What pipes are used for water supply?
As an important component of building and municipal construction, water supply pipes are widely used in the process of urbanization in my country. Therefore, what pipes are used for water supply is particularly important in the construction process.
Today, I have made a simple summary of the selection of pipes for common water supply and drainage systems. I hope it will be helpful to you.
Rigid polyvinyl chloride (PVC-U) water supply pipe
PVC-U pipes are made of sanitary polyvinyl chloride (PVC) resin as the main raw material, and are added with appropriate amounts of stabilizers, lubricants, fillers, color enhancers, etc., and are extruded and molded by plastic PVC-U drainage pipe extruders and injection molding machines. Through cooling, curing, shaping, inspection, packaging and other processes, the production of pipes and fittings is completed. It has excellent physical and chemical properties, chemical corrosion resistance, high impact strength, low fluid resistance, and a 30% increase in flow rate compared to cast iron pipes of the same caliber. It is resistant to aging and has a long service life of not less than 50 years. It is an ideal material for building water supply and drainage. It is light and durable, easy to install, and effectively speeds up the progress of the project. It saves construction costs and can greatly reduce construction costs compared to cast iron pipes of the same specifications.
Application scope: urban tap water supply and water supply projects, building internal and external water supply projects, industrial and mining enterprise water supply projects, underground fire protection water supply projects, farmland water conservancy water supply and irrigation projects, garden and horticulture greening water supply projects, aquaculture water supply and drainage projects, etc.
High-density polyethylene (HDPE) drainage pipe
HDPE is a highly crystalline, non-polar thermoplastic resin. The appearance of the original HDPE is milky white, and it is translucent to a certain extent in the thin section. In the water supply and drainage pipeline system, plastic pipes have gradually replaced traditional pipes such as cast iron pipes and galvanized steel pipes and become the mainstream pipes. Compared with traditional pipes, plastic pipes have significant advantages such as light weight, corrosion resistance, low water flow resistance, energy saving, easy and quick installation, and low cost, and are favored by the pipeline engineering industry.
HDPE pipes are mainly used for: municipal engineering water supply systems, indoor water supply systems of buildings, outdoor buried water supply systems and buried water supply systems in residential areas and factory areas, old pipeline repair, water treatment engineering pipeline systems, industrial water pipes for gardens, irrigation and other fields, etc.
Random copolymer polypropylene (PP-R) water supply pipe
PP-R pipe is also called type III polypropylene pipe. It is made of random copolymer polypropylene through extrusion into pipe material and injection molding into pipe fittings. It is a new type of plastic pipe product developed and applied in Europe in the early 1990s. PP-R is a new generation of pipe material in the late 1980s, which uses gas phase copolymerization process to make about 5% PE randomly and uniformly polymerized in the molecular chain of PP (random copolymerization). It has good impact resistance and long-term creep performance.
Advantages of PPR pipe: moderate price, stable performance, heat resistance and heat preservation, corrosion resistance, smooth inner wall without scaling, safe and reliable pipeline system, and no penetration, with a service life of up to 50 years. It is said to never scale, never rust, never leak, and green advanced water supply material.
Disadvantages of PPR pipe: high construction technology requirements, special tools and professionals are required for construction to ensure system safety.
PPR pipe application areas:
1. Hot and cold water systems of buildings, including central heating systems;
2. Heating systems in buildings, including floors, wall panels and radiant heating systems;
3. Pure drinking water supply systems;
4. Central (central) air conditioning systems;
5. Industrial piping systems for transporting or discharging chemical media.
Polyethylene (PE) water supply pipe (PE80, PE100)
No heavy metal salt stabilizer is added during the processing of PE pipe. The material is non-toxic, has no scaling layer, and does not breed bacteria, which effectively solves the secondary pollution of urban drinking water. Except for a few strong oxidants, it can resist the erosion of various chemical media; there is no electrochemical corrosion.
Under the rated temperature and pressure conditions, PE pipes can be safely used for more than 50 years. PE pipes have good toughness and high impact resistance. Heavy objects can directly press over the pipe without causing the pipe to rupture. The strength of the hot-melt or electric-melt interface of PE pipe is higher than that of the pipe body, and the joint will not be disconnected due to soil movement or live load. The pipe is light, the welding process is simple, the construction is convenient, and the comprehensive cost of the project is low.
Aluminum-plastic composite water supply pipe
Aluminum-plastic composite pipe is the earliest water supply pipe to replace cast iron pipe. Its basic composition should be five layers, that is, from the inside to the outside, plastic, hot melt adhesive, aluminum alloy, hot melt adhesive, and plastic. There are three main types of aluminum-plastic water supply pipes on the market: the first type has polyethylene inner and outer layers, the second type has cross-linked polyethylene inner layer and polyethylene outer layer, and the third type has cross-linked polyethylene inner and outer layers and aluminum in the middle layer.
Aluminum-plastic composite pipes have low loss, can be cut arbitrarily, are easy to install, and are convenient to construct. They have good thermal insulation performance, and the inner and outer walls are not easy to corrode. Because the inner wall is smooth, the resistance to fluid is very small and can be bent at will. The accessories are pure copper, which is expensive. The inner diameter of the copper parts is smaller than the inner diameter of the aluminum-plastic composite pipe, the caliber flow is small, and if the installation is not good, it is easy to leak when it expands and contracts due to heat and cold.
