pipe sizing for seismic gas valve

thelonghikeDecember 12, 2010

I'm stumped on the sizing I need for a seismic gas shutoff valve for my home. The pipe from the utility is 3/4 inch before and after the gas meter. It then immediately branches off to two 1" pipes that serve a hot water heater, gas dryer, furnace and pool heater. I'm thinking if the pipe coming out of the meter is 3/4" a similarly sized valve should be fine. But a supplier wants to sell me a 1.5" valve, which would be a LOT of trouble to install. Can a gas plumber give me some advice? Thanks.

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The longer the section of reduced diameter the greater effect on flow.

A 1 inch valve should be more than adequate if it is 'full bore."

For valves that are NOT full bore, going up one size is not uncommon.

    Bookmark   December 12, 2010 at 7:12PM
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