49
I-800
SNAKING / DEFLECTION OF PIPE
Snaking is particularly necessary on the lengths that have been solvent
cemented during the late afternoon or a hot summer’s day because their
drying time will extend through the cool of the night when thermal con-
traction of the pipe could stress the joints to the point of pull out. This
snaking is especially necessary with pipe that is laid in its trench (neces-
sitating wider trenches than recommended) and is back-filled with cool
earth before the joints are thoroughly dry.
Loop Offset for Contraction:
Maximum Bending Deflections
For Given Lengths of CPVC, SDR 13.5 (73°F)
NOTICE
• After CPVC pipe has been solvent cemented, snake the pipe, according to the
following recommendations, beside the trench during its required drying time.
• Be especially careful not to apply any stress that will disturb the undried joint.
• Snaking is necessary to allow for any anticipated thermal contraction that will take
place in the newly joined pipeline.
Pipe
Size
inch
mm
Length of Run (L) in feet
2
5
7
10
12
15
17
20
25
30
35
40
45
50
Pipe Deflection (D) in inches
3
/
4
1.3
7.8
15.4
31.3
45.1
70.5
90.6
124.4
195.9
282.1
383.9
–
–
–
20
1
1.0
6.3
12.3
25.0
36.0
56.3
72.3
100.1
156.5
225.2
306.6
400.4
–
–
25
1
1
/
4
0.8
5.0
9.7
19.8
28.5
44.6
57.3
79.3
123.9
178.4
242.8
317.2
401.4
–
32
1
1
/
2
0.7
4.3
8.5
17.3
24.9
39.0
50.1
69.3
108.2
155.9
212.2
277.1
350.7
433.0
40
2
0.6
3.5
6.8
13.9
20.0
31.2
40.0
55.4
86.6
124.7
169.7
221.7
280.6
346.4
50
LOOP LENGTH
OFFSET
OFFSET
2 LOOP LENGTHS
PIPE
L
}
D
I-800 2755 Rev_I.fm Page 49 Tuesday, September 13, 2005 8:46 AM