An UltraZap 50mm non-return valve lets water flow one way only and closes the moment the pump stops. That keeps the pump and its line primed, stops treated water draining back, and prevents the backflow that can empty a filter box or scour a pond bottom — the same protection matters in an aquarium sump or a fish tank’s plumbing run. A small part with a big effect on how the system behaves.

Good to know:
– 50mm size for 50mm PVC pipe runs
– Prevents backflow and keeps pumps primed
– Glues into the line in the direction of flow
– For pond, aquarium and fish tank plumbing