The patented pressure relief (blow-off) valve is an important safety feature supplied with all Accusump cylinders. It is designed to vent excess air pressure to prevent the Accusump cylinder from dangerous overpressure. Factory set to open at 175 psi.
We recommend replacement of the valve periodically, especially if the Accusump is mounted in an extremely hot environment. Failure of this valve is very rare, but it is possible for debris to get stuck inside the valve and prevent proper functioning.