Leaking Gorton #2

lutorm

So today I got my fourth Gorton #2 back, this one directly from Gorton. And it leaks too. I made a Youtube video so people can tell me if this is normal or not:



<a href="http://www.youtube.com/watch?v=8GMC0Yj2BUM">http://www.youtube.com/watch?v=8GMC0Yj2BUM</a>

gerry gill

I suspect a problem with your system.

you are just having to many bad vent issues for it to be the vents..you have some system issue i would bet on it..i had a customer recently who purchased her own main vents. I put them on for her..they were blowing thru..i found a clogged pigtail..once i got the pressure of the steam under control and the intensity of the steam under control (by adjauting the firing rate of the boiler) the very same gorton vents were working just wonderfully..you have system issues..quit blaming the vents..are you really operating at the same pressure as the empire state building?

lutorm

What issues?

I think you commented before, so I reiterate: Both pigtails are clean, and both of the just bought gauges are consistent with a maximum pressure of 2psi. The 0-3 shows 2psi, the 0-30 doesn't budge, and they are on separate, 1 month old pigtails.



I agree that it seems unlikely all these vents would be bad and that something must be up, but unless there is a conspiracy between the pressuretrol and the two gauges, I don't see how it can be the pressure.

Mark N

Leaking Gorton

How long had the boiler been running when the pressure got up to 1.5 psi and then 2 psi?   Why hadn't the the pressuretrol turned off the boiler?  Do you have a Burnham boiler?  Bunham recommends .5 cut-in and a 1 cut-out.  Does the pressure go that high every time the boiler runs?   The pressure should at most be a few ounces.  I can't see the pressure getting that high until all the vents on the rads have closed.  The thermostat should be satisfied long before thay happens. 



Mark

lutorm

Intentionally

I intentionally cranked the thermostat up until the system was pressure cycling to test whether the vent was leaking. It starts pressure cycling after about 30-40 minutes of continuous burning, starting from cold rads.  Normally it doesn't do that unless it's recovering from a setback.



It is a Burnham boiler, and the pressuretrol is as low as the pressuretrol can go (I've essentially removed the adjustment spring) which turns out to be about 1.1 cut-in / 2.1 cut-out. (It's not very stable ether, the cut-out has changed from 1.6 to 2.1 over the past weeks...)



I'm certainly entertaining the thought of replacing the pressuretrol, but the question here is whether the vent should behave like that. I was under the impression that 2psi is some sort of "norm" for steam system (according to Dan's books), so one would think that the vent would be functional up to those pressures. (Of course, I can't find any specs about the Gorton vents and what their maximum pressure is. My Hoffman radiator vents state 10psi max pressure.)



Are there other things could cause the vent to leak?

Jamie Hall

2 psi

is regarded as a maximum for one pipe and standard two pipe steam -- a maximum.  They work better on less; say 1.5 psi.  Vapour systems are meant for less -- 8 ounces or so -- and may not heat at all, or very unevenly, on more.



The 2 psi rating on the vent is the working pressure, at which it can reopen after it closes.  Anything over that and it will close and stay closed until the system shuts off.  The 10 psi rating on the Hoffmans is a "to withstand" pressure; in theory, they shouldn't be destroyed even if subject to that much pressure.  In practice... especially if they are older, they may collapse at somewhat less pressure.  Gortons behave in much the same way.  Both of them can leak at pressures greater than the working pressure.



Do get a vaporstat...

Mark N

Boiler

What is the size of your boiler? How many sq.ft. of EDR are your rads? Maybe the boiler is oversized. You shouldn't be cycling on pressue after 30 mins. If your boiler is properly sized for your system should be closer to 1 hour. How does your system run when your just maintaining temp?



Mark

lutorm

Not sure

... about the boiler. I can't find a plate on it and Burnham has a whole series of similar models. Any idea how I go about identifying it?



Based on my pressure cycling duty cycle of about 180s on / 90s off, I'd guess my boiler is oversized  by about 180+90/180, ie 1.5, so I think you're correct that the boiler is oversized. I have no idea when the burner was inspected, either, so it could also be out of adjustment.

David Nadle

IDing boiler

Measure the width and compare it to Burnham's catalog. Compare rated EDR to connected EDR.



Anyway you can get cut out pressure down to 1.5?

lutorm

Never mind

I found it. The boiler says 105k BTU/h input. The output fields are blank but looking at the Burnham independence data sheet on the web, it looks like the model with 105k input is DOE heating capacity 87k, IBR rating for steam 65k.



