Gas Regulator on Steam System

felzani

Hi Everyone,



I'm just looking for a little help in determining if I should throttle back the flow of gas to my boiler.



First off, I've posted before. The details of my system can be found throughout this thread:

<a href="http://www.heatinghelp.com/forum-thread/132834/Steam-Main-Venting-Residential">http://www.heatinghelp.com/forum-thread/132834/Steam-Main-Venting-Residential</a>



After that, last night I tried to determine how much gas I was using during a cycle. I captured a bunch of info and a timeline and I'm hoping folks can help me from there.



<span style="text-decoration:underline;">Control Data</span>

<ol><li> Outside Temp: <strong>36F</strong>

</li><li> TStat Setting: <strong>63F</strong>

</li><li> TStat Temp when system kicked on: <strong>62F</strong>

</li><li> TStat Temp when system turned off: <strong>64F</strong>

</li><li> Gas meter reading at the start: (see 1st image ... not sure how to read the dials)</li></ol>



<span style="text-decoration:underline;">Timeline</span>

<ol><li> <strong>10:12pm</strong> - Boiler kicks on. Water Flute: 1/2 full; Boiler Pressure Gauge: 0 PSI (2d image)

</li><li> <strong>10:22pm</strong> - Steam at mains (as determined by hearing hissing and warm piping in the Hartford Loop). Gas meter reading (not sure). Water Flute: 1/6 full; Boiler Pressure Gauge: 8-9 PSI (3d image).

</li><li> <strong>10:37pm</strong> - Gas meter reading (4th image). Water Flute: For the first time it's visibly empty; Boiler Pressure Gauge: 11-12 PSI (5th image).

</li><li> <strong>11:12pm</strong> - Boiler off. Gas meter reading (6th image). Water Flute: Empty, but filling (water visible for first time since prior to 10.37pm); Boiler Pressure Gauge: no change.

</li><li> <strong>11:29pm</strong> - Boiler still off. Water Flute: 1/2; Boiler Pressure Gauge: 10 PSI (7th image).

</li><li> <strong>11:49pm</strong> - Boiler still off. Water Flute: no change; Boiler Pressure Gauge: 7-8 PSI (8th image).</li></ol>



<span style="text-decoration:underline;">Closing Notes</span>

<ol><li> We have other appliances that use gas in our house, but (1) no one was cooking (range and stove are both electric lit), (2) the hot water heater was off and (3) I cut the gas to the fireplace. Furthermore, the room that the fireplace heats was 68 degrees when I started my test.

</li><li> I already agree that the low water cutoff is an issue, but I think it's something I can address independent of the gas valve and the pressure gauge. While I'm happy to take comments on it, I'd really like to focus on the former two issues in this thread.

</li><li> In fairness, I'm not sure if the 4th image was from 10:22pm or 10:37pm, but I don't think it matters very much.

</li><li> The pressure gauge on the boiler is probably broken. I find it hard to believe that the unit wasn't break-dancing if it was truly at 12 PSI.</li></ol>



Thanks in advance!

Matt

furnacefigher15

Call a pro before making any change

It is not advisable to willy nilly change gas pressure settings.



1- if the boiler is sized right, it needs every rated btu it can get to produce enough steam to feed all of your radiators.



2- Lowering the boiler pressure setting will likely save much more.



3- Changing fuel pressure changes flue gas characteristics. In order to know it is safe a combustion analysis would be required.

icesailor

Gas regulators:

Don't take this the wrong way, but you have far too much time on your hands.

Don't futz with gas pressure. The expression "The laws of unintended consequences"  comes to mind. The correlation to that "No good deed goes unpunished". I know what I am doing and "I" wouldn't do what you are asking. I'm not a "Steamer" but what I am learning here, there are a lot more things to do to a steam system to improve it and lowering the gas pressure to slow it down isn't way up the list. Getting your system to run at 1/2# would be a bigger plus. A perfectly vented system is another. I would personally try to get your system as good as it can get before futzing with the gas pressure.

And I definitely wouldn't touch anything unless I had (which "I" do) a digital combustion analyzer. And have experience using it.

I hope that no one else is in this building while you are playing fast and loose with the safety of the occupants and the building.

