Soft Seat
A valve seat or seat ring made from resilient materials - PTFE, RPTFE (reinforced), DEVLON, or elastomers (EPDM, Viton, NBR). Achieves bubble-tight shutoff (ANSI Class VI). Temperature limited to the seat material rating (PTFE to 200 degrees C). Susceptible to fire damage - paired with metal backup seat for fire-safe designs.
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Frequently Asked Questions
What is Soft Seat used for in industrial valves?
A valve seat or seat ring made from resilient materials - PTFE, RPTFE (reinforced), DEVLON, or elastomers (EPDM, Viton, NBR). Achieves bubble-tight shutoff (ANSI Class VI). Temperature limited to the seat material rating (PTFE to 200 degrees C). Susceptible to fire damage - paired with metal backup seat for fire-safe designs.
When should I specify Soft Seat for valve body or trim?
Soft Seat is specified when the process fluid, temperature, or pressure requirements exceed what standard carbon steel (A216 WCB) or austenitic stainless steel (A351 CF8M) can handle. Material selection must consider corrosion rates, maximum and minimum design temperatures, and compliance with NACE MR0175 for sour service. Vajra Industrial Solutions can supply valves in Soft Seat with full mill certificates.
Is Soft Seat compatible with sour (H2S) service per NACE MR0175?
Material qualification for sour service (NACE MR0175 / ISO 15156) depends on the hardness limits, heat treatment condition, and UNS designation of the specific alloy. For H2S-containing service, the valve material order and PMI (positive material identification) must be verified against the applicable NACE material group. Contact Vajra Industrial Solutions for material recommendations specific to your H2S partial pressure and chloride conditions.
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