The "Pop-Action" design permits the RegO Pressure Relief Valve to open slightly to relieve moderately excessive pressure in the container. When pressure increases beyond a predetermined point, the valve is designed to "pop" open to its full discharge capacity, reducing excess pressure quickly. This is a distinct advantage over ordinary valves which open gradually over their entire range, allowing excessive pressure to develop before the relief valve is fully open. All RegO internal, semi-internal, and external relief valves incorporate this "Pop-Action" design.

Designed specifically for use as a primary relief valve on ASME cargo tanks for transportation and bobtails with 2" and 3" F.NPT couplings.