1.Metal tube

(1) Galvanized pipe
(2) Galvanized pipe
(3) Stainless steel pipe

2. Plastic pipe

(1) UPVC pipe
In fact, it is a kind of plastic pipe, and the joints are usually glued together. UPVC pipes have poor frost resistance and heat resistance. Therefore, hot and cold water pipes are rarely used. PVC pipes are suitable for electric wire pipes and sewage pipes. The scientific and technological circles have discovered that the chemical additive phthalate, which can make PVC softer, has a great impact on the kidneys, liver, and testes in the human body and can cause cancer. , Kidney damage, damage to the human body's functional reconstruction system, and affect development (only cold water is not good for hot water, and it is easy to be brittle in winter).

(2) PPR tube
As a new type of water pipe material, it can be used as a cold pipe or a hot water pipe. Because of its non-toxicity, light weight, pressure resistance, and corrosion resistance, it is becoming a popular material. It is also suitable for hot water pipes and even pure drinking water pipes. The interface of the PPR pipe adopts hot-melt technology, and the pipes are completely fused together, so once the installation and pressure test pass, there will be no longer aging and water leakage like aluminum-plastic pipes, and the PPR pipe will not scale. The main defects of PPR water pipes are: high temperature resistance, poor pressure resistance, long-term working temperature can not exceed 70 ℃; large linear expansion coefficient, the pipe is easy to deform after hot water, which affects the appearance; each length of straight pipe is 4 meters / Root, the coil is 100 meters---300 meters. And can not be constructed at a small angle. If the pipeline is laid for a long distance or there are many corners (small angles), a large number of joints will be used in the construction; the pipes are cheap but the price of the accessories is relatively high.

(3) PB tube
Polybutene (PB) resin was first synthesized by Italian professor G. Natta in 1954, and industrial production began in 1964. In 1965, the first polybutene (PB) heating piping system appeared in the Austrian Plastics Association, which is exciting. The thing is, the system is still running today. In the following 50 years, the application of polybutene (PB) piping system has been continuously promoted, and it is applied to the radiator heating connection piping system in the building, the ground radiant heating system and the domestic cold and hot water piping system. Polybutene (PB) resin is a high-molecular polymer composed of carbon and hydrogen. Compared with traditional materials such as metals and ceramics, it is easy to process, easy to recycle, and has low energy consumption throughout its life cycle. It is a green and environmentally friendly environment. Friendly materials. From the structural point of view, polybutene (PB) is a linear isotactic semi-crystalline thermoplastic material, which is non-toxic and pollution-free during processing and use, and can be repeatedly heated for molding. Therefore, polybutene (PB) combines the advantages of hygiene, processability, surface finish, strength, flexibility and connectivity, and achieves a comprehensive balance in physical properties, thermodynamic properties, and functionality, thus giving poly Butene (PB) plastic pipes have many unique characteristics, which can open up a wide range of applications in the field of fluid transportation systems, especially in the field of hot water transportation systems in buildings.

(4) PE-RT tube
PE-RT stands for heat-resistant polyethylene. It is the abbreviation of Polyethylene of raised temperature resistance. It is a kind of non-crosslinked polyethylene that can be used for hot water pipes. Some people also highlight its non-crosslinking characteristics and call it " High temperature resistant non-crosslinked polyethylene". It is a medium-density polyethylene produced by a special molecular design and synthesis process. It adopts a copolymerization method of ethylene and octene, and obtains a unique molecular structure by controlling the number and distribution of side chains to improve the resistance of PE. Thermal. Due to the existence of short octene chains, the macromolecules of PE can not be crystallized in a flaky crystal, but penetrated through several crystals, forming a connection between the crystals, it retains the good flexibility of PE, high Thermal conductivity and inertness, while making it more pressure resistant, this modification method is similar to the common PPR on the market. PE-RT pipes can be used for all use levels of hot water pipes specified in ISO10508.

(5) PPH
The high-density polypropylene pipes used in drain (sewage) water pipes, waste water pipes, rainwater pipes, and exhaust pipes should comply with the regulations of DIN53457 (ISO/R1133, ISO/R179, RAL), and the installation method should use electric welded sleeves and butt joints as far as possible Method construction.

(6) PP-B
Because of the use of fusion technology in construction. Therefore, it is also commonly known as hot melt tube. It is non-toxic, light weight, pressure resistant and corrosion resistant, and is becoming a popular material, but it is still less used in decoration projects. Generally speaking, this material is not only suitable for cold water pipes, but also for hot water pipes and even pure drinking water pipes.

