Water Supply Tank Drains and Overflows
| |||
---|---|---|---|
Tank Capacity
(gallons)
|
Drainpipe
(inches)
|
Overflows
| |
Up to 750
|
1 1/4
| ||
751 to 1,500
|
1 1/2
|
1 size larger than supply pipe
| |
1,501 to 3,000
|
2
| ||
3,001 to 5,000
|
2 1/2
| ||
5,001 to 7,500
|
3
|
1 size larger than supply pipe; minimum size, 4 inches
| |
Over 7,500
|
4
|
Fixture Supply Pipe Sizes
| ||
---|---|---|
Fixture Pipe
|
Fixture Supply
(inches)
| |
Bathtubs
|
1/2
| |
Combination sink and tray
|
1/2
| |
Dishwashing machine, domestic
|
1/2
| |
Drinking fountain
|
3/8
| |
Flushing rim sink
|
3/4
| |
Hose bibb
|
1/2
| |
Hot-water tanks, domestic
|
1/2
| |
Kitchen sink, hotel or public
|
3/4
| |
Laundry trays
|
1/2
| |
Lavatories
|
3/8
| |
Service sink
|
1/2
| |
Shower, multistall
|
3/4
| |
Shower stalls
|
1/2
| |
Urinal, pedestal, direct flush valve (flushometer)
|
1
| |
Urinal, stall, blowout or washout; direct flush valve (flushometer)
|
3/4
| |
Urinal tank
|
3/8
| |
Wash fountains, duo
|
1/2
| |
Wash fountains, all others
|
3/4
| |
Washing machine, domestic
|
1/2
| |
Water closet direct flush valve (flushometer)
|
1
| |
Water closet tank
|
3/8
|
Maximum Number of Flush Valves
(First floor above the ground)1
| |||||||
---|---|---|---|---|---|---|---|
Pneumatic Tank or Underground Main Pressure
(pounds per square inch)
|
Ferrule Size
(inches)
| ||||||
1
|
1 1/2
|
2
|
3
|
4
|
6
|
8
| |
Using iron pipe
| |||||||
30
|
—
|
1 (200 feet)
|
2
|
12
|
50
|
180
|
450
|
40
|
1 (25 feet)
|
1 (400 feet)
|
4
|
24
|
80
|
220
|
450
|
50
|
1 (50 feet)
|
1
|
7
|
40
|
110
|
220
|
450
|
60
|
1 (75 feet)
|
2
|
7
|
40
|
110
|
220
|
450
|
70
|
1 (100 feet)
|
3
|
7
|
40
|
110
|
220
|
450
|
Using copper tubing
| |||||||
30
|
—
|
1 (250 feet)
|
3
|
15
|
55
|
200
|
450
|
40
|
1 (30 feet)
|
1 (500 feet)
|
6
|
30
|
110
|
220
|
450
|
50
|
1 (65 feet)
|
2
|
9
|
40
|
110
|
220
|
450
|
60
|
1 (100 feet)
|
3
|
9
|
40
|
110
|
220
|
450
|
70
|
1 (135 feet)
|
4
|
9
|
40
|
110
|
220
|
450
|
NOTES:
| |
---|---|
1
|
Numbers shown in parentheses designate maximum allowed distance
of fixtures from a pneumatic tank or underground main.
|
Minimum Size of Tank
(gallons)
| ||||||
---|---|---|---|---|---|---|
Street Pressure1
(pounds per square inch)
|
Number of Water Closets2
| |||||
1
|
2
|
3
|
4
|
7
| ||
30
|
150
|
170
|
190
|
210
|
300
| |
40
|
60
|
70
|
80
|
90
|
120
| |
50
|
40
|
50
|
60
|
70
|
90
| |
60
|
35
|
40
|
50
|
60
|
70
|
NOTES:
| ||
---|---|---|
1
|
Deduct 1/2 pound per square inch from street pressure for each
foot that fixtures are located above the bottom of the tank.
| |
2
|
Two urinals equal one water closet.
|