CMP Replacement SuperFlo Pump Union Kit, 21063-350-000

The CMP 21063-350-000 is the replacement union kit for Pentair SuperFlo pumps. The unions are the threaded connections that join the pump to the suction and return plumbing so it can be disconnected without cutting pipe.

Why unions fail

They take the load every time the pump is taken out for service, and they are the joint most likely to start weeping as a pump ages. Once the sealing face is scored or the nut has been over tightened, tightening it further makes the leak worse rather than better. New union hardware is the repair.

When to fit it

The kit goes on easily while the pump is already broken loose for a shaft seal, a lid o-ring or a basket change, so it is worth adding to that job rather than pulling the plumbing apart twice.