The MCB/MCQ pump union nut is an original spare part for the MCB and MCQ series of pool pumps. The nut is a key connecting element of the union fitting that tightens the pipe flange to the pump inlet or outlet and ensures a watertight connection.
The nut material is resistant to chlorinated pool water and to the mechanical stress of repeated tightening and loosening. The precise thread design matches the original specifications of the MCB and MCQ pumps.
Replacing the union nut is necessary when a leak is detected at the union connection area or when cracking occurs due to material ageing. Proper tightening of the nut with a wrench prevents water leakage even at full pump operating pressure.
