Elastomer Technology

Shieldseal 661 - Radiation grade

A specially developed 'soft grade' of ethylene-propylene (EPDM) elastomer for the manufacture of seals and other flexible products that are subjected to high levels of ionising radiation.

Typical applications

Precision cut gaskets for flange sealing duties with liquids and gases in the presence of ionising radiation, where only low closing forces are available.  Also flexible custom mouldings for use where radiation resistant materials are required. 

Evaluated for resistance to ionising radiation by monitoring changes in important physical properties over time while irradiated with gamma radiation. Further information on these tests as carried out by independent test house Centronic Raditec and James Walker Technology Centre can be supplied to customers on request. 

Special features

  • Outstanding radiation resistance
  • Excellent compression set resistance for efficient long-term fluid sealing
  • Very low levels of ions such as Cl- and SO42- that can leach from materials to promote metalwork corrosion within a nuclear reactor
  • Exceptional low-temperature flexibility
  • Long service life
  • Excellent value for money

Operational properties of Shieldseal 661
Hardness: 50 IRHD 
Compression set: 35%, when irradiated for 680 hours at a dose rate of 130Gray/h (total dose 88kGray) @ 40°C. 
Chemical properties: Excellent resistance to a wide range of chemicals. Also resistant to atmospheric ageing.
(Typical values quoted: Please consult James Walker before using for specification purposes)

How supplied
Shieldseal 661 is available as moulded products and precision cut gaskets. We are also willing to partner with equipment manufacturers and end-users to develop, prototype and evaluate materials or specific components for custom applications.