There are many types of pipes used in water supply and drainage projects. This article summarizes 16 commonly used pipes and introduces them comprehensively.
1.Rigid PVC-U Pipe
The PVC-U pipe is made of sanitary polyvinyl chloride (PVC) resin as the main raw material, adding appropriate amount of stabilizer, lubricant, filler, color enhancer, etc., extruded by plastic extruder and injection molded by injection molding machine, through cooling, solidification, Shaping, inspection, packaging and other processes to complete the production of pipes and fittings.
The advantages of PVC-U pipes: light weight, corrosion resistance, small water flow resistance, energy saving, quick installation, and low cost.
Scope of application: urban tap water supply projects, building internal and external water supply projects, industrial and mining enterprise water supply projects, buried fire protection water supply projects, farmland water conservancy water supply irrigation projects, gardening and greening water supply projects, aquaculture water supply and drainage projects, etc.
2.PP-R water supply pipe
PP-R pipe is also called three-type polypropylene pipe, which is made of random copolymerized polypropylene, extruded into pipe, and injected into pipe fittings.It is a new type of plastic pipe product developed and applied in Europe in the early 1990s.In the late 1980s, PP-R adopted the gas phase copolymerization process to randomly and uniformly polymerize about 5% of PE in the molecular chain of PP (random copolymerization) and became a new generation of pipeline materials.It has good impact resistance and long-term creep performance.
Advantages of PPR pipe: moderate price, stable performance, heat and heat preservation, corrosion resistance, smooth inner wall without scaling, safe and reliable piping system, impermeable, and service life of up to 50 years.Known as never scale, never rust, never leak, 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 fields:
1.Hot and cold water systems for buildings, including central heating systems;
2.Heating systems in buildings, including floor, siding and radiant heating systems;
3.Pure drinking water supply system;
4.Central (centralized) air conditioning system;
5.Industrial piping systems such as conveying or discharging chemical media.
3.Aluminum-plastic composite water supply pipe
The aluminum-plastic composite pipe is the earliest water supply pipe to replace the 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 to the outside.
The aluminum-plastic composite pipe has good thermal insulation performance, and the inner and outer walls are not easy to corrode. Because the inner wall is smooth, the resistance to the fluid is small; and because it can be bent at will, it is convenient for installation and construction.
There are three main types of aluminum-plastic water supply pipes on the market:
The first is that the inner and outer layers are polyethylene, the second is that the inner layer is cross-linked polyethylene, the outer layer is polyethylene, and the third is that both inner and outer layers are cross-linked polyethylene, and the middle layer is aluminum.The first type is generally used in cold water piping systems, and the latter two are generally used in hot water pipes.
Also known as copper tube. A type of non-ferrous metal pipe, which is a pressed and drawn seamless pipe.
Advantages: The copper pipe is hard, not easy to corrode, and resistant to high temperature and high pressure. It is the best water supply pipe.
Disadvantages: high price.
5.Light gauge stainless pipes
Stainless steel strip or stainless steel plate with a wall thickness of 0.6~2.0mm, pipes made by fusion welding processes such as automatic argon arc welding.
The domestic thin-walled stainless steel water pipe is a new type of pipe that came out in the late 1990s. Due to its safety and hygiene, high strength, good corrosion resistance, durability, long life, maintenance-free, and beautiful appearance, the current stainless steel water pipe has a strong development momentum. , Has been widely used in building water supply and direct drinking water pipelines.
The light gauge stainless pipe has the following outstanding advantages: excellent mechanical properties, superior wear resistance, good safety and health performance, good temperature resistance, good heat preservation performance, smooth inner wall and small water resistance; beautiful appearance, clean and fashionable, 100% reliable Recycling and reuse; help to save water resources; wide range of use; long service life and low overall cost.
6.Hot-dip galvanized steel pipe
Galvanized steel pipes are divided into cold-galvanized pipes and hot-dip galvanized pipes, the former has been banned.The hot-dip galvanized pipe is to make the molten metal react with the iron matrix to produce an alloy layer, so that the matrix and the coating are combined.Hot-dip galvanizing is to pickle the steel pipe first. In order to remove the iron oxide on the surface of the steel pipe, after pickling, it is cleaned by ammonium chloride or zinc chloride aqueous solution or a mixed aqueous solution of ammonium chloride and zinc chloride, and then sent to hot dip coating tank.Hot-dip galvanizing has the advantages of uniform coating, strong adhesion, and long service life.The hot-dip galvanized steel pipe substrate undergoes complex physical and chemical reactions with the molten plating solution to form a corrosion-resistant zinc-iron alloy layer with a tight structure.The alloy layer is integrated with the pure zinc layer and the steel pipe substrate.Therefore, it has strong corrosion resistance.
