Water hammer

[swedtug]

over the winter I have mounted gauges in the wheelhouse, but it sounds like the water Hammering in the gauge measuring receiver pressure.
sound comes and goes, I have tried to adjust it out by fiddling the valves without success,
I have a valve on the receiver and one on the pressure gauge. and approximately 6 feet tube between. What to do?
.

Översätt

[DetroiTug]

Hello,

It needs a shock arrestor on the pump. They sell devices for modern day house plumbing that work and sometimes just a vertical pipe on the exit side of the pump with a cap that can capture air will work also.

-Ron

[swedtug]

Thank you but it is the receiver between HP and LP cylinder. so it's steam pressure that goes into LT cylinder. but some sort of shock arrestor might work.

[johngriffiths]

I once encountered hammering on a Stuart 6a when compression on the HP raised the pressure sufficiently to lift the slide valve. The only other thing I can think of is condensate building up and being carried over, that will make things smack a bit.

John

[steamdon-jr]

look up mini restor, they have many sizes and applications, what I like about them is they do not rely on air but have small spring loaded pistons which have the air encapsulated at the top of the done which allows them do be mounted vertical or horizontal.

[swedtug]

Thanks for the help, I have a piston valve on HP cylinder, but have had problems with condensate in the LP cylinder, tried to open the drain cocks, but it didn't take away the sound.
The mini restor sounds intresting, Perhaps that is what I need.

[TahoeSteam]

How well insulated is your engine?

[Lopez Mike]

Exactly my thought. Remarkable to have that much condensation in the receiver unless either the insulation is non existent or there is a slight throttle leak when stopped that is filling up the receiver.

How sure are you that the hammering is coming from the receiver? I'd suspect a reciprocating pump of some sort first.

[marinesteam]

How does the needle on the gauge behave while the noise is occurring? Does the behavior or noise change when the valve at the receiver is closed? Is the mounting of the line to the gauge loose and banging on something?

From wikipedia "Water hammer (or, more generally, fluid hammer) is a pressure surge or wave caused when a fluid (usually a liquid but sometimes also a gas) in motion is forced to stop or change direction suddenly (momentum change). A water hammer commonly occurs when a valve closes suddenly at an end of a pipeline system, and a pressure wave propagates in the pipe. It is also called hydraulic shock."

If the flow in the receiver is being suddenly stopped that would fit the definition and might be a cause of your noise. Improper timing, loose receiver mounting or improperly sized receiver could be things to look at.

Cheers

Ken

[swedtug]

the engine is fairly well insulated, I have even isolated the underside of the cylinders, so think not that I am getting condensation from there. but have had problems with priming in the boiler. in times when oil separation has been failing in the hotwell.
but that has not happened since I cleaned the boiler last time.

the needle on the pressure gauge behaves similarly when sound is heard as it is silent. It shows between 1.5-2.5 kg 20-36 psi of pressure .
improperly sized receiver is very possible, couse I have designed everything without any drawing.