non return valves

[TJAGAIN]

having just fitted a no flow water alarm to my boat i was wondering if anyone knows of where i may be able to fit into the line a non return valve ? it would be useful on my boat as the outlet is above but not that much above the water line

 

[TJAGAIN]

sorry it should have read the outlet from my bilge pump (got water alarms in my mind from fitting one today)

 

[Jean]

If you really feel that you need one, make sure that your pump can still provide sufficient flow with the pressure drop across the NRV. Typical domestic NRV's, for example, drop around 0.1 bar, which is too much for some circulating pumps even to open them.

 

[pvb]

You don\'t need one...

It's not a particularly good idea to put a non-return valve in a bilge pump outlet. Instead, just arrange the outlet pipe so that it rises in a swan-neck before dropping down to the outlet skin fitting.