, andis 3.0 mm, and the bolt nominal diameter is M39.

the experiment is performed in ambient temperature

Strain gauges are attached to the longitudinal axis ofenvironment. Tightening applies as initial axial bolt

all 24 bolts, and the axial bolt force can be measured

forces of 34.2kN, 68.5kN, 102.7kN and 136.9kN

and recorded by connecting to a strain gauge. All

corresponding to mean gasket stresses of 10, 20, 30,

strain gauges are pre-calibrated. The amount ofand 40MPa. After tightening, helium is introduced,

leakage from the pipe flange connection is measured

and the leakage is measured.

15）

SUS304by the following equation（1）using the pressure drop
method.
13

Technical Papers

hysteresis are seen in the compression anddecompression curves. These behaviors are also takenStress［MPa］

into consideration in the FEM analysis for calculation.

Figure2Dimensions of 24-inch pipe flange connection

3. Gasket characteristics

Compression amount［mm］

Figure4

Gasket compression characteristics

3-2）Sealing property
In the same manner as the compressive characteristics,

stress relationship of No.GF300 gasket are measured

a platen device shown in Figure 3 is used to measurein advance by experiments, and the measured values

the relation between gasket leakage and gasket

are used for FEM analysis.

stresses in accordance with JIS B 2490. The gasket iscompressed in stages by a material-testing machine3-1）Compression characteristics

and the leak rate is measured when the material isFirst, the compression characteristics of the No.GF300

loaded with helium at 2 MPa. The gas leaked from thegasket at room temperature are measured using thegasket is collected by the rubber O-ring and sleeve,

experimental equipment shown in Figure 3. The size

and measured using a soap membrane flow meter.

of the platen for compression test is JIS 10K 50A with

Figure5 shows the measured leakage-gasket stressraised face. A gasket is inserted between a pair ofrelationship. The vertical axis shows the logarithmic

platens and compressed by a material-testing machine,display of the amount of leakage, and the horizontal

and the amount of compression at that time isaxis shows the gasket stress. It can be seen that themeasured. Figure4 shows the stress-compression

greater the gasket stress, the smaller the leakage.

amount relationship（compression characteristics）

When the gasket stress was 30 MPa or more, theobtained by the material test. Non-linearity andleakage was very small and could not be measured, so

Leak rate［Pa・m3/s］

the data are not shown.

Gasket contact-stress［MPa］

Figure3

Gasket characteristic measuring equipment

Figure5Gasket leakage-stress relationship
14

Winter 2019

The compression characteristics and leakage gasket

No.36

Evaluation of Mechanical Properties and Sealing Performance of 24”Pipe Flange Connections with No.GF300 Gasket

4. FEM analysis

analyses, fluctuations in axial bolt force and gasket
contact stress distribution are calculated.

Figure6 is an FEM analysis model of a 24 inch sizedgasketed pipe flange connection. A general-purpose
code ABAQUS is used for the analysis and the

5. Experimental and FEM Analysis results

Winter 2019

number of elements is 2695 and the number of nodes

5-1）Axial bolt force

is 4408. Considering the symmetry of the pipe flange

Figure8 shows the results of axial bolt force

connection, the 1 / 96 model（1 / 48 in the circumferential

fluctuations reacting to internal pressure fromdirection and 1 / 2 in the axial direction）is used. In

experiments and FEM analysis. The horizontal axis is

this model, for simplification, the hexagonal nut has a

the internal pressure, the vertical axis is the axial bolt

circular shape with an equivalent cross-sectional area,

force, the solid line is the experimental result, and theand the screws are omitted. Figure7 shows thebroken line is the FEM result. The axial bolt force ofboundary conditions in the FEM analysis. All

the experimental results is the average value of 24

elements are constrained in each direction at thebolts. Initial tightening is applied as axial bolt forces

symmetric interface. An initial tightening force is

34.2kN, 68.5kN, 102.7kN, and 136.9 kN, whichapplied to the bolt model by applying an axial load,correspond to gasket contact-stresses of 10 MPa, 20

and it is restrained when an internal pressure load isMPa, 30 MPa, and 40 MPa, respectively. Under all

applied. The internal pressure exerts pressure on theconditions, the axial bolt force decreased as theflange and the inner surface of the pipe.

internal pressure increased. It is considered that thisElastic elements are used for flange and bolt models,is because the flange rotation increases due to theand ABAQUS gasket elements are used for gaskets.

internal pressure and the bolt axis contracts.

This ABAQUS gasket element can take into accountExperimental results and FEM analysis are in fairly

non-linearity and hysteresis characteristics. In FEM

good agreement, indicating the validity of the FEM
analysis.

No.36

Pipe flange

Axial bolt force［kN］

GasketM39 Bolt
Figure6

FEM analysis model of pipe flange connection

Internal pressure［MPa］

Figure8Bolt axial force fluctuation during applicationof internal pressure

Internal pressure P5-2）Gasket contact-stresses and leakage
Figure9 shows the gasket contact stress distribution at thetime of tightening and at the time of applying 2 MPainternal pressure obtained from FEM analysis. The
Bolt axial force

average gasket contact-stress at initial tightening is 10
MPa, 20 MPa, 30 MPa and 40 MPa. In all the contour

Figure7
15

Boundary conditions for FEM analysis

diagrams obtained, it can be seen that the gasket outerTechnical Papers

diameter is disengaged from the flange flat seat and isstress relationship also shown in Figure4 obtained by

not in contact with the flange and that the contact

experiment11）, 12）. Figure10 shows a comparison of thestresses are zero. Looking at the data at the time ofleak measured experimentally and the estimated leak.

initial tightening, the contact stress becomes larger

The vertical axis is the leakage per unit length by

toward the outer diameter side due to the flange

dividing the total leakage by the contact of the gasket atrotation. It can also be seen that the gasket contact-

the outer circumference. It can be seen that the larger

stress on the inner diameter is zero even when thethe gasket contact-stress, the smaller the leakage. Inmean gasket contact-stress is large. This is because theaddition, the estimated leakage and the experimental

inner diameter of the gasket is separated from theresults are in good agreement, demonstrating theflange by the flange rotation and is not in contact withvalidity of the leakage estimation method and FEM

the flange In addition, it was found that the change inanalysis.

was very small. When internal pressure applied, the sumof the gasket contact stresses decreases due to thethrust force in the axial direction.
Here, the leakage from the flange connections isestimated from the gasket contact-stress distribution
obtained from the FEM analysis and the leakage gasket

