All wiring shall be installed in right Pipe & Fittings Rigid PVC Conduit and secured with proper fittings. All conduit and fittings shall be manufactured according to standard of CSA or UL, which includes all outlets, elbows and junction boxes Pipe & Fittings products.
Exposed conduit shall be securely attached and supported with straps that are installed at the recommended spacing specified in the National Electrical Code, Article 352.30. Expansion
fittings for PVC conduit shall be provided to compensate for thermal expansion and contraction where the length change is expected to be ¼ in or greater in a straight run between securely mounted items such as boxes, cabinets, elbows, or other conduit
terminations in accordance with the National Electrical Code, Article 352.44. You can custom the conduit fittings according to the standards of yours or your designs.
SOLVENT CEMENTING of PVC conduit
All connections should be made using and applying solvent cement.
SOLVENT CEMENTING IN COLD WEATHER:
• Store pipe and fittings in a heated area. Prefabricate as much of the system as possible in a heated area.
• When not in use, store sealed solvent cement and primer between 41°F and 70°F. Do not use open flame or electric heaters to warm cements and primers.
• Take care to remove moisture, ice and snow from the mating surfaces.
SOLVENT CEMENTING IN HOT WEATHER:
• At the time of assembly, the surface temperature of the mating surfaces should not exceed 113°F. Shade or shelter the joint surfaces from direct sunlight for at least 1 hour prior to joining
and during the joining process. If necessary, swab the mating surfaces with clean, wet rags to reduce the surface temperature (thoroughly dry surfaces before apply-ing primer or cement).
• Make joints during the cooler early morning hours.
• Apply cement quickly and join pipe to fitting as quickly as possible after applying the cement.
• Keep solvent cement container closed or covered when not in use, to minimize solvent loss.
SOLVENT CEMENTING IN WET CONDITIONS
Solvent cement products can contain hazardous chemicals and volatile organic compounds (VOC), which emit smog-forming chemicals that can be harmful to users or installers and to our environment. Most of these products pollute indoor and outdoor air quality causing respiratory and eye irritation.
• Mating surfaces must be dry when the joint is made.
• Work under a cover or canopy to keep rain off pipe and fittings.
• Work quickly after drying the pipe and fitting to avoid condensation.
• Allow a longer cure time before the system is tested or used.
STORAGE AND HANDLING OF SOLVENT CEMENT AND PRIMER
Solvent cement and primer contain highly flammable solvents. Follow all specific safety precautions provided on container label and Material Safety Data Sheet.
Remarks：
- Keep primer and solvent cement away from heat, sparks and open flame.
- Keep containers tightly closed except when in use.
- Ensure proper ventilation of work area and avoid inhaling solvent vapors.
- Where the possibility of splashing exists, wear proper eye
- protection or a face shield.
- Avoid contact with skin.
SUPPORT STRAPS：
Rigid PVC conduit must be supported with straps when installed in above ground applications. These straps should be installed snugly, while allowing linear movement of the conduit. See the table below for recommended maximum spacing of support straps.
STORING CONDUIT AND FITTINGS:
Store conduit and fittings at the same temperature, otherwise they may expand and contract at different rates and become incompatible.
MAXIMUM OPERATING AND AMBIENT TEMPERATURES
When installing conduit according to the National Electrical Code (NEC), Westlake Pipe & Fittings PVC Conduit can be used with up to 90°C (194°F) wiring.
Westlake Pipe & Fittings Rigid PVC Conduit and fittings can be installed in locations with an ambient temperature not exceeding 122°F.
EXPANSION JOINTS:
According to the National Electrical Code, if the amount of expansion expected due to temperature variance during and after construction is more than 1.8″, expansion joints must be used.
Westlake Pipe & Fittings recommends the use of expansion joints whenever the expected temperature change is greater than 25°F.
EXPECTED EXPANSION:
The coefficient of linear expansion for PVC Rigid Conduit is as follows:
3 x 10-5 in (expansion/contraction) / in (pipe length) /°F (change in temperature).
Remarks:
The following chart shows the amount of expansion ex-pected with various pipe lengths/temperature changes. If the rigid conduit is installed in an exposed location, 30°F should be added to the amount of temperature change (∆T) due to the effects of radiant
heat.
REQUIRED NUMBER OF EXPANSION JOINTS:
The following table shows the amount of travel that is available with each trade size of Westlake Pipe & Fittings Rigid conduit expansion joints:
The required number of expansion joints can be calculated using the following formula:
The number of expansion joints calculated above should be rounded up to the nearest whole number.