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Individual fixtures Minimum fixture outlet pipe size Number of units
Bar Sink 1/2 inch 1.0
Bathtub 1/2 inch 4.0
Bath/shower combo 1/2 inch 4.0
Bathtub or bath/shower combination with a 3/4-inch bathtub fill valve 3/4 inch 10.0
Clothes washer 1/2 inch 4.0
Dishwasher, domestic 1/2 inch 1.5
Hose bib 1/2 inch 2.5
Hose bib, each additional 1/2 inch 1.0
Kitchen sink, domestic 1/2 inch 1.5
Laundry sink 1/2 inch 1.5
Lavatory (wash basin) 1/2 inch 1.0
Shower (per head) 1/2 inch 2.0
Water closet, 1.6 GPF gravity tank 1/2 inch 2.5

NOTES:

  1. The listed fixture unit values represent their total load on the cold water service. The separate cold water and hot water fixture unit value for fixtures having both cold and hot water connections may each be taken as three-quarters (3/4) of the listed total value of the fixture.
  2. The listed minimum supply branch pipe sizes for individual fixtures are the nominal (I.D.) pipe size.

Fixture unit table determining water pipe and master size

Meter and street
services, inches
Building supply and
branches, inches
Maximum allowable length in feet
40 60 80 100 150 200 250 300 400 500 600 700 800 900 1000

Pressure Range -- 30 to 45 psi**

3/4 3/4 16 16 14 12 9 6 5 5 4 4 3 2 2 2 1
3/4 1 29 25 23 21 17 15 13 12 10 8 6 6 6 6 6
1 1 36 31 27 25 20 17 15 13 12 10 8 6 6 6 6
3/4 1-1/4 36 33 31 28 24 23 21 19 17 16 13 12 12 11 11
1 1-1/4 54 47 42 38 32 28 25 23 19 17 14 12 12 11 11
1 1-1/2 85 84 79 65 56 48 43 38 32 28 26 22 21 20 20
1 2 85 85 85 85 85 85 82 80 66 61 57 52 49 46 43

Pressure Range -- 46 to 60 psi **

3/4 1/2*** 7 7 6 5 4 3 2 2 1 1 1 0 0 0 0
3/4 3/4 20 20 19 17 14 11 9 8 6 5 4 4 3 3 3
3/4 1 39 39 36 33 28 23 21 19 17 14 12 10 9 8 8
1 1 39 39 39 36 30 25 23 20 18 15 12 10 9 8 8
3/4 1-1/4 39 39 39 39 39 39 34 32 27 25 22 19 19 17 16
1 1-1/4 78 78 76 67 52 44 39 36 30 27 24 20 19 17 16
1 1-1/2 85 85 85 85 85 85 80 67 55 49 41 37 34 32 30
1 2 85 85 85 85 85 85 85 85 85 85 85 85 85 83 80


Pressure Range -- over 60 psi **

3/4 1/2*** 7 7 7 6 5 4 3 3 2 1 1 1 1 1 0
3/4 3/4 20 20 20 20 17 13 11 10 8 7 6 6 5 4 4
3/4 1 39 39 39 39 35 30 27 24 21 17 14 13 12 12 11
1 1 39 39 39 39 38 32 29 26 22 18 14 13 12 12 11
3/4 1-1/4 39 39 39 39 39 39 39 39 34 28 26 25 23 22 21
1 1-1/4 78 78 78 78 74 62 53 47 39 31 26 25 23 22 21
1 1-1/2 85 85 85 85 85 85 85 85 81 64 51 48 46 43 40
1 2 85 85 85 85 85 85 85 85 85 85 85 85 85 85 85

** Available static pressure after head loss.
*** Building supply, 3/4 inch nominal size