Leak rate［Pa・m3/s・m］

the circumferential distribution of gasket contact stress

Winter 2019

Gasket contact-stress［MPa］

Figure10

 omparison of measured and estimatedC
leaks from gaskets

6. Discussion
6-1）‌Effect of nominal diameter of pipe flange
connection on axial bolt force fluctuation
Figure11 shows the values of the load factor wheninternal pressure is applied to the 2 inch, 4 inch,
8 inch, 12 inch, 16 inch, 20 inch, and 24 inch pipe
flange connections incorporating the No.GF300 gasket
calculated from FEM analysis. The average target
gasket contact-stress is 20 MPa, and the internalpressure is set to 2 MPa. The load factor shown on
the vertical axis is the increment rate of the axial bolt
force when an external force（in this case, internalpressure）is applied. A positive value means that theaxial bolt force increases, and a negative value
indicates that the axial force decreases. It was foundthat the load factor tends to decrease as the nominal
diameter of the pipe flange increases. This is because
the larger the nominal diameter of the pipe flange, theFigure9 Gasket contact-stress distribution obtained from FEM analysis

smaller the bending rigidity of the flange ring, and
16

No.36

flange rotation is likely to be promoted when internalpressure is applied, and as a result, the bolt is easily
contracted. Figure12 shows the gasket contact stress
distribution for each nominal diameter pipe flange.
The horizontal axis is the ratio of the gasket widthand is dimensionless. Under all dimensional conditions,the gasket contact-stress decreased when internalpressure was applied, but this became more apparent
as the nominal diameter increased. It is consideredthat the larger the nominal diameter, the larger thearea for receiving the internal pressure, the larger thethrust force, and the larger the value of the loadfactor, so that the ratio of the loss of gasket contactstress increases.
Figure13 shows the leakage estimated by the same
method as the result in Figure10 for a 2 inch to 24
inch pipe flange connections. The average value of thetarget gasket contact stress is 30 MPa, and thedividing the total leak by the gasket outer contact

Nominal diameter［inch］

Figure13 E
 ffect of pipe flange nominal diameter on leakage
amount per unit length

circumference. As the nominal diameter of the pipe
flange increases, the leakage per unit length increases,
but the vertical axis is not a logarithmic scale but alinear scale, and the difference is not so large inreality.
6-2）‌Comparison of sealing properties of pipeflange connections using No. GF300
and No. 6596V expanded graphite filledgasketLoad factor

Figure14 shows the relationship between the leakage
per unit length and the gasket contact-stress of thepipe flange connections using No. GF300 and No.
6596V expanded graphite filled gasket. As before, thepipe flange connection size is ASME class 300 24
inches and the internal pressure is 2 MPa. The

Figure11Nominal diameter［inch］

validity of the FEM analysis method has been confirmed

 ffects of nominal diameter on load factor inEpipe flange connections

by comparing the FEM analysis and the experiment

Gasket width ratio

Figure12

17

for the pipe flange fastener using No. 6596V. It was

Leak rate［Pa・m3/s・m］

Gasket contact-stress［MPa］

Winter 2019No.36

leakage is the leak per unit length obtained by

Estimated leakage amount［Pa・m3/s・m］

Evaluation of Mechanical Properties and Sealing Performance of 24”Pipe Flange Connections with No.GF300 Gasket

 adial gasket contact stress distribution in theRconnection of each pipe flange nominal diameter

Gasket contact-stress［MPa］

Figure14 C‌ omparison of seal performance of each pipe
flange connection using No. GF300 and No. 6596V

Technical Papers

observed that when the gasket contact stress is（4） Using FEM analysis and basic gasket data, it was

smaller, the leakage rate is relatively large, but whenclarified that the larger the nominal diameter ofthe gasket contact stress is larger, the sealing

the pipe flange, the smaller the load factor andproperty of the pipe flange connection using thethe larger the leakage amount.

No. GF300 is better than that of the pipe flange（5） It was clarified that No. GF300 exhibits higher

connection using the No. 6596V. The pipe flange

sealing performance than a pipe flange

connection using expanded graphite, which has theconnection using an expanded graphite filled

filler material of No. 6596V, exhibits good sealingspiral wound gasket when a recommended

performance even with relatively small stress. On thesurface pressure of 35 MPa is applied. From theother hand, it is considered that the No. GF300 could

strength calculation, it was found that even in

not conform to the flange surface with a smaller

the pipe flange connection to which the spiralstress, but was able to when the gasket contact-stresswound gasket cannot be applied, the sealing

became larger, and exhibited a higher sealing

performance of GF300 is equal to or better thanproperty by compression of the material. From thethat when the spiral wound gasket is used.

strength calculations, some pipe flange connections
are not applicable for spiral wound gaskets. However,it was found that in these locations, the sealing
property of No.GF300 is same or better than that

1）T . TAKAKI, K. SATO, Y. YAMANAKA, T.
FUKUOKA, "Effects of Flange Rotation on the
Sealing Performance of Pipe Flange Connections",

7. Conclusions

ASME PVP Vol.478,（2004）, pp.121-128.
2）T . SAWA, N. OGATA, T. NISHIDA, "Stress

In this study, the mechanical properties of ASME

Analysis and Determination of Bolted Preload inclass 3000 24 inch pipe flange connection with No.

Internal pressure", Transactions of the ASME,

GF300 were investigated by experiment and FEM

Journal of Pressure Vessel Technology, Vol.124,

analysis, and the following conclusions were obtained.

（2002）, pp.22-27.

（1） In accordance with JIS B 2490, the compression3）T. KOBAYASHI, T. NISHIDA, Y. YAMANAKA,

characteristics and leakage gasket contact-stress"Effect of Creep-Relaxation Characteristics ofrelationship of No. GF300 were measured.

Gaskets on the Bolt Loads of Gasketed Joints",（2） ‌The leakage from the pipe flange connection was

ASME PVP Vol.457,（2003）, pp.111-118.

estimated from the above gasket characteristics

4）Ministry of Health, Labour and Welfare, "Law forand the gasket contact stress distribution results

Partial Amendment of the Order for Enforcement of

were obtained from the FEM analysis. In

the Industrial Safety and Health Law", Cabinet

addition, both results were in good agreement

Order No. 349（2008）.

with the experiment demonstrating the validityof the estimation method.

5）
Nippon Valqua Industries, Ltd., GASKET, Catalogue
No.YC08,（2016）.

（3） Through FEM analysis and experiments, it was6）K. SATO, A. MURAMATSU, T. KOBAYASHI,

clarified that the axial bolt force decreases due

T.SAWA,"FEM Stress Analysis and Sealing Perfor-

to flange rotation when internal pressure ismance of Bolted Flanged Connections using PTFE

applied to the 24 inch pipe flange connection

Blended Gaskets under Internal Pressure", PVP

with No. GF300. It was also shown that the FEM

2 015 - 4 52 6 8 , Proceeding of ASM E PV P 2 015

analysis results are in good agreement with theexperimental results.

Conference,（2015）.
7）K . SATO, T. SAWA, T. KOBAYASH I ", FEM
18Winter 2019obtained from the spiral-wound gasket.

8. References

No.36

Evaluation of Mechanical Properties and Sealing Performance of 24”Pipe Flange Connections with No.GF300 Gasket

S T R E S S A NA LY S I S of L ong- t er m S e a l i ng
Performance for Bolted Pipe Flange Connections

PVP2010-25499, Proceeding of ASME PVP2010
Conference,（2010）.

with P TFE Blended Gaskets under Elevated11）Y. OMIYA, T. SAWA, Y. TAKAGI", Stress Analysis

Temperature" PVP2016-63372, Proceeding of ASME

and Design of Bolted Flange Connections under

PVP 2016 Conference,（2016）.

