How to Guide

112
Plastics Technical Manual
Hydronic Heating, Chilled
Water or Geothermal
Applications
When plastic piping is used for recirculating systems such
as hydronic, chilled water or geothermal heat pump systems,
careful consideration of piping material characteristics and
system requirements must be made. This includes taking
into account pressure, temperature, flow velocity, design
stresses, environmental factors and the chemical resistance
of the piping materials to the fluids (heat-transfer fluids,
anti-freeze solutions and other chemicals) in the system.
Ultimately the engineer, designer or owner must evaluate
these characteristics and system requirements in order
to select the correct piping product for the particular
application. The table below highlights some of the key
points to consider when designing or installing these types
of systems.
This manual is not a complete engineering reference
addressing all aspects of design and installation of these
systems. Many excellent references are available on
this topic. The International Ground Source Heat Pump
Association: www.igshpa.okstate.edu or The GEO Exchange
at www.geoexchange.org.
“DOs” for all hydronic applications
• DoinstallCPVCSchedule80domesticwatersystemsusing
IPS P-70 or Oatey Industrial Grade primers.
• Do install CPVC Schedule 80 domestic water systems
usingIPS714orOateyCPVCHeavyDutyOrangesolvent
cements.
• InstallinaccordancewithbothCharlottePipeandFoundry’s
andsolventcementmanufacturer’srecommendationsand
installation instructions.
• Followrecommendedsafeworkpractices.
• Verifythatthemaximumoutlettemperatureandpressureof
the boiler is less than the temperature and pressure rating
of the pipe (see charts below).
• Always use the proper derating factors with FlowGuard
GoldandCorzanCPVCpipetondthepressureratingat
the applicable operating temperature.
• Always follow applicable codes and approvals when
installing plumbing and heating equipment.
• Ensurethatthesystemdesignallowsforthermalexpansion
and contraction as recommended in the Charlotte Pipe and
FoundryPlasticsTechnicalManual.
• UseonlyCPVCxbrassthreadedtransitionttingswhen
installing FlowGuard Gold systems.
• Usepropersolventcementingpractices,includingbeveling
andproperdaubersizing.
• Alignallpipingsystemcomponentsproperlywithoutstrain.
Do not bend or pull pipe into position after being solvent
welded.
• ProvideadditionalsupporttothebrasssideofaCPVCx
brass transition or other metallic components to support
the weight of the metal system.
• Usecheck valves, heat traps or back ow preventers to
prevent cross-connections between hot and cold water lines.
• Flush the interior of heat exchangers or the exterior of
condenser coils thoroughly with mild ionic detergent solution
to remove incompatible oils prior to piping installation.
• Rinse with clean water to purge the system as a nal
flushing.
• Verifythatallboilercleaningandsealingchemicalsused
in the hydronic radiant heating system are compatible with
CPVC.
“DON’Ts” for all hydronic applications
• Do not exceed the operating temperature or operating
pressure of the piping system.
• DonotuseCPVCmaleorfemaleadapterswithplastic
molded threads for FlowGuard Gold systems.
• DonotusetheCPVCpipingsystemtosupportanymetallic
components.
• Do not use compression ttings for hydronic radiant
heating applications.
• Donotusesolventcementthatexceedsitsshelflife,has
become discolored or has gelled.
• DonotuseCPVCteesorotherCPVCcomponentsashot
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.