7.12 Kink Repair
RAUPEX pipe is
fl
exible and resists kinking even at temperatures well
below freezing. If the pipe does become kinked,
fl
ow may be
obstructed or reduced. Kinked pipe must be repaired.
Straighten the pipe by heating the area with a heat gun, rotating the
heat gun around the pipe to evenly heat the surface. Always use
caution when operating a heat gun and never use a torch or open
fl
ame to heat the pipe.
When fully heated, the pipe will become transparent. When the kink is
gone, turn off the heat gun and let the area cool. (It is normal for
small bubbles or wrinkles to appear.) This type of heating will anneal
or stiffen the pipe, making it stronger but also less
fl
exible in the
heated area. Therefore, do not try to bend the pipe in the same spot.
This may require a slight adjustment of fasteners.
WARNING
-
Never use a torch, open
fl
ame or heat gun on a pressurized system.
Exceeding the temperature pressure ratings will result in dangerous
separation of materials leading to serious injury or death.
7.13 Installing Sprinklers
The sprinklers must be installed in accordance with their listing and
limitations. Follow all sprinkler manufacturers' guidelines for threading
sprinkler into FIREPEX
fi
re sprinkler
fi
ttings.
Sprinkler wrenches are installation tools speci
fi
cally designed for use
with residential sprinklers. The appropriate wrench must be used with
the individual sprinkler to provide the proper leverage when tightening
and to minimize slippage during installation.
CAUTION
Using wrenches other than those designated by the
fi
re sprinkler
manufacturer may damage the
fi
re sprinkler.
7.14 Pressure Testing
REHAU has a detailed pressure test procedure for testing a REHAU
PEXa piping system as set forth below.
WARNING
-
Failure to follow proper safety precautions for an air pressure test
could result in dangerous separation of the material, leading to
serious injury or death.
-
Use personal protective equipment. To reduce the risk of eye injury,
always wear close-
fi
tting protective eye wear with side protection.
Eye wear must be impact-rated and marked as complying with ANSI
Z87.1.
-
Never use a torch, open
fl
ame or heat gun on a pressurized system.
Exceeding the temperature pressure ratings will result in dangerous
separation of materials leading to serious injury or death.
-
Never rework a connection that is under pressure. Depressurize the
system, cut out connection and replace.
-
To reduce the risk of personal injury, only quali
fi
ed persons
conducting and/or inspecting the pressure test should be present.
The following recommended pressure test procedure applies to both
compressed air and hydrostatic (water) testing:
7.14.1 General Recommendations
-
A pressure test must always be performed prior to closing in the
system (e.g., behind drywall).
-
Perform test using water or air at ambient temperature. Do not
exceed 150 psi (1030 kPa) for the piping system. Verify maximum
pressure limits are not exceeded for all system components prior to
performing the pressure test.
-
When air pressure testing with polymer
fi
ttings do not
exceed 120 psi (825 kPa).
-
For RFH and SIM systems, a pressure test must always be per-
formed on the system prior to and during the installation of the
thermal mass to ensure that RAUPEX pipe and connections are leak
free. For dry systems (e.g., joist space), a pressure test must be
performed after installation and up to the time that the system is put
in operation.
-
Tests shall comply with local codes where applicable and, where
required, shall be witnessed by the building of
fi
cial.
7.14.2 Pressure Testing with Air
Air can store a high amount of energy as compared to water during a
pressure test. Due to this higher energy, different failure modes of
system materials must be understood by persons conducting the
pressure test.
-
If a thermoset polymer (e.g., PEXa pipe) is over-pressurized and fails
(bursts), it does so in a ductile mode, meaning that the pipe will
swell and then split with no separation of fragments.
-
If a rigid thermoplastic polymer material (e.g., PPSU) is over-pres-
surized and fails (bursts), it does so in a brittle mode and can result
in separation of the material.
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