How to Guide
108
Plastics Technical Manual
2.  Short-term elevated pressure performance
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D 2846 Standard (Table 5) which requires that CPVC-
CTS systems (pipe, fittings, and cemented joints) have 
the capability of withstanding short-term pressure tests 
at 180°F of at least 521 psi for 6 minutes and 364 psi 
for 4 hours.
Flanges and Unions
Please see the section of this technical manual for complete 
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Horizontal and Vertical 
Support
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spacing should be in accordance with applicable plumbing 
and building codes.
Vertical CPVC piping should be properly supported and have 
a mid-story guide, unless thermal expansion requires another 
design.
The pipe should not be anchored tightly by the support, but 
secured in a manner to allow for movement caused by thermal 
expansion and contraction. It is recommended that you use 
clamps or straps that allow pipe to remain away from the 
framing, thus reducing the noise generated when pipe is al-
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chemically compatible with CPVC. 
HVAC Condensate Drain Lines
Exercise caution when using FlowGuard Gold
®
 CPVC pipe or 
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frigerant systems contain oils that may damage CPVC products. 
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coils may contain residual oils from the manufacturing process 
which can cause cracking of CPVC. Caution should be exercised 
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or as condensate-drain lines from air conditioning systems. 
Confirm the compatibility of CPVC with residual oils prior to 
installation. The interior of heat exchangers or the exterior of 
condenser coils may be thoroughly cleaned with a detergent 
solution to remove incompatible oils prior to piping installa-
tion. A rinse with clean water to completely clean the system is 
advisable as a final flushing. Charlotte Pipe and Foundry will 
not accept responsibility for failure resulting from exposure 
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Low Temperature 
Recommendation
Like most materials, PVC and CPVC become more brittle at 
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(32°F). Charlotte Pipe and Foundry recommends taking proper 
precautions when installing systems at low temperatures 
including providing proper insulation. If a system is designed 
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Pipe recommends the following: 
1.  Reduce water hammer pressure surges to a minimum 
by:
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  b.  Reducing pump start-up pressure surges with slow 
start-up motors and rubber expansion devices.
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second for PVC and 8-feet per second for CPVC CTS.
2.  Provide more than minimum Charlotte Pipe recommended 
support spacing.
3.  Thrust blocking at branches, changes in direction and end 
of runs.
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changes occur in runs.
5.  Strictly follow chemical-resistance recommendations.
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SPECIAL CONSIDERATIONS
Prior to installing PVC or CPVC piping in hydronic 
applications, it is important to flush the interior of the heat 
exchangers and the exterior of the condenser coils 
thoroughly with a mild ionic detergent solution to remove 
incompatible oils. Failing to do so could result in system 
failure and property damage.
Verify that all boiler cleaning and sealing chemicals used in 
hydronic radiant heating systems are compatible with PVC 
or CPVC. Failure to do so could result in system failure and 
property damage.
Equipment leaks in refrigeration or HVAC systems may 
release POE oils or other contaminants into the piping 
system. These oils and contaminants are incompatible with 
PVC or CPVC and such exposure may result in pipe or 
fitting failure regardless of flushing.










