2008年11月9日星期日

Pipe (material)


Materials

Historic water mains from Philadelphia included wooden pipes
The manufacturing of pipe uses many materials including ceramic, metal, concrete, and plastic.
Pipe may be made from a variety of materials. In the past, materials have included wood and lead (Latin plumbum, from which we get the word plumbing).
Metal pipes are commonly made from unfinished, black (lacquer), or galvanized steel, brass, and ductile iron. Copper tubing is popular for plumbing systems.
Plastic tubing is widely used for its light weight, chemical resistance, non-corrosive properties, and ease of making connections. Plastic materials include polyvinyl chloride (PVC), chlorinated polyvinyl chloride (CPVC), polyethylene (PE), cross-linked high-density polyethylene (PEX), polybutylene (PB), and acrylonitrile butadiene styrene (ABS), for example.
Pipe may also be made from concrete or ceramic. These pipes are usually used for low pressure applications such as gravity flow or drainage.
Concrete pressure pipe for water lines can be made in accordance with American Water Works Association () standards of C-303 or L-301. C-303 pipe has a round bar helically wound around the steel cylinder and all surfaces are then coated with cement mortar. C-301 is a prestressed pipe and is made using two different techniques. The first method has a steel cylinder which has been lined with concrete and after the concrete cures the prestressing wire is wound directly on the steel cylinder and the exterior is then coated with cement mortar. The second method encases the steel cylinder in concrete which is then prestessed after the concrete cures and the exterior is then coated with cement mortar. C-303 pipe can be manufactured in from 10" through 72" and C-301 goes from 36" through 144". Working pressure is generally less than 300 psi.
Reinforced concrete can be used for large diameter concrete pipes. This pipe material can be used in many types of construction and is often used in the transport of storm water. Usually such pipe will have a receiving bell or a stepped fitting, with various sealing methods applied at installation.

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