A single acting reciprocating pump lifts a liquid of specific weight 9.0 kN/m3 from a pressurized storage reservoir to an overhead container. The free surface in the supply reservoir is at an elevation of 3.5 m above the centre of the pump. The ambient pressure over the liquid surface in the supply reservoir is 27 kN/m2 (vacuum). The other relevant data relating to the pump are as follows:
Length of the suction pipe = 6.0 m
Diameter of suction pipe = 10 cm
Minimum pressure anywhere in the system =27 kPa (abs)
Length of stroke = 50 cm
Diameter of cylinder = 20 cm
Atmospheric pressure = 99 kN/m2 (abs)
Determine the maximum speed admissible in rpm.