Vibration in steam pipes

polly

A few days ago we had a new float valve(low water cutoff and feeder)installed on our H.B. Smith steam boiler. Last night the house vibrated so hard and loud that out tenants upstairs thought there was an earthquake. We have since pinpointed the problem: serious vibration in the steam pipes - not a hammering but a loud,steady vibration that can last for 8 seconds. It seems to occur just as the boiler shuts off, as I can hear the furnace off but gurgling after I have rushed downstairs to locate the problem. The on-call plumber, from the place that installed the new float valve, said he's not a steam guy and we have to wait until tomorrow to hear from the company. I am very worried about the sytem, as the vibration is so stong that I'm afraid it might do some damage. There seem to be so few people who know much about old steam systems. Any idea of what the problem is? Thanks.

polly

vibration in steam pipes

A few days ago we had a new float valve(low water cutoff and feeder)installed on our H.B. Smith steam boiler. Last night the house vibrated so hard and loud that out tenants upstairs thought there was an earthquake. We have since pinpointed the problem: serious vibration in the steam pipes - not a hammering or banging but a loud,steady vibration that can last for 8 seconds. It seems to occur just as the boiler shuts off, as I can hear the furnace off but gurgling after I have rushed downstairs to locate the problem. The on-call plumber, from the place that installed the new float valve, said he's not a steam guy and we have to wait until tomorrow to hear from the company. I am very worried about the sytem, as the vibration is so stong that I'm afraid it might do some damage. There seem to be so few people who know much about old steam systems. Any idea of what the problem is? Thanks.

[Deleted User]

Polly.

Sounds like a large boiler. Also sounds like the noise was not there until after the control was replaced. The control is probably feeding after the burner shuts off. That indicates a problem in the system that should be addressed.

The noise you hear might not be coming from the system, but is caused by the new water feeder. I am not kicking anyone. However, we have found that the McDonnell 47 & 51 water feeders, and improperly supported water lines are not friends. The poppet in the feeder assembly can, under certain conditions, act just like a loose faucet washer. When activated, and particularly when closing off, the poppet can cause the connected water piping to shake like an earthquake. Some have described it as a "super sized vibrator."

We always install a pressure reducing valve ahead of the feeder to reduce the pressure and the shaking. Works better than trying to find the offending piece of pipe.

Sounds like you need someone to address the underlying problem, and then fix the feeder. If I am correct, the noise is not dangerous, and you can wait until the snow lets up.

Good luck.

MIKE6

noise

I just had a similar problem.After the steam boiler shut off there was a jingling or rattle in the steam pipe.I followed the noise around the house,had me going for awhile.I found a valve before the radiator to the second floor bedroom maaking the noise.I turned the valve a half turn and it stopped.
Mike

Steamhead

I ran into something similar

on a Marsh Vapor system. Seems the king valve (in the steam main just above the header, not used much in residential applications) was partly shut. When the steam got going it set up a harmonic vibration that rattled the LWCO, gauge, Vaporstat, and anything else it could find.

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Mark A. Custis

Nice thinking

I was clueless until you mentioned water hammer. I think a PRV or smaller pipe or gate valve will stop the house from walking down the road, with the new parts. If there is a shut off before the new stuff, crank it a few turns to the closed side to keep the cold water from banging.

Mark

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