A reciprocating pump design that uses four drive rods.
A quadruplex pump design has little advantage over a triplex or quintuplex pump design. They are rarely made, usually only for custom applications. Their largest setback is within their flow characteristics.
Where a triplex pump design sees a fluctuation of flow rate between 82% and 107% (25% difference), a quintuplex pump design sees a fluctuation of 94% to 102% (8% difference), a quadruplex sees a fluctuation between 78% and 111% (a 33% difference).
Quadruplex pumps see larger fluctuations in flow rate compared to the two alternative pump sizes. In addition, the fluctuation occurs four times per crankshaft revolution compared to a triplex’s three per crankshaft revolution.
Overall, pressure spikes in a quadruplex pump will be larger, faster, and potentially more damaging to the equipment and surrounding systems.
It is recommended to use careful consideration for the use of a triplex or a quintuplex pump, before purchasing a quadruplex pump.