Gas PipingQuestion 261 of 360
A sizing table (natural gas) shows 1/2-inch pipe carries 92 cfh and 3/4-inch pipe carries 190 cfh at the governing length. A section supplies a 40,000 BTU/hr wall furnace plus a 45,000 BTU/hr water heater. What is the smallest size that works?
a.The load exceeds both sizes
b.1-inch is required
c.Cannot be determined
d.1/2-inch pipe, because the combined load is 85 cfh
Explanation
Add the inputs: 40,000 plus 45,000 equals 85,000 BTU/hr, which is 85 cfh of natural gas. The 1/2-inch pipe carries 92 cfh, which is more than 85, so it is adequate at that length. The smallest listed size that meets the 85 cfh demand is 1/2-inch.
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