Piping /Venting

gfreynolds · February 24

A year ago I hired a local heating contractor in Upstate NY to replace some steam piping that was leaking in the main line. There are not very many knowledgeable steam heating contractors in my area. The contractor replaced around 25 feet of the 2" main line with 2" copper, along with another 20 plus feet of 1 1,/2" wet return line back to the boiler. I know this is not the preferred method but it works. The boiler and piping is in a crawl space with only around 50" of head clearance to the floor joist. This is a single pipe system feeding six radiators.

When we fired up the system this year there is alot of clanging, gurgling and hissing from the radiator vents. This lead me to believe we have venting and balancing problem. So checked the radiator vents and pitch. Found only one radiator with no pitch back to the valve. So I raised it up 1/4" inch. One of the sources I checked, (Chatgpt) suggested the Hoffman 75H on the main line is too small. and should add a second vent. So I added the second vent. A Groton #2 vent, and I also raised both up arouund 8" by building an antler line. This didn’t help much if at all. Now these vents are at the end of the main line and about the same height of the last riser, and only six inches down stream in the top of the tee that drops into the wet returm.

The next thing I looked into was the boiler WL compared to the end of the main. The boiler WL is 24" above the floor and the end of the main is around 42". Which is way too low. So I removed the vents at the tee on the end of the main and Installed a 12" x 3/4" nipple capped off. Now I have a false WL of 28" above the boiler. This has helped out a little.

I am now thinking I have a piping and a venting problem. Given the proximity of the last riser to wet return and the false WL. I really don't have a dry return line. So maybe what needs to be done now is; extend the main a couple of feet of pipe away from the last riser, add a tee. The bottom of the tee drops into the wet return and top is extened up and capped. Using the same 1 1/2 "pipe in order to keep the false WL 28" above the boiler WL. Plus reinstall the Groton 2 vent in the short main extension

. Looking for some and comments.

BTW the way the boiler is in a crawl space head clearance to floor joist is around 50" So my false WL is between floor joist.

EBEBRATT-Ed · February 24

Hard to find anyone that know steam up there.

I would suggest making a sketch of the piping showing the different elevations. Hard to figure it out just by reading.

Sounds like your going to have to keep your pressure very low to make this work

Captain Who · February 24

I am not getting the false waterline notion (you eliminated your main vents?) but you have an A dimension of 18 in., which, if you keep the pressure low and you don't have a large boiler could be enough. It will be important to keep the steam dry and the water quality good.

Jamie Hall · February 24

What is the elevation of that return pipe in relation to the water line in the boiler? And how does it connect with the boiler? As @EBEBRATT-Ed said, a diagram with elevations (relative to the boiler water line) would be very helpful here.

dabrakeman · February 24

Was there no such gurgling, clanging and banging before the section of main was replaced? If not, assuming your water quality is good and no bouncing seen in the sight glass (may be OK since no new oily steel pipe was added to the system) I would take a close look at the added section of pipe and how it is joined with the steel. Any potential for water entrapment?

Intplm. · February 24

Be certain that all pipes are pitched back toward the boiler. No sags in the pipe and none that are level. And as mentioned above little pressure. Your gauge should read zero.

patrykrebisz · February 24

do you have low pressure gauge installed on your boiler (0-3 or 0-5psi)? if not you must have one to know your ACTUAL pressure. what is your ptroll set to?

mattmia2 · February 24

what makes you think you need a dry return? it looks like a parallel flow system.

gfreynolds · February 24

Thanks for the fed back. Yes the system did some clanging and banging before the new piping, but there was a dip in the main line where the section was replaced. The copper was joined to the steel with brass fitting.

As for slope the near header piping is 52" from the floor and it continues to slope down to 32" at the end of the main shown in the picture. Where I added the 12" capped nipple and the water drops straight down into the wet return.

No outside gauge and the Honeywell pressure switch is set to .5 pressure. The pig tail was removed and cleaned last year after the replacement piping. I also added a container of SQUICK cleaner fired it up then drained it out of times. No skimmer tap. No real bouncing in the sight glass.

One other interesting no the old piping didn't have a vent and it did have a false water extender in the wet return. See picture below

Captain Who · February 24

So before you said the main dropped to 42in. It is actually 32 in.? What is the distance from the boiler WL to the bottom of the header? The main is how long and starts at what height?

gfreynolds · February 24

Jamie Hall · February 24

So that wet return — the last bit of piping — is 8 inches above the water line? How does it connect to the boiler?

The slopes of the various main sections — end to end — are fine, but do double check that there are no sags!

Captain Who · February 24

The way you drew it the boiler doesn't have a header or an equalizer? That can't be right?

So that "wet return" is sometimes a dry return and sometimes a wet return? Could be a recipe for disaster. Any way you can drop it down below the boiler WL?

Wait, that 38 in. at the end of the main isn't really "off WL" it is from the floor, so 14 in. off WL? So then the wet return is 16 in. below the WL?

gfreynolds · February 25

Yes the wet return is roughly 16 inches above the water line. There is only that short nipple separating the end of the main and the last riser. I had a Hoffman 75H on the top of it. I was lead to believe it was too small. So I raised it up around 8" and added Groton #2. It didnt help much if at all. Now I am wondering if I can place it up stream around 15" before the last two risers.

ethicalpaul · 12:08AM

Yes the wet return is roughly 16 inches above the water line.

then it’s not wet!

Jamie Hall · 12:34AM

https://forum.heatinghelp.com/discussion/comment/1889612#Comment_1889612

It's a steam main extension, then. Even more important to know how it is connected to the boiler.

Mad Dog_2 · 12:42AM

How far Upstate NY are you? Mad Dog

Captain Who · 1:20AM

Hold on here. End of main is 38 in. above the floor? Then there is a 30 in. drop down to the wet return? So that puts the wet return at 8 in. above the floor correct? If the NWL of the boiler is 24 in. above the floor that would mean that the wet return is 16 in. below the NWL of the boiler, right?

Piping /Venting

Comments

Categories