PEX Installation Manual

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IM-PF 724596 0416
10.1 General
Viega PEX systems should be designed following standard plumbing engineering practice. Follow local codes to
determine minimum tubing size and required xture pressures.
Pressure drop through ttings can be estimated from the charts below. Values are expressed in equivalent length
of PEX, so add the values for the relevant ttings to the length of tubing in the run, and then determine the total
pressure drop from the charts on the following page.
To determine the pressure drop through runs of ViegaPEX Ultra and FostaPEX tubing, refer to the pressure drop
chart on the following page. For a known ow rate, tubing size and tubing length, the pressure drop through the
run can be easily determined.
PEX Crimp Eco Brass Fittings
Size Coupling Elbow Tee Run Tee Branch
⅜" 2.9 9.2 2.9 9.4
½" 2.0 9.4 2.2 10.4
¾" 0.6 9.4 1.9 8.9
1" 1.3 10.0 2.3 11.0
PEX Crimp PolyAlloy Fittings
Size Coupling
Elbow Tee Run Tee Branch
⅜" 10.9
22.3 N/A N/A
½" 7.1
16.5 7.2 17.9
¾" 4.8
17.4 6.6 17.7
1" 4.5
18.0 6.0 17.0
PEX Press Bronze Fittings
Size Coupling Elbow Tee Run Tee Branch
⅜" 2.9 9.2 2.9 9.4
½" 2.0 9.4 2.2 10.4
¾" 1.0 8.0 1.0 9.0
1" 1.0 10.0 2.0 10.0
1¼" 2.0 11.0 2.0 11.0
1½" 2.0 13.0 2.0 12.0
2" 1.0 19.0 2.0 18.0
10 System Sizing and Calculations
PEX Press Polymer Fittings
Size Coupling Elbow Tee Run Tee Branch
⅜" 4.5 14.3 6.5 14.7
½" 2.6 12.6 3.9 14.0
¾" 2.5 18.9 3.6 19.1
1" 3.1 17.7 3.8 18.4
1¼" 4.0 18.6 6.4 18.7
1½" 5.2 29.4 7.9 28.3
2" 8.9 36.4 10.2 37.5
10.2.1 Viega PEX Press friction loss — equivalent feet of SDR9 PEX tubing
10.2.2 Viega PEX Crimp friction loss — equivalent feet of SDR9 PEX tubing
10.2 Viega PEX fittings