Internal Pressure", PVP2014-28606, Proceeding of8）K . S AT O , T. S AWA , R . M O R I M O T O , T.

ASME PVP 2014 Conference,（2014）.

KOBAYASHI, "FEM Stress Analysis and Mechanical12）
Y. OMIYA, T. SAWA", Stress Analysis and Sealing

Characteristics of Bolted Pipe Flange Connections

Performance Evaluation of Bolted Pipe Flangewith PTFE Blended Gaskets Subjected to External

Connections with Smaller and Larger Nominal

Bending Moments and Internal Pressure", PVP2017-

Diameter under Repeated Temperature Changes",

65332, Proceeding of ASME PVP 2017 Conference,

PVP2014-28730, Proceeding of ASME PVP
2014, Conference,（2014）.

（2017）
9）Y . TAKAGI, T. SAWA, H. TORII, Y. OMIYA,

13）A . MURAMATSU, K. SATO, M. U. KHAN,"Effects of Scatter in Bolt Preload on the Sealing

T.SAWA,"FEM Stress Analysis and the Sealing

Performance of Pipe Flange Connections Under

Performance evaluation of Bolted Pipe Flange

Internal Pressure （Case Where the Nominal

Connections with Large Nominal Diameter Subjected

Diameter of Pipe Flange Connection is 20"）", PVP

to Internal Pressure", PVP2016-63407, Proceeding of

PVP2010- 25499, Proceeding of ASME PVP2010

ASME PVP 2016 Conference,（2016）.

Winter 2019

Conference, （2010）.
10）Y . TAKAGI, T. SAWA, H. TORII, Y. OMIYA,"Effects of Scatter in Bolt Preload on the Sealing
Performance of Pipe Flange Connections Under
Internal Pressure （Case Where the Nominal

14）Japanese Industrial Standards. JIS B 2490 "Testmethod for sealing behavior of gaskets for pipe
flanges",（2008）.
15）
A NSI / ASME B 16.5,"Pipe Flanges and Flanged
Fittings",（1996）.

Diameter of Pipe Flange Connection is 20"）",No.36

Kouji Satou
Corporate Research andDevelopment Group
Product Development
Division

Toshiyuki Sawa
Hiroshima University,
Professor Emeritus
19

Xing Zheng
China Research Institute
Seal Engineering
Development GroupTechnical Papers

Lining Tank（Application）

1. Introduction

attachment of the sheet to the head reduces theamount of scraping to the sheet surface when

Following on from the previous article on“Lining Tank”

attaching the sheet, and drastically reduces（Basic version）, this article will overview thescratches on the surface and contamination of the“Application”.

sheet.

In the basic version, we have described the types and・‌The sheet before reformation is processed into acharacteristics of fluoropolymers, the fluoropolymer

square, and there are few welding lines. This

sheet lining process, and the basic points to note in

reduces the risk of problems such as broken

the design of fluoropolymer lining tanks, etc. Thiswelds.
・‌The reformation temperature is higher than thelining process and the sheets for lining that we handle.

vulcanization temperature of the adhesive, so
there is less residual stress in the sheet.

2. Characteristics‌of our lining
processing method

This reduces the risk of adhesive peeling problems.
The above three effects could be expected.

This article describes the manufacturing process ofNo.36

our high-purity fluoropolymer lining tanks,
characteristics of our processing technology.
2-1）Reformation‌and attachment offluoropolymer lining sheet to the head part
Fluoropolymer lining tanks generally have a

Winter 2019

time, we will introduce the characteristics of our sheet

Figure1

 anks made byTother manufacturers

Figure2

Our liner

fluoropolymer sheet attached to the metal can of the

Figure1 shows a lining tank constructed by anotherouter shell. The sheets are rolled up and cut into

company. There are many weld lines on the head at

strips for use. Strips of the sheet can be attached as is

the bottom.

to the body part of the can, but the head part has a

Figure2 shows the liner of the head part with our

curved surface and it is difficult to attach strips ofheating reformation and there are no weld lines.

sheet, so the sheet is attached in several equal parts.

The liner of a tank with an internal diameter of more

In our attachment method, the lining sheet of the headthan 1200 mm will have one or two welding lines as

shape is heated and molded before use.

shown in Figure3.

By processing the lining sheet for the head in advance,
it is possible to：・‌The combination of the vacuum attachment
method described below and the reforming
20Lining Tank（Application）

In the conventional method of attaching the sheet, ascraping jig press the liner against the tank. This
causes abrasion scratches on the entire surface of theliner.
In vacuum bonding, it was realized that the sheet ispressed against the tank at atmospheric pressure, so
Figure3

The liner in the head part of a large tank

The maximum internal diameter for head part

only a small portion of the sheet, such as the edge ofthe sheet, is scraped, and the scraped area is greatly
reduced.

reformation is φ2800. Three sheets are connected by
2 automatic welding lines and reformed. The

Figure6 shows a photograph of the head part attachedconnection between the head liner and the body liner

by the vacuum attachment method, and Figure7 is a

is also welded automatically because the head liner

magnified photograph.

reaches the body.
2-2）Vacuum attachment method with fewer
scratches on the sheet surface
The vacuum attachment method is a method in which

Winter 2019a flat sheet or a head molded sheet is placed along the
body of a can, and the air between the back of the
sheet and the body of the can is removed to create avacuum, so that the lining sheet is pressed against the
body of the can at atmospheric pressure and could bebonded without scraping.

No.36

In this attachment method：・‌Reduces the scratches on the surface of the sheet

Figure6 ead of a tank with liner attached by vacuumHbondingand contamination of the sheet.
・‌Makes it possible to bond evenly and the bonding
strength is stable.
The above two effects could be expected.
2-2-1）‌Appearance of head part attached by
vacuum attachment method

Figure4 shows an image of the scraping attachment
method used by other companies.
Figure5 shows an image of the vacuum bonding
method which our company developed.

Figure7

Enlargement of the surface of our liner

2-2-2）Surface roughness after lining

The following are the results of comparing the liner
surface of a tank head when“attachment by scraping”
is used and“head reforming + vacuum bonding”isFigure4 Rubbing Attachment
21

Figure5 Vacuum Attachment

used to attach using M－PTFE sheets.

Technical Papers

Figure9 shows the surface roughness of the liningtank processed by the vacuum bonding method, and it
was Ra 0.25μm.
Figure10 shows a graph of measurements of thesurface of a sheet with conventional attachment, and it
was Ra 0.34μm.
2-3）Stable quality by mechanized welding
Figure11 shows the cross-section of the welded part ofthe liner.
The liner of the lining tank is joined by PFA welding.
Figure8

Electron micrograph of the scraped area

There are two stages of welding: beveling at the endof the liner, followed by priming welding with PFA
rods, and then band welding（reinforcement welding）
using PFA strips.
liner

Figure11

Figure9Liner surface of our company（Ra 0.25μm）

Winter 2019priming welding

band welding

liner

Cross-sectional shape of band weld

We use self-propelled welders（automatic welders）for
welding strips to stabilize“temperature”“speed”,
and“pressure”, which are important conditions for welding.
As a result, compared to manual welding by operators,
the welding conditions were more stable and thestrength variation significantly reduced.
In addition, it is now possible to weld strips with lessundulation, meandering, and deformation of thewelding line.
Furthermore, while other companies use a 14 mm
width for manual strip welding, we have increased thestrip width to 17 mm through mechanization to
improve the welding strength and increase thewelding part’s reliability.