Call a Pro. They are out there. I help anyone. But, some, I have to wish them Health, Happiness and Long Distance.

BobC

Don't wait to fix ths

If your pressure gauge is reading correctly (pressure gauges have been known to lie) your steam pressure is MUCH TO HIGH.You don't need anything over 2PSI for that system to work. High pressure burns fuel and does you no good. I suspect the gauge is defective because a boiler is not going to maintain pressure for that amount of time with the flame off.



What is the pressuretrol set to? Get the readings from the front and the little white dial inside the box.



The waterlevel in the gauge glass should not move more than about 1/4" up and down. Yours appears to be pulling down all the way which means you may have a partially blocked return line. Does the boiler shut down when that gauge glass empties? From your description it seems the system may be shutting down because the thermostat is satisfied. If the low water does not shut down your boiler the low water cutoff may not be working and you risk destroying the boiler buy running it with little or no water. Low water cut offs are not cheap but a new boiler will COST A LOT MORE.



If your timing is correct it looks like your boiler ran for an hour to satisfy the thermostat and that is a long time. This may indicate bad venting on the steam mains. Steam cannot enter the pipes till the air is expelled and you are paying the gas company to expel all that air. What kind of main air vent is on your steam mains and how long does it take for it to get hot. My main air vent gets hot about 12 minutes after the boiler starts up, yours may be different if it is longer or not insulated.



Also what kind of air vents are on your radiators and do they seem to heat up about the same time?



Bob

Mark N

High Pressure

Matt



Has the pig tail ever been cleaned? Looking at the pictures are the lights on the LWCO lit? Has the probe of the LWCO ever been cleaned? The cut-in on the pressuretrol should be set .5 psi and the diff wheel set to 1. If the water is dropping completely out of the sight glass the LWCO should kick the boiler off. When the level is good the light in the LWCO should be green. when the level is low the red light should come on and the boiler turn off. I would think that the pressure gauge is inaccurate. At 12 psi I would think that every vent would be screaming. I would think that much pressure would destroy the vents. Running 1 hour to satisfy the tstat is way to long. My system just ran a little over 16 minutes to keep my house at 70, it is in the low 30's out this morning.

icesailor

Vents:

Consider this: (my third world understanding of steam system)

If you put a pot of water on the stove, it will boil. There will be no pressure. If you put a lid on it and leave the burner on high, the excess steam will push under the lid. One pot of water will make 1200 pots of steam. If you turn down the burner so that the water boils but cools so that it condenses back to water and it falls back in the pot, you have perfect equilibrium. That's is what you need in a steam system.

If you have a steam heat system at rest, and the boiler holds X amount of condensed water, the system will hold Y amount of air. All you need is for the X water in the boiler to convert into Y steam vapor to rise into the system and replace the Y amount of air. The air vents do this. The faster you get the air out of the system, the faster the steam will fill the system. A perfect system will have no restriction and it is only the weight of the condensed water and gravity that sends the water back to the boiler. To be re-heated. The steam is at 212 degrees if there is no system pressure. The higher the pressure, the hotter the steam. But the radiators will only be as hot as the steam. If you make the system pressure higher, the steam and the radiators will be hotter. If you pull a vacuum in the system, the steam will be lower than 212 degrees. The steam and the radiators will be cooler. That is the same as going up in altitude. I think that water boils on Mt Everest at 135 degrees.

If you need to run more than 2# to get the steam around in your system, you have a problem that needs to be addressed before anything else.

This isn't a hydronic hot water system where you can down fire to the point that the water in the system is emitting low temperatures. Steam only Emmit's when it is steam from the water in the boiler and is out in the system. Giving up its heat and converting back to water. Where it goes back to the boiler for a re-heat job.

You need to forget everything about hot water systems, gravity or forced. Steam is steam and is different.

