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Permi-L Filter Elements
Precoatable, backflushable, string wound filtersfor condensate polishingA Need for Clean Condensate
Conventional and nuclear power plants have a constantneed to polish water that is condensed from steam. It
is important that fine particulate and dissolved
contaminants are removed from the condensate before
the feed water is reintroduced into the boiler. If left alone,these particulates and dissolved contaminants canbecome concentrated enough to cause major problems
to boilers and turbines—leading to unexpected
downtime and costly repairs.
Filtration and deionization play a major role in preventing
contaminant build-up in plant equipment and piping.
Condensate polishing can:■Remove particulate and dissolved contaminantsfrom water■

Extend equipment life■

Minimize equipment downtime■

Minimize costly repairs

State-of-the-Art Technology
Pall’s Permi-L powdered, precoatable elements aredesigned specifically for condensate polishing
applications. Permi-L elements are high-quality, string
wound elements that exhibit no resin leakage andprovide extended service life—addressing the concernsthat operators have when selecting precoatableelements for condensate polishing.

Expert Knowledge, Superior Support
In addition to providing exceptional products, Palloffers its customers expert application knowledge andsupport.
Pall’s Permi-L resin retaining elements advance thecutting-edge technology of powdered resin precoat
demineralizers. Years of research and development,along with strong customer partnerships, have enabled
Pall to advance its technology and become a leader inprecoat condensate polishing.
We work closely with our customers to understandtheir needs and develop solutions that address theirproblems. Our strong customer relationships provide
us with the direction that’s needed to meet the needsof the industry.

Permi-L elements

2www.pall.com

Filtration Technology Designed forCondensate Polishing■

Resin retaining elements with a longer service life
than conventional elements■

Higher quality precoat which reduces resin use anddisposal costs

NewCoated■

No resin bleed-through due to tighter surface retention■

Minimal extractables through the use of pure materialsof construction

Backflush

After Backflush

Unique Features Provide Added Value
Consistent permeability

Fiber media integrity

Resin retaining elements that have variations inpermeability will produce variations in precoat quality.
Resin retaining elements that lack precise permeability
have shorter run times and lives, and yield poorer waterquality.

Damage caused by repeated precoating, use andbackflushing of conventional resin retaining elements
can be considerable. Deterioration of the conventional
fiber matrix causes poor precoats which leads toshortened element life.

Pall understands the importance of uniform permeability
and follows strict procedures throughout the
manufacturing process to ensure consistency. Permi-L
elements are integrity tested to verify performance.

Pall identified the conventional element damage as apotential resin bleed-through concern. Accordingly, Palldesigned its Permi-L resin retaining elements with acontinuous filament yarn, to add strength and durability
to the fiber matrix. This proprietary technology increases
the long-term structural integrity of the fiber matrix of
the Permi-L element.

Surface vs. depth filtration
Conventional resin retaining elements utilize a depth
capture design which causes particles to be trapped
within the fiber matrix. Once trapped, these particles will
not backflush entirely. In contrast, the optimal resin
retaining element works as a surface filter causing theparticles to remain on the upstream side of the element,
which allows efficient backflushing.
Permi-L resin retaining elements feature distinct
technology that’s not found in conventional elements.
Permi-L elements use tight pores on the surface of theelement for optimizing surface filtration. Therefore,
excellent backflushing results are achieved by keeping
the powdered resin and corrosive contaminants on thesurface of the element.

Minimal extractables
The staple yarn found in conventional resin retaining
elements contains pigments and delusterants. These
additives contain harmful cationic, anionic and organic
contaminants which are released into the condensate.
The fiber used to manufacture the Permi-L elements isfree of pigments and delusterants. As a result, harmful
extractable contaminants are reduced, giving customers
a resin retaining element with one of the lowest
extractable levels available.

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3Internal radial sealing

Ordering Information

Sealing mechanisms used on conventional resin
retaining elements frequently rely upon horizontal fiberpressure to seal the yarn to the end caps. The integrityof the end cap seal can change due to the pressure
upon the fiber matrix.

Pall Part Number = PERMI-L

1

Table 1

Table 3The unique, proprietary, internal radial sealingmechanism of the Permi-L element eliminates thisconcern. The internal radial sealing eliminates epoxy,polymer bonds, loose felt, and plastic pieces. Permi-Lelement end connections are welded to stainless steel
center cores.

Code

Cartridge
lengths (cm/in)
nominal

52
57
60
70

132.1/52
144.8 /57
152.4/60
177.8/70

UNRT3

4CodeEnd
configurations

AEAS

Double open end
Single open end
NPT fitting
Metallic retrofit(2.5 cm / 1 inch)AR

Table 4

Table 2
Code2Media material

CodeGasket material

Polypropylene
Nylon
RytonBlank

No gasket
required
EPDM

P

To see how Pall is helping enable a greener, safer
and more sustainable future, visit www.pall.com/green.

Power Generation
25 Harbor Park Drive
Port Washington, New York 11050+1 516 484 3600 telephone+1 888 873 7255 toll free US
Portsmouth - UK
+44 (0) 23 9233 8000 telephone+44 (0) 23 9233 8811 fax
industrialeu@pall.com

Visit us on the Web at www.pall.com
Pall Corporation has offices and plants throughout the world. For Pall representatives
in your area, please go to www.pall.com/contact.
Because of technological developments related to the products, systems, and/orservices described herein, the data and procedures are subject to change without
notice. Please consult your Pall representative or visit www.pall.com to verify that
this information remains valid.

© Copyright 2012 Pall Corporation. Pall, andare trademarks of Pall Corporation.
® Indicates a Pall trademark registered in the USA. Filtration. Separation. Solution.SM is a service
mark of Pall Corporation.

PGPERMILEN

Produced in the USA

December 2012