7.Welded steel pipe
It can be divided into straight seam welded pipe and spiral welded pipe. It can be used in fire water supply pipe network. It has the advantages of high strength and strong strain resistance, but its corrosion resistance is poor, so it should be treated with anticorrosion. Steel pipes of the same diameter have different thicknesses, so the wall thickness should be indicated when selecting.
Longitudinal welded pipe: the production process is simple, the production efficiency is high, the cost is low, and the development is rapid.
Spiral welded pipe: The strength is generally higher than that of straight seam welded pipe. It can use narrower blanks to produce welded pipes with larger diameters, and can also use the same width of blanks to produce welded pipes with different diameters. But compared with the straight seam pipe of the same length, the weld length is increased by 30~100%, and the production speed is lower. Therefore, most of the welded pipes with smaller diameters adopt straight seam welding, and most of the large diameter welded pipes adopt spiral welding.
8.PVC-C water supply pipe
PVC-C resin is used as the masterbatch, and it is extruded at high speed by adding anti-impact agent, stabilizer and other auxiliary materials.
1.Strong: Since PVC-C is stronger than PP-R, PB and PEX, less hooks and brackets are needed. PVC-C can withstand higher pressure. Under the same flow rate, compared with PP-R, PB and PEX pipes, PVC-C pipes can use smaller pipe diameters.
2.Easy to install: It can be connected with a special fusion agent, and no special tools are required for installation, which is suitable for surface installation and concealed installation.
3.Corrosion resistance: PVC-C is not easy to permeate oxygen, so the metal parts in the system will not be corroded due to oxidation.
4.Good flame retardancy: The oxygen index of PVC-C is 60, and its combustion ability is very low.
5.Unaffected by residual chlorine: Unlike polyolefin pipes, PVC-C pipes will not be affected by residual chlorine in water after long-term use, and will not crack and collapse.
6.Acid and alkali resistance: PVC-C has a strong anti-corrosion ability for both acid and alkali, and can be used to transport HCL and NaOH liquids.
7.Bacteria are not easy to reproduce: After many tests, it has been confirmed that bacteria in PVC-C pipes are not easy to breed, and the growth rate of bacteria is 1/60 of PEX pipes, 1/10 of copper pipes, and 1/4 of steel pipes. The test amount of Legionella in the water sample is 1/13 of the PEX tube and 1/17 of the PP-R tube.
8.Low thermal expansion coefficient and aging resistance: Compared with other plastic pipes, the thermal expansion coefficient of PVC-C pipe is small, about 1/2 of other plastic pipes such as PP-R, PB and PEX. PVC-C pipes have strong UV resistance and can be used outdoors, while ordinary polyolefin pipes cannot.
9.Superior hygienic performance standards: PVC-C cold and hot water pipes have been tested by many international water quality and sanitation authorities, and the results are superior to the standards for drinking water by the World Health Organization and the Ministry of Health of the People’s Republic of China.
The PE pipe is processed without adding heavy metal salt stabilizer, the material is non-toxic, without scaling layer, and does not breed bacteria, which effectively solves the secondary pollution of urban drinking water.In addition to a few strong oxidants, it can resist the erosion of a variety of chemical media; No electrochemical corrosion.PE pipes can be safely used for more than 50 years under rated temperature and pressure.PE pipe has good toughness, high impact strength, and heavy objects directly press the pipe, which will not lead to pipe rupture.The strength of PE pipe hot-melt or electrofusion joint is higher than that of pipe body, and the joint will not be disconnected due to soil movement or live load.The pipeline is light, the welding process is simple, the construction is convenient, and the comprehensive cost of the project is low.
10.ABS Engineering plastic water supply pipe
The material used to manufacture pipes is a mixture of acrylonitrile-butadiene-styrene, in which ABS resin is the main ingredient. Only the additives needed to improve its physical, mechanical and processing properties are added. The additives should be evenly dispersed.Density of propylene wax-butadiene-styrene (kg/m3): 1000 ≤ ρ≤ l070.The acrylonitrile in the raw material of propylene wax-butadiene-styrene shall be greater than 20 (mass fraction), and other components shall not be greater than 5% (mass fraction).Raw materials shall be made into pipes and tested according to the provisions of GB/T 18252. The minimum required strength MRS ≥ 14 MPa, and the minimum value of the overall service (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 pipe system used for drinking water transmission shall meet the requirements of GB/T 17219-1998.
