Advantages and disadvantages of PE pipes and PVC pipes

PE (polyethylene) pipes

PE (polyethylene) pipes are now widely used in actual projects.

Advantages:

(1) Good low temperature performance

(2) Resistant to mechanical vibration

(3) Good toughness and can be coiled

Disadvantages:

(1) The melting point is 100 to 130 degrees Celsius, which is not suitable for hot water pipes. It is suitable for working temperatures not exceeding 40°C.

(2) Prone to stress cracking and not easy to stain

Scope of application:

Suitable as cold water pipes, widely used as drinking water pipes and rainwater pipes

Connection method:

1. Hot melt connection When pipes and fittings made of the same thermoplastic plastic are connected to each other, a special hot melt machine is used to heat the surface of the connection part, and the main materials at the connection contact surface are fused to each other. After cooling, the connection becomes a whole. Hot melt connections include butt hot melt connections, socket hot melt connections and electric fusion connections.

2. Electric fusion connection When connecting the same thermoplastic plastic pipes, insert a special electric fusion pipe fitting, and use the electric fusion connection machine to energize the electric fusion pipe fitting, relying on the resistance wire pre-buried inside the electric fusion pipe fitting to generate the required heat for welding. After cooling, the pipe and the electric fusion pipe fitting are connected as a whole.

PVC pipe
Rigid polyvinyl chloride pipe refers to polyvinyl chloride pipe with no or a small amount of plasticizer, which is usually divided into types I, II, and III. Type I is ordinary rigid polyvinyl chloride, Type II is UPVC with added modifier, and Type III is chlorinated PVC pipe with good heat resistance.
Advantages:
(1) Insoluble in non-polar solvents such as petroleum and mineral oil, and can withstand general acid and alkali corrosion.
(2) Has good self-extinguishing performance
(3) Meets the drinking water hygiene indicators and can meet the strict requirements for drinking tap water.
(4) The general selling price is 30% cheaper than galvanized pipes and 40% cheaper than ductile iron pipes. In addition, the product is light in weight and easy to construct, so the total project cost has an advantage of at least 20%.
(5) The technical standards are the most complete, with national standards for pipes and fittings, the most complete installation technical specifications, and the most complete construction acceptance specifications.
(6) The product specifications are the most numerous, with pipe diameters ranging from DN20 to DN750, and all-plastic pipe fittings ranging from DN20 to DN200. Pipes with diameters above DN200 also have metal pipe fittings and plastic steel pipe fittings for connection.
(7) Smooth inner diameter reduces water transport energy consumption
Disadvantages:
(1) Not suitable for hot water pipes, can be used as domestic water supply pipes, but not as direct drinking water supply pipes
(2) Easy to crack when impacted
(3) Some low-quality counterfeit UPVC pipes are added with plasticizers during production, which can cause medium pollution and greatly shorten the aging period of UPVC pipes
Connection methods:
(1) Adhesive connection (rigid connection)
(2) Elastic sealing ring connection (flexible connection)
(3) Flange connection
(4) Threaded connection For pipes and fittings with diameters from DN20 to DN160, pipes and pipes can be connected by two connection methods at the same time. However, in actual construction, we believe that adhesive connection should not be used in the construction of buried pipes with a diameter of DN63 or above. The reasons are:
(a) The use of flexible connections in buried pipes can more effectively resist terrain subsidence, external impact, etc.
(b) There is a lot of groundwater in some areas. If the bonding method is used, the adhesive will not have bonding strength when it comes into contact with water and oil when the adhesive is applied to the bonding interface.

PE pipes are safe and non-toxic, and have better flexibility and impact resistance than PVC. They can be used for underground gas pipelines and tap water pipelines.
PVC pipes have chloride ions precipitated after a long time of use, so they are not suitable for tap water pipes. They have poor impact resistance and are not suitable for gas pipelines. However, PVC pipes are low in price, high in hardness, and expand and contract under the influence of temperature. They are often used for drainage pipes and rainwater pipes.