User Guide

Plumbing Design Assistance Manual l Appendix E – Expansion arm and loop calculations l 151
½" PEX pipe expansion arm
Delta
T (ΔT)
Run
(ft)
Delta L
(in)
Flexible arm
length (in)
L1
(in)
L2
(in)
PEX has a free-body thermal expansion rate of 1.1"/10°F ΔT/100 ft. (27.94mm/5.56°C ΔT/30.48m).
10
50 0.55 7.04 1.41 2.81
60 0.66 7.71 1.54 3.08
70 0.77 8.32 1.66 3.33
80 0.88 8.90 1.78 3.56
90 0.99 9.44 1.89 3.78
100 1.1 9.95 1.99 3.98
20
50 1.1 9.95 1.99 3.98
60 1.32 10.90 2.18 4.36
70 1.54 11.77 2.35 4.71
80 1.76 12.59 2.52 5.03
90 1.98 13.35 2.67 5.34
100 2.2 14.07 2.81 5.63
30
50 1.65 12.19 2.44 4.87
60 1.98 13.35 2.67 5.34
70 2.31 14.42 2.88 5.77
80 2.64 15.41 3.08 6.17
90 2.97 16.35 3.27 6.54
100 3.3 17.23 3.45 6.89
40
50 2.2 14.07 2.81 5.63
60 2.64 15.41 3.08 6.17
70 3.08 16.65 3.33 6.66
80 3.52 17.80 3.56 7.12
90 3.96 18.88 3.78 7.55
100 4.4 19.90 3.98 7.96
50
50 2.75 15.73 3.15 6.29
60 3.3 17.23 3.45 6.89
70 3.85 18.61 3.72 7.45
80 4.4 19.90 3.98 7.96
90 4.95 21.11 4.22 8.44
100 5.5 22.25 4.45 8.90
60
50 3.3 17.23 3.45 6.89
60 3.96 18.88 3.78 7.55
70 4.62 20.39 4.08 8.16
80 5.28 21.80 4.36 8.72
90 5.94 23.12 4.62 9.25
100 6.6 24.37 4.87 9.75
½" PEX pipe expansion arm
Delta
T (ΔT)
Run
(ft)
Delta L
(in)
Flexible arm
length (in)
L1
(in)
L2
(in)
PEX has a free-body thermal expansion rate of 1.1"/10°F ΔT/100 ft. (27.94mm/5.56°C ΔT/30.48m).
70
50 3.85 18.61 3.72 7.45
60 4.62 20.39 4.08 8.16
70 5.39 22.02 4.40 8.81
80 6.16 23.55 4.71 9.42
90 6.93 24.97 4.99 9.99
100 7.7 26.32 5.26 10.53
80
50 4.4 19.90 3.98 7.96
60 5.28 21.80 4.36 8.72
70 6.16 23.55 4.71 9.42
80 7.04 25.17 5.03 10.07
90 7.92 26.70 5.34 10.68
100 8.8 28.14 5.63 11.26
90
50 4.95 21.11 4.22 8.44
60 5.94 23.12 4.62 9.25
70 6.93 24.97 4.99 9.99
80 7.92 26.70 5.34 10.68
90 8.91 28.32 5.66 11.33
100 9.9 29.85 5.97 11.94
100
50 5.5 22.25 4.45 8.90
60 6.6 24.37 4.87 9.75
70 7.7 26.32 5.26 10.53
80 8.8 28.14 5.63 11.26
90 9.9 29.85 5.97 11.94
100 11 31.46 6.29 12.59
110
50 6.05 23.33 4.67 9.33
60 7.26 25.56 5.11 10.22
70 8.47 27.61 5.52 11.04
80 9.68 29.52 5.90 11.81
90 10.89 31.31 6.26 12.52
100 12.1 33.00 6.60 13.20
120
50 6.6 24.37 4.87 9.75
60 7.92 26.70 5.34 10.68
70 9.24 28.84 5.77 11.53
80 10.56 30.83 6.17 12.33
90 11.88 32.70 6.54 13.08
100 13.2 34.47 6.89 13.79
Table E-3: PEX pipe expansion arm calculations ½" to 3"
PEX has a free-body
thermal expansion rate of 1.1"/10°F ΔT/100 ft. (27.94mm/5.56°C ΔT/30.48m)