Drip line causing water hammer - how to resolve

rich pickering

The pipe was changed as part of a rework of the condensate pipe. Instead of a direct run to the condensate pipe, the drip runs another fifteen feet.

I have some photos I can post tomorrow.

rich pickering

I have a drip line at the end of a main that connects to the condensate line. When the system runs and steams, there is loud hammer pounding when the drip line starts flowing into the condensate line. The condensate line feeds a boiler feed tank. There are no traps. The system pressure is 8-oz.

Any suggestions on how to quiet this down? The pipe is new and pitches more than adequately. The pipe has three 90* elbows on the way to the condensate pipe.

Thanks,

Steve

Charlie from wmass

When was the pipe changed and was it replaced as it had been or modified? Size changed, pitch changed? Was the pipe reamed? Any pictures?

Jamie Hall

Looking forward to pictures

but in the meantime, is there a long or longish horizontal run in the new drip which is above the water level? I can't, off hand, think of any where else you could get a slug of water moving fast enough to make a hammer except in such a long line... if so, is there any hope of lowering it so it is always full of water?

rich pickering

Yes, the drip now has a horizontal pitched run of roughly fifteen feet.

Steve Garson_2

Photos

Here are the photos

rich pickering

The pipe in the photo runs around 30inches to a 90* elbow going right for eight feet to another 90* elbow going right to a last 90* elbow to the condensate pipe. The pipe has a good pitch for the entire run.

rich pickering

Jamie:

It is a longish run that is horizontal. You can hear the condensate dripping/running down the pipe. And since it isn't full, you know there is also steam in the pipe.

Is this a situation where a trap is needed?

gerry gill

so do i have this right?

are you telling me that that little **** pipe is handeling both start up condensate load from the steam main, and steam also since you said its going to a feed tank..if the feed tank is vented, then isn't steam free to push air out that dinky pipe, then the steam enters the pipe along with all the condensate..if the air can get out the steam will go in, right? from your description, which i hope is wrong, and your picture, i don't see how it cannot help but to hammer.

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"

rich pickering

Gerry:

I should clarify: that little pipe is the drip that is below the take-off to a five foot long radiator. The steam main continues another five feet and then drops to the condensate pipe.

Jamie Hall

Not a gamblin man

but I'm going to be that that horizontal run above the water line is your problem. Even if it is well pitched, I can easily believe that you could get slugs of water in there being pushed by high velocity air or steam, and wham-o.

I don't see a decent solution except to lower that run so it is below the normal boiler water line (bring a longer vertical leg down from the main to below the water line, THEN run the horizontal to where it needs to go. Maybe there's a better way... but I doubt it. I don't think a trap will help...

Steve Garson_2

Might a larger pipe for the drip help? Or would it be a crap shot?

Another thought: the main return leg for the main is just four feet away. Perhaps we should try plugging this drip and see if it lessens the hammer, or simply makes it worse but in a different place.