New Steam boiler; higher pressure on pressuretrol

ChrisJ

EzzyT said:

The homeowner reached out to me, had me come out to the house and looked over the entire steam system.
The boiler is about 25% oversized.
The header is definitely to small along with not being high enough above the the boilers normal water line.
There is about 20’ section of the 3” steam main that is counterflow with no condensate drip.
The main venting needs to be upgraded along with all the radiator vents.

Did they approve the work yet?
It's the smartest move they could make.

EzzyT

I just sent out the estimate yesterday to get the boiler and system back in proper working order.
I know that homeowner is going to see what they can get back from the contractor that did the work.

Jamie Hall

It's always so helpful to have someone who knows what they are doing actually looking at the situation -- thank you. @EzzyT !

mattmia2

Just a thought on comparing to the old boiler. The burner could have been downfired so it could have been a significant amount smaller than what is on the ratings plate.

PMJ

EzzyT said:

I just sent out the estimate yesterday to get the boiler and system back in proper working order.
I know that homeowner is going to see what they can get back from the contractor that did the work.

Can I assume "get the boiler back in working order" meant keeping the 25% oversize one and changing the header? Or does a decision on replacing the boiler depend on who will agree to eat how much of the work done so far?

EzzyT

@pmj My approach would be to keep the boiler repipe with a 5” drop header, install a 2 stage gas valve triggered by a vaporstat.

ChrisJ

EzzyT said:

@pmj My approach would be to keep the boiler repipe with a 5” drop header, install a 2 stage gas valve triggered by a vaporstat.

 interesting 

EzzyT

One approach was to down size the boiler by removing a couple of the sections to get close to the edr load but then a new jacket burner tray assembly and draft hood would need to be ordered. I looked into that approach but those parts harder to come by then getting a new boiler especially since Weil McLain as discontinued the EGH line along with there wouldn’t be a warranty warranted by the manufacturer.
It’s definitely going to be a challenge for the homeowner to get anything back from the original contractor especially without getting lawyers involved.

PMJ

EzzyT said:

@pmj My approach would be to keep the boiler repipe with a 5” drop header, install a 2 stage gas valve triggered by a vaporstat.

Thanks. I hope to see photos of that header down the road.

SteamingatMohawk

Regarding the question about pressure drop versus steam flow, there is a calculation available on the engineers toolbox:

https://www.engineeringtoolbox.com/steam-pressure-drop-calculator-d_1093.html

For residential steam purposes, the answer is very small. The example I used is saturated steam (not superheated) at 2.3psig with a specific volume of 23.385 cuft/lb (the reciprocal is the density, which is the value called for in the equation (1/23.385 = 0.042762455 lb/cuft, rounded to 0.0427)).

I used 2" schedule 40 pipe for the inside diameter.

I used 200lb/hr to get a number that wasn't 0 psi. That's about 200,000btu/hr, actually 194,000 if you use 970 BTU/lb.

One thing to remember is if flow doubles, pressure drop is 4 times as much.






So, for 100 feet of 2 inch pipe at 2.3 psig, the pressure drop is 0.2psi (note, since the number is so small it is impossible to know how close it is to the 0.2....it is between .150 and .249 from what we learned about rounding in school.

Bottom line the pressure in the pipe is because of the ability or inability of the generated steam to get out of the system, not the actual flow rate of the steam.

Check it out.

jimmyenz17

Thanks everyone for your comments and special thanks to @EzzyT .
In short, near-boiler piping (especially the header diameter and height) are a major contributors to the pressure build up, followed by inadequate venting (on the Main and radiators) and obviously the 25% oversized boiler.
This is so frustrating. Only if I had a time machine! I wish I could have done it the first time correctly with @EzzyT . In my defence, it's not like I looked for a "cheap" plumber. I did a lot of research to find a good reputable plumber that was recommended locally (but I did not have enough knowledge to know that a good plumber does not mean a Heating specialist). This plumber has installed many hot water and steam boilers around here, which is scary to me. Probably most home owners don't even go to the mechanical room to check what could be wrong.

I am working on seeing what I can get back from the installer (the boiler did not pass inspection), since essentially the installation of the steam boiler needs to be done, so much is wrong with it. Huge cost.
I also did not mention in this threat, but the installer also did my Hot-water boiler at the same time, which @EzzyT looked at. I did not post anything about that here since this is Steam Only forum. Anyway, The hot water boiler needs to be re-piped as well; so many things wrong (it also failed town's inspection, but they fail on basic stuff, the inspector had no clue about near boiler piping etc as expected).

I did email NJ's State Board of Examiners of Master Plumbers to see what their response is. I will most likely need to take legal action to get something back before re-doing the job with @EzzyT . This has been such a nightmare. Thanks again for everyone's input. I continue to learn from all of you. I'll keep this thread updated as things occur.

109A_5

jimmyenz17 said:

I did not post anything about that here since this is Steam Only forum.

Not just Steam... Just start a different thread. However, you are probably past that now, Good Luck.

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