Reciprocating Pump Having a Combination Check Valve and Relief Valve

Abstract

A reciprocating pump having a combination check valve and relief valve is disclosed. The pump includes a pump body having an inlet, an outlet and a pumping chamber. A biasing element provides a force that biases a movable seat toward sealing engagement between a first region of the movable seat and a fixed seat at the inlet. A movable checking element is movable away from a second region of the movable seat when fluid flows in one direction through a passageway in the movable seat. The movable seat also acts as a relief valve wherein the first region of the movable seat disengages the fixed seat if the movable checking element is being forced into engagement with the second region of the movable seat by a force that exceeds the force of the biasing element against a third region of the movable seat.

Description

BACKGROUND OF THE INVENTION[0001]The present invention relates generally to reciprocating pumps, and more specifically to diaphragm or piston pumps. In either case, the pump generally has two check valves; a first to allow the material being pumped to enter the pumping chamber, but not to exit, and a second to allow the material to exit the chamber but not to reverse flow and reenter the pumping chamber.[0002]With electrically operated pumps, in the event the discharge is closed or experiences an obstruction, sometimes referred to as a deadhead situation, the electrically operated pump must be turned off immediately to avoid a potentially dangerous or damaging spike in pressure, or the system must have a relief valve to bleed off the excess pressure created as the pump continues to run.[0003]In air operated diaphragm pumps, this is not a problem. An air operated pump simply will stall if the back pressure of the pumped material exceeds the air pressure used to move the diaphragms. T...

AI Technical Summary

Benefits of technology

The disclosure provides a reciprocating pump with a combination of a check valve and a relief valve. This pump overcomes the limitations of prior art designs. The pump has a fixed seat at the inlet, a biasing element seat at the inlet, and a movable checking element. The pump also has a movable seat with a passageway and three regions that engage with the fixed seat, the movable checking element, and the biasing element. The biasing element provides a force that biases the movable seat toward sealing engagement with the fixed seat. The movable checking element is moveable away from the second region of the movable seat if fluid flows in one direction through the passageway. The movable seat acts as a relief valve when the force created by the biasing element is greater than the force opposing it. The pump may use a ball or a flapper as the checking element. The combination of a check valve and a relief valve makes the pump more efficient and reliable.

Problems solved by technology

Although this feature is useful, air operated pumps are very energy inefficient.

This prevents them from being widely used for a range of process applications.

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