Gas & FuelCâu 67 / 110
A propane branch must deliver a 75,000 BTU/hr appliance at a longest length of 40 ft. Propane is 2,500 BTU/ft^3. The 40 ft table lists 1/2 in = 45 cfh and 3/4 in = 95 cfh. What is the required cfh and minimum pipe size?
a.18 cfh, 1/2 in
b.24 cfh, 1/2 in
c.30 cfh, 1/2 in
d.30 cfh, 3/4 in
Giải thích
cfh = 75,000 / 2,500 = 30 cfh, which is within the 45 cfh capacity of 1/2 in pipe at 40 ft, so 1/2 in is adequate. Because propane carries 2.5 times the energy per cubic foot of natural gas, the required cfh and pipe size are smaller for the same BTU load. Always convert BTU to cfh using the correct heating value for the fuel.
Trích dẫn luật: IFGC §402.4Luyện miễn phí toàn bộ 110 câu hỏi — không cần đăng ký.
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