Figure10Liner surface of another company（Ra 0.34μm）

22

No.36

Lining Tank（Application）

stress relief
structure

Figure15

Our nozzle construction method

2-4-2）Liquid collection cup structure

The structure of the liquid collection cup at the bottom
Figure12  Welding with an automatic welding machineof the tank is the same as that of the nozzle.

Figure13 Our product - Automatic welding（M－PTFE－ET）

Winter 2019

Figure13 shows a strip weld done by automatic welding,which is wider and has less meandering.
2-4）Safety design of the component structure
2-4-1）Nozzle structure

No.36

 he cause is damage to
Figure16 ‌L ining around the Figure17 ‌T
the weld between theliquid collection cup
collecting cup and sheet
is detachedliningsheet band welding

The tube part of the nozzle is a part that has many
problems with welding because it is difficult to adhere
it tightly to the body of the can.
Other companies use a structure where the expansion
and contraction stresses of the liner due toliquid collection cup
the bodyof the canFigure18 E‌ xamples of construction Figure19
by other companies‌Our construction
methodtemperature changes are directly applied to the weld,
as shown in Figure14. As shown in Figure15, theinside of the tank is also flare processed, and this

3. Selection of lining material

flared part receives the stress, so the welding part is

We use three types of materials of fluoropolymer

not subjected to expansion and contraction stress.

lining sheets, PTFE, PFA, and M－PTFE. Two typesof sheets are used for the adhesion method: chemicaletched sheets with fluoropolymer surface that is
chemically processed and glass-backed sheets
laminated with glass cloth sheet.

delamination

3-1）Functionality evaluation of our lining sheetsNozzle activity and loss examples due totemperature change

The following table shows an in-house evaluation of

expansion andcontraction

Figure14

the five functionalities of our lining sheets on a 5-point
scale.

23

Technical Papers

Evaluated sheets

3-1-1）Surface smoothness

PTFE-ET：PTFE chemical-etched sheet

The following is a photograph of the surface of three

M-PTFE-ET：‌Modified PTFE chemical-etched

types of lining sheets made of different materials andsheet（PLP Sheet）
M-PTFE-GB

surface roughness：‌Modified PTFE glass-backed
sheet

PTFE-GB：PTFE glass-backed sheet

PFA（NEW）-GB：PFA glass-backed seat
PFA（HP-PLUS）-GB：PFA glass-backed sheet
Evaluation details
Surface smoothness

Figure20

PTFE－ET×100

Figure21 Ra 0.29μm：‌Indicates the quality of dirt
removal during washing.

Adhesion performance：‌Indicates the quality of theadhesive strength between
the sheet and the adhesive.
Welding performance ：‌I n d i c a t e s t h e w e l d i n greliability of the sheet’s

Figure22 M－PTFE－ET×100

Figure23

Ra 0.24μm

Figure24 NEW PFA×100

Figure25

Ra 0.03μｍ

Winter 2019connecting parts.
Permeation resistance ：‌Permeation resistance tochemical solutions.
Affects‌
the life expectancy
of chemical solution permeation.
Price：‌‌Indicates the quality of thecost of the sheet.

Table1lining sheet

Functional evaluation of sheets for lining
evaluation: (excellent) 5・4・3・2・1 (poor)
surfaceadhesion
weldingpermeation
pricesmoothness performance performance resistance

PTFE-ET

3

3

3

4

5

M-PTFE-ET

4

3

4

5

4

PTFE-GB

3

3

3

2

3

M-PTFE-GB

4

3

4

4

2

PTFE-GB

5

3

5

3

2

PFA（HP-Plus）-GB

5

3

5

4

1

Note 1 ET: Etched sheet, GB: Glass Backing, M: Modified.
Note 2 Values are rated on a 5-point scale to indicate the quality.

PTFE：Highest surface roughness.

M-PTFE：‌Surface roughness is slightly lower thanPTFE.

NEW PFA ：The surface is the smoothest.
This measurement is at the stage of the sheets, andthe surface roughness Ra after lining varies greatly
due to the difference in lining construction methods
described above.
3-1-2）Adhesion performance

Fluoropolymers are non-adhesive, so even if anadhesive is applied to a fluoropolymer sheet, it will not
stick and peel off.
To add adhesiveness to fluoropolymer sheets in our
etching processed sheets, chemical etching is
conducted to add adhesiveness after the sheets are
24

No.36

Lining Tank（Application）

manufactured.

same as the welding rod and strip material, could

On the other hand, glass-backed sheets are made bytheoretically be said to have better fusion during

anchoring fluoropolymer sheets and glass cloth sheets

welding and higher welding stability.

by melting PFA between them to make them

Guessing from the fluoropolymer material（molecularadhesive.

structure）, the welding stability would be PFA>
M－PTFE>PTFE.
3-1-4）Permeation resistance
There is no difference inbonding strength between
the etching sheet and theglass-backed sheet.

It is known that the permeation of chemicals occurs
mainly in the amorphous part inside the polymer.
Figure28 schematically depicts the crystal structure of
a fluoropolymer sheet in the cross section.
▪ Permeation model

crystalline part

amorphous part

Figure26 Bonding strength (shear) of ET sheets and GB sheets
C-F bond

Figure26 shows the shear strength test results of ET
sheet and GB sheet bonded to metal using rubber

Winter 2019No.36

adhesive.
The peeled areas are all metal surfaces and have thesame adhesive strength.
3-1-3）Welding performancepolymer conformation of
PTFE in the cross-section

Figure28

Image of chemical permeation into fluoropolymer

Figure27 shows a comparison of the weld strength of

The part where molecules are lined up orderly fashion

the lining sheets.

is the crystalline part, and the part where molecules
are intricately intertwined is the amorphous part.

Weldability

The crystalline part is densely packed with molecules
and has a high density.
The amorphous part has a low density due to theentanglement and random arrangement of molecules.
Therefore, the more crystalline the sheet, the greater
the specific gravity.
The chemical permeates through the amorphous partand gradually diffuses through the sheet. Eventually,
it reaches the body side of the can, which is the backFigure27

Results of weld strength measurement

side of the sheet with the adhesive surface.

（PLP：this is a sheet of M－PTFE, but a sheet manu-

Figure29 shows the specific gravity of fluoropolymer

factured by our company with improved permeationand the amount of hydrochloric acid permeation. The

resistance.）graph also shows the specific gravity of fluoropolymer

There is no significant difference in the weld strength

sheets available on the market.

of all sheets in the temperature range where they are
generally used. However, the PFA sheet, which is the25Technical Papers

the difficulty of slow cooling.
The translucent part on the GB side is shown in thephoto where the specific gravity has become low.
Figure31 shows a cross-section of our PLP sheet.
high specific gravity（SG 2.19）

Figure29

Permeability against the specific gravity offluoropolymers

This figure shows that the amount of chemical
permeation decreases with the specific gravity.
PTFE gelate can retain its shape even if it exceeds

Figure31

the melting point. So it is possible to control the

Cross-section of PLP sheet

PLP sheet is a polymer that could be denser thancharacteristic can be used to control the degree of

PTFE, and since the etching process that does not

crystallization.

require heat treatment that could gelate the sheet,

The specific gravity of PTFE generally available on

without lowering the specific gravity.

