Seal Materials
EPDM
(Ethylene Propylene Diene Terpolymer)
EPDM is a great choice when a lower-cost material is needed to handle such media as weak acids, alkalis, and low-pressure steam within the material’s temperature limitations. EPDM is not recommended for use with hydrocarbons or stronger acids.
Contact us about NSF-61-rated EPDM
GCV EPDM has a max media temperature of 295°F.
Valve Series – S20, S21, S27, S30, S31, S40, S71, SC3, SC4, and SC9.
BUNA-N
(Nitrile Butadiene Rubber, NBR)
As the seal industry’s most widely used and economical seal, BUNA-N is a practical choice when a hydrocarbon-resistant seal material is needed. This material does have limitations when exposed to oxidizing media types.
GCV Buna-N has a max fluid temperature of 180°F. (1) (2)
Valve Series – S20, S21, S27, S30, S31, S40, S71, SC3, SC4, and SC9.
FKM
(Fluoroelastomer, FPM, Viton®)
FKM is a highly resilient material and is a popular choice in the oil and gas industries. The material is widely used when dealing with aggressive fuels and chemicals that would rapidly degrade other rubbers.
GCV FKM has a max fluid temperature of 230°F. (1) (2)
Valve Series – S20, S21, S27, S30, S31, S40, S71, SC3, SC4, and SC9.
FFKM
(Perfluoroelastomer, Kalrez®)
FFKM contains higher levels of fluorine than standard FKM. This gives FFKM a much higher temperature range and near universal chemical compatibility. These impressive attributes, however, result in higher costs than traditional FKM materials.
GCV FFKM max fluid temperature – contact sales/technical support (1) (2)
Valve Series – S30, S31, and SC9.
PTFE
(Polytetrafluoroethylene, Teflon®)
PTFE is still the go-to choice for most steam applications and those requiring a chemically inert seal material. PTFE is not easily compressed, which does impact its ability to form a positive seal at low pressures and cryogenic temperatures.
GCV PTFE has a max fluid temperature of 366°F. (1) (2)
Valve Series – S21, S30, S31, S40, SC4, and SC9.
Rulon®
(Fluoropolymer, Blended-PTFE)
Rulon® is a proprietary blended PTFE range of compounds now owned by Saint-Gobain. Rulon® builds off the many positive attributes of PTFE to provide a material with better wear characteristics than standard PTFE compounds. GCV typically uses Rulon® over PTFE for cryogenic applications due to its ability to form a more effective seal at lower temperatures.
GCV Rulon® has a max fluid temperature of 366°F. (1) (2)
Valve Series – S30 and S31.
Notes
(1) Nylon-6 plastic valves do not carry the same max temperature rating as their metallic equivalents. Contact technical support for these valve service temperatures.
(2) High temperature and cryogenic service applications may require special configurations or assembly procedures. Contact technical support for further information.
Disclosure – The above-listed max fluid temperatures are generic approximates for reference purposes only. The media/chemical in use sets the actual max material service temperatures, providing it does not exceed the given max GCV rating. Please consult a reliable source such as Compass Publications Chemical Resistance Guides for an accurate allowable temperature range. You may also contact GC Valves technical support for assistance at the email address below.
technical@gcvalves.com