7.4.9.3.Size of Fixture Outlet Pipes

(1) Except as provided in Sentence (2), the nominal pipe size of fixture outlet pipes shall conform to Table 7.4.9.3. (2) The part of the fixture outlet pipe that is common to 3 compartments of a sink shall be one NPS larger than the largest fixture outlet pipe of the compartments that it serves. (See Note A-7.4.9.3.(2)) (3) Where clothes washers do not drain to a laundry tray, the trap inlet shall be not less than NPS 2 and be fitted with a vertical standpipe that is not less than 600 mm long measured from the trap weir and terminates above the flood level rim of the clothes washer. (See Note A-7.4.9.3.) (4) In an individual dwelling unit, where multiple shower heads are served by one shower receptacle, the fixture outlet pipe shall be not less than NPS 2. Table 7.4.9.3. Minimum Permitted Size of Fixture Outlet Pipe and Hydraulic Loads for Fixtures (1) Forming Part of Sentences 7.4.9.3.(1) and 7.4.10.2.(1) Minimum Nominal Pipe Size of Fixture Hydraulic Load, fixture units Fixture Outlet Pipe, NPS Autopsy table 1½ 2 Bathroom group (a) with flush tank n/a 6 (b) with direct flush valve n/a 8 Bathtub (with or without shower) 1½ 1½ Bath: foot, sitz or slab 1½ 1½ Beer cabinet 1½ 1½ Bidet 1¼ 1 Chinese range 1½ 3 Clothes washer (a) domestic(1) n/a 1½ with NPS 2 trap (b) commercial n/a 2 with NPS 2 trap Cup Sinks 1¼ ½ Dental unit or cuspidor 1¼ 1 Dishwasher 1 (no load when connected to (a) domestic type 1½ garbage grinder or domestic sink) (b) commercial type 2 3 Drinking fountain 1¼ ½ Fish tank or tray 1½ 1½ 2 with NPS 2 trap Floor drain(2) 2 3 with NPS 3 trap Garbage grinder, commercial type 2 3 Icebox 1¼ 1 Laundry tray (a) single or double units or 2 single units with common trap 1½ 1½ (b) compartments 1½ 2 Lavatory (a) barber or beauty parlor 1½ 1½ (b) dental 1¼ 1 1 with NPS 1¼ trap (c) domestic type single, or 2 single with common trap 1¼ 1½ with NPS 1½ trap (d) multiple or industrial type 1½ According to Table 7.4.10.2. Macerating Toilet System ¾ 4 Potato Peeler 2 3 Table 7.4.9.3. (Cont’d) Minimum Permitted Size of Fixture Outlet Pipe and Hydraulic Loads for Fixtures (1) Forming Part of Sentences 7.4.9.3.(1) and 7.4.10.2.(1) Minimum Nominal Pipe Size of Fixture Hydraulic Load, fixture units Fixture Outlet Pipe, NPS Shower drain Total volume of discharge from all shower heads and body sprays: (a) from 1 head 1½ 1½ (b) from 2 or 3 heads 2 3 (c) from 4 to 6 heads 3 6 Sink (a) domestic and other small types with or without garbage 1½ 1½ grinders, single, double or 2 single with a common trap 1½ with NPS 1½ trap (b) other sinks 1½ 2 with NPS 2 trap 3 with NPS 3 trap Urinal (a) pedestal, siphon jet or blowout type 2 4 (b) stall, washout type 2 2 (c) wall (i) washout type 1½ 1½ (ii) other types 2 3 Water closet (a) with flush tank 3 4 (b) with direct flush valve 3 6 Notes to Table 7.4.9.3.: (1) See Note A-Table 7.4.9.3. (2) No hydraulic load for emergency floor drains.