Winter 2019

cooling conditions that affect crystallization. This

the market, considering productivity is about 2.14 to
2.16. However the specific gravity of our sheets forlining is finished to about 2.18 to improve
permeability. PFA is a molten polymer, and it isdifficult to control the cooling conditions due to its
molding method, so the specific gravity is generally in

No.36

the range of 2.14 to 2.15.
Figure30 shows a cross-section of M－PTFE－GB
sheet.
high specific gravity（SG 2.19）

Figure32

  low specific gravity（SG 2.15）

Figure30

Cross-section of M－PTFE－GB sheet.

 pecific gravity, thickness and permeability ofS
fluoropolymers

This figure shows that the thickness of the sheet isalso an important factor in permeation resistance.
3-1-5）Price

It is necessary to gelate the sheet when laminating

Figure33 shows the relationship between the surface

the glass cloth to the sheet to produce PTFE－GB andsmoothness of the lining sheet and the market price of

M－PTFE－GB sheets. Cooling is conducted after

the lining sheet, and Figure34 shows a schema of thegelation, but the specific gravity decreases because of

relationship between surface smoothness and26

Lining Tank（Application）

permeation resistance.
The right side of the horizontal axis indicates higher

4. Conclusion

functionality, and the upper side of the vertical axis
indicates higher cost.

Since the start of lining tank production, our company
has responded with any queries from our customers
regarding our product defects. We always inform ourcustomers if there is any update regarding our
production method. Although the causes ofabnormalities differ, they could be roughly classified

Cost

into three categories.
These are“chemical permeation,”“unexpected structuraldefects,”and“inexperienced construction techniques”.
We have been investigating the causes of each problem
Surface smoothness

Figure33

Surface Smoothness：Costand making improvements.
For example, for chemical permeation, we have beenworking on selecting materials for lining sheets andincreasing the density of the sheets. For structuralof the body of the can and improvement of the nozzle

Cost

Winter 2019problems, we have been working on design methods
structure as described in the previous article. For
construction technology, we have been working on theautomation of welding strips.
With the rise of the semiconductor industry,
resistancecleanliness, which was not a requirement for chemical

Permeation Resistance：Cost

plants, has become more important, and the

The cost of fluoropolymer raw materials is：development of vacuum bonding and head liner

PFA＞ M－PTFE＞ PTFE

molding technologies enabled us to reduce scratches

The cost of providing adhesion is ET＞ GB.

to the liner surface as much as possible.

The surface smoothness of the base sheet is PFA＞

We will continue to strive to develop new technologies

M－PTFE＞ PTFE.

to meet the demands of the market.

This is due to the different characteristics of the raw

Our next article will introduce an overview of thematerials and the processing methods used to maketechnologies we are currently working on and ourthe sheets. However, the method of lining attachment

future goals.

Permeation

No.36

Figure34also needs to be considered.

Takeshi Yokoyama
Assistant To High Performance Plastics
Product Manager
27

Product Introductions

Long-Lifetime FEPM TOUGHUORO™

1. Introduction
Tetrafluoroethylene propylene rubber（FEPM）is a

lifetime FEPM with improved heat resistance andsteam resistance by utilizing our proprietary mixing
design technology.

type of fluororubber（FKM）. It is a copolymer oftetrafluoroethylene（TFE）and propylene（P）and has
a different molecular structure compared to ordinary

2. Characteristics of TOUGHUORO™
Compared to our existing FEPM, D0970 and D0890,（VDF）and hexafluoropropene（HFP））.

TOUGHUORO™ is a material with significantly

Table1 shows the molecular structure of FEPM and

improved heat resistance and steam resistance. BelowFKM.

are the various characteristics of TOUGHUORO™.
Table1

Molecular structure of FEPM and FKM

Type

Molecular structure

FEPM２-１）Compression set characteristics properties
Compression set is used as an indicator for heat
resistance in sealing material.
Under the same environment, a smaller compression
set means the sealing material can be used favorably

FKM（Copolymer）

for a longer period of time.
Figure1 shows the measurement and calculation
methods for compression set.
In general, compression set of 80% is considered asWith this molecular structure, FEPM has characteristics

sufficient for life expectancy of material used forsuch as superior steam resistance and chemicalsealing1）, but the compression set of TOUGHUORO™

resistance which were weak points for FKM. FEPM isshowed better results than our existing FEPM and it isused as sealing for food and beverages facilities andanticipated to have a 4 - fold longer in air at 200℃ .

sealing for tire vulcanizing devices.
However, with advancements in functionality offacilities and downsizing, the chemicals used for cleaning
the facilities have become higher in temperature andconcentration, and facilities are used in tougher
environments, leading to more demanding properties
for sealing material.
In this article, we will introduce the steam-resistant SS
series and low compression set ZS series of
TOUGHUORO™ that we have developed as a long-

Winter 2019

fluororubber（FKM; copolymer of vinylidene fluoride

Compression Set（%）
InitialheightCross
SectionCompression ratio（%）
Heightafter test

Before test

During test

SpacerCompression Set（%）

Figure1

After test
Spacer（Initial height）−（Height after test）（Initial height）−（Spacer height）

 easurement and calculation methods
M
for Compression Set
28

No.36

Long-Lifetime FEPM TOUGHUORO™

Figure2 shows the results for compression set in air at
200℃ .

Compression Set（％）

CS＝80％
Seal Limit

4-foldNo bulister

bulister

TOUGHUORO™-SS70

D0970

Figure4 ross section of specimen after Compression Set  
C
test in steam at 230℃２-3）A
 cid resistance and alkali resistanceproperties
Regarding acid resistance and alkali resistance ofTOUGHUORO™-SS70, it is equivalent or higher thanTime（h）

Figure2Compression Set in air at 200℃

that of D0970. Since heat resistance ofTOUGHUORO™ has improved, it can be used underhigher thermal conditions.
Figure5 shows the results for change in volume after theUnder steam conditions, HNBR and EPDM have beenacid and alkali immersion test.

used conventionally to suppress foaming phenomenon
difficult to use these materials due to their characteristics.
Our newly developed TOUGHUORO™ has improved
mechanical strength as well and even under 230℃

No.36

Test conditions：90℃×168h

called blister 2）, but in conditions over 150℃, it wassteam conditions, no signs of blisters were confirmed,
making it possible to use as a good sealing material.
Figure3 shows the application area in stream of
TOUGHUORO™ and various materials.

