Law Supply, Inc.
Web Page - Friction Loss Chart
Velocity in Ft./SEC.  Fiction Head Loss in feet of water per 100ft. of pipe
1/2" PVC Sch-40
1/2" Sch-40 Steel Pipe
3/4" PVC Sch-40
3/4" Sch-40 Steel Pipe
1" PVC Sch-40
1" Sch-40 Steel Pipe
1-1/4" PVC Sch-40
1-1/4" Sch-40 Steel Pipe
1-1/2" PVC Sch-40
1-1/2" Sch-40 Steel Pipe
2" PVC Sch-40
2" Sch-40 Steel Pipe
2-1/2" PVC Sch-40
 .
3" PVC Sch-40
 .
LBS. per square in. = Head in ft. x .433
Head in ft. = lbs. per sq. in. x 2.31'

Loss through fittings in terms of equivalent lengths of pipe
TYPE FITTING
& APPLICATION
PIPE & FTG.
MATERIAL
(Note 1)
EQUIVALENT LENGTH OF PIPE
NORMINAL SIZE FITTING & PIPE
1/2"
3/4"
1"
1-1/4"
1-1/2"
2"
2-1/2"
Insert Coupling
Plastic
3
3
3
3
3
3
3
Threaded adapter
Plastic or copper
to thread
Copper
Plastic
1
3
1
3
1
3
1
3
1
3
1
3
1
3
90° standard elbow
Steel
Copper
Plastic
2
2
4
3
3
5
3
3
6
4
4
7
4
4
8
5
5
9
6
6
10
Standard tee
Flow through side
Steel
Copper
Plastic
4
4
7
5
5
8
6
6
9
8
8
12
9
9
13
11
11
17
14
14
20
Gate Valve
Note 2
2
3
4
5
6
7
8
Swing Check Valve
Note 2
4
5
7
9
11
13
16
Note 1: Loss figures are based on equivalent lengths of indicated pipe material
Note 2: Loss figures are for screwed valves and are based on equivalent lengths of steel pipe
*Loss figures for copper lines are approximately 10% higher than shown for plastic.

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Last updated 05/19/2003