King County Navigation Bar (text navigation at bottom)
Public Health - Seattle & King County
Site Directory

Public Health Webpage Directory

Public Health Center & Office Locations

For Care Providers

Health Advisories & Resources

For Educators

Health Educators Toolbox

About Us

History & Profile

Jobs

Employee Directory

Contact Us

Public Health
Seattle & King County
401 5th Ave., Suite 1300
Seattle, WA 98104

Phone: 206-296-4600
TTY Relay: 711

Click here to email us

Subscribe to Free Email Alerts!

Click here to learn more

magnifying glass Advanced Search
Search Tips
Home » Homeowner's plumbing permit » WSFU

Public Health Plumbing Program
Water Supply Fixture Units (WSFU) and minimum fixture branch pipe sizes

» Instructions for creating a printer-friendly page.

Individual Fixtures b
Minimum Fixture Outlet Pipe Size a
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
Bidet
1/2 inch
1.0
Clothes washer
1/2 inch
4.0
Dishwasher, domestic
1/2 inch
1.5
Hose Bibb
1/2 inch
2.5
Hose Bibb, 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
Water Closet, 1.6 GPF Flushometer Valve
Consult with inspector
***
a. Size of the cold branch pipe, or both the hot and cold branch pipes.
b. For unlisted fixtures, refer to a listed fixture with a similar flow rate and frequency of use.

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
1/2**
6
5
4
3
2
1
1
1
0
0
0
0
0
0
0
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

Updated: Tuesday, October 10, 2006 at 11:52 AM

All information is general in nature and is not intended to be used as a substitute for appropriate professional advice. For more information please call 206-296-4600 (voice) or TTY Relay: 711. Mailing address: ATTN: Communications Team, Public Health - Seattle & King County, 401 5th Ave., Suite 1300, Seattle, WA 98104 or click here to email us.

King County | Public Health | News | Services | Comments | Search

Links to external sites do not constitute endorsements by King County.
By visiting this and other King County web pages, you expressly agree to be bound by terms
and conditions of the site. The details.