Theoretical power required (in watts) to drive a reciprocating pump is (where w = Specific weight of liquid to be pumped in N/m3, Q = Discharge of the pump in m3/s, Hs = Suction head in metres, and Hd = Delivery head in metres)

• wQHs
• wQHd
• wQ(Hs - Hd)
• wQ(Hs + Hd)