Natural gas pressure drop, pipe sizing and pressure

I think you are interpreting it correctly. But, 0.5 psig seems high for regular natural gas. Or, is it propane? Either way, 1 psi is 27.7 in-wc. So that would make the inlet pressure almost 14 in-wc. But as most gas appliances have regulators, I guess that might be ok.

You are correct. You need the pressure at the appliance when it is running. With the appliance NOT running you would have the correct pressure on even a 1/4" line.

I agree. It makes sense based on simple physics.

The question is, what exactly pressure should I see on the onlet when the heater is running.

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"...an inlet gas pressure of 0.5 psig or less ..."

It's not any _specific_ pressure; it's that it's not too high and that whatever it is can be maintained under flow conditions.

On Sat, 16 May 2015 11:40:50 -0400, snipped-for-privacy@snyder.on.ca wrote in

Isn't there a pressure regulator near the meter at entry point.

OK, an update: I have decided that

Before you plumb it all in, have you figured out how much it's going to cost to heat the pool? Around here, NJ, almost no one uses them because of the huge operating cost. They have them sitting there, because they were installed with the pool, but they rarely if ever use them. I guess if it's small, it might not be too bad. But for an inground one that's 30 or 40K gallons, which isn't unusual, it costs a lot of money. The fact that it's 200K BTUs tells you something. The largest home gas furnace is 120K btus.

If you have some room for a solar array, you can operate it for close to free. But they have drawbacks too, the large size needed being one. Whether you want one on the roof or have a space out of sight in the yard is another.

You can use a pool cover with either, which helps a lot. But that's a pain and some folks won't put up with it, don't like the look, etc.