wet steam?

al leone

In my eternal search for the cause of a very load water-hammer at or neer a particular radiator on the 3rd floor of my house, I removed said radiator and opened the service-valve to see if I was infact getting water or steam. I was
hearing gurguling sounds and then got a little water followed by misty or wet steam. can this be my cause for water hammer? I checked the piping for pitch and also cranked the psi down. I also made sure to pitch rad. after install. Its quiet for a night or two and them BAMM!
can anyone help?

al leone

wet steam?

In my eternal search for the cause of a very load water-hammer at or neer a particular radiator on the 3rd floor of my house, I removed said radiator and opened the service-valve to see if I was infact getting water or steam. I was
hearing gurguling sounds and then got a little water followed by misty or wet steam. can this be my cause for water hammer? I checked the piping for pitch and also cranked the psi down. I also made sure to pitch rad. after install. Its quiet for a night or two and them BAMM!
can anyone help?

Ken_8

Dry steam is

the result of many factors; most of which are in the basement.

The near-boiler piping is critical.

Boiler water "quality" is equally so.

Dimension "A" is key (as is the pressuretrol setting)

Riser and main sizing is also.

Pipe insulation and venting are critical. Riser location, sizing and how the take-offs are run are key.

The vent on each rad is important.

Where should you start looking?

You need Holohan's book: TLAOSH or, You got steam?

Either that, or go to "Find a Contractor" above, plug in your zip code, and get an expert to make some sense out of it for you.

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

Jamie Hall

insulaton, pitch

check the pitch on all the lines, all the way back to the main -- it's got to pitch to drain. Also, are all runouts and risers insulated? No insulation plus a low spot could do what you're describing.

David Efflandt

undersize riser?

My most distant 2nd floor radiator on north side of home makes gurgling sounds and plugs the air vent in a week if I vent it too rapidly, particularly in very cold weather. I suspect that is because condensate forming in the cold riser pipe and radiator is fighting the steam in a marginally sized riser. Basement piping does have a dry return just before the riser.

Venting the radiator more slowly allows sections to heat one at a time, reducing condensate, and the vent has lasted for years. Although, not all sections heat up during short cycles in mild weather.

This could be even worse if the riser is undersize to a 3rd floor. But you may have other issues to be addressed if the steam is actually banging (rather than knocking due to pipe binding somewhere during expansion/contraction).