Automatic air drain on air vent

Automatic air drain on air vent

My pump is installed on a sailboat for fresh water. Fresh water tanks are flexible and there is often air passing into water hose. I must unscrew the air vent cap to remove air and prime the pump. I wonder if I can install an automatic air drain, like on radiators at home. I don’t find the characteristics of the air vent cap screw. Could you help me fixing this? I assume many people have this problem with flexible tanks. Thank you

Asked by: Guest | Views: 199

Total answers/comments: 1

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Guest [Entry]

"Hi @llq , can you check whether the air is coming from the tank or from something in the plumbing before the pump? a 3-way valve, faucet, connection or the filter?

The pump shouldn’t have problems priming, the air vent is there to be used only when the gears are completely dry or the pump is very old and the gears are worn out.

If you see that the issue is in the filter, unscrew it on both sides and add some teflon tape to the connections. When placing the tape, make sure that no abundance of it makes it way into the pump, because it could be an issue for the check valve (if your pump is electronic).

If the issue is in a faucet, connection or three-way valve before the pump, apply the same principle of trying to stop the air from going into the hoses. Some use the “liquid seal” for all the connections, to be sure.

Anyway, the air vent cap screw should be a metric M5 (I’m on holiday, if you need to be absolutely sure I have to check), but automating the vent it’s not a real solution, but a workaround :)"