RIV 230 Brass Pressure Relief Valve, Free Discharge

The RIV 230 is a spring operated pressure relief valve with free discharge, listed by RIV Rubinetterie Italiane Velatta in the Opale series of its Slurry Tankers and Biogas line. A spring holds a disc onto the seat; when tank pressure overcomes the spring the disc lifts and the excess vents straight to atmosphere through the windows in the side of the body, and the disc reseats as the pressure falls.

The application is the tanker barrel itself. A slurry or vacuum tanker is pressurised to discharge its load and evacuated to fill it, and both directions have to be limited: a pressure relief valve caps the positive side while a vacuum relief valve breaks the negative side. Fitting only one of the pair leaves the barrel exposed in the other direction. The same arrangement is used on biogas digestate tanks and on transfer equipment built from tanker components.

The valve is brass with the body cast and the lifting ring on top. The item in the catalogue photograph is the 2 in size, cast into the body. When ordering, state the size, the thread form of the male connection, and the set pressure required; RIV also lists a calibrated and sealed variant of this family for duties where the setting must be fixed and witnessed.