The most commonly used PVC pipe (formerly referred to as rigid nonmetallic conduit) is made of polyviny chloride, which is a thermoplastic polymer. Solventtype cement is used for PVC connections and terminations.
The two most popular types of PVC are as follows:
- Schedule 40: Permitted underground (direct burial or encased in concrete) and aboveground
- (indoors and outdoors exposed to sunlight) where not subject to physical damage. Some Schedule 40 is marked for underground use only. Schedule 40 has a thinner wall than Schedule 80.
- Schedule 80: Permitted underground (direct burial or encased in concrete) and aboveground (indoors and outdoors in sunlight) where subject to physical damage. Schedule 80 has a thicker wall than Schedule 40.
The main differences between above ground and underground listed PVC are its fire resistance rating and its resistance to sunlight (UV).
PVC conduit is permitted :
- concealed in walls, floors, and ceilings.
- in corrosive areas if the pvc pipe is suitable for the chemicals to which it is exposed.
- for underground installations.
The Plastic Pipe and Fittings Association (PPFA) is composed of more than seventy-five companies involved in the manufacturing of products for plastic piping systems. PPFA has been a major force in educating the North American market since 1978 in thermoplastic residential, commercial, and industrial piping products and installations. The Design Guide has been published by the PPFA with the express purpose of educating the engineering and construction community to the design benefits of Polyvinyl Chloride (PVC) piping systems in commercial and industrial projects
PVC or vinyl can be found in just about every home or business, in hundreds of applications. Because of the physical nature of this amazing plastic, it can be rigid, flexible, weather or heat resistant, impact resistant, thick or thin, and any color one can imagine. PVC’s major uses are in the following industries: medical, automotive, electronics, toys, packaging, and construction