In a pump system, a coupling serves which primary function?

In a pump system, a coupling serves which primary function?

• A. To regulate flow between stages
• B. To support radial loads
• C. To seal the shafts against leakage
• D. To connect the shafts of the motor and pump

Answer: (D)

The key idea is that a coupling is there to transmit power from the motor to the pump while keeping the two shafts connected as a single rotating system. It links the motor shaft to the pump shaft so torque can pass through, and it also allows a bit of misalignment and distance between the two pieces for maintenance and installation purposes. It doesn’t regulate the flow, which is handled by the pump design and control valves. It also doesn’t bear the radial loads or take on shaft sealing—that’s handled by bearings and seals respectively. So connecting the shafts of the motor and pump is the primary function.

The key idea is that a coupling is there to transmit power from the motor to the pump while keeping the two shafts connected as a single rotating system. It links the motor shaft to the pump shaft so torque can pass through, and it also allows a bit of misalignment and distance between the two pieces for maintenance and installation purposes. It doesn’t regulate the flow, which is handled by the pump design and control valves. It also doesn’t bear the radial loads or take on shaft sealing—that’s handled by bearings and seals respectively. So connecting the shafts of the motor and pump is the primary function.