What has been said by others is telling you what I am saying. Fix your other problems like the surging. Fix the other problems. Insulate your pipes. Fix the vents. Make the return flow with no restrictions. Then, futz with the flame. But you will find that that isn't going to be needed.

felzani

re: Gas Regulator on Steam System

First off, I have to say I really appreciate all the suggestions from folks. I'll do my best to respond individually, but will try to hit the big stuff first:



Not sure if people had a chance to check the thread I reference above. If so, you'd see that I've provided all my rads' respective EDRs as well as the main vents are brand new (1 Hoffman 75 + 1 Gorton #2), having been installed only last year. the image in the first post (on that other thread) should have the boiler specifics also. the thread also mentions the other optimizations that have been made to the system i think i'm beyond the simple stuff. here's the link for convenience:

http://www.heatinghelp.com/forum-thread/132834/Steam-Main-Venting-Residential



after that, i don't know where people are getting that i want the system operating at 12 PSI. that's insane and after re-reading my post it baffles me as to how anyone could think that. i even note that the gauge is probably broken.



i hadn't mentioned this in either post - and i'm not even sure it matters - but the system is direct vented so there is no flue.



@furnacefigher15 - you should be able to answer your own questions from the info in the other thread. again, try to get past that gauge ... the system is not really at 12 PSI.



@icesailor - the principle i was after - and it's even mentioned in dan's book - is that you don't want to make steam too fast because the quicker you make it, the quicker your vents close. making steam too fast has consequences as well. also, what does this mean: "I hope that no one else is in this building while you are playing fast and loose with the safety of the occupants and the building." Can you explain what part of taking pictures and noting the time is "fast and loose?" i have to say that I think that was a bit uncalled for.



@BobC - i'm with you. there are notes in that other thread, but the trol has a cut-in of .5 and the wheel's at 1.5. the possibility does exist that the trol is broken, but it is wired correctly and the pigtail is clear. furthermore, blowing into the tail i can hear the trol click. also, like you said, there's just no way the system would maintain that pressure that long after it turned off, and like i and @Mark N said a system at that pressure would be showing other signs (like violently shaking and - at the very least - making a lot of noise) while running. the night that i took the data it was the tstat which shut off the boiler, yes. the LWCO is suspect, i agree, but i have seen it shut off the system, just not last night. the light was green. i have seen the second light blink red during the time when it shut down the system. as i mentioned, i will definitely be looking into that. the main vents themselves weren't hot at the 10 minute mark, but as i mentioned i did hear air exiting. also, at that 10 minute mark the hartford loop was hot -- i have to believe that was a result of the water returning to the boiler. in that other thread i mentioned that all radiators get hot at the same time, but never are all the coils hot (again, another reason why i was thinking the steam is getting made too quickly). hopefully this is helpful info.



@icesailor - i get your analogy, but i think you need to check your numbers. unless your pot of water is full, you're not going to get 1200 pots of steam. also, i believe the ratio you're going for is more in the neighborhood of 1650:1, not 1200:1. also, water boils on mt everest at 156F, unless we're talking about different mt everests.



can anyone help me read the dials on the gas meter?



lastly, it's only because i'm trying to be thorough that i've posted here in the first place. to get that second opinion, and more importantly to make sure it's done right.



great discussion so far, please let's keep it going. thanks!

BobC

Digits measuring CCF of gas

The four digits indicate 100CCF units of gas, the two dials are to measure smaller units. I can't read the markings on your dials but on my gas meter they are 1/2CCF and 2CCF. You can ignore these dials for the boiler gas consumption



Your first picture of the gas meter reads 0027 and the sixth reads 0028 so that means you have used one unit of gas (100 CCF), in Boston that translates to about $1.65 for that heating cycle. That would be equivalent to about 0.7 gallons of heating oil.



hope that helps,



Bob

Mark N

Gas Meter

Matt



Clock the gas meter to determine if your firing at the correct rate. You can google how to do it. Make sure only the boiler is firing when you do it. If your boiler is firing at 140000Btu's per hour you right on the money. You need to determine where the water is going if you have wet returns they might be clogged and the water is taking too long to return.

icesailor

Re:

bill_105

The gas part

Is there a APB out for Tim Mc. yet?

felzani

Meter

Thanks @BobC, that's helpful. I thought the dials were for the 10s and 1s, but not the case. I'll just ignore them. You're right on the charge of $1.65 ... my Nov bill was 128 CCF for $176. That being said, though, my Jan '11 bill was 354 CCF for ~$600. I've gotta believe there's a way to get that CCF consumption down (and subsequently the $$$) if I can get the boiler to run less. Not that Mark N and I are neighbors, but looks like my system ran ~4x longer at 7F lower.



