Valve Disc & Gasket Changes

Valve Disc and Gaskets are sometimes changed/substituted for better performance with a given fluid. The change is represented by the insertion of a letter representing the substituted Disc/Gasket material (see examples below).

Seal Material Temperature Range Application Seal Recommendations
Buna-N -40°F to +250°F Water, Air, Brine, Gas, Oil, Solvent
PTFE -500°F to +500°F Liquid Oxygen, Cryogenics
Viton® -20°F to +400°F Diesel Fuel & Gasoline
Gaseous Oxygen applications Viton provides tighter seating

Valve Type Disc / Gasket Changes:

V ----- Viton® Disc (i.e. Type 18A44 with Viton® Seals becomes 18AV44)
T ----- PTFE Disc (i.e. Type 18A44 with PTFE Seals becomes 18AT44)
B ----- Buna-N Disc (i.e. Type 16L44 with Buna-N Seals becomes 16LB44)

Viton® is a registered trademark of DuPont Performance Elastomers.