Circle Seal Controls 5133B-2MP-500 Inline Pressure Relief Valve

The Circle Seal Controls 5133B-2MP-500 Inline Pressure Relief Valve is a compact inline relief device rated for 500 psi cracking pressure, designed to vent excess pressure from small-diameter lines and protect downstream equipment. It features a brass body with neoprene O-rings and 1/4 in NPT end connections configured inline (inline male/female options are typical in this family). The valve offers precise cracking pressure with zero leakage up to a high percentage of the set point and a positive reseat, with tamper‑proof adjustment to prevent drift. As part of Circle Seal Controls’ relief‑valve lineup (the 500/5100 series), it is offered with PED certification and CE marking on most models, and the family includes options for vent‑to‑atmosphere or inline configurations across sizes from 1/8 in to 1-1/4 in.