Knowledge of water supply pipe fittings

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TX that is being decorated is often full of doubts about what kind of pipes to choose. In fact, as long as you understand the basic knowledge of pipes, it is not difficult to choose. In the past, cast iron pipes were mainly used for water supply. Sand mold cast iron pipes are mainly used outdoors, and galvanized cast iron pipes are used indoors, It can also be divided into cold (

TX under decoration is often full of doubts about what kind of pipes to choose. In fact, it is not difficult to choose as long as you understand the basic knowledge of pipes.

varieties of water supply pipe fittings

in the past, the pipes used for water supply were mainly cast iron pipes. Sand mold cast iron pipes were mainly used outdoors, and galvanized cast iron pipes were used indoors, which can be divided into cold (electric) galvanizing and hot galvanizing. China has stipulated to eliminate sand mold casting pipe fittings and cold galvanized cast iron pipes from June 1, 2000, gradually restrict the use of hot-dip galvanized cast iron pipes, and promote the use of aluminum-plastic composite pipes, plastic pipes, etc. Therefore, there are three main categories of pipelines currently used. The first is metal pipe, such as hot-dip plated cast iron pipe lined with plastic, steel pipe, stainless steel pipe, etc. The second type is plastic clad metal pipe, such as plastic clad steel pipe, aluminum plastic clad pipe, etc. The third type is plastic pipe, such as PP-R (cross-linked polypropylene high-density mesh engineering plastic)

the state also stipulates that all kinds of pipes and fittings involving drinking water pipelines must be approved by the health department before they can be sold

commonly used plastic codes and meanings in water supply pipelines:

PP-R cross-linked polypropylene high-density mesh engineering plastic

PE high-density polyethylene


Pb polybutylene

PEX cross-linked polyethylene

comprehensive performance requirements of water supply pipelines

as a water supply pipeline, it is required to be hygienic, safe, energy-saving and convenient. Therefore, the inspection of a pipeline should start from four aspects. Namely, sanitation: pipes and fittings must not cause any damage to human body. Safety: it has sufficient strength, excellent mechanical properties, aging resistance, heat resistance and other properties. Energy saving: smooth inner wall, corrosion resistance, small resistance to fluid, good heat preservation performance. Convenience: the connection and construction are convenient and reliable, with the possibility of popularization and use

if the above four requirements are not met, the user's health and property safety will be damaged

introduction to several water supply pipes

1 aluminum plastic composite pipe

aluminum plastic composite pipe is the first water supply pipe to replace cast iron pipe. Its basic composition should be five layers, that is, plastic, hot melt adhesive, aluminum alloy, hot melt adhesive and plastic from the inside out

aluminum plastic composite pipe has good thermal insulation performance, and the inner and outer walls are not easy to be corroded. Because the inner wall is smooth, the resistance to fluid is very small; And because it can be bent at will, it is convenient for installation and construction. As a water supply pipe, the aluminum-plastic composite pipe has sufficient strength, but if the horizontal force is too large, it will affect the strength, so it is suitable to be exposed or buried in the wall, but it should not be buried underground. The connection of aluminum-plastic composite pipe is of ferrule type, so the first thing in construction is to pass strict pressure test to check whether the connection is firm. The second is to prevent frequent vibration to loosen the ferrule. Third, sufficient installation amount should be reserved in the length direction to avoid pulling off

2. Plastic clad copper pipe

plastic clad copper pipe uses pure copper (red copper) as pipe fittings and is covered with PE plastic. From the perspective of comprehensive performance, plastic clad copper pipe is slightly better than aluminum-plastic composite pipe. For example, the strength is better, the service life is longer, and the heat resistance is also better. But the insulation performance is slightly poor

pure copper has extremely high corrosion resistance. After a period of use, a layer of green oxide will appear on the inner surface. But it basically has no effect on the service life, flow rate and fluid resistance of the pipe. Aeruginosa is not harmful to human health, and has certain killing ability to bacteria. There are two installation methods of plastic clad copper pipe: ferrule type and welding type, and the welding type is more reliable

copper pipe, stainless steel pipe:

in addition to poor thermal insulation performance, other indicators such as strength, service life and fluid resistance are very good, so it is suitable to be used as cold water pipe. If it is used for hot water transmission, thermal insulation sheath shall be added. The connection mode is mainly ferrule type, and the copper pipe can also be welded

inner plastic lined galvanized cast iron pipe:

that is, a layer of plastic is lined on the inner wall of ordinary galvanized pipe to make it have the properties of corrosion resistance, low resistance, good heat preservation, and high strength of galvanized pipe itself. This kind of pipe is mostly connected by rib

plastic pipe:

plastic pipe can have sufficient strength, service life, safety and hygiene as long as the material selection meets the standard requirements. It has the best insulation performance among all pipelines. The plastic pipe adopts hot-melt welding with high reliability. As long as the construction is correct and the pressure test is normal, there will be no leakage and falling off at the pipe welding





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