Steam Main Pitch

Nick_37

We are having the main steam pipe in our crawl space replaced as part of a renovation project. I have a concern that to navigate the waste stack and main beam the contractor has had to put in a joint which may cause a bottleneck with the steam. The pipe pitches across and then has to pitch down and under the main beam before hitting a 90 degree for the return. Can anyone tell me if this might be an issue? Also I had installed 2" insulation on the original pipes as the crawl space itself isn't insulated. The contractor is saying that 1" should be enough. Thoughts?

KC_Jones

Which direction is the boiler? Also is this a parallel flow or counter flow? Both pieces of information are needed to answer the pitch question. As far as insulation what happened to your 2" insulation? If you had and want 2" insulation then go for it. That being said in general there is diminishing returns with the thicker insulation. Most on this site agree that 1" is the best bang for the buck. Going thicker is better, but you get diminished returns for your investment. The bottom line though it's your house and your decision IMHO.

Abracadabra

Unrelated to your question, but is that yellow LVL notched on the left side?

Nick_37

I hadn't noticed that but it looks like it is. I will need to check. Assume that's a flag?

Nick_37

It is parallel flow with the position of the boiler to the left with the return line starting after a 90 degree angle.

KC_Jones

If the boiler is to the left in both of those pictures and it is parallel flow then yes you have a problem. Steam mains on parallel flow must always pitch away from the boiler. What yours is now doing is going back uphill so condensate will build up behind those 2 45° elbows and block the steam from going further. That being said I think this can be made to work, but they will have to add a drip line before the elbows and have that go back to the boiler to drain the condensate. I see no provision for that. All that being said it appears in the pictures like the pipes are all pitched to the left like they are pitched back towards the boiler. Is that what is going on? Is their plan to drain the condensate back to the boiler effectively making that a counter flow? If that's the case it won't work. A parallel flow can not be changed into a counter flow without extensive re piping....and honestly it would be a foolish thing to do IMHO.

Abracadabra

What 90? If the boiler is to the left and it's parallel flow, it won't work like that. You're going to need to drip the main before the 45s.

Nick_37

All the pipes are pitched to the left back towards the boiler. The 90 degree angle is just to turn the corner back towards where the boiler is located.

KC_Jones

Did the contractor re pitch this main to make this change? If that pipe continues to the right then has a 90° elbow and has a return pipe back to the boiler then ALL the pipes should be pitched to the right not the way it is now. The highest point of a steam main on a parallel flow system should be at the boiler, the lowest point should be at the end of the main. It sounds like your contractor doesn't know what they are doing.

Abracadabra

We'll if this is a completely new main and the contractor intends on this being a counterflow main, it'll work, only if the counterflow is sized correctly and piped correctly back near the boiler. Otherwise you'll have hammering like there's no tomorrow.

KC_Jones

Abracadabra said:

We'll if this is a completely new main and the contractor intends on this being a counterflow main, it'll work, only if the counterflow is sized correctly and piped correctly back near the boiler. Otherwise you'll have hammering like there's no tomorrow.

They would have to repipe all the near boiler piping for counterflow correct? What if there are 2 mains? This would get quite complicated wouldn't it?

Abracadabra

KC_Jones said:

Abracadabra said:

We'll if this is a completely new main and the contractor intends on this being a counterflow main, it'll work, only if the counterflow is sized correctly and piped correctly back near the boiler. Otherwise you'll have hammering like there's no tomorrow.

They would have to repipe all the near boiler piping for counterflow correct? What if there are 2 mains? This would get quite complicated wouldn't it?

You can setup one main parallel and the other counterflow, as long as everything is piped properly. You can even have a main be both parallel first and then switch to counterflow as long as long as the counterflow portion is dripped properly back to a return at the point where the counterflow begins. Without more pics of how this new main was installed it's difficult to tell what's going on in this situation.

KC_Jones

Another thing I would guess is a possible issue is pipe size? If it was parallel flow and is now couterflow wouldn't the pipe size need to be checked? The EDR for a given pipe size changes based on the system type doesn't it? Just asking for the benefit of the OP. It can be done, but it's not as simple as just changing the pipe pitch and calling it a day.

Fred

The pipe pitches across and then has to pitch down and under the main beam before hitting a 90 degree for the return.
If I am reading the OP's post correctly, he appears to be saying the Main comes from the right and pitches down under the beam, turns right and returns to the boiler. If my interpretation is correct, the boiler is on the left and the Main loops around the basement, into the crawl space and then exits the crawl space as a return on the left. That's the way it should be and that drop should not be a problem. (again assuming my interpretation is correct).

KC_Jones

I think Abracadabra hit the nail on the head, more pictures of piping are needed to make a more intelligent conclusion.

