Mud Pump Relief Valves

Mud  pumps must be equipped with pressure relief valves. These valves prevent too high a pressure from being built up in the circulating system. The relief valves most commonly used in Shell operations are the Cameron type “B” reset relief valve and the Cameron shear relief valve. A discharge line should be connected between this valve and the drilling fluid tank. For safety reasons, this relief valve discharge line must be tied down securely with its end facing down into the tank.

Cameron Shear Relief Valve

The Cameron shear relief valve pops open when the pressure setting is exceeded. The tripping pressure of the valve is determined by the strength of the shear pin. In this design, the valve snaps fully open, and there is no erosion of the piston or bore. A chart is printed on the manufacturer’s nameplate from which it is possible to see which size of the shear pin is needed for the required pressure limitation.

Cameron Type “B” Reset Relief Valve

The Cameron type “B” reset relief valve provides the following features:

• It opens fully when pressure is exceeded.

• The pressure setting is indicated by a pointer.

• The pressure setting can be changed with pressure on the valve by turning an adjusting nut.

• The valve design prevents leakage or erosion.

• All parts are enclosed.

• The valve is set by a reset lever.

• The valve can be opened at any time by pressing a release button.

The diagram below shows the valve’s operation.