47WDXPW
Well-known member
How much WC would 4 oz or 1/4 pound of natural gas be ?
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Measuring NG water column
- Thread starter 47WDXPW
- Start date
7 google is your friend
ctfjr
Well-known member
Here is 'a' link to conversion calculator:
http://www.convertunits.com/from/water+column+[inch]/to/oz/in%5E2
its approx 1.7 in wc per oz
http://www.convertunits.com/from/water+column+[inch]/to/oz/in%5E2
its approx 1.7 in wc per oz
BD1
Well-known member
One pound is 28'' .
Thanks for the responses, my Sterling model GG 45,000 Btu heater's installation manual under gas piping requirements for natural gas calls for supply inlet pressure 5.0 inch WC min, and 14.0 WC max, with my supply of .25psi (17.5767 WC) is this close enough not to need a pressure reducer ?
98ssuck
Well-known member
Are you measureing .25 psi or is that the nominal pressure supplied to you?
From my yellow jacket test gauge.....6 osi = 10.4 " wc. You have ~ 7.0"wc.
The real question is, was your reading at the heater while it was fired up or when it was off or fan only?
You want a measurement when the unit is fired up.
You do not need a pressure reducer as your supply pressure is at the low end of the heater spec.
Does the piping to the heater supply other loads? If yes, you may want the other load consuming while you take readings at the heater.
The real question is, was your reading at the heater while it was fired up or when it was off or fan only?
You want a measurement when the unit is fired up.
You do not need a pressure reducer as your supply pressure is at the low end of the heater spec.
Does the piping to the heater supply other loads? If yes, you may want the other load consuming while you take readings at the heater.
BD1, the conversion chart link listed above calls for 70.306 WC for 1psi.
BD1 is correct.....1psi = 27.7" h2o = 16 osi = 70.3 centimeters h2o.
HoosierBuddy
Well-known member
The most common supply pressure for natural gas is when the Gas Company provides the customer with 7-inches w/c, and virtually all NG appliances are built with that in mind.
The reason (if anyone cares) is that residential gas meters are factory calibrated to be accurate at 7-inches w/c (at sea level). Since all gasses are compressible, if they gave you more or less pressure than that, the meter wouldn't be accurate without taking additional steps to correct it....which there are many ways to do...but they all add to cost.
If you live in a high altitude area, your gas company probably provides you with a higher pressure to compensate the metering for the altitude...but that discussion is going to involve math...and it's too early for that.
Phil
The reason (if anyone cares) is that residential gas meters are factory calibrated to be accurate at 7-inches w/c (at sea level). Since all gasses are compressible, if they gave you more or less pressure than that, the meter wouldn't be accurate without taking additional steps to correct it....which there are many ways to do...but they all add to cost.
If you live in a high altitude area, your gas company probably provides you with a higher pressure to compensate the metering for the altitude...but that discussion is going to involve math...and it's too early for that.
Phil
From my yellow jacket test gauge.....6 osi = 10.4 " wc. You have ~ 7.0"wc.
The real question is, was your reading at the heater while it was fired up or when it was off or fan only?
You want a measurement when the unit is fired up.
You do not need a pressure reducer as your supply pressure is at the low end of the heater spec.
Does the piping to the heater supply other loads? If yes, you may want the other load consuming while you take readings at the heater.
My measurement was made at a valve that was left for future use and with out the other appliances in use (house heater-gas stove) I will do it again with them on thanks. What is 6 osi,I have been a pipe fitter for many years and don't remember seeing that measurement.
ctfjr
Well-known member
Guys I have an older glass manometer in a U bend configuration does it matter what diameter the tube is for use with a WC for a natural gas heater ?
no, it doesn't