Install Instructions

Fastening the Viega PureFlow System
70 of 88
IM-PF 724596 1021 PureFlow Water System (EN)
12.10.5 U-Type Expansion O󶈴set
The U-type expansion loop integrates four 90° elbows that form a “U”
pattern.
With this arrangement ⅕ of the “L” dimension is applied as the width
(represented as L3) while ⅖ of “L” is applied as each leg in the other
dimension (represented as L4).
Calculate the necessary L3 and L4 dimensions or use the chart below,
which was 󶈵gured using the maximum run for a single expansion
compensator (50 feet).
L = 20.7"
L3 = ⅕ (L)
L3 = 20.7"/5 = 4.14"
L3 = 4.14"
L4 = ⅖ (L)
L4 = 2(20.7")/5 = 8.28"
L4 = 8.28"
The fastener shown on the L3 leg may be required to provide additional support depending on how the expansion loop is installed (horizontal/vertical).
U-Type Expansion O󶈴set (inch) per 50 linear feet of run
Tubing
ΔT(° F)
Tube
nom.
60 80 100 120 140 160 180 200
L3 L4 L3 L4 L3 L4 L3 L4 L3 L4 L3 L4 L3 L4 L3 L4
Viega
PureFlow
PEX
¾" 4.1 8.2 4.7 9.4 5.3 10.5 5.8 11.6 6.2 12.5 6.7 13.3 7.0 14.2 7.5 14.9
1" 4.6 9.3 5.3 10.7 6.0 12.0 6.6 13.1 7.1 14.2 7.6 15.1 8.0 16.0 8.5 16.9
1¼" 5.1 10.2 5.9 11.8 6.6 13.2 7.2 14.5 7.8 15.6 8.4 16.7 8.9 17.7 9.4 18.7
1½" 5.6 11.1 6.4 12.9 7.2 14.4 7.9 15.7 8.5 17.0 9.1 18.2 9.6 19.3 10.2 20.3
2" 6.4 12.7 7.4 14.7 8.2 16.4 9.0 18.0 9.7 19.5 10.4 20.8 11.0 22.1 11.6 23.2
U-Type Looped O󶈴set
L3
L4L4
4 - 6" 4 - 6"
∆L/2 ∆L/2
LT
Anchor point Anchor point
U-Type Expansion
L4 = 8.28"
L3 = 4.14"
L4 = 8.28"