Design & Sizing第 2 / 110 题
Using the 0.408 velocity relationship v = 0.408 x Q / d^2 (v in ft/s, Q in gpm, d in inches inside diameter), what is the velocity of 18 gpm flowing in a pipe with a 1.00 in inside diameter?
a.3.7 ft/s
b.7.3 ft/s
c.10.2 ft/s
d.14.7 ft/s
解析
v = 0.408 x 18 / (1.00)^2 = 7.34 / 1.00 = 7.3 ft/s. Because d^2 = 1, the velocity equals 0.408 x Q directly. This sits just under the 8 ft/s limit commonly set for cold-water piping to control erosion and water hammer.
法律依据: UPC §610.0免费刷完整 110 道题库 — 无需注册。
同考点相关题目
- A residential branch serves the following fixtures with these water-supply fixture unit (WSFU) values: 8 water closets (tank) at 2.5 each, 8 lavatories at 1 each, and 8 showers at 2 each. What is the total demand load on the branch?
- Cold-water piping is commonly limited to a maximum velocity of about 8 ft/s. Using v = 0.408 x Q / d^2, what is the approximate maximum flow a pipe with a 1.025 in inside diameter (nominal 1 in type L copper) can carry without exceeding 8 ft/s?
- A fixture is located 46 ft above the water meter. Using 0.433 psi per foot of elevation, how much static pressure is lost to elevation between the meter and that fixture?
- A system has 62 psi at the meter. It must overcome 22 psi of elevation, 14 psi of friction loss in the piping, and deliver a fixture that requires 8 psi minimum flow pressure. What residual pressure remains at the fixture?
- A copper water line has 90 ft of straight pipe. Fittings add an equivalent length of 3 ft each for four elbows and 8 ft for one gate valve. What is the developed (equivalent) length used for friction-loss calculations?
- Available pressure for friction is 30 psi and the total developed length of the water line is 150 ft. What is the maximum allowable uniform friction loss per 100 ft of pipe (the value used to enter a sizing chart)?