|| CPVC Pipes & Fittings
Frequently Asked Questions About CPVC
||Where should I use
ECOTUBE CPVC is designed for use in hot and cold water distribution systems.
ECOTUBE CPVC systems are ideal for all potable water needs of piping in a
typical single-family home, apartment, motel, codominium, mobile homes,
manufactured homes, light commercial and institutional strurer. Other
applications of hot water piping as central heating, radiant floor heating and
solar energy can be adapted to CPVC. However, please check with the
manufacturer of the heating unit before using CPVC in these applications.
2. What is the expected life of a water distribution
CPVC piping systems have been installed and operating since 1960 and these
facilities are still performing flawlessly for more than 40 years. ECOTUBE CPVC
system design and standards incorporate significant engineering safety factors
which lead to a long service life. CPVC piping is not susceptible to corrosion.
Electroly size or scale buildup in areas where water, soil and / or weather
conditions are aggressive. We firmly believe that CPVC plumbing systems will
provide a service life as long as or longer than other materials on the
3. Will an ECOTUBE CPVC system provide a financial
benefit to the owners in terms of utilities expense?
Yes. The thermal conductivity of a metal is 2500 times greater than that of a
CPVC system. The improved insulating characteistics associated with CPVC can
generate long-term savings for a home energy-conscious owner or tenant. CPVC
will keep water hot for a much longer period than metal tubing.
4. How can I use CPVC if I run under a concrete
When using CPVC under slab, you must pressure test the system before pouring
the slab. In addition, it is wise to use a 1 foam insulating pipe at
changes in direction, where the pipe emerges from the slab, and at construction
joints, the pipe should also be supported in smooth bottom trenches, the
backfill of which whould be free of rock and debris which could damage the
5. Should specific types of primers and solvent
cements be used on a CPVC system? Are specific colors required?
Solvent cement used should always be for CPVC use specifically, and
manufactured to meet the requirements of DIN 8080 - 8079 & AStmF493 or
equivalent. All-purpose cements should not be used. Purple primer manufactured
for PVC pipe is acceptable. Orange CPVC solvent cements facilitate
identification. De-pigmented CPVC solvent cement and primers are available and
are acceptable in various jurisdictions. Clear cement / primer provide a neater
6. I was told that CPVC pipe ends may split during
installation. Why should it occur? How can these cracks be prevented?
Most cracks are initiated by rough handling, this handling can occur during
shipment, while being inventoried at the wholesaler, or while on the job site.
In addition, fine cracks can be caused by cutting the pipe with dull or damaged
ratchet cutters, or using ratchet cutters when temperatures are below 10 °
C. The vast majority of cracks occur during the colder months. When ambient
temperatures are below 10 ° C, CPVC, like most other plastics such as PP,
PE, PVC-U, may become somewhat brittle and must be handled more carefully. To
reduce problems resulting from cracked product, several measures can be
7. What about CPVC piping in the walls?
- Educate your installers. Make them aware of the potential problem and
instruct them to handle CPVC in an appropriate way.
- Use a saw or a circular pipe cutter with a plastic cutting blade (serrated
# 151P or similar) to cut your pipe to length.
- Inspect pipe ends thoroughly before making a joint. If a crack is evident,
cut off any split portion before proceeding.
- In cold weather, gripping the pipe tightly around the cutting area for
about 10 seconds before making the cut will warm the pipe and reduce potential
CPVC can be embedded within walls, provided that the following points are
As the pipe thermally expands, tensile stresses will be developed. Concrete
will contain the CPVC; other materials may not, eg: plaserboard. The developed
tensile stress, ó , is given by the equation:
- Embed firmly in the wall, with the piping contained continously with
concrete. (The other alternative is to allow the pipe to move freely under
thermal expansion. Problems will occur if the pipe is neither completely
embedded nor able to expand freely) concrete should be homogeneous, without
gravel or stones which risk damaging the pipe. Ensure that the pipe is at least
2.5 cm from the outside surface.
- Do not embed demountable fittings.
- At exit and entry points, protect pipes with a sleeve.
- Pressure testing must be done before concrete is poured.
C=Coefficient of thermal expansion
This calculated developed tensile stress may be compared to the surrounding
material (plasterboard, concrete, etc.) to give an indication whether the
material will contain the pipe, or wheter the pipe will crack the wall.
C=6.3 x 10-5 cm/cm°C
8. Is CPVC resistant to U.V. exposure?
If we compare CPVC to some other commonly used piping materials.
Polyethylene and polypropylene:
U.V. acts as a powerful catalyst for the oxidation process that breaks the
polymer chains, leading to weakness in the pipe and loss of hydrostatic
The main process of degradation is dehydrochlorination, while slightly
accelerated by U.V., it does not break the polymer chains significantly after
outdoor exposure, being mainly limited to a surface discoloration. There is a
loss of impact resistance due to the impact modifiers losing efficiency. This
may even result in increased modulus.
If a portion of the piping system will be left exposed to U.V. light, a
standard grade of exterior latex paint will adequately protect the pipe.
- There is no significant loss of stress bearing capability
- 30 years of outside service in southern California.
- Impact resistance mainly an installation issue (before exposure to UV).
9. Is CPVC quieter than a metallic system?
Yes, we can compare the velocityof sound in CPVC to that in copper and water.
The velocity of sound in:
The sound will travel in the material with the fastest possible velocity. This
means that in a copper system, the sound travels in the copper, whilst in a
CPVC system, sound travels in the water and the system is as quite as
10. What about scale build up?
Scale build up is a function of roughness of the pipe, as measured by the
Hazen-Williams «C» factor used in the formula for calculating
friction head losses in piping systems.
| Increased value for C
|| Less friction
|| Less pressure drop
|| C Factor
|| After 4-40 years service
| copper / steel
With metal systems, once corrosion attack starts, (eg: the green color when
copper reacts with chlorides in water to form copper chloride) this starts a
vicious circle leading to scale build up. With CPVC, there is no corrosion and
hence scale build up is inhibited.
11. Is condensation reduced with CPVC?
Yes, for a given ambient air temperature and water temperature in the pipe, the
relative humidity must be 10-15% higher with CPVC to get the same degree of
condensation; for the same humidity level and water temperature can be ±
10 ° C higher than for copper to get the same degree of condensation.