How to Guide

109
Cold Weather Considerations
For CPVC
Store pipe in a heated area whenever possible.
Pressure Rating
For derating of maximum working pressure at elevated tem-
peraturespleaseseethePressure/TemperatureintheDesign
and Engineering Data section of this manual.
Temperature
For maximum working temperature and derating factors please
seethePressure/TemperatureintheDesignandEngineering
Data section of this manual.
Heat Build-Up
In addition to considering ambient air and operating tempera-
tures in a piping system, piping designers must consider the
radiant effect of sunlight when selecting piping material. Test-
ingtotheASTMD4803StandardTestMethodforPredicting
HeatBuild-upinPVCBuildingProductsindicatesthatradi-
ant heat from the sun can increase pipe surface temperatures
by 50°F or more, possibly causing a piping system to exceed
maximum working temperature or de-rating pressure carrying
capability. Painting dark-colored pipe with light-pigmented,
water-based paint may reduce, but will not eliminate, heat
build-up.
Thermal Expansion
For information on thermal expansion please see Expansion
and Contraction in the Design and Engineering Data section
of this manual.
Expansion Tanks do not compensate for linear expansion and
contraction of the pipe and fittings. Expansion tanks are de-
signed to compensate for the expansion of the liquids within
the system.
Testing
Please see the Testing and Inspection section of this manual.
Thermal Conductivity and
Sweating of CTS CPVC
Due to its low coefficient of thermal conductivity, FlowGuard
Gold
®
CPVC retains hot water longer and reduces condensa-
tion and sweating.
Thermal Conductivity
Thermalconductivityisdenedas“transferofheatfromone
part to another part of the same body,or from one body to
SPECIAL CONSIDERATIONS
In understanding spray polyurethane foams, there are two
general areas of concern for CPVC pipe and fittings;
(1) chemical compatibility and (2) potential damage to
pipe and fittings due to high temperatures generated as a
result of the exothermic chemical reaction during the
installation and curing process. It is possible to apply
polyurethane foam insulation properly without damage to
CPVC pipe and fittings. However, the use of polyurethane
foam insulation in conjunction with CPVC has resulted in
the failure of CPVC pipe and fittings and property damage.
Therefore, Charlotte Pipe and Foundry does not
recommend the use of polyurethane spray on foam
insulation in conjunction with its CPVC pipe and fittings.
The following precautions are recommended in cold-weather
situations.
1. FreezeIssues
CPVC is a ductile material, which expands and contracts
morethanmetallicplumbingpipe.However,CPVC,like
all other piping materials, needs to be protected from
freezing.Allmodelplumbingcodesrequirethatpiping
exposedtofreezingtemperaturesbeproperlyinsulated.
2. FrozenCPVCWaterLines
Drain the system if overnight temperatures are likely to
drop below 32°F. CPVC may split like other materials
whenwaterfreezesinit.
Immediately take action to eliminate the source of cold
aircausingthefreezingcondition,thenthawthewater
lineifpossible.Ifthefrozensectionofpipeisaccessible,
heatedaircanbeblowndirectlyontothefrozenareaby
usingalowwattageheater/blower.Also,electricalheat
tapescanbeappliedtothefrozenarea.NOTICE: To avoid
damagingthepipewhenthawingafrozenCPVCwater
line, the heat source should not exceed 180°F.
3. Handling
Refrain from unnecessary abuse. Do not drop pipe from
trucks, drag pipe on the ground, step on pipe or drop pipe
on the ends.
Inspect pipe ends for hairline cracks before making a joint.
If any indication of damage or cracking is evident at the
tube end, cut off at least 2 inches beyond any visible crack.
Do not use dull or broken cutting tools. A wheel-type pipe
cutter is recommended.