Spring-loaded valve is a self-actuated safety relief device which acts with the aid of a spring assembly that is designed to open at a predetermined pressure. The spring-loaded valve includes conventional, balanced-bellows, and balanced-piston types.

These valves are flanged type and are based on API 526 standard. These sizes vary from 1”x2” up to 8”x10” with flange ratings of #150×150 up to #2500×300.