Heat Link PEX-a, Руководство по установке

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14
®
Link Heat
On 100ft of 2" PEX with a temperature change of 100°F the expansion is 11 inches.
(Coefficient of expansion is the same for all PEX sizes)
∆L = α ×∆T × L
∆L = (1.1"/10°F/100ft) × 100°F × 100ft
∆L = 11"
Without a proper offset (see page 15 ) this can easily damage fittings and the
installation location.
2" Tubing shown
11" Expansion
Drill shown
for scale
Expansion & Contraction
PEX has a high rate of thermal expansion. The design and installation of every piping system
shall include means to accommodate its expansion and contraction caused by temperature
changes, movement of the soil, building shrinkage or structural settlement.
For systems using PEX 1" and smaller the tubing will generally flex enough to eliminate the
need for expansion offsets so long as tubing is installed as per the guidelines in this manual.
However, for systems using PEX larger than 1", installation must allow for expansion and
contraction using appropriate offsets.
Calculate the expansion offset (D) using the formula:
D = C × √ (Ø+0.125) × ∆L
C = 12 (PEX material specific constant)
Ø = PEX outside diameter (nominal size + 1⁄8")
∆L = Expansion of L (Length of Run)
∆L = α × ∆T × L
α = coefficient of expansion = 1.1"/10°F/100ft
∆T = change in temperature of PEX
A fixed point does not allow the PEX to move (such as at a fire stop or tubing anchor).
A guide allows the PEX to slide during expansion and contraction.