Butterfly Disc & Seat Material Matrix
Technical reference · Supreme Valves India · Updated 2026-10-28
Direct answer: Match body to pressure-containing duty, disc to corrosion, and seat to temperature/media. A common export RFQ is WCB body + SS316 disc + EPDM or PTFE seat — write all three.
| Body | Disc | Seat | Typical duty |
|---|---|---|---|
| WCB | SS316 | EPDM | Water / utility Class 150 |
| WCB | SS316 stellited | RTFE / metal | Higher wear / temp process |
| CF8 / SS304 | SS304 | EPDM | Treated water PN16 |
| CF8M / SS316 | SS316 | PTFE | Chemicals / chlorides caution |
| DI | SS / NI-plated | EPDM | Waterworks PN10/16 |
| NAB | NAB / SS | EPDM / PTFE | Seawater |
WCB CL150 butterfly RFQ · Offset selection blog · EPDM vs NBR vs Viton
Frequently asked questions
Can I use EPDM on oil?
EPDM is poor with hydrocarbons. Use NBR or other oil-resistant elastomers per chemical guide.
Why SS316 disc on WCB body?
Cost of carbon body with stainless disc corrosion resistance — very common on international BOQs.
When is metal seat required?
High temperature, fire-safe, or abrasive duties where elastomers/PTFE are out of range.
All technical resources · Request valve RFQ
Confirm governing values against the current standard edition and the approved datasheet for each order.