The union nut is a connecting element that tightens and fixes the UV lamp in the body of the sterilization unit of the pool system.
A correctly tightened nut guarantees that the lamp is in the precise position for maximum sterilization efficiency while maintaining the watertightness of the joint.
The part is made of plastic resistant to the chemicals contained in pool water and to UV radiation.
Replacement is recommended if the original nut cracks or deforms, as it could otherwise cause leakage and shorten the service life of the UV lamp.
