Gas PSI

superdave

Hi All,

   I am in Ma. and this pass week has been cold out. I have been out strait on pipe freeze call and no heat calls. Most of the no heat calls are from low gas PSI. I put a test on the gas and getting readings of 2.8" - 4' at static. Does any one know of a Mod/Con boiler that can run on low PSI???  I can get the systems to start up if there is 4" but when she gos into high fire it drops out and PSI drops down to about 3.5" before she locks out.  Is there a boiler that can go lower and is there a boiler that wont go into lock out and need to be rest after so many tries??

icesailor

Low gas pressure:

According to what we were told at a Veissmann School, the Vitodens 200 and the onboard computer and gas valve will keep it working at those low gas pressures. It just won't modulate and be as efficient. The question came up because there was a student there with his employees from New York City and he said that all the street gas in some area he worked in was low pressure like this. And he asked what happens. That is what he was told.

You are experiencing one of the many disregarded negatives of Natural Gas for heating in many areas. Lack of pressure due to high consumption and no way to overcome the low pressures without blowing up equipment by increasing the pressures.

Negative Gas Pressure gas valves just hate low incoming gas pressures.

Consumers be damned. Stockholder get paid first. If there's anything left over, it can go to infrastructure.

icesailor

For informational purposes,

Just for informational purposes, the same thing can happen with LPG if the load is too high and the surface area of the tank is too small to get proper vaporization. If you see a freeze line on the tank and it is a sheet of ice, or it is an underground tank, check the valve and regulator on the top of the tank. If it is a block of ice, you need to warm it up.

Been there, seen that fixed that.

I know of an application with a HUGE gas boiler, with four 1,000 gal. underground tanks. During a really bad cold spell, the burner would go off at night but would fire right up in the morning. The problem turned out that the liquid in the tanks was so cold that it froze the ground and the tanks couldn't get enough warmth from the ground. The pressure would drop and the burner would go out. By morning, enough gas had vaporized to let it run. The heat of the day helped with vaporization.

They considered switching to liquid but that has problems and they would have had to pre-heat the liquid to get consistent vaporization.

superdave

What is funny.

What is funny is if people loss power they don't call an election complaining. But if they lose heat due to low gas PSI you become the punching bag.

Last time we had a big storm the city lost power and some the boilers are on back up generators they had no problem working until power came back on line. PSI dropped under 2" and it is the guy that installed the heating system fault. Then the Gas Company told them that you can't use Mod/ Con boiler in this area.

I am just tyring to see if others are having the same problem with other boiler at low PSI. It wouldn't be as bad if the boilers didn't lock out but I agree with the safety of thing.

icesailor

Disputable:

I think that some might dispute that comment from the Gas Company.

Like my Comcast Cablevision.

At 3:00 PM, it's fine. At 8:00 PM.I get error messages saying something about "interrupted signal" or something like that, But at 3:00 AM, ALL the channels are fine. I called Comcast and they said the signal was fine when they checked it at 9:00 AM and 4:00 PM.

Why not at 8:00 PM? "It was fine at 9:00 AM and 4:00 PM, why would it be any different at 8:00 PM?



Really?

SWEI

CPCN

The gas utility is allowed a monopoly in exchange for meeting certain service standards.  Your PUC (or whatever they call it there) may be worth contacting.

superdave

thanks

Can you forward my last post back on line I sent it to you only.



Thanks

SWEI

Sent to me?

or to Ice?  I don't see anything in either my inbox or my spam folder.

Tim McElwain

As someone who spent 28 years

working for a New England gas utility "What else is New" the low pressure areas of all major cities with old cast iron mains have this problem.



Just a word of warning to installers, if you are looking at updating an existing system and it is in the inner city you may not want to look at Mod/Cons period. Wonder what we will do when the DOE decides to have all 90 plus equipment. You better install a wood burner or a pellet stove. My pellet stove just keeps humming along and my 1950's warm air furnace with Powerpile has been very efficient because it just keeps running.



Atmospheric gas systems are very forgiving. I have seen systems operating at less than 2" W.C. pressure and still have a small flame on the burner at least giving some heat to the consumer.



Time of day is also an issue early AM and around supper time with increased demand. Houses on dead end streets, cul-de-sacs are also a problem.



Because of the internal set-up of a negative pressure gas valve the inlet pressure to the valve is critical for the valve to give the volume of gas required at high flame demand. If you do not put it in you will not get it out.

superdave

90%

I know what you mean but we are being told that the date for 90% or higher is coming up quick Look at AC SEER how that just keeps going up.



I still can't find one of my last replay does any one know how to find it in this system??

Jamie Hall

And it's getting cold

again here in CT... never mind in, say Minnesota.



But the gas pressure problem isn't going to go away all that quickly -- it's not only older pipes in urban areas, or dead end feeds etc.  There is only a certain amount of gas one can push through the main pipelines without risking overpressure in the pipelines.  Until more pipelines are built, this will be a recurring scenario -- and with the pressure to switch to gas from the government (at least here in Connecticut) I don't see it doing anything but getting worse.

icesailor

Old leaking gas pipes:

And then there's all those old leaking gas pipes in the systems where old steel pipes are like Swiss cheese and disbursing in the ground. Just waiting around for a source of ignition.

Like last year in Springfield, MA where there was a unknown source of gas odor around a strip mall. It went on  for days. Finally, some gas company with a probe, put his probe through a rotten pipe without realizing it because the pipe was so Holy, and it wasn't marked on any maps. The building accumulated gas in the cellar of a building and found a source of ignition.

BOOM!!!

Blame the poor Union employee for the decisions of the suits to not cap off an unused, abandoned gas service, still connected to a main.

If petroleum providers were leaking product at a fraction of the rate that gas utilities are, there would be an investigation. They would make it illegal to sell petroleum products.

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