Polyethylene and pipe industry
Polyolefins are used for the production of various types of pipes in various applications, such as drinking water pipes, sewage, gas, heating pipes and home plumbing, solid material pipes, drip irrigation and protective pipes (for example, for passing wires and cables). Polyolefin pipes were noticed and used since about forty years ago, and gradually with the recognition of the advantages and functions of these pipes and the gradual improvement of the properties of polyolefins used in pipe production, they replaced concrete, steel, cast iron and PVC pipes in many applications. became The flexibility and toughness of polyolefinic pipes has made it much easier and cheaper to move and operate pipelines than steel or concrete pipelines. The flexibility of these pipes provides the possibility of bypassing obstacles and reducing joints and connections. These pipes (especially large sizes) are easily welded and there is no need to use fittings. In addition, the resistance of these pipelines against earthquakes is much higher than other types of pipes. Also, the suitable chemical resistance of these pipes against acidic and alkaline environments has made their use more widespread. Polyolefin pipes are classified in two ways:
A) Pressure classification
A-1) Pipes under pressure
A-2) Pipes without pressure (gravity, gravity)
b) structural classification
B-1) Single wall pipes (smooth)
B-2) Constructed wall pipes
Pipes under pressure
Non-pressure pipes
High temperature applications
Low temperature applications
House plumbing
heating
Chemistry
industrial
drinking water
gas
sewage
Chemistry
industrial
sewage
drainage
Wire and cable protection
gutter
Among the types of polyolefin, high-density polyethylene (HDPE) is now used mainly in most applications, except in drip irrigation pipes, which are usually low-density type because the inner surface of the pipe is smoother with LDPE and water transfer with pressure drop. Less is done. In addition, the flexibility of low-density polyethylene is very suitable for this application. In heating applications, such as solar heating systems or home plumbing, it is practically not possible to use regular polyethylene, and usually either polypropylene or cross-linked polyethylene (PEX) is used.
