Selection of drainage pipes
General drainage pipe can be divided into rigid pipe and flexible pipe (plastic pipe) according to its characteristics.
(1) rigid pipes rigid pipes include cast iron pipes, concrete pipes, ceramic pipes, etc., which are all pipes made of traditional materials. Their advantages are good rigidity, high ring stiffness, but poor anti-corrosion performance. Its biggest shortcoming is easy to break (except cast iron pipe), leakage is serious, easy to cause secondary pollution.
(2) according to its pipe wall structure, plastic pipe and plastic drainage pipe can be divided into two categories: solid wall plastic pipe and structural plastic pipe. Solid wall pipe has hard polychloroacetylene pipe, glass reinforced plastic sand pipe and PE pipe, the structure wall pipe is divided into single (double) wall corrugated pipe, reinforced pipe and winding pipe three categories. According to the ministry of construction on the release of chemical building materials technology with the announcement of the product of the spirit, is applied to a new type of pipe drainage is mainly plastic pipe material, its main varieties include: PVC tube (PVC -u)/polyvinyl chloride (PVC) core layer foam pipe (PVC -u), polyvinyl chloride (PVC) double-wall corrugated pipe, glass fiber reinforced plastic (PVC -u) sand inclusion tubes (RPMP), plastic spiral coil pipe (HDPE/PVC -u), polyvinyl chloride (PVC) radial reinforcement tube (PVC -u), etc. Compared with the traditional rigid pipe, plastic pipe has the characteristics of light weight, corrosion resistance, high compressive strength, health and safety, small water flow resistance, energy saving, metal material saving, improved living environment, long service life, convenient installation, etc., which has received the favor of the pipeline engineering field. To this end, many developed countries plastic products manufacturers and pipeline engineering industry for extensive cooperation, invested a lot of manpower. Carry on the omni-directional development research, material and financial resources to make production materials synthesis, pipe fitting manufacturing technology, design theory and construction technology of the development and perfection, and accumulated rich practical experience, prompting plastic pipe in pipeline engineering occupies very important position, and form a kind of inevitable development trend. Plastic pipe is one of the chemical building materials which are mainly used in China.
At present, the production of plastic pipe material are mainly PVC, polyethylene, polypropylene and other common thermoplastics and phenolic resin, epoxy, polyester and other types of thermosetting resin glass fiber reinforced plastic bakelite, fluorine plastics and asbestos, etc., they are widely used in building construction of tap water supply piping system, water drainage, health the exhaust and pollution emission, underground drainage pipes, rainwater pipe and wire installation kit with wire and cable, etc. Here a few kinds of more extensive use of plastic tube points, for reference.
1. Hard PVC (UPVC) pipe PVC is the most widely used plastic, it is a multi-functional material, through the change of formula, can be made into hard and soft two. PVC chlorine content of 56.8%, because of the chlorine, PVC has self-extinguishing, which is very beneficial for its use as building materials. Hard PVC, namely UPVC, UPVC pipe is PVC resin as the main raw material, adding stabilizer, impact modifier, lubricant and other additives, by kneading, plastic refining, granulation, extrusion processing. Pvc-u pipes are widely used in chemical industry, paper making, electronics, instrumentation, oil and other industrial fluid pipeline corrosion protection, but cannot be used for conveying aromatic alkyne, fat acetylene, aromatic halogen derivative of acetylene, ketone and nitric acid, etc.), on agriculture irrigation and drainage tube, building, ships, vehicles armrest and wire and cable to protect casing, etc. Hard polyvinyl chloride (UPVC) is a variety of plastic pipe consumption of the largest variety, is also the new chemical building materials are vigorously developed at home and abroad. The adoption of this kind of pipeline can play a positive role in alleviating the situation of steel shortage and energy shortage in our country, with remarkable economic benefits. UPVC tube has the following characteristics: (1) good chemical corrosion, no rust. (2) with self-extinguishing and flame retardant. (3) good aging resistance, can be used between -15°C and 60°C for 20-50 years. (4) the inner wall is smooth, the inner wall has surface tension, it is difficult to form scale, the fluid transport capacity is 43.7% higher than cast iron pipe. (5) light weight, easy to expand, bonding, bending, welding, installation work is only one third of the steel pipe, low labor intensity, short time limit. (6) resistance performance is good, volume resistance of five 1 * 10 square Ω, five of 3 * 10 square, cm, breakdown voltage 22 kv/mm ~ 26 kv/mm. (7) low price. (8) metal energy saving, but the pressure resistance is bad, noise big, in order to solve this defect, South Korea in the early 1970 s research and development of a new type of building drainage pipe -- -- -- -- -- - deadened the noise of pvc-u pipe, its inner surface with six triangular convex type spiral line, make the water continuous spiraling flow along the pipe wall, the drainage drainage condition of the formation of optimal rotation, thus good silencing effect at the bottom of the riser, reducing the noise; At the same time, the sound tube unique structure can make the air in the middle of the tube forming gas discharge directly, no need to like in the past the other special ventilation tube, 10 times the high-rise building drainage ventilation capacity, displacement increase 6 times, the noise is lower than ordinary UPVC drainage pipe and cast iron pipe db 30 ~ 40 db, deadened the noise of UPVC pipe with censored pipe fittings, drainage effect is good.
High density polyethylene (HDPE) plastic pipe polyethylene (PE) plastic pipe with polyethylene resin as raw material, with a certain amount of additives, through extrusion molding, processing. PE is a kind of crystalline high polymer, crystallinity and density, the higher the general density, crystallinity is also higher. PE according to the density can be divided into two categories, namely high density polyethylene (HDPE) and low density polyethylene (LDPE). High density polyethylene pipe with its excellent chemical properties, toughness, wear resistance and low prices and installation costs by the pipeline industry attention, it is only after PVC, the use of the second plastic pipe material. Its specific characteristics are as follows: (1) unique structure, high strength, compressive impact resistance; (2) smooth inner wall, low friction resistance and large overflow; (3) anti-corrosion, non-toxic and pollution-free, outstanding environmental protection; (4) convenient connection, good seal of the joint, no leakage; (5) light quality, fast construction, reduce costs; (6) long buried service life. High density polyethylene (HDPE) double-wall corrugated pipe is a kind of material saving, strong rigidity, good bending, with corrugated outer wall, smooth inner wall of the pipe. Compared with the ordinary pipe with the same specification and the same strength, the double-wall pipe can save 40% of material. In Europe and the United States, HDPE double wall corrugated pipe in a considerable range of steel pipe, cast iron pipe, cement pipe, asbestos pipe and ordinary plastic pipe, is widely used as drainage pipe, sewage pipe, underground cable pipe, agricultural irrigation pipe. Polypropylene (PPR) plastic pipe polypropylene plastic pipe with polypropylene resin as raw material, add an appropriate amount of stabilizer, through extrusion molding and processing, the product has a light weight, corrosion resistance, high heat resistance, construction convenience and other points. The density of polypropylene (PPR) is the smallest through plastics, about 0.89g/cm3~0.91g/cm3. PPR combustion and PE close, flammable and will be low, causing flame spread. Its heat resistance is better, at 100°C still can maintain normal temperature tensile strength of half. PPR is also a crystalline polymer with higher tensile strength than PE. In addition, the chemical resistance of PPR is also close to PE. Polypropylene plastic pipe is suitable for conveying fluid medium (including corrosive fluid medium) in chemical industry, petroleum, electronics, medicine, diet and other industries and all kinds of civil buildings. The connection of polypropylene plastic pipe USES adhesive to bond more, at present market sells adhesive kind is a lot of, use asphalt resin adhