A weight loaded pressure blower relief valve offers a rugged, trouble free design.

Connection size is 3″ MPT.
Maximum Diameter: 9.25″
Overall Height: 9.875″
Threaded Length: 1.5625″
Material of Construction: Cast Iron
Maximum Allowable Set Pressure: 15 psig
Minimum Allowable Set Pressure: 3 psig
Relief Volume at 15 psig: 1990 cfm
Relief Volume at 3 psig: 790 cfm

The operation of the blower relief valve is simple. As the service line air pressure reaches the pressure setting, the weight loaded cap is forced upwards off the valve seat. As the pressure increases, the cap rises to expose the discharge ports. The flow through capacity of the valve is such it will relieve the pressure to the desired set point and prevent damage to the blower and other appurtenances. The valve must be sized properly to allow the venting of the excessive flow. If the valve is undersized, excessive pressure could result in the service line.

The blower relief valve automatically reseats itself as the line pressure is reduced.

The last three digits of the model number designates the set point. As an example VRWPS10P030 represents a set point of 3.0 psig. If the last three digits are changed to 150, the set point is 15.0 psig.
Valve is not recommended for set pressure below 3 psig.

OPERATION: A weighted cap rides on a machined seat, when the pressure exerted on the cap is greater than the weight of the cap plus any weights on the cap. The cap raises to let air escape. The relief valve does not fully relieve until the weight of the cap and the accumulation factor of the valve is exceeded. The accumulation factor is the percent of set point pressure required to initially move the cap. The accumulation factor on these blower relief valves is approximately 25%. The set pressure can be modified by removing or adding weights. Each weight represents a 0.5 psi change in set point.

INSTALLATION: The relief valve must be mounted in the vertical position to function properly. Overhead clearance must be great enough to allow full travel of the cap. The blower relief valve should be installed on the discharge side of the blower, before any restrictions, and preferably immediately after a silencer if one is used.

MAINTENANCE: Rotate the cap by turning by hand on a monthly basis. Use a light oil on the machined surface of the body (seat) to prevent rust and insure proper operation.

OEM Part Numbers

The table below shows the OEM part number for each set point as well as the number of weights required to reach the desired set point (each weight adds 1/2 PSI)