(7) PEX tube
Cross-linked polyethylene pipe (PEX) Generally speaking, this material is thermally welded. The advantages of pex pipe: good pressure resistance, nominal pressure 1.25MPa, de16mm burst pressure greater than 6MPa, de20mm burst pressure greater than 5MPa; wide temperature resistance range ：-70——95℃ (short-time 110℃); resistant to acid and alkali corrosion, can be used for the transportation of a variety of chemical substances; high temperature resistance, excellent low temperature performance; smooth inner and outer walls of the pipe, low resistance, no scaling; clean, no pollution, It can save people the pain of citing "yellow water" and "rusty water"; 　The use of special pipe fittings can be easily and quickly installed without tapping, buckling, and welding; it is easy to bend and flexible, which saves pipe fittings; light weight, Compared with the same period, the pipe length is only 1/10 of that of galvanized steel pipe; it has good thermal insulation performance; it has a long service life, at 70℃, working pressure ≤0.8MPa, and the continuous service life is 50 years. The defect is that the connection cannot be hot-melted, which limits its scope of application in HVAC and water supply.

3. Composite pipe

(1) Aluminum-plastic composite pipe
It is the first water supply pipe to replace cast iron pipe. Its basic structure should be five layers, namely plastic, hot melt adhesive, aluminum alloy, hot melt adhesive, plastic, etc. from the inside to the outside.
The aluminum-plastic composite pipe has good thermal insulation performance, the inner and outer walls are not easy to corrode, because the inner wall is smooth, the resistance to fluid is small; and because it can be bent at will, the installation and construction are convenient. As a water supply pipeline, the aluminum-plastic composite pipe has sufficient strength, but if the lateral force is too large, the strength will be affected. Therefore, it should be constructed as an open pipe or buried in the wall, but it is not suitable to be buried in the ground. The connection of the aluminum-plastic composite pipe is of the ferrule type, so the first step in the construction is to pass a strict pressure test to check whether the connection is firm. The second is to prevent frequent vibration and loosen the ferrule. The third is to leave enough installation amount in the length direction to avoid pulling off.

(2) Steel-plastic composite pipe
Steel-plastic composite pipe, the product uses seamless steel pipe and welded steel pipe as the base pipe, and the inner wall is coated with high-adhesion, anti-corrosion, food-grade sanitary polyethylene powder coating or epoxy resin coating. The water-supply galvanized and plastic-coated composite steel pipe made of pre-treatment, pre-heating, internal coating, leveling, and post-treatment processes is an upgraded product of the traditional galvanized pipe. The product implements the CJT120-2000 industry standard of the Ministry of Construction. Caliber range DN15--DN1200 can be painted with flanges and pressure grooves. Length 6m, 9m, 12m and indefinite length. Coating wall thickness is between 100 microns and 500 microns, usually 350 microns. Pipeline connection threaded connection, flange connection, clamp connection pre-treatment Chemical dip tank method, physical sandblasting method Coating varieties Thermoplastic polyethylene powder (PE), thermosetting epoxy powder (EP) and other powder coatings Product characteristics

1． Hygienic, non-toxic, no fouling, no microorganisms, and guarantee of fluid quality.
2.  Resistant to chemical corrosion, soil and marine organism corrosion, and cathodic disbondment resistance
3． The installation process is mature, convenient and fast, and the connection is similar to ordinary galvanized pipes.
4． Good weather resistance, suitable for harsh environments such as deserts and saline alkalis.
5． The pipe wall is smooth, the conveying efficiency is improved, and the service life is long.

(3) Outer layer welding type
The outer layer welding type aluminum-plastic composite pipe includes an outer layer of random copolymer polypropylene co-extruded plastic layer, and a hot-melt adhesive layer is connected to the inner surface of the random copolymer polypropylene co-extruded plastic layer. The inner surface of the mixture layer is connected with an aluminum tube layer, the inner surface of the aluminum tube layer is connected with a hot melt adhesive layer, and the inner surface of the hot melt adhesive layer is connected with a polyethylene co-extruded plastic layer; the utility model It has excellent high temperature resistance and small thermal deformation characteristics of aluminum-plastic composite pipes, and the reliability of hot melt connection with PP-R pipes. It can be widely used in cold and hot water pipes and drinking water systems, heating pipes, floors, walls, and heating. Systems, solar heating, cooling systems, industrial fluid conveying systems, central air-conditioning systems, compressed air pipeline systems and other fields.

(4) Bimetal composite type
Lined with stainless steel composite pipe, the product is based on galvanized steel pipe and lined with thin-walled stainless steel, which can not only meet the advantages of stainless steel safety, sanitation, health and durability, but also eliminate the problem of plastic pipe pollution, and the price is also higher than that of copper pipes. And the stainless steel pipe saves a lot, and can be installed and constructed safely, conveniently and reliably, and has a high pressure-bearing capacity. It is a new type of environmentally friendly, green and energy-saving product.