Hi,

I am looking for a pressure relief valve which should open at approximately 20 bar (~300psi), and dump the (high side) overpressure to the low pressure side of the refrigeration system.

Compressor unit will be about 1HP running R404a and ethane in an autocascade.

What valves are recommended for this purpose?

Many of the valves I thought suitable for this, such as the Danfoss KVR (which is in fact a condensing pressure regulator) are not designed for safety purposes.