Systems & CodeCâu 35 / 110
A building drain serving fixtures below the elevation of the public sewer manhole must be protected against sewer backflow. Which device is required on that low-level drainage?
a.An air gap
b.A vacuum breaker
c.A backwater valve
d.An air admittance valve
Giải thích
Fixtures below the next upstream manhole rim are subject to backflow from a surcharged sewer and must discharge through a backwater valve, which closes when flow reverses. Fixtures above that level must not drain through the backwater valve so they are not blocked when it closes. Vacuum breakers and air gaps protect potable water, not drainage.
Trích dẫn luật: UPC §710.0Luyện miễn phí toàn bộ 110 câu hỏi — không cần đăng ký.
Câu hỏi liên quan cùng chủ đề
- A wet-vented bathroom group discharges 5 DFU to a wet vent section. Wet vent capacity limits are 1-1/2 in = 1 DFU, 2 in = 4 DFU, and 3 in = 6 DFU. What is the minimum wet vent size?
- A circuit vent serves a battery of floor-mounted fixtures on a horizontal branch. What is the maximum number of fixtures a single circuit vent may serve, and where is the vent taken off?
- A commercial kitchen installs a grease interceptor rated for a flow of 35 gpm. Using the common rule that grease capacity in pounds is about twice the gpm rating, what nominal grease retention does this unit provide, and what is its purpose?
- A basement floor drain sits 3 ft below the elevation of the upstream sewer manhole cover. During a main surcharge, how much backpressure head could push up through that drain if unprotected, using 0.433 psi per foot?
- A hot-water recirculation loop loses 4,000 BTU/hr to the piping. The pump must circulate enough water so it cools only 20 F while replacing that loss. Using Q (gpm) = BTU/hr / (500 x delta-T), what recirculation flow is required?
- A temperature-and-pressure (T and P) relief valve on a water heater is rated to open at 210 F and 150 psi. What is the required disposition of its discharge pipe?
Cập nhật gần nhất: · quy trình kiểm tra
Đội Ngũ Biên Tập PrepPass · Đối chiếu với Master Plumber Licensing Exam (UPC/IPC-based) · Quy trình kiểm tra