Nick_37

Fred said:

The pipe pitches across and then has to pitch down and under the main beam before hitting a 90 degree for the return.
If I am reading the OP's post correctly, he appears to be saying the Main comes from the right and pitches down under the beam, turns right and returns to the boiler. If my interpretation is correct, the boiler is on the left and the Main loops around the basement, into the crawl space and then exits the crawl space as a return on the left. That's the way it should be and that drop should not be a problem. (again assuming my interpretation is correct).

That is a perfect interpretation and that answers my question. You guys are awesome!

Fred

@Nick With that new piping, be prepared to skim your boiler a couple times after you start to see the water in the sight glass start to bounce a lot. The oils in that new piping will wash back to the boiler and float on top of the water. Normal for any system that has a new boiler or piping on it. May take 2 or 3 skim sessions at probably 1 week intervals.

vaporvac

The bigger the pipe the thicker the insulation. There's a chart somewhere on this site with suggestions. However, for an uninsulated space 2" should be minimum. Most of the suggestions for insulation on this site are concerned with pipes within the jacket of the house and even then IR cameras have shown quite a startling difference in heat loss between 1" and 11/2". However 1" is definitely better than none! This is really only important if there are rads coming off and it's not at the end as the steam collapses and heads to the return instead of your rads. The$ difference isn't that much for a short run.

Nick_37

Fred said:

@Nick With that new piping, be prepared to skim your boiler a couple times after you start to see the water in the sight glass start to bounce a lot. The oils in that new piping will wash back to the boiler and float on top of the water. Normal for any system that has a new boiler or piping on it. May take 2 or 3 skim sessions at probably 1 week intervals.

My boiler does not have a dedicated skim tap. Any thoughts on the best way to do this? As you can see all the near piping is copper (courtesy of PSEG and the prior owners).

Abracadabra

Skim by removing the plug in the tee next to the gauge glass.

Fred

Yep, as Abracadabra says, you do have a skim port, next to your sight glass.

Nick_37

Abracadabra said:

Skim by removing the plug in the tee next to the gauge glass.

Not sure I'm following. The tee that is connected to the pressure gauge?

Fred

No, that 1-1/2" (maybe 2") pipe that has a plug in the end of it and a riser on top of it. Use the plug end to skim.

Nick_37

That makes sense. Looks like its been sealed in since it was installed. Is it easy to remove?

Fred

Nick said:

That makes sense. Looks like its been sealed in since it was installed. Is it easy to remove?

It should come out. Be thnakful the plug isn't in the boiler block. They are hard to get out. Spray around the plug with some PB Blaster for 2 or 3 days before you try to take it out. That should help.

Nick_37

Will a regular pipe wrench do it?

Fred

It should. If need be, put a short pipe extension on the wrench for more leverage. Use another pipe wrench on the Tee so that you don't twist the Tee in any way.

Nick_37

I have one with an extension so that shouldn't be a problem. Will I have to reseal the plug once its done or is tension enough?Any tips on what to skim it into as I don't have skim tap. Would it be easy to install a skim tap in the future?

Fred

Reseal it with teflon tape. That will make it easy to get off next time. If you can screw a reducing elbow on it to take it down to 3/4", turned down then a short 3/4" nipple then you can screw a garden hose on it and run it to a floor drain.

Nick_37

The plug has been sealed in with something and I am struggling to get it out. Tried the PB Blaster without luck.

Fred

Lordy, Lord. That looks like about the only place you have to do any skimming. You have to get it off somehow.

Steamhead

Nick said:

My boiler does not have a dedicated skim tap. Any thoughts on the best way to do this? As you can see all the near piping is copper (courtesy of PSEG and the prior owners).

That piping may also be too small. It looks like 2-inch. That's a Dunkirk boiler, despite the fact that it may have another brand name on it, and this type of boiler does not tolerate bad piping. The outlet tapping is 2-1/2-inch and that's what should come out of it.

Abracadabra

Nick said:

The plug has been sealed in with something and I am struggling to get it out. Tried the PB Blaster without luck.

Torch and judicious use of a hammer will help break the plug loose... along with a big **** wrench... What kind of a wrench are you using?

Nick_37

Big wrench with a three foot iron pipe attached for leverage which has started to chew up the plug.

Steamhead

You'll need an impact wrench with the appropriate 8-point socket. That's pretty much the only way these will come out. Ask us how we know that..............

jumper

Counterflow is unfairly disrespected.Main can begin close to waterline.With proper connections you can drip each riser into a separate return a la parallel.Then there's more headroom and main can be simpler.

Fred

jumper said:

Counterflow is unfairly disrespected.Main can begin close to waterline.With proper connections you can drip each riser into a separate return a la parallel.Then there's more headroom and main can be simpler.

Whaaat? How does this relate to getting a plug out of a skim port?

JUGHNE

A search on the wall for "removing pipe plugs" will give you pages of ideas. Read maybe the first 3 pages for ideas and also cautions on what not to do. Icesailor had some hole saw methods etc.

jumper

Why not pickle and clean pipes and fittings before assembly?