Slightly Off Topic: Frozen Regulator (stumped)

I'm sorry, I know this is off topic. But I figured that this was a good place to get some good advice.

I have a new maxitrol regulator (210D fwiw) going to a Maxon ovenpack burner (has seperate pilot line/regulator).
The regulator is outside. The burner is used intermittently. It was off last night, and the temperature dropped 30F (from mid 50's to low 20's). This morning it seems to have been frozen. When they put a bit of heat on it, they heard a pop and it started working properly.
It's a new regulator. I installed it myself. It was brand new out of the box.
As a temporary fix they've wrapped it in heat tape, but I'm wondering if there's anything that can be done to prevent this from recurring.
My guess is that the moisture in the gas itself adhered to the parts in the regulator preventing them from working properly. (since it wasn't moving because the burner had been shut off).


Has anyone run across this issue? What can be done to prevent it from happening again?




Thanks in advance..




Russ

Russ said:

When they put a bit of heat on it, they heard a pop

Click to expand...

I'm sorry, Russ, but this is what I envisioned behind that innocent phrase, "put a bit of heat"...



thoughts:
1) If memory serves, doesn't dropping gas pressure raise the dewpoint, causing moisture to condense which will then freeze in cold weather? It's Saturday morning and I'm too lazy to find my dewpoint tutorial, but I think that's the direction of dewpoint temp vs pressure.

If so, accumulated moisture can sit inside the plumbing, unnoticed until it's cold enough to freeze, at which time it hangs up either the gas valve, or more likely the regulator itself, which is where the pressure drop and hence the condensing would take place, assuming my dewpoint assertion is correct.

If running, assuming it's natural gas which comes from an underground line somewhere at 55°F, the gas flow is warm enough to keep any water in the line in a liquid state. But when the burner gets turned off, everything cools to ******t northern clime temperatures in the 20's (°F) and there's ice.

2) If it's a modulated system, could the modulating motor linkage have enough ice on it to prevent it from driving to open for purge ? (doubtful, unless you had a real ice storm)

3) Moisture intrusion into the regulator itself. Regulators have an atmospheric port, that little drilled hole to allow atmospheric pressure on one side of the diaphragm. Is the regulator exposed to rainfall where the lots of moisture could have gotten into the regulator

Dan

I would not call heat tracing a temporary fix. It is a solution, very common. You can also use a protective enclosure ( heated if necessary)
see links below

http://www.tycoflowcontrol-eu.com/products_results.asp?Selection=Instrument+Enclosure+Systems&m=1

http://www.tycoflowcontrol-na.com/ld/AGIMC-0341-US.pdf

Russ said:

I'm sorry, I know this is off topic. But I figured that this was a good place to get some good advice.

I have a new maxitrol regulator (210D fwiw) going to a Maxon ovenpack burner (has seperate pilot line/regulator).
The regulator is outside. The burner is used intermittently. It was off last night, and the temperature dropped 30F (from mid 50's to low 20's). This morning it seems to have been frozen. When they put a bit of heat on it, they heard a pop and it started working properly.
It's a new regulator. I installed it myself. It was brand new out of the box.
As a temporary fix they've wrapped it in heat tape, but I'm wondering if there's anything that can be done to prevent this from recurring.
My guess is that the moisture in the gas itself adhered to the parts in the regulator preventing them from working properly. (since it wasn't moving because the burner had been shut off).

Has anyone run across this issue? What can be done to prevent it from happening again?

Thanks in advance.. Russ

Click to expand...

Is this industrial or residential??
Is this the gas meter the shutoff or a pressure regulator?

Gas does have some water content and will for sure if someone left water in the line after installation.

Generally (at least in Seattle) this equipment is the property of the gas company - they have responsiblity for maintenance and repair.
Many gas lines will have a tee and a short 6" nipple pointing downward to catch junk and water in the line. Do you have one? If not then maybe you should.

Think I would have the gas company come out and look this over. They may get a little upset with you if you tinkered around in their domain ie their area of responsiblity / their equipment -- but gas is nothing you want to fool around with unless you really know what you are doing. The utilities are very forgiving as long as you are not cheating the meter - then they get downright nasty.

Dan Bentler

Dan
Thanks you just brought back a the memories of a bad install that we had to correct. It was nursing home and the other contractors just stopped providing support & then closed shop.
Easy fixes. This home had 5 new 15 ton rooftop package units variable speed. Top of the line nice units. In the installers hast to get in and out they did not provide driplegs for the gas valves.Once all the units had driplegs added the gasvalves replaced all but one was problem free.
Here is the fun stuff. The installers added humidifiers to the units. One of them had a screw thru the water so unit would call for heat and humidity the water from the humidifier would plug the equalizing line on the gas valve. This inturn stopped the the show on this unit. The only time this unit ran was after 4 pm it was in the common rooms so it only happened after working hours or on the weekends when we where not onsite.

Not much more than what you have already done, Russ. We had these at a Zinc Refinery I worked at in Oklahoma. It was so much fun going out in the middle of the night at 15 degrees with a 20 mile an hour wind "sweepin' down the plain."

We put heat tape and insulated the worst offenders.