Kunkle 918 Safety Relief Valve — 1/2″ x 1″ NPT, D Orifice (Vacuum, Viton (FKM) Seat)

The Kunkle 918 is a full-nozzle safety relief valve with bronze body and bonnet and a resilient soft seat, giving superior leak-free performance versus a metal seat. This 1/2″ x 1″ NPT variant — D orifice, 0.121 in² — is available across a 6–29 in Hg range for Vacuum service with a Viton (FKM) seat, carrying Non-code — no ASME stamp. Temperature range -10°F to 250°F, set by the seat material. Neoprene, Silicone, Kalrez®, Aflas® and HNBR seats are also available — ask when requesting a quote. Threaded side outlet allows piped-off discharge to eliminate fugitive emissions.