About the radiators, there are 7 of these:



http://www.cfa.harvard.edu/~tcox/pics/NewDigs/slideshow/9.html



with a total of 32 sections. They are ~38" tall, so according to TLAOSH that should make each section about 4 ft^2 EDR, making it a total of 128 ft^2 EDR or 128*240 = 31 kBTU/h.



The IBR rating includes pickup, right? So that would mean the boiler is twice the size we need? Wow, I thought it was oversized but not by that much.

Mark N

Burnham IN-4

I have the same boiler.  The IBR rating does not include the pick-up factor.  The pick-up is the difference between IBR and the Gross output or DOE heating capacity.  The IN-3 would be better for your system.  It would seem your boiler is twice as big as you need.  This boiler makes twice as much steam as you need no wonder your pressure is so high. 



Mark

nicholas bonham-carter

leaking gorton

here's a thought: can "wet steam" be slightly cooler, and subsequently fail to close the thermostatic part of the vent all the way, so that it leaks?

definitely get a vaporstat. --nbc

Mike Kusiak_2

Boiler oversize

As I recall when you moved into the house, all the basement piping was uninsulated, which contributed to the total EDR of the system. Possibly, when they sized the Burnham boiler they took all this uninsulated piping into account and added it to the EDR of the radiation. When you insulated all the piping, you may have brought about the unintended consequence of reducing the total effective EDR to the point that it grossly oversizes the boiler? In any case, doesn't seem that there is much you can do about it other than replacing the boiler which is probably not an option.



Do you recall how much different your cycling ratio was before you insulated all the piping?

lutorm

Yeah, maybe...

I guess this is possible, though there isn't that much piping in the basement. The steam mains is a total of 45ft 2" pipe, and the return and runouts make another 42ft of 1" pipe.

Not including fittings, that's a total of 42 square feet of area.



I never got a measurement on the cycling before insulating. I mean, I measured it, but that was before I cleaned the pigtail so it was only cycling on the LWCO test periods at that time.



The house was converted from one 3-story residence into 3 apartments about 20 years ago. I'm wondering if they only had one boiler before then and when they put in separate heating systems for each floor didn't downsize enough.



I guess it's not possible to just remove one of the 3 burner rails, is it?

lutorm

Interesting point

I wondered about this, too. I skimmed the boiler for 2 hours yesterday, we'll see if that makes a difference.

DavidK_2

weird - I'm not a pro, but,

in my limited experience this is not normal



4 bad vents does sound weird. They should be able to handle 2psi. Maybe there is grunge in the boiler, or pipe, that is getting blown up and preventing the valve from closing? Or maybe they have a bad batch. Do you live at high altitude (maybe the boiling temperature is not high enough to fully shut the valve)?



I'd take that one back off. Make sure the valve seals properly (by trying to blow through it while upside down - the valve not you Shake it around a bit. See if it still seals well. Maybe rinse it out well to make sure no crap is stuck inside preventing it from closing. Maybe try boiling it (but I don't know how you would have it hot enough to activate, but still be cool enough to blow through).



Have all 4 released about the same amount of steam.

Mike Kusiak_2

Piping EDR

The 42 sq ft of piping EDR you effectively removed still amounts to around 33% of the present radiation, so it seems to be a significant factor. I would assume that the installer oversized the boiler some anount in addition just to "be safe".



I wouldn't try to remove a set of burners, as this could affect the combustion, introducing excess air through the unfired section. In addition there could be additional thermal stresses on the cast iron boiler sections due to unequal expansion. You might try to "clock" the gas meter to see what your actual firing rate and BTU input really is.



Probably your best bet is to avoid big setbacks and insure operation so that the thermostat is satisfied before the system builds enough pressure to cycle the pressuretrol.

lutorm

Did that

The clocking, that is. If you input a heating value of 1028 BTU/ft^3, you get almost exactly 105k/h, so it seems to be properly adjusted.



I don't have a feel for what matters with the burners, that's why I asked. There's no problem adjusting a gas stove, so why is it different on these systems? Or do stoves just have really poorly controlled combustion?

lutorm

Crud?

Boston -- so no, not high altitude. And they haven't been the same; one was basically stuck shut, one leaked like crazy, and two have been like in the movie.



I guess it's possible that there's crud being blown down the return line, since the vent is right at the end of the dry return and there was no vent before. If the return line has crud in it, maybe the entry of high-speed steam can pick stuff up and drag it into the vent? Though, when I took the return apart to add the T to the vent, it seemed pretty clean.



