Non-return Valves
Stop back-flow and reverse rotation before they wreck a machine.
What they are
One job: air goes forward, never back. Without one, a stopped machine can windmill backwards or take the full system pressure the wrong way, and neither ends well.
What we do
- NRVs supplied for every common line size.
- Replacement of flapped and sprung valves that have failed quietly.
- Checks during services: a leaking NRV rarely announces itself.
- Fitting alongside relief valves as a protective pair.
Getting the choice right
Match the NRV to the pulse. Positive displacement machines hammer flap valves that would live forever on smooth flow, so type and position matter as much as line size. Fit close to the machine, in the orientation the maker intended.
On manifolds, every machine needs its own valve. One shared NRV protects nothing.
What goes wrong
- Silent failure: the flap wears or sticks and nothing announces it until a stopped machine spins backwards.
- Slamming on shutdown: the wrong type for the duty, hard on the valve and everything near it.
- Leak-back on standby sets: running blowers quietly feeding a stopped one is wasted power.
- Corroded internals in wet air: worth opening at services, because they rarely leak visibly.
Typical duties
multi-blower manifolds, aeration headers, conveying lines.
Need help choosing or fixing a blower?
Straight answers on sizing, faults and replacements, from engineers who work on every make.