A balanced bellows safety relief valve adds a metal bellows above the disc, sized to match the disc’s exposed area, which cancels out the effect of backpressure acting on the top of the disc. This keeps the set point accurate and consistent regardless of variable or superimposed backpressure downstream, a problem that would otherwise shift the set point on a conventional spring loaded valve. The bellows also shields the spring and guiding surfaces from the process fluid, which protects the moving parts from corrosive media and extends service life in aggressive applications.

Common Applications

• Applications with variable or built up backpressure
• Corrosive process fluids requiring spring protection
• Refinery and chemical plant relief service on shared header systems
• Applications where accurate set point control is critical