User Guide

Plumbing Design Assistance Manual l Appendix E – Expansion arm and loop calculations l 159
Table E-3: PEX pipe expansion arm calculations ½" to 3"
3" 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 15.73 3.15 6.29
60 0.66 17.23 3.45 6.89
70 0.77 18.61 3.72 7.45
80 0.88 19.90 3.98 7.96
90 0.99 21.11 4.22 8.44
100 1.1 22.25 4.45 8.90
20
50 1.1 22.25 4.45 8.90
60 1.32 24.37 4.87 9.75
70 1.54 26.32 5.26 10.53
80 1.76 28.14 5.63 11.26
90 1.98 29.85 5.97 11.94
100 2.2 31.46 6.29 12.59
30
50 1.65 27.25 5.45 10.90
60 1.98 29.85 5.97 11.94
70 2.31 32.24 6.45 12.90
80 2.64 34.47 6.89 13.79
90 2.97 36.56 7.31 14.62
100 3.3 38.54 7.71 15.41
40
50 2.2 31.46 6.29 12.59
60 2.64 34.47 6.89 13.79
70 3.08 37.23 7.45 14.89
80 3.52 39.80 7.96 15.92
90 3.96 42.21 8.44 16.89
100 4.4 44.50 8.90 17.80
50
50 2.75 35.18 7.04 14.07
60 3.3 38.54 7.71 15.41
70 3.85 41.62 8.32 16.65
80 4.4 44.50 8.90 17.80
90 4.95 47.20 9.44 18.88
100 5.5 49.75 9.95 19.90
60
50 3.3 38.54 7.71 15.41
60 3.96 42.21 8.44 16.89
70 4.62 45.60 9.12 18.24
80 5.28 48.74 9.75 19.50
90 5.94 51.70 10.34 20.68
100 6.6 54.50 10.90 21.80
70
50 3.85 41.62 8.32 16.65
60 4.62 45.60 9.12 18.24
70 5.39 49.25 9.85 19.70
80 6.16 52.65 10.53 21.06
90 6.93 55.84 11.17 22.34
100 7.7 58.86 11.77 23.55
2½" 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).
100
50 5.5 45.60 9.12 18.24
60 6.6 49.95 9.99 19.98
70 7.7 53.95 10.79 21.58
80 8.8 57.67 11.53 23.07
90 9.9 61.17 12.23 24.47
100 11 64.48 12.90 25.79
110
50 6.05 47.82 9.56 19.13
60 7.26 52.39 10.48 20.95
70 8.47 56.58 11.32 22.63
80 9.68 60.49 12.10 24.20
90 10.89 64.16 12.83 25.66
100 12.1 67.63 13.53 27.05
120
50 6.6 49.95 9.99 19.98
60 7.92 54.72 10.94 21.89
70 9.24 59.10 11.82 23.64
80 10.56 63.18 12.64 25.27
90 11.88 67.01 13.40 26.80
100 13.2 70.64 14.13 28.25
130
50 7.15 51.99 10.40 20.79
60 8.58 56.95 11.39 22.78
70 10.01 61.51 12.30 24.60
80 11.44 65.76 13.15 26.30
90 12.87 69.75 13.95 27.90
100 14.3 73.52 14.70 29.41
140
50 7.7 53.95 10.79 21.58
60 9.24 59.10 11.82 23.64
70 10.78 63.83 12.77 25.53
80 12.32 68.24 13.65 27.30
90 13.86 72.38 14.48 28.95
100 15.4 76.30 15.26 30.52
150
50 8.25 55.84 11.17 22.34
60 9.9 61.17 12.23 24.47
70 11.55 66.07 13.21 26.43
80 13.2 70.64 14.13 28.25
90 14.85 74.92 14.98 29.97
100 16.5 78.97 15.79 31.59
160
50 8.8 57.67 11.53 23.07
60 10.56 63.18 12.64 25.27
70 12.32 68.24 13.65 27.30
80 14.08 72.95 14.59 29.18
90 15.84 77.38 15.48 30.95
100 17.6 81.56 16.31 32.63