User Guide
Table Of Contents
- Introduction
- Codes, Standards, and Certifications
- PureFlow Press Fittings
- PureFlow Crimp Fittings
- PureFlow Tools
- Product Instructions
- Tubing Overview
- Design Considerations
- ManaBloc Systems
- Installing PureFlow Systems
- Storage Recommendations
- Handling Viega PureFlow PEX Tubing
- Removing PureFlow Connections
- Repairs
- Freezing
- Water Heaters
- Heaters, Flues, Vents, and Recessed Lights
- Fastening the PureFlow System
- Supporting PureFlow PEX Tubing
- Installation Considerations
- Noise and Water Hammer
- Shower Valves
- Electrical Grounding
- Expanding Foams
- Fire Stop Compounds
- Tubing Expansion
- Calculating Expansion Loops and Offsets
- Domestic Hot Water Circulating Systems
- Installing Viega PureFlow Fittings
- PureFlow PEX Tubing Installed in Slab
- Installing PEX Under a Slab
- Installing PEX Below Grade as Service Line
- Pressure Testing PureFlow Systems
- System Disinfection
- Limited Warranty
Installing PureFlow Systems
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PG-PF 724998 0320 PureFlow System
Water Heaters
Viega PureFlow PEX tubing should not
be connected directly to gas-red water
heaters. The high temperatures of these
appliances can damage the tubing.
When connecting a Viega PureFlow
system to a gas-red water heater,
install a minimum of 18" of metallic
piping between the water heater and
tubing, keeping tubing more than 6"
away from the vent pipe. Where local
code allows, Viega PureFlow PEX tubing
may be connected directly to electric
water heaters and used for hot water
recirculation lines that do not come within
6" of the gas heater vent.
A minimum of 18" of metallic piping is required
between a gas-fired water heater and PEX tubing.
Viega PureFlow PEX may be used to
connect to instantaneous/tankless
water heaters or other hot-water-
producing devices. However, consult
manufacturer’s recommendations for
use with plastic tubing and ensure
temperature and pressure do not exceed
the maximum ratings of the tubing.
Freezing
The exibility of Viega PureFlow PEX
tubing makes it resistant to damage
from freezing, but precautions to prevent
freezing should be taken when low
temperatures might be encountered.
Insulating each PEX tube individually or as
a group is not generally necessary if the
PEX tubing is installed within the insulation
envelope of the structure, i.e., the heated
area. For example, the tubing may be
installed under the insulation in the attic or
within an interior wall of a heated space.
PureFlow PEX tubing
systems should not
be intentionally
subjected to freezing.
Do not use open torch
or excessive heat to
thaw PureFlow PEX
tubing. Tubing failure or damage can result.
Heat (DO NOT USE A TORCH) must be applied
directly to the frozen tubing section. Temperature
on tubing shall not exceed 180°F.
Several suitable methods exist to thaw
PureFlow PEX tubing:
• Hot water
• Wet, hot towels
• Hand-held hair dryer
• Low-wattage electrical heating tape (self limiting)
• A commercial system that pumps heated
water through a tube to the ice blockage
and returns the cooled water for reheating