Maybe I should run the boiler with the vent removed for a while to try to blow stuff out?

Mike Kusiak_2

Gas combustion

The combustion of an atmospheric gas boiler is pretty much determined by the physical parameters of the burner, heat exchanger flue passage size and draft conditions. Since these factors are pretty much fixed, there is an optimum firing rate for a given boiler.  If the gas input is reduced, the gas to air ratio will be reduced, introducing excess air through the exchanger. This tends to reduce the flue temperature and therefore the efficiency.



I have heard of people downsizing an atmospheric boiler by removing one or more burners and plugging the corresponding gas orifices, but it is not recommended. First of all the manufacturer would not approve for liability reasons since you are changing the design from what was tested and approved by the safety agencies. Also as mentioned before, there might be excess thermal stress on the exchanger since some sections are being heated and some not, especially so if cold air flow is allowed through the unfired sections.

DavidK_2

crud can be many things

dirt - rust - excess pipe dope or teflon tape - Drilling or threading residue. It doesn't take much to stop a needle valve from closing all the way.



I don't know about running it open - you may get more steam than you want. Maybe make sure the vent valve is clear, clean, and working - then reinstall it and see what happens on the first cycle (or maybe temporarily install it with a piece of cloth to cover the entrance)



I'm no pro, but the Gorton vents seem to be pretty simple. A float sitting on top of a bemetal, with a needle and seat valve at the top. They should close when the bimetal strip gets hot, or there is water in the chamber. Too bad they were not designed to be opened up (and serviced). My guess is - poor construction or quality control - either the bimetal strip is not working right, or the valve is not closing right (or like I said it could be crud getting stuck in the valve)



If I was looking for a business opportunity I see two obvious options - a low pressure pressuretrol that works as described, and a high capacity vent that works reliably (and can be serviced). For the price these things sell for I'm surprised nobody has done this - except perhaps that steam is viewed as a "dead" technology since it is not really conducive to condensing exhaust boilers.

lutorm

New movie

I made another youtube video, this one shows how the water is seeping through if you blow through it upside down. Our hot tap water is actually hot enough to close it, so this is even when it's closed.



[url=http://www.youtube.com/watch?v=wuyx6nJZRXs]http://www.youtube.com/watch?v=wuyx6nJZRXs



So is that more water than expected?

DavidK_2

I have no idea how hard a person can blow

But you've got a low pressure gauge so you could find out.



The vent should close when it gets hot, and it should no leak at pressures less than 2 lb/in**2



If you (or your boiler) can blow harder than that perhaps it can  (and should) leak.



Does the vent leak during normal operation, or only when you force your boiler to pressure cycle?



My guess right now - either you have something stopping the valve from closing, or, they are getting sloppy with build quality. I don't know what the valve parts of made of. Maybe they are soft and will seal better with use (at least until they get too worn)



I which I could be of more help. I don't have a #2. And even if I did I don't know if I'd open and probably destroy it to help a stranger - though I have done stranger things to help strangers.



I'd be tempted to put that valve in big pot of water - oriented upright as it would be installed - and boil it in hopes that the needle and seat would form together and seal. Maybe it just needs to be broken in? Or just buy several #1's - or a different brand.

TomM

how hard a person can blow

(FYI- just blew ~35oz/in^2 full force)

Mark N

IN-4

I don't think your boiler is an IN-4.  My IN-4 has 5 burners.  Maybe it is an older model. 

lutorm

Yeah, it's not an IN4

I don't recall the model, it's not an IN4, but it has a 4 in it. Something like BNSE4-SNCP. I assume the 4 is their 105k BTU/h model.

Steamhead

Look closely at those radiators

they look a bit bigger than the usual 2-column units. The depth (front to back) of a section on a standard 2-column rad is around 7-1/2". If yours are deeper they will have a higher EDR rating.



For an example of what I mean, go here and scroll down to the Star radiator pages:



[url=http://www.heatinghelp.com/files/articles/1065/210.pdf]http://www.heatinghelp.com/files/articles/1065/210.pdf



The Star is a 2-column radiator with a rating of 7 square feet per section.

lutorm

I did:

Thanks for that info. In fact, they are pretty much 7" even in depth and the sections (not counting mating surfaces) are just under 2" wide. So it sounds like they're actually a bit smaller than standard then.

steam-rookie

Following your thread

I am about to order the gorton #2`s for my system. I have been following your thread about them. Have you had any new developments in regard to the leak?