Steam System - Peculiar near boiler piping / Wet return

john johanson

Brad,

Thanks for the comments.

I was worried about the near-boiler piping; you confirmed my suspicion. We'll have to get it fired up, then see how the issues pan out.

Re the waterline/header dim:
I'm not sure of the differential. The pressuretrol appears to be a subtractive pressuretrol. The "main" was set to 15 psi when i checked it (not a good sign i imagine), but it doesn't have a "differential" scale. I didn't want to take it apart without a professional to see if there is a scale interior to the housing. Any idea on what it going on with this pressuretrol?

I'd imagine the higher the differential, the more distance you need between the waterline/header?

Re the wet return:
Glad to hear that is alright... it makes sense, the wet return is basically like a large water tank.

Thanks again for the comments!

John

john johanson

Steam- Near-boiler piping / Wet return Questions

I am volunteering with a non-profit who recently purchased a pair of historic stone church buildings for rehabilitation, one of which has an old one-pipe steam heating system.

The system has been out of use for roughly 5 years and we are attempting to revive it (using professionals).
I have little prior knowledge of steam, but just read, absorbed, and enjoyed "You've Got Steam Heat!".

Assessing our system after reading the book, I was scratching my head on a few things, which I am hoping to get some input on:


1) Near Boiler Piping:

Our boiler is shown in the attached photos "boiler-xxx".
Basics like the distance from water to header seem fine (~28"); however, I am having trouble understanding if the way the equalizer and take-offs are situated relative to the header is correct.

On boiler-left.jpg, you can see that what appears to be the equalizer seems to be routed off of one of the risers, not after the take-offs like the book shows. Also, the takeoff is located between the risers.

How does this near-boiler setup strike you?
Just looking for some feedback or wisdom as to whether this setup seems fine, or may need some rearranging.



2) Wet Return:

Does the wet return (below the water line) need to be pitched towards the boiler?

I'm asking because our wet return has an upward jog in it of about 6-8" on its way back to the boiler, but from that point appears carefully pitched. Photos "wet-return-xxx" show this.



I also threw in a photo of the radiators and the church exterior for good measure

Brad White_199

Nice Building!

Where is this church by the way?

Some Comments:

1) The basic boiler outlet piping is all wrong. There are two side-outlets near the top that collide where the mains feeding the system leave the header. These have to combine into a common header pipe before they depart for the radiators.

I would also consider, in the final configuration, hanging that header from structure above. Right now all of that piping weight is being borne on the boiler tappings.

2) The equalizer is on one side only, the left side looking at the front view. That too wants to be a single line after the departure of the distribution mains.

Besides, all of the returning main condensate which does not get sucked out toward the radiators falls back into the boiler. No way that condensate in any quantity would decide to avoid gravity and make a hard turn into a smaller pipe that you have.

3) Your waterline to header dimension may be fine, but that is based on 1 PSI differential. At what pressure do you operate?

4) Your return going into that "equalizer" is a long shot which can promote water hammer in a big way. It really wants to dip lower then rise into the equalizer (one that is properly piped coming down from a proper header of course!) and connect thereto with a close-nipple.

5) As for the wet return, so long as it is all below the waterline, it will flow back to the boiler- it essentially becomes part of the boiler. The flow is self-siphoning. As water stacks behind the low part, it will flow up and over the dam so to speak.

I have designed returns dropping below slabs then rising a foot out of the ground and dropping into the top of a return, all below the waterline mind you, which work well, no hammering nor loss of flow. An steady, slow flow of gradually warming return making it's way home.

Just a few thoughts, hardly all that can be said, just my $0.02

Brad

john johanson

Answer...

Forgot to answer your first question.

The church is in Troy New York, a small city in the capital district, next to Albany (the state capital). The city has amazing 19th century architecture, and a lot of steam systems!

There are more photos of the church on our website if you are interested: http://www.cactroy.org

Brad White_194

Pressure

A system like that should operate on a pound or less. A vaporstat would make a good investment, just vent the mains well ahead of the radiators and vent the radiators properly.

Failure to vent will have the burner shut down prematurely on pressure, but air pressure, not steam pressure.

10 PSI? Empire State Building only runs on 2 to 3 on a cold day... I mean, nice church but Faye Wray and the gorilla won't be stopping by anytime soon.

Charlie from wmass

Will need to check it out one of these days as my girl's kid sister goes to R.P.I. I live right over the border in Lee,MA.

john johanson

Pressure Mistake

I made a mistake on the pressuretrol actually.

The subtractive pressuretrol appears to be a backup (set to 15 psi); the main pressuretrol is mounted to the side of the boiler with a cut-in pressure of about 1.5 psi (I haven't pulled it apart to find the cut-out yet).

Thanks for the tip re the Vaporstat, I'll look into it.

Mad Dog_2

Well,.........................SIR

You have Darin Cook of Thermal Perfection right under yer nose. He knows The Steam. Mad Dog

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

john johanson

area

Charlie,
Our phone number is on the website: http://www.cactroy.org
If you want to get inside and check out the steam system, give us a call if you're going to be in the area.

john johanson

Thermal Perfection

MadDog,
Thanks for the tip.
I actually just spoke with Darin this morning

Brad White_200

Silly me

Darin Cook absolutely. I was a bit detached from the details, but Darin gets the nod in my book. Glad you both connected.