Cross-linked polyethylene (PE-X) water supply pipe
Cross-linked polyethylene pipe (PE-X) is a new generation of green pipes due to its good hygienic properties and comprehensive mechanical and physical properties. Since the 1980s, it has been used for the transportation of various fluids including drinking water and hot water.
Cross-linked polyethylene pipes use high-density polyethylene as the main raw material. Through the action of high-energy rays or chemical initiation, the linear macromolecular structure is transformed into a spatial network structure. The produced cross-linked polyethylene pipes can be used for a long time at -75~95℃ (short-term 110℃) and 0.6~2MPa pressure, with a service life of up to 50 years. This type of pipe is currently the dominant water heating pipe in the world’s floor heating industry.
Copper tube (seamless copper tube)
Copper tube, a kind of non-ferrous metal tube. It is a pressed and drawn seamless tube. It has high low-temperature strength. It is often used to manufacture heat exchange equipment (such as condensers, etc.). It is also used to assemble low-temperature pipelines in oxygen production equipment. Copper tubes with small diameters are often used to transport pressurized liquids (such as lubrication systems, oil pressure systems, etc.) and as pressure gauges for instruments. Copper tubes have the characteristics of being strong and corrosion-resistant, and have become the first choice for modern contractors to install tap water pipes, heating and cooling pipes in all residential commercial houses.
Advantages: Copper tubes are hard, not easy to corrode, and are resistant to high temperatures and high pressures. They are the best water supply pipes.
Disadvantages: High price.
Thin-walled stainless steel pipes
Austenitic thin-walled stainless steel pipes refer to stainless steel pipes with a wall thickness to outer diameter ratio of no more than 6%. After the chromium in the thin-walled stainless steel pipe reacts with oxygen and oxidants, a passivation effect is produced, forming a thin and tough dense passivation film Cr2O3 on the surface, which acts as a protective coating against corrosion.
Stainless steel pipes have high strength, strong corrosion-resistance, good toughness, excellent vibration and shock resistance, and are not brittle at low temperatures. They can ensure the purity of water quality during water delivery and are durable and recyclable as decorative materials.
Hot-dip galvanized steel pipes
Hot-dip galvanizing is to react molten metal with the iron matrix to produce an alloy layer, thereby combining the matrix and the coating.
Hot-dip galvanizing is first to pickle the steel parts. In order to remove the iron oxide on the surface of the steel parts, after pickling, they are cleaned in an ammonium chloride or zinc chloride aqueous solution or a mixed ammonium chloride and zinc chloride aqueous solution tank and then sent to the hot-dip galvanizing tank. Hot-dip galvanizing has the advantages of uniform coating, strong adhesion, and long service life.
Welded steel pipes
It can be divided into straight-seam welded pipes and spiral-welded pipes. It can be used in fire water supply pipe networks. It has the advantages of high strength and strong strain resistance, but its corrosion resistance is poor and should be treated with anti-corrosion. Steel pipes of the same diameter have different thicknesses, so the wall thickness should be indicated when selecting.
Straight seam welded pipe: simple production process, high production efficiency, low cost, and rapid development.
Spiral welded pipe: The strength is generally higher than that of straight seam welded pipe. It can produce welded pipes with larger diameters with narrower billets, and can also produce welded pipes with different diameters with billets of the same width. However, compared with straight seam pipes of the same length, the weld length increases by 30~100%, and the production speed is lower. Therefore, smaller-diameter welded pipes are mostly welded by straight seam welding, while large-diameter welded pipes are mostly welded by spiral welding.
Chlorinated polyvinyl chloride (PVC-C) water supply pipe
The pipe fittings made of chlorinated polyvinyl chloride resin as raw material have significant advantages in its durability, corrosion resistance, acid, and alkali resistance, aging resistance, low thermal expansion coefficient, thermal conductivity, good flame retardancy, and excellent hygienic properties. CPVC pipes meet the hygienic standards of all plastic hot and cold water pipes in my country and have very good market prospects.
Abroad, CPVC is widely used in the manufacture of household hot and cold water delivery pipes and fittings. Its pipes have low heat loss, no water droplets, no scale accumulation, and can be used sustainably at 82°C and 0.7MPa, and has been certified as potable water by the National Environmental Sanitation Foundation of the United States. In addition, because the ignition point of CPVC is much higher than that of wood, reaching more than 450°C, CPVC has been used in the manufacture of fire sprinkler systems abroad. At present, China has also begun to use CPVC pipes in fire protection systems.
Heat-resistant polyethylene (PE-RT) water supply pipe
As a plastic pipe, heat-resistant polyethylene not only has good stability, corrosion resistance, and connection reliability compared with traditional metal pipes such as steel pipes and iron pipes, but also has the characteristics of energy saving, no scaling, simple installation, and convenient construction, which can meet all requirements of internal pipes of floor heating systems.
