Steam vent placements

nick31

Hi all, first time posting here so hopefully I’m doing this right. I have a question on steam vent placements. I’ll post a picture of the near boiler piping, some branches to radiators and spots where there are vents and spots where it looks like vents used to be but are now plugged. I’m assuming they’re plugged because they were leaking water at one point so someone just plugged them. Before I put vents in I figured I’d ask first. The second picture is a vent that from time to time shoots out water with a pretty high velocity. It does it in spurts like it’s surging. I assuming this is because the vent is either too small or lack of vents on the system but I’m doing a lot of assuming here. The third picture is by far the farthest radiator from the boiler so I would imagine I would need a vent that would let air out fast like a Gorton #2. For reference I’m an hvac tech who just started his own one man company that is fascinated by steam and trying to learn everything I can. 

One other thing I thought was weird. There’s 7 total radiators all 1 pipe with steam vents on the opposite end of the radiator valves except one is a 2 pipe. I didn’t think you could do that, unless I’m looking at it wrong. I’ll also post pictures of that radiator. Currently all radiators work even that 2 pipe radiator. 

Any info on this is much appreciated!! 

Jamie Hall

The first question -- well not the first -- is that yes you can have a mix of one pipe an.d two pipe radiators. The main trick is that the two pipe radiators do need somewhere for the air to go. So there needs to be a vent -- at least one -- somewhere on that return line. Hard to say where, but you can trace it,,,

Those vents on the mains are woefully small, and even if they are working they need to be replaced with larger ones (such as Gorton #1 or #2. The plugged locations may have been vents, though they are not in the best places.

As for the spurting vent -- what pressure are you running at? It may be simply overpressured -- but two things: first, it shouldn't have water near it, and you need to think about how it gets there, and second, if it is spurting, it's probably failed.

nick31

I appreciate the response! So if you look at the picture of the boiler the branch coming off the vertical tee is the branch where the 2 pipe radiator is coming from. That is also the side that has the two plugs where vents used to be. So that branch doesn’t have any main vents at all. 

The farthest vent doesn’t have the height to fit a gorton #2 but I can put a #1 there. The one that was spitting does have the height for a #2 but from what I’ve read a gorton #2 should be used on the farthest branch. Is it ok to still put one there or will that affect the system? 

The pressure was at 4 psi and I turned it down to 1. My thought on why the water was there is because I don’t have 24” on my riser off the boiler. I was thinking of extending the riser and repiping the equalizer to give myself at least 24” from the water line to the header. Possible even putting in a drop header. I do have megapress so it can be done pretty easily that way it’s 100% dry steam. 

Steamhead

If the spurting vent is the one in the second pic, the reason is obvious: the tee where the vent is placed is a reducing tee, and the reduction in the tree causes water to back up in it. That tee needs to be replaced with a standard tee followed by an eccentric reducer.

This problem can also cause other vents in the system to spurt.

ethicalpaul

There’s no such rule as “the longest main should have a #2”

the rule is “try to vent the mains such that steam reaches each main’s vent at roughly the same time. And with haste.”

several variables might come into play including size and length of pipe, and insulation state.

but any working main vent is better than a plug and a Gorton or Maid O Mist #1 (equivalent to “D”) can vent a lot of air

nick31

If the spurting vent is the one in the second pic, the reason is obvious: the tee where the vent is placed is a reducing tee, and the reduction in the tree causes water to back up in it. That tee needs to be replaced with a standard tee followed by an eccentric reducer.

That makes sense. About two feet before that vent there was a pin hole leak in a pipe that I fixed with a couple megapress couplings and a new section of pipe. Everything I’ve read you can use megapress on steam systems, is that true? Since the fix I haven’t had any water hammer in the pipe so I don’t think the fittings create a pool of water. I can cut that tee out and put in a press x press x female tee then a short nipple to the eccentric reducer. 

Also, do you think the lack of height on the boiler riser is causing wet steam and that’s why water is by that vent as well? Or is that kind of a stretch. 

ethicalpaul

My opinion, based on watching my boiler with sight glasses on the steam supply pipes, is that your boiler, provided the water quality is good (cleanish, no oil film, and no weird chemicals), and provided that the steam outlet is at least the size indicated in the installation instructions, will not surge. I say your riser and other near-boiler piping shown is fine.

Some will complain about your split main (rather than having each main come from the header), but that won't cause any problems IMO. Your steam will go where the lowest pressure is and won't be confused by that tee.

The way for you to tell is if your water level drops dramatically (like over an inch) at any time during the steaming cycle. If it does, you will know that your boiler is sending water up to your mains.

gfrbrookline

Don't put copper on a steam system, stick with iron pipes, it costs more to install but it last longer and you won't have electrolysis issues which will cause more leaks. Also adding copper will cause expansion issues that can become noise issues.

If you added copper right before the now spurting vent it is likely caused by the addition of the copper causing the steam to cool much faster then it did in the iron pipe, turning to water, which was compounded by the issue @Steamhead raised so it spits right out of your vent. You may have gotten away with the previous piping but the addition of the copper piping pushed it over the edge with additional condensate.

gfrbrookline

Once you replace the copper in your system you should upgrade to Gorton 1 and 2's and insulate your mains to improve your systems efficiency. The cost of the fiberglass insulation will pay for itself in about two years but will make you more comfortable immediately.

The plugs look like they may have been previous main vent based on there piping. I would put Gorton 1's on them and see if you heat up faster. Pic's 2, 3 and 5 were definitely main vent locations at one point. Pic 4 I don't think ever had a vent.

EBEBRATT-Ed

The second picture with the reducing tee if that is a steam main and the flow is right to left that will get water in the vent as @Steamhead mentioned. If it is a return increasing in size heading left to right towards the boiler then it is ok.

If you re pipe your header bring the second steam main down so you have two mains coming off the header

nick31

 

Don't put copper on a steam system, stick with iron pipes, it costs more to install but it last longer and you won't have electrolysis issues which will cause more leaks. Also adding copper will cause expansion issues that can become noise issues.

There’s no copper in the system the press I used was all black pipe megapress. Im going to swap out all the main vents and fix that reducing tee. 

gfrbrookline

Sorry, every time I see press I assume copper.