Just wondering if anyone knew what effect a larger than normal water content
in natural gas would have on energy output of a furnace?
I have a gas pipe that goes through an unheated area, and I'm having
condensation plugging the pipe on the coldest mornings.
This line has been in place for 20 years and I've never seen the problem
until the last two weeks.
The local gas company doesn't have any answers on why so much water vapor of
Could it be they are stretching the cubic feet with water vapor?
Pretty much reduce it in direct proportion to the molecular
I'd venture that over the twenty years condensation and what entrained
moisture there is has built up in a low point and is now of sufficient
volume to have become a problem. I would expect if you shut the gas
off and either drained the line or blew it out w/ compressed air your
problem will go away for at least another twenty years. (Assuming, of
course, the gas company has been out and checked for and didn't find
HIGHLY unlikely -- to the point of a blanket "no". There's an outside
chance there could have been some moisture introduced during some
maintenance activity, I suppose, but injecting water, no. Oh, one
other pretty remote possibility could be a water trap somewhere has
failed in the distribution system, but in general those are at
collection points and compressor stations, etc., not even close to
residential customers (unless, of course, you just happen to be near
such a facility).
My gas lines in my house had a "T" with a leg about 8" long, capped
off. The leg was vertical and was designed to serve as a moisture trap
Do you have these? If so, shut off your system and see if the gas
company will drain them for you??
Actually, I realize I didn't put down the most likely culprit being a
water trap in your line that has filled up...look for a stub w/ a
shutoff valve and cap or a lower loop plumbed into the supply line also
w/ cutoff valve(s) and unions or other removable connections to drain
If the gas piping happened to be hung such that the water drained back to
the meter, wouldn't the meter fail?
The inlet and outlet are both at the top of the meter housing.
In the last two weeks about a quart of water that I've drained would have
ended up in the meter.
At a low point, I have a tee and a downward pointing stub that catches
water, but the problem is
that it's filling up in maybe 5 days during cold weather.
Very interesting. Last Winter I call the gas company because my
burners were giving a very orange flame. They sent a guy out within a
half hour and said that's a CO problem! When the guy arrived, the
flame had gone back to normal blue.
But they were talking of gas shortages back then and I wondered what do
they add to the natural gas supply to "thin it out". Propane was the
answer and that is more expensive and burns hotter than natural gas, so
it didn't make sense. Water vapor makes more sense.
Joseph Meehan wrote:
Water vapor would make no sense. Condensed it takes up very little
space and it would likely condense along the way and air mixed with natural
gas would only cause problems. On the other hand air could be used (cheap
and it would not likely condense, but it would cause a hazard if the ratio
got too high. There is nothing I can think of that would work and would
not cost more than natural gas. Also the regulators would take a very dim
view of any such stuff.
Correct deduction on water vapor. But, depending on the service area,
it is possible the utilities are making up supplies from imported LNG
by "re-liquifying" it. In order to do that an meet Btu requirements,
etc., it is sometimes desirable to use some inerts. There are three
basic possibilities used--nitrogen, air, or flue gas. Of these, air
and to a certain extent, flue gas do have entrained moisture to greater
or lesser degrees. Also, particularly in western areas, the newer gas
fields making up for the depleting earlier fields are high in methane
and inerts/contaminants as compared to historical supplies since, say,
the 30s & 40s when the shift from "manufactured gas" to natural gas
became prevalent until quite recently.
So, there is a possibility of OPs supplies having some mixing issues,
but the supposition that there is water vapor induced on purpose is a
fallacy. It certainly does seem as though recently there must be a
difference in his supply if it is requiring draining a trap so
frequently is required regularly. If his supply is so high in
moisture, however, it would seem that all homes in his area would be
suffering as well, so unless he's "just lucky" in having a location
that collects the moisture in an unheated area that freezes, there
should be enough complaints to cause some action by the utility. If
that isn't occurring, makes it seem as though there still might be some
localized problem but I can't come up w/ a really plausible scenario
I've been wondering that myself ... there seems to be a lot more water
in the gas these days ... like maybe more water than gas :-) I've got
those pumps on my furnaces ... the water condenses out into a reservoir
and gets pumped (condensate pump) form there into the abs drain. On the
old furnace, which was also high efficiencey, it was sufficient to just
drain the water off under the basement slab.
Where are you, in relationship to the age of the gas main system. If you are
in an old city still using cast iron pipes sealed with oakum and lead, the
same way that cast iron sewer and drain pipes are sealed, you probably are
on wet gas. New systems use dry gas because they do not need to keep the
seals moistened. The old systems were built for manufactured gas which had a
lot of moisture in it. The new dry gas has to have steam injected to prevent
the oakum seals from drying out and leaking. Sometimes they will use oil
vapour. In old cities you will find iron fittings in the sidewalks and/or
roads with the word "drip" cast in the small lid. These are not a comment on
peoples attitudes but a place where excess moisture or oil will drip down
to, allowing it to be pumped out.
My best friend runs his vehicles on compressed natural gas, his
compressor is in his basement, he pumps to 1500 pounds.
He had to add a heater to prevent condensation freezing and complains
the company equitable has become sloppy about water getting in gas.
his cars have been on natural gas since the mid 70s but his troubles
only began a few years ago.
have you called the gas company and complained?
They sent a tech out. He made sure the meter wasn't damaged, and pretty
much just told me
all I can do is redo the piping to allow insulation, etc to lessen the
condensation. When I said that he forgot to ask how
old this installation was (20 years), he started getting more and more
vague. I started to
get the feeling that he had heard all this many times recently.
Several more attempts at asking about why this happens after 20 years got
On the way out, I mentioned that this was good info for me on deciding what
kind of heat to use
in some other properties I'm developing. The guy just smiled.
not that this will eliminate the problem, but let's spotlight it. ask
the gas company replace the gas meter and look inside the pipes with
the meter removed, with a licensed experienced hvac man or plumber.
and check with your neighbors for similar problems. they may be very
happy to hear from you if they have heating problems.
bill allemann wrote:
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