It can be seen that the wide application of heat-resistant polyethylene pipes in urban heating projects in the future has become an inevitable trend, and the research on the performance and processing technology of heat-resistant polyethylene pipes is also very necessary and has practical significance.
Acrylonitrile-butadiene-styrene (ABS)
Engineering plastic water supply pipe
The material for making pipes is a mixture of acrylonitrile-butadiene-styrene, in which ABS resin is the main component, and only additives required to improve its physical, mechanical properties and processing properties are added, and the additives should be evenly dispersed. The density of acrylonitrile-butadiene-styrene (kg/m3) is: 1000≤ρ≤l070. The acrylonitrile in the acrylonitrile-butadiene-styrene raw material should be greater than 20 (mass fraction), and the other components should not be greater than 5% (mass fraction). The raw materials should be made into pipes and tested according to GB/T 18252. The minimum required strength MRS ≥ 14 MPa and the minimum value of the overall use (design) coefficient C is 1.6.
The production of ABS pipes and fittings shall comply with the provisions of GB/T 20207. Chlorinated polyvinyl chloride pipeline systems used to transport drinking water shall comply with the requirements of GB/T 17219-1998.
According to the chemical resistance and sanitation of the material, it is suitable for the transportation of fluids such as powders, liquids, and gases in industries such as pressure water supply and drainage, sewage treatment and water treatment, petroleum, chemical industry, power electronics, metallurgy, mining, electroplating, papermaking, food and beverage, air conditioning, medicine, and construction.
Steel-lined (coated) plastic composite water supply pipe
Steel-plastic composite pipe, the product is based on seamless steel pipe and welded steel pipe, and the inner wall is coated with high adhesion, anti-corrosion, food-grade hygienic polyethylene powder coating or epoxy resin coating. The diameter range DN15–DN1200 can be coated with flanges and pressure grooves. Length 6m, 9m, 12m and irregular length Coating wall thickness between 100 microns and 500 microns, usually 350 microns.
Product features:
1. Sanitary and non-toxic, no scale accumulation, no breeding of microorganisms, and guaranteed fluid quality.
2. Resistant to chemical corrosion, soil and marine biological corrosion, and cathode stripping.
3. The installation process is mature, convenient, and fast, and the connection is similar to that of ordinary galvanized pipes.
4. Good weather resistance, suitable for harsh environments such as deserts and saline-alkali.
5. The pipe wall is smooth, improves transportation efficiency, and has a long service life. Common steel-plastic composite pipes are steel-lined polypropylene composite pipe (GSF.PP), steel-lined polyvinyl chloride composite pipe (GSF.PVC), steel-lined polyethylene composite pipe (GSF.PE), and steel-lined polytetrafluoroethylene composite pipe (GSF.F4).
Lined stainless steel composite steel pipe
The lined stainless steel composite steel pipe implements the urban construction industry standard CJ/T192-2017. It is a composite thin-walled stainless steel pipe on the inner wall of the steel pipe. This bimetallic composite steel pipe greatly improves the corrosion resistance of the steel pipe in the process of water, hot water, gas, natural gas, and oil transportation. It has a smooth surface, low fluid resistance, and retains the high mechanical strength of the steel pipe.
It can be welded, grooved, and threaded. It has the advantages of good sealing and overcomes the defects of easy corrosion of galvanized steel pipes and easy leakage and aging of plastic pipes connected by hot melt. It is an ideal product for upgrading gas, water, and oil pipes.
Glass fiber reinforced plastic sand (RPM) pipe
The pipe is made of high-strength glass fiber reinforced plastic as the inner and outer reinforcement layers, and the middle is made of cheap quartz sand/resin as the core layer to improve the rigidity of the pipe, and then supplemented with a tough acid and alkali corrosion-resistant lining layer and an outer protective layer that meets the requirements of the working environment to form a composite pipe wall structure. RPM pipes can be produced by centrifugal casting or winding process. Therefore, there are two types of composite pipes: composite pipes, wound pipes, and centrifugal casting pipes. When the centrifugal casting process is used, the glass fiber uses short chopped fibers; when the winding process is used, the glass fiber uses long fibers. The maximum diameter of the centrifugally cast RPM pipe is 2400mm, and the maximum diameter of the fiber-wound RPM pipe can reach 4000mm. It is a thermosetting plastic pipe.
Its characteristics are 1) Good corrosion resistance. 2) Lightweight and high strength. 3) Easy to install. 4) Smooth inner surface with high flow capacity. 5) Good low-temperature resistance. 6) Good thermal insulation performance.
Reinforced polypropylene (FRPP) molded pipe
A glass fiber-reinforced polypropylene (FRPP) pipe is produced using raw materials treated with a glass fiber-modified polypropylene coupling agent.
The products have the characteristics of corrosion resistance, high strength, leakage resistance, small internal resistance, tensile strength, bending resistance, low cost, long life, easy installation and maintenance, etc. They are widely used in petroleum, chemical, electric power, textile, metallurgy, pharmaceutical, papermaking, food, mining, garbage disposal, construction and other industries for corrosive liquid transportation and process pipelines, and are deeply trusted by users.