Change of volume（％）

Winter 2019２-2）Steam resistance properties

TOUGHUORO™-SS70

TOUGHUORO™

Figure5 C hange in volume of TOUGHUORO™ after acidand alkaline immersion test２-４）W ater-glycol based flame-retardant
hydraulic oil resistance properties
Resistance of TOUGHUORO™-SS90 to water-glycol
f lame-retardant hydraulic oil （HYDOL HAW,
manufactured by MORESCO）is equivalent or higher
Figure3

Applicable area in steam of
TOUGHUORO™ and various materials

than D0890.
The pass or fail judgment was made by stretchchange ratio and volume change ratio（judgment

Figure4 shows a cross-section of the sample after

criteria: within ±50% change in elongation, within

compression set test in steam at 230℃ .

+10% change in volume were judged as ○ , those that29

Product Introductions

slightly exceeded the criteria were judged as △, those that

Test conditions：120℃×1000h
25%Compression、φ29×12.5h

clearly exceeded the criteria were judged as ×3））.
Table2 shows the resistance of TOUGHUORO™ toTable2Compression Set（％）

water-glycol based flame-retardant hydraulic oil.
Resistance of TOUGHUORO™ to water-glycol
based flame-retardant hydraulic oil
TOUGHUORO™-SS90

D0890

Change inElongation○○

Change inVolume○○Test conditions：120℃×1000h

TOUGHUORO™-SS90

Figure6

It was confirmed that TOUGHUORO™-SS90 issuperior in regards to compression set and it is ompression Set of  TOUGHUORO™ to Cwater-glycol based fire-retardant hydraulic oil

anticipated to enable use for a longer period. Figure6
shows the compression set after the water-glycol
based flame-retardant hydraulic oil test.

Material characteristics of TOUGHUORO™
Developmental products
Low compression set
ZS series

Steam-resistant SS series

Material name
TOUGHUORO™
-SS70

TOUGHUORO™
-SS80

TOUGHUORO™
-SS90

TOUGHUORO™
-ZS80

Hardness（ShoreA）

74

84

90

85

Tensile strength
（MPa）

23.1

24.6

22.8

24.3

Elongation
（%）

190

150

110

120

100% Modulus
（MPa）

8.3

15.2

20.9

19.9

16

19

18

14

14

20

18

11

22

26

27

21

20

26

27

19

No.36

physical properties

Compression set test_200℃×70h
Compression set（%）
in airCompression set（%）
in steamCompression set test_230℃×70h
Compression set（%）
in airCompression set（%）
in steam

Winter 2019

Table3The values are measured values, not standard values.

30

Long-Lifetime FEPM TOUGHUORO™

２-5）Food Sanitation Act
TOUGHUORO™ is a material conforming to thecriteria designated in the Ministry of Health, Labourand Welfare Notification No. 595 （Dissolution
conditions: Used at temperatures over 100℃）.

Rotary joint seals
３．Tire manufacturing market
Sealing for curing press to car tire
４．Food and beverages market
Sealing for food and beverages facilities
５．Nuclear power market

２-6）Product shape

High-temperature, dynamic seals

TOUGHUORO™ can be manufactured into productswith various cross-section shapes and large-diameterssuch as O-rings（No.4640）, V packing（No.4631）andX-rings（No.4641）.

4. Conclusions
TOUGHUORO™ introduced in this article is a material
that shows its best characteristics in high temperature

Winter 2019
No.36

２-7）Mechanical properties

steam conditions. In the future, higher demands may

There are two grades of TOUGHUORO™, the steam

be placed on sealing material, but it is considered that

resistant SS series and the low compression set ZS

this would be able to sufficiently answer thoseseries.

demands.

Table3 shows the physical characteristics andWe would like to continue developing new materials

compression set in 200℃ air/steam for each grade.

and improving existing materials to correspond to therequests of our users.

3. TOUGHUORO™ applications
TOUGHUORO™ has superior heat resistance and5. References

stea m resista nce a nd t he f ollowing uses a re１）T oshio Kawamura: Valqua Review, Vol26, No.6（1982）

considered:２）H irofumi Zushi: Valqua Technology News, No.31

１．Mining market（2016）

Bit seals３）K en Suzuki: Valqua Technology News, No.24（2013）

２．Steel market＊“TOUGHUORO”is a trademark of VALQUA, LTD.

Hirofumi Zushi
Corporate Research and Development Group
Product Development Division31

Product Introductions

Low Torque & Long-Lifetime Swivel
Joint LFR JOINT™
1. Introduction
The aging of the population, one of the major social

customers’ maintenance cost reduction and productivity
improvement of facilities using the techniques wehave fostered as a manufacturer of seal products.

issues in Japan, is currently causing a very serious
situation in the manufacturing field as well. In
particular, the aging of experienced workers in the
manufacturing field has been progressing, but

2. ‌Issues of conventional
swivel joints
A swivel joint is a collective term for a joint whichof techniques has not been keeping up with the speed

has the ability of continuous rotation and oscillatingof aging. The decline in technical ability in the field ismovement at low speed. It is widely used as analready happening in the production field of every

important part which carries various types of liquids

company. Additionally, the trend of aging population（such as hydraulic oil, air, water, etc.）considered as

is rapidly spreading overseas, and this is also a

blood in each process.

significant issue from the global perspective.

Winter 2019securing enough young engineers and the succession

In such situation, actions to streamline operating costs
at each process are intensifying by considering all the

No.36

various factors together including maintenance offacilities. This is because in order to gain maximum
benefit with limited number of staff, streamlining witha more permanent perspective, which takes man-hour
for maintenance and long-term reliability into account,is now required in addition to short-term cost
reductions in purchasing facilities and materials.
These issues are not only the matters imposed on theequipment that are the main force in a process, butalso items such as sealing materials and joints, whichhave been considered as consumable supplies but
have considerable roles to play.
LFR JOINT™, the swivel joint introduced in this issueof Valqua Technology News, is a solution-type of
product developed while collecting customers’comments from the field.
We would like to introduce this product because it is a
product which makes a significant contribution to our

Figure1

Cutaway model of LFR JOINT™
32

Low Torque & Long-Lifetime Swivel Joint LFR JOINT™

For example, swivel joints are applied as joints in theis high. These factors cause the swivel joint to havehose part of robots installed in automatic production

an extremely high rotational resistance and hinderslines of the aluminum diecasting process to reduce thethe intended rotational and oscillating movement.

load on the hose by eliminating twists caused by the

In addition, rubber is generally not a material which is

robots’ complicated movements and high frequency ofresistant to abrasion. Therefore, O-rings are severely

operation.

worn down, especially under adverse lubrication

However, swivel joints generally have high rotational

conditions at high temperature and high pressure, andresistance and the effect of load reduction on the hose

this results in shortening the life of the swivel joints

is not sufficient, causing premature fractures in thethemselves.

hose. This has been an issue that considerably
decreases productivity of the process.
As another example, under severe environmental

4. Solution by LFR JOINT™

conditions（high temperature, pressurized liquid, dust,

LFR JOINT™ is a swivel joint which solved the long-etc.）such as in steel plants, there were some cases instanding issues with swivel joints and realized bothwhich the interval between maintenance of the

low-torque and long life.

production line became shorter because the sealing

Various innovative designs are applied to the sealingmaterial on swivel joints were quickly worn down.

mechanism and also to peripheral aspects such as theseal groove. In this issue of Valqua Technology News,

Winter 2019the sealing mechanism is explained.

