
Several types of researches were done to model and simulate the reciprocating pump rod stiffness change even through mechanical spring, hydraulic actuators, and pneumatic actuators. The objective of this research is to simulate the effect of changing the reciprocating pump rod stiffness value on the reciprocating pump performance and its starting requirements. Changing the reciprocating pump rod stiffness value was done through a pneumatic system by changing the air pressure supplied to the pneumatic cylinder inside the pneumatic system, this can be considered a change in the reciprocating pump rod stiffness. A test rig was manufactured to experimentally investigate the impact of rod stiffness change on the performance of reciprocating pumps and its starting requirements. The test rig key components are test rig frame, reciprocating pump system, AC electric motor with its gearbox, Scotch Yoke mechanism, pneumatic system, instrumentations and measuring devices. Simulating the reciprocating pump rod stiffness change through pneumatic cylinder can affect the starting requirements of the reciprocating pump such as the starting torque and the current. From the results above, the starting torque requirements were decreased by an average of 19 %, power consumption corresponding to the peak starting torque was decreased by an average of 9% and the overall system performance and efficiency were increased by an average of 10%.