According to the chemical resistance and hygiene of the material, it is applicable to the transportation of powder, liquid and gas in industries and construction fields such as pressure water supply and drainage, sewage treatment and water treatment, petroleum, chemical industry, power electronics, metallurgy, mining, electroplating, paper making, food and beverage, air conditioning, medicine, etc.
11.Plastic-coated steel 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 polyethylene powder coating or epoxy resin coating with high adhesion, anti-corrosion and food-grade sanitation.Diameter range DN15-DN1200 can be coated with flange and pressure groove.The wall thickness of the coating with length of 6m, 9m, 12m and variable length is between 100μm and 500μm, usually 350μm.
1.It is sanitary, non-toxic, free of scale, free of microorganisms, and ensures fluid quality.
2.It is resistant to chemical corrosion, corrosion of soil and marine organisms, and cathodic stripping.
3.The installation process is mature, convenient and fast, and is similar to the connection of ordinary galvanized pipe.
4.Good weather resistance, suitable for harsh environments such as desert and saline-alkali.
5.Smooth pipe wall, improved conveying efficiency and long service life.Common steel-plastic composite pipes include:GSF.PP composite pipe,GSF.PVC composite pipe,GSF.PE composite pipe,GSF.F4 composite pipe.
12.Plastic lined steel pipe
It can be divided into straight welded pipe and spiral welded pipe.Can be used in fire water supply network.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 with the same diameter have different thicknesses, so the wall thickness should be indicated when selecting.
Longitudinal welded pipe: simple production process, high production efficiency, low cost and rapid development.
Spiral welded pipe: its strength is generally higher than that of straight welded pipe. It can produce welded pipe with larger pipe diameter with narrow blank, and it can also produce welded pipe with different pipe diameters with blank of the same width.However, compared with the straight seam pipe with the same length, the weld length increases by 30~100%, and the production speed is lower. Therefore, the small-diameter welded pipes are mostly straight welded, while the large-diameter welded pipes are mostly spiral welded.
13.Cast iron pipe
Ductile iron pipe is a kind of cast iron pipe, which is used as buried water supply pipe.
Compared with steel pipe, it has the advantages of low price, simple manufacturing and strong corrosion resistance; The disadvantage is brittle and heavy.
Data shows that there are pipes between DN40 and DN80, but the design manual only lists the specifications above DN80. There is no change in pipe wall thickness due to the nominal pressure, and it is not necessary to specify the nominal pressure level.
HDPEis a thermoplastic resin with high crystallinity and non-polarity.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 obvious advantages such as light weight, corrosion resistance, small water flow resistance, energy saving, simple and rapid installation, and low cost, and are favored by the pipeline engineering community.
HDPE pipes are mainly used for municipal engineering water supply system, indoor water supply system of buildings, outdoor buried water supply system and underground water supply system of residential quarters and factories, repair of old pipelines, water treatment engineering pipeline system, industrial water pipes in gardens, irrigation and other fields.
15.FRPP Moulded pipe
FRPP pipe is produced from glass fiber modified polypropylene raw material treated with coupling agent.The product has the characteristics of corrosion resistance, high strength, leakage resistance, small internal resistance, tensile strength, bending resistance, low cost, long service life, convenient installation and maintenance, and is widely used in petroleum, chemical industry, electric power, textile, metallurgy, pharmaceutical, paper making, food, mining, garbage treatment, construction and other industries, as well as corrosive liquid transmission and process pipeline, which is deeply trusted by users.
The pipe is made of high-strength glass fiber reinforced plastic as the inner and outer reinforcement layer, and the middle is made of cheap quartz sand/resin as the core layer to improve the rigidity of the pipe, and the composite pipe wall structure is composed of a tough acid-alkali corrosion resistant inner layer and an outer protective layer meeting the requirements of the working environment.RPM pipe can be produced by centrifugal casting or winding process. Therefore, there are two types of composite pipe winding pipe composite pipe and centrifugal casting pipe.When centrifugal casting process is adopted, chopped glass fiber is used; When the winding process is adopted, the glass fiber adopts long fiber.The maximum diameter of centrifugally cast RPM pipe is 2400mm, and the maximum diameter of filament wound RPM pipe is 4000mm. It is thermosetting plastic pipe.
Its characteristics are:
1.Good corrosion resistance
2.Light weight and high strength
4.The internal surface is smooth and has high circulation capacity
5.Good low temperature resistance
6.Good thermal insulation performance