Gasoline Check Valve Noise
Gasoline Check Valve Noise
(OP)
A check valve in an automobile's fuel delivery module (inside the fuel tank) makes a screeching noise in about 10% of the assemblies and the screeching noise is voltage dependent. Any ideas on valve noise design for liquids to minimize noise and references for valve noise design?





RE: Gasoline Check Valve Noise
If it is only present in 10% of cases then you have a variability problem, not a design problem, most likely. I'd be looking at moulding part lines creating cavitation, and things like that. If you can reproduce the problem on the bench then you should be able to home in on bad parts very quickly.
Alternatively it could be an istalation problem - perhaps some cars strain a vital isolator and create a sound path.
Cheers
Greg Locock
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RE: Gasoline Check Valve Noise
2)My first thought for a screeching check valve is a leak that set up a "Venturi Oscillation." Fluid flows through a gap, the pressure decreases in the gap causing the gap to narrow which reduces the flow, the pressure increases and the gap opens, etc, etc, etc.
RE: Gasoline Check Valve Noise
Are you sure its not a fuel return valve making the loud noises? or it's relief valve?
RE: Gasoline Check Valve Noise
I'd suspect too much pressure drop across the valve, like when we leave the outside faucet cracked (not really off) with certain lawn sprinklers attached, or pressure reducing valves for a steam turbine http://
RE: Gasoline Check Valve Noise
RE: Gasoline Check Valve Noise
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The pressure drop vs flow for several types of check valves, with various spring weights is provided at link above. Despite the description of viton seals, the provided views suggest to me the seats are metallic.
First I'd qualify the flows at various voltages of the test pump(s). Then I'd get a couple of noisy valves, a couple of quiet valves, and a Bosch residual pressure valve. Then I'd carefully dissect them, paying attention to things like perfectly reliable free motion of the valve, as-installed spring pressure, (if coil springs) spring wire diameter, number of coils and free length, and details of seat width and the machining adjacent to the seats (sharp edges, burrs, percent seat contact, and anything else I could think of).
I think there maybe too much spring pressure, maybe exacerbated by a seat machining detail or loose or binding pilot
The truth is out there. I mean in there.
RE: Gasoline Check Valve Noise