Movement of equipment

5. Sealing mechanism of LFRJOINT™
In order to solve the issues of swivel joints, LFR
SEAL™, a sealing material for rotational movement

No.36

was specially developed for LFR JOINT™. Figure3
shows a cross-section diagram of LFR SEAL™.
Figure2

Example of premature fractures in the hose

ElastomerResin

3. Cause of the issues
The two issues of swivel joints described above, 1）high rotational resistance and 2）short life, are largely
due to the sealing material that is used.
O-rings, mainly made from rubber, are commonlyused as the sealing material for swivel joints. During
low-speed rotation or oscillating movement, this O-ring

Figure3

Cross-section diagram of LFR SEAL™

fills the gap by sliding against the rotational axis and5-1）Torque reduction

prevents liquid leakage.

In order to reduce torque in swivel joints, it isHowever, due to the characteristics of rubber

necessary to reduce sliding resistance of the sealingmaterial, frictional resistance when sliding against thematerial, but we considered that sliding resistance isrotational axis is extremely high. Furthermore, thisrelated to friction coefficient, contact area with thetendency is even more significant when fluid pressureother surface（rotational axis）, and tension force. The

33

Product Introductions

resulting design was produced by resolving each of5-2）Life prolongationthese factors and is shown in Figure3.

It can be said that improving the durability of thesealing material is an effective means for life

Ⅰ.Friction coefficient

prolongation of the swivel joints because the life of

Resin of low friction coefficient was compounded withswivel joints is deeply related to leakage from sealingelastomer by forming them simultaneously inside thematerial.

sealing where the other surface（rotational axis）

This sealing employs resin for the sliding face of thecomes in contact.

sealing and its durability is superior to an O-ringwhich slides on a rubber face. Also, as described in

Ⅱ.Contact area

5-1, the mechanism to reduce torque decreases friction

When fluid pressure is applied, a tilt generated by theheat generated during the sliding of the sealing andtapered face of the non-pressurized side coming into

this reduces abrasion and fatigue of the sealing

contact with the groove face makes it possible tomaterial.

control the contact area of the arc sealing face that isin contact with the rotational axis. Thus, the increasein the contact area resulting from increased pressure
can be suppressed as shown in Figure4.

6. Effects of LFR JOINT™
6-1）Increasing the life of accessories suchas hose material

Fluid pressure

Figure6 shows a comparison of rotational torque of
LFR JOINT™ and a conventional swivel joint with an
O-ring. It shows that torque rises only slightly with

The tapered face ofthe non-pressurizedside comes in contact
with the groove face

Figure4

Control of the contact area

Ⅲ.Tension force

The volume of external diameter of elastomer at thebase was reduced and the inner face and the outer

Rotational torque（N·m）

LFR JOINT™, even if fluid pressure is increased.

No.36

LFR JOINT™
Swivel joint with an O-ringface that become the sealing face were designed to bearc-shaped to reduce tension force.
Pressure（MPa）
ReducedvolumeFigure6Comparison of rotational torqueThis considerably reduces the rotational load on
accessories such as hose material.
In market performance, the lifetime of hoses was
actually extended, and the life-prolongation effect evenreached a maximum of ten times longer in somecases.

Figure5Winter 2019

Tilting of thesealing

Suppresses
increase ofcontact area

Shape of external diameter of elastomer part34

Low Torque & Long-Lifetime Swivel Joint LFR JOINT™

6-2）Life improvement of joints
Figure7 shows a product life comparison of LFRJOINT™ and a swivel joint with an O-ring, andTable1 shows the test conditions.

O-ring for conventional swivel
joints（leakage after approx. two
hundred thousand times ofoscillation）

LFR SEAL™ attached to LFR JOINT™
（capable of continuous
operation even after approx.
four hundred thousand times ofoscillation）

This shows that maintenance costs for joints can be
reduced because the life of LFR JOINT™ is more than

Durability for numberof times（oscillation）

double when compared to our conventional joints.
Approx.
over 400
thousandtimes

Figure8

Approx. 200
thousandtimes
Swivel joint with an O-ring

Figure7
Table1LFR JOINT™

Life comparison

Test condition for life comparison

 omparison of sealing cross-sections before andCafter life testing

7. Conclusions
The Valqua Group aims to evolve into an“H&Scompany”that provides not only sealing products but

Winter 2019

Fluid

Air

Pressure

0.7 MPa

unit product that is a part of our strategy.

Temperature

120℃

We will continue to develop products to meet market

Angle of oscillation

90 degrees

demand, but also dig out unmet needs together with

Diameter of rotational axis

φ42

our customers and work hard to provide true

Also, Figure8 shows a comparison of the cross-also peripheral services and this product is our firstsolutions by merging innovative technologies andservices.

sections of the sealing material before and after life

No.36

testing. The thinner line represents the cross-section
before the test and the solid line after the test.
The O-ring for conventional swivel joints was severely
worn away after approximately two hundred

8. References
１）Akihiro Nagano, Valqua Technology News, No.30,
9-13, 2016

thousand times of oscillation and this abrasion caused
leakage. On the other hand, LFR SEAL™ attached to
LFR JOINT™ did not show any major abrasion evenafter approximately four hundred thousand times ofoscillation and was still capable of continuous
operation.

＊LFR JOINT and LFR SEAL are trademarks of VALQUA, LTD.

Ryosuke Nishi
Research and Development Headquarters
Product Development Division 1
35

Recent Technology News Back Issues
No.35 Summer 2018
● Greetings

Senior Executive Officer Director of Corporate Research and Development Group

Mutsuo Aoki

● Customer Solutions	Seal Training for Maritime Technique Training in Compliance with an
International Convention （STCW Convention）
H&S BUSINESS GROUP

Takahiro Yamamoto● Customer Solutions（Contribution）
	Cleaning Plant Facilities Using a Low-Pressure Composite Water Flow Cleaner（Cavitation Cleaning）
Masaru Kitagawa

Blue Engineering, LTD.

● Technical Papers
Design Guidelines and Troubles for DYNAMICBELLOWSTM and Countermeasures
Sales Group

Technical Solution Division

Masafumi Ina

Lining Tank（Basics）
 Assistant To High Performance Plastics Product Manager Tomoyuki Kikukawa
Atsuyoshi Iwata

Corporate Research and Development Group Product Development Division Ⅱ● Product Introductions
Substitute Sealants for Refractory Ceramic Fiber
Masato Hamade

Corporate Research and Development Group Product Development Division Ⅰ● From Nippon Valqua Industries, Ltd. to“VALQUA, LTD.”

