What are the benefits of soft seat valves versus metal seat designs?
Pressure relief valves with soft seats offer the benefit of zero seat leakage when compared to valves with metal seats. A typical metal seat valve is allowed to leak a certain amount based on American Petroleum Institute Standard 527, Seat tightness of Pressure Relief Valves. Valves with “O” ring seats also offer the benefit of simpler maintenance by eliminating the necessity of lapping the seat and disc as replacement of the “O” ring and a light cleaning of the nozzle may be all that is necessary. Valves with “O” ring seats do have limitations based on the temperature range of the elastomer that is selected and the users’ ability to find a compound that is compatible with the service fluid. Most “O” ring valves are limited to a maximum temperature of 450 F depending on the material selected. All Farris valves are available with an optional “O” ring seat in a variety of materials including Viton, Buna N, ethylene propylene, silicone and Kalrez.
