Gaskets and Sheet Jointings

Elast-O-Pure® Hygienic Clamp Gaskets

Elast-O-Pure® Hygienic Clamp Gaskets, based on Elast-O-Pure® EP75 Black ethylene-propylene-diene elastomer, have been developed by James Walker to meet the stringent requirements of the pharmaceutical and bioprocessing sectors.

Elast-O-Pure® EP75 Black is a highly developed material, compounded in-house by James Walker, that possesses significantly enhanced properties in comparison to other EPDM compounds.

Our Elast-O-Pure® Hygienic Clamp Gaskets are designed for use with clamp systems in pharmaceutical, bioprocessing and other industry sectors where  biocompatibility, Total Organic Carbon (TOC) content, and dead space avoidance are prime considerations.


  • Biocompatibility: Elast-O-Pure® EP75 Black has been independently tested in accordance with, and fully complies with the requirements of USP 30 Class VI. Full reports of testing against the various aspects of compliance are available to customers on request.
  • FDA compliance: Elast-O-Pure® EP75 Black complies with FDA 21 CFR 177.2600.
  • Total Organic Carbon value: When independently tested, following extraction procedures in accordance with USP 381, Elast-O-Pure® EP75 Black demonstrated significant, class-leading performance in comparison to its three main competitors. Whilst there is no specified limit stated in the USP document, the remarkably low TOC value displayed by Elast-O-Pure® 75 Black mininises any potential for contamination. 

Special features of Elast-O-Pure® Hygienic Clamp Gaskets

  • Long service life for best value and economy in use.
  • Long-term dimensional stability, with very low compression set, for excellent long-term gasket sealability.
  • Remarkably low TOC value minimises any contamination.
  • Compatible with a wide range of process chemicals, including acids and alkalis used in CIP systems.
  • Excellent resistance to steam - ideal for SIP sterilisation systems.
  • Low adhesion to stainless steel - providing clean release and disassembly after long use.
  • Exceptionally wide temperature range.
  • Full batch traceability, with Elast-O-Pure® EP75 Black elastomer compounding and gasket moulding undertaken in-house by James Walker.

Dimensional stability & dead space avoidance
The excellent long-term dimensional stability of Elast-O-Pure® EP75 Black, when under load, minimises any tendency for our Hygienic Clamp Gaskets to intrude into the product flow area or, conversely, to shrink back to form recesses. Such defects could lead to dead spaces where contaminants from previous product flow might accumulate.

Intrusion testing has been independently undertaken in accordance with ASME BPE-2007 for a number of different size Elast-O-Pure EP75 Black gaskets installed in clamps and ferrules supplied by Advanced Couplings Limited. In all cases, the measured intrusion/recess was either zero, or significantly less than the +/-0.6mm limit allowable. 

Resistance to steam cycling
To check the adhesion resistance of our Elast-O-Pure® EP75 Black gaskets under a steam cleaning process, we have performed customer trials under a steam cleaning regime; subjecting the gasket to 500 thermal cycles from clean steam at 130°C (266°F) in a line assembly.

Each cycle comprised one hour in clean steam, and a return to room temperature before re-exposure to steam. On completion of 500 cycles, the assembly was dismantled and the gasket was removed cleanly, without leaving any residue on the metal surfaces.

Typical properties of Elast-O-Pure® EP75 Black

Temperature (maximum):
+135°C (+275°F), with excursions to +180°C +356°F) in steam for SIP.
Temperature (minimum): -40°C (-40°F)
Hardness: 76 IRHD
Tensile strength: 16.4MPa (2320psi)
Elongation at break: 130%
Compression set, 168 hours @ +100°C (+212°F): 6%
Compression set, 168 hours @ +125°C (+257°F) typical autoclave temperature: 11.4%

Industry specific immersion testing

Purified water: 4 weeks at +125
°C (+257°F)
Volume change, %:
Change in tensile strength, %: +48
Change in elongation at break, %: +7
Charge in hardness, IRHD: -1 

Water For Injection (WFI): 4 weeks at +80°C (+176°F)
Volume change, %:
Change in tensile strength, %: +8.5
Change in elongation at break, %: +11
Change in hardness, IRHD:  -2

CIP 100® (4% by volume in de-ionised water):
4 weeks at +60
°C (+140°F)
Volume change, %: +2.6
Change in tensile strength, %: -9.7
Change in elongation at break, %: -7
Change in hardness, IRHD: -2
(CIP 100® is manufactured by Steris - based on potassium hydroxide. CIP 100® is a registered trademark of Steris Corporation) 

CIP 200® (4% volume in de-ionised water)
4 weeks at +20°C (+68°F)
Volume change, %: +0.1
Change in tensile strength, %: -24
Change in elongation at break, %: -16
Change in hardness, IRHD:
(CIP 200® is manufactured by Steris - based on phosphoric acid. CIP 200® is a registered trademark of Steris Corporation)

How supplied
Elast-O-Pure® Hygienic Clamp Gaskets are supplied in size from 1/2" to 12". Size ranges include: BS4825 part 3, 1991; BS4825 Non-Standard; BS Schedule 5 Pipe; BS Schedule 40; ISO 2852; ISO 1127; ISO 2037; Mini Series Ultra Bore. Custom sizes manufactured to order.

We are also willing to partner with equipment manufacturers in the pharmaceutical and bioprocessing sectors to develop, prototype and evaluate materials and/or specific components for custom applications.

In addition to Elast-O-Pure® EP75 Black ethylene-propylene (EPDM), we also manufacture seals, gaskets and components in other USP Class VI elastomers, including:

  • Elast-O-Pure® GF75 Black - genuine DuPont™ Viton® pharmaceutical grade fluoroelastomer (FKM).
  • Elast-O-Pure® SIL70 Translucent - platinum-cured pharmaceutical grade silicone (VMQ).