Thanks, also, @Mark N, I'll do some research and let you know what I find. I think the boiler's manual also has steps how to do it, although - at first blush - it seems like it's going to be really difficult since there's not a great way to capture a detailed measure. The obvious for example is that for the test I ran my value is "1". Having said that, though, I'm sure I'm missing something obvious! Oh, wait, I see ... I don't need to monitor it for the cycle, but just a smaller control time.



I looked at the dials. They both spin counter-clockwise and for each 360d rotation of the left dial, the right dial appears to move through ~108d. Does that help? I guess I will need to figure that out in order to clock it (based on one website I found anyway).



As always, thanks for the help and I'll write again soon ... hopefully later tonight.

Mark N

Main Piping

Matt



I took a good look at the diagram of your system piping that you provided in your previous post. Your main piping is somewhat unconventional. I can see that the location of your boiler was moved when the new boiler was installed. The purple main is conterflow coming out of the boiler. This is not piped correctly. All the steam that leaves your boiler flows through this main. Do you have the "Lost Art of Steam Heating"? Page 83 shows how counterflow should be piped. Was the counterflow section added when the boiler was moved? That would also explain why the purple main loops over itself. Do the purple and orange main tie together at their ends and share a common dry return? The returns should be separate. I would think that the firing rate of your boiler is fine. Your real problems are the water hanging up in your system and extremely slow steam distribution. If you really want to decrease your heating bill you need to speed up the distribution of steam. You should be able to heat your house in 20 to 30 minutes, not an hour. The steam leaving your boiler could be holding up returning condensate in your counterflow main. Where your mains tie together the steam is coming from opposite directions. I would not doubt that this slows the distribution of steam and holds up the condensate trying to return to the boiler.

icesailor

Gas Pressure:

And futzing with the gas regulator won't solve your problem like correct piping will.

Mark N

Savings

Matt



Do your radiators have covers? I used to have them, got rid of them because the type I had caused my boiler to run longer to satisfy the tstat. In my case it was about on average 10 minutes per cycle. Over the course of a heating season that adds up to quite a bit of gas.

felzani

re: Gas Meter

I apologize for the lapse and I've finally gotten back to this after Chrismas and the kids claimed my past couple weeks.



As a note, about a week ago I took a closer look at the meter and the clocking dials are 1/2 CCF and 2 CCF, respectively. The shape of the plastic cover distorted my view and it wasn't until I looked up at the dials that I was able to see those measures on them. Thanks to everyone that helped me understand how they work!



After that, I just clocked the meter (yes, it was the only thing using gas at the time). It took the 1/2 CCF dial 53 seconds to make three rotations. That's approximately 18 seconds per rotation. I plotted that against the chart here:

http://www.hvacprotech.org/toc/clocking_gas_meter.htm



And for the 1/2 CCF that's 102 cubic feet/hr. If my BTU rate is 1000 then that means the boiler's rate is 102,000 BTUs/hr. That being said I'm not sure how to confirm that 1000 BTU rate?



@Mark N, you're right in how you're reading the colored pipe diagram from the other post. The way it's piped now is how the plumbers decided to do it when we had the old system replaced. I don't have the book you mentioned (I only have the "We Got Steam Heat" one), so I don't have that reference you mentioned. A good piece of that purple piece is new as of the replacement ... essentially the leg from where the boiler is to the large dotted circle (in the middle) is new. The purple and orange mains tie together where the blue line starts. They basically meet in the middle of the diagram and return to the boiler from there (via a Hartford Loop). They aren't separate and you can actually "see" how they meet up in this pic:

http://www.heatinghelp.com/images/posts/4644/resize_DSCN3521.JPG



The big circle on the bottom right of the image is the spot where the purple and blue lines meet (please disregard the main vents that you see ... the picture was taken before we had them replaced).



Does that info help at all?

Mark N

Gas Meter

Matt



My boiler happen to be running when I read your post this morning. So I clocked it. My boiler is an IN-4, 105kbtu input, it is one size smaller than yours. I clocked the 1/2 ccf dial 5 times and got 18sec for 1 rotation. That is right on the money for my boiler. Your input is 140kbtu should be timing the 1/2ccf dial at 13 sec per rotation. You seem to be under fired, check the size of of the gas pipe to the boiler.