Install Instructions

Viega PureFlow System Design Considerations
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IM-PF 724596 1021 PureFlow Water System (EN)
6.5 System Sizing and Calculations
The Viega PureFlow system 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 tubing, 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 Viega PureFlow PEX
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.
6.5.1 General
6.5.2 Viega PureFlow Fittings Sizing
6.5.2.1 Viega PureFlow Press Friction Loss
PureFlow Press Zero Lead 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
PureFlow 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
6.5.2.2 Viega PureFlow Crimp Friction Loss
Friction loss equivalent feet of SDR9 PEX tubing:
Friction loss equivalent feet of SDR9 PEX tubing:
PureFlow 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
PureFlow 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