Winter 2019No.34 Winter 2018

No.36

Sheet Gaskets for High-Temperature Use VALQUA HEAT RESIST SHEET™ No.HRS
Satomi Takahashi

Corporate Research and Development Group Product Development Division Ⅰ● Recent Technology News Back Issues【Customer Solution Feature】● Greetings

President & CEO

Toshikazu Takisawa● Introduction to Valqua Technology News No. 34 Winter 2018‌
	

Senior Executive Officer

Director of Corporate Research and Development Group

Mutsuo Aoki

● Commentary

ASME PVP 2016-Awarded Paper● Technical Papers

Evaluation of the Mechanical Behaviors of Pipe Flange Connections with PTFE Gaskets Subjected to Bending Moment

	

Corporate Research and Development Group

Mitsubishi Chemical Corporation

				Product Development Division Ⅰ

Koji Sato

University of Hiroshima Toshiyuki Sawa				

Akira Muramatsu

Ｈ＆Ｓ BUSINESS GROUP

Numazu College
Corporate Research and Development GroupRiichi Morimoto

Takashi Kobayashi

Product Development Division Ⅰ

Yuta Motono

Performance Evaluation of Improved EPDM Material under High-temperature Environments
Corporate Research and Development Group

Product Development Division Ⅰ

Ken Suzuki

		

CHUBU Electric Power Co.,Inc.

Shinichi Matsuda

		

CHUBU Electric Power Co.,Inc.

Takuya Sugimura
36

Guidelines on Gasket Selection, Selection Troubles, and Countermeasures
Sales Group● Contribution

Technical Solution Division

Asuka Matsushita

Considerations for Tool Selection and Installation of Fastening Bolts for Flanges with Large Nominal Diameters
Managing Director

Shinichi Kitahara

Ｈ＆Ｓ Business Group

Hajime Nonogaki

Product Development Division Ⅰ

Masato Hamade

TORQUE SYSTEM Co.,Ltd.

● Business Introduction

H&S Demonstration Car● Product introduction

Improved Seal Paste
Corporate Research and Development GroupMulti-Purpose Gland Packing for Chemical Applications
Corporate Research and Development Group

Product Development Division Ⅰ

Syuuzi Sugawa

Corporate Research and Development Group

Product Development Division Ⅰ

Masato Hamade●Recent Technology News Back Issues

No.33 Summer 2017
【Customer Solutions Special】● Greetings	Winter 2019

● Technical Papers

Senior Excutive Officer

Director of Corporate Research and Development Group

Unsuitable Usage Conditions of Gaskets and Countermeasures

Sales Group

Evaluation of Basic Sealing Properties of the PipeTechnical Solution Division

Toshihiko Enishi

Flange Connection with Metallic Flat Gasket‌

Corporate Research and Development Group Development Division

	

No.36

Mutsuo Aoki

SHINKO PLANTECH CO., LTD.

Kouji Satou

Yasuharu Kondou

	Professor Emeritus at the University of Hiroshima	Corporate Research and Development Group

Toshiyuki Sawa

Satomi Takahashi

Troubles While Mounting Gaskets and Countermeasures‌	Sales Group Technical Solution Division

Satoshi Akiyama

An Introduction and How to Use Seal Quick SearcherTM（SQS） –Elastomer Version–	

Corporate Research and Development Group Development Division

Seal Training Center (STC) –Interactive Training for Sealing Operation‌

	● Contribution

Ｈ＆Ｓ BUSINESS GROUP

Akira MuramatsuManagement of Tightening of Flanged Fasteners at Plants

Mitsubishi Chemical Corporation

●Recent Technology News Back Issues

37

Akira Ueda

Mizushima Plant Mechanical Group 2

Maintenance and Engineering Department

Riichi Morimoto

Aim for earth and people friendly production

Sheet Gasket
UNIVERSALHYPER ™（UF300）
This is a sheet gasket that enables gasket
integration in chemical lines.
In addition to high temperature and long-term
stability, chemical resistance has been improved,
greatly expanding the range of applicable ﬂuids.
It can be used for both strong acid and strong
alkali lines.

BLACKHYPER ™（ＧＦ300）
It is a best-selling seat gasket with a high reputation for reliability
and high cost performance, backed up by proven market
experience.
■UF300, GF300● Allowable temperature ranges : −200 to 300°
C
● Maximum pressure : 3.5MPa※Please refer to the product catalog and technical data.

ThinkPark Tower 24F
2-1-1 Osaki, Shinagawa-ku, Tokyo 141-6024, Japan
Contact : VALQUA, LTD. http://www.valqua.com
TEL：(81)3-5434-7376
FAX：(81)3-5436-0562

VALQUA's Sales Network■JAPANVALQUA, LTD.
【Main Number】【Sales Group】

TEL : (81)3‑5434‑7370
TEL : (81)3‑5434‑7380

FAX : (81)3‑5436‑0560
FAX : (81)3‑5436‑0571

VALQUA SES CO., LTD.
TEL : (81)436‑20‑8511

FAX : (81)436‑20‑8515

VALQUA TECHNO, LTD.
TEL : (81)3‑5434‑7520

FAX : (81)3‑5435‑0264■CHINA

VALQUA(SHANGHAI) TRADINGCO., LTD.
TEL : (86)21‑5308‑2468 FAX : (86)21‑5308‑2478
SHANGHAI VALQUA FLUOROCARBON PRODUCTS CO., LTD.
【Head Oﬃce】
TEL : (86)21‑5774‑1130 FAX : (86)21‑5774‑1244【Jingansi Oﬃce】 TEL : (86)21‑3253‑5588 FAX : (86)21‑3253‑5568■KOREA

VALQUA KOREA CO., LTD.
【Head Oﬃce】
TEL : (82)2‑786‑6718【Ulsan Oﬃce】
TEL : (82)52‑227‑6717

FAX : (82)2‑786‑6719
FAX : (82)52‑227‑6719■TAIWANTAIWAN VALQUA ENGINEERING INTERNATIONAL, LTD.
【Head Oﬃce】
TEL : (886)7‑556‑6644 FAX : (886)7‑556‑9907【Hsinchu Oﬃce】 TEL : (886)3‑572‑0467 FAX : (886)3‑573‑7232【Luzhu Oﬃce】
TEL : (886)7‑696‑2400 FAX : (886)7‑696‑7100■SINGAPOREVALQUA INDUSTRIES SINGAPORE PTE.LTD.
TEL : (65)6352‑2650
FAX : (65)6352‑2653

No.36 Winter 2019

ThinkPark Tower 24F
2-1-1 Osaki, Shinagawa-ku, Tokyo 141-6024, Japan■THAILANDVALQUA INDUSTRIES(THAILAND), LTD.
【Head Oﬃce】
TEL : (66)2‑324‑0400
FAX : (66)2‑324‑0787【Rayong Branch】 TEL : (66)38‑026‑136
FAX : (66)38‑026‑137■USA

VALQUA AMERICA, INC.
TEL : (1)408‑962‑5030

FAX : (1)408‑962‑5031

VALQUA NGC, INC.
TEL : (1)713‑691‑1193

FAX : (1)713‑691‑4407■VIETNAM

VALQUA VIETNAM CO., LTD.
【Head Oﬃce】
TEL : (84)220‑357‑0078 FAX : (84)220‑357‑0079【Hanoi Branch】 TEL : (84)24‑3222‑2213 FAX : (84)24‑3222‑2216*The VALQUA registered trademark stands for VALUE and QUALITY.
*The contents of this journal also appear on our home page. *Unauthorized reprinting/reproduction is prohibited.