Hi,

In a NH3 process refrigeration plant, I need to regulate a BPRV that is not doing it's job. It is intended to maintain the evaporating pressure constant but it is variating according to the compressor suction pressure. The valve is 6" and the photo is:
bprv unibev can 2.jpg
Any one recognizes this kind of valve? I need to know the reference or manufacturer so that I can search for the manual, but in the body or the documentation available nothing exists.

Thank you in advance for any information.

Best regards, Carlos