HEROSE has now expanded its 0685X and 0681X series to include an O-ring variant. Compared to the previous soft sealing plate and the metal sealing variant, the new O-ring seal offers improved tightness until the valve reacts.
The O-ring is available in viton (FKM) and nitrile butadiene rubber (NBR) making it cheaper than vespel sealing plates. The seal is available for valves with orifice sizes from 10 mm to 18 mm. The seat tightness is defined in accordance with API 527. Safety valves of types 06850/06855 and 06810/06815 with soft sealing O-ring offer zero bubble tightness with a reproducibility of up to 20 reaction cycles. A default value of 10-3 mbar l/s is guaranteed for external tightness. The O-ring seal can be used for pressures of between 3 bar and 250 bar.
