Water hammer from new drip line - Help!

rich pickering

I am in the midst of a big renovation project that has one pipe steam. The plumber moved a 3/4-inch drip line that previously ran 4-feet horizontally to an elbow running to the condensate pipe near the floor. There is one radiator with 75 EDR fed by the pipe above the drip line.

To open up required floor space, this drip now runs:
four feet in the other direction (1st photo), then after an elbow, goes ten feet to the right to another elbow
four feet (2nd photo) and then a elbow down
four feet, through a convector, then down to the floor condensate pipe.

Now there is very loud steam hammer. (Surprise?!) The pipes are pitched very nicely. The condensate line being fed has a boiler feed tank thirty feet toward the boiler and a condensate tank/pump in the other direction, with a nine foot rise from the ceiling.

Is there any correct this problem?
Perhaps larger pipes than the 3/4-inch, since the horizontal run is so long?

I need to get this figured out fast. The plumber is a real nice guy and says he knows steam, but I think he doesn't know what he doesn't know. If you know what I mean!

Help!

clammy

drip

Steve that drip should drop straight down instead of running horizontal and only turn horizontal after it's below the water line i realize that it goes to a reciever tank ,if it still hammering i would check the boiler pressure to ensure it's low and either install a small trap or water seal if it's blowing steam into the reciever.Before your repiping did you have this promblem?peace and good luck clammy

Jamie Hall

There's another thread

around here somewhere with a similar problem -- and the same solution. Somehow that drip has got to go straight down to below the water line and then -- and only then -- turn. Then it can go pretty much wherever you need to go with it. As Clammy said, you do want to check and make sure all the rest of the essentials are good, too -- but you've got to get that drip modified.

Steve Garson_2

Since the pipe is in the middle of the room, going straight down isn't an option if we are to use this room.

I can have the pipe go down to the water line immediately at the first wall, instead of running near the ceiling like it does today.

If we do that, will a larger pipe reduce the water hammer, since the pipe run is over 20 feet plus elbows? I'm going to have to have the contractor cut open the new wall to do this, so I want to be sure it is done right. (I told him not to cover the walls until this was figured out!)

Steve

Jamie Hall

I won't guarantee

anything -- but it surely couldn't hurt to go right down at the first possible wall there. Also I would go with bigger pipe until you get to the water line (1 1/2", say). You can stay with the smaller pipe from there (as an example, I have 3" steam mains; the main drips are also 3" to the water line, then 1 1/2" from there back to the boiler -- which is about 100 feet for one of them).

Also I'd like to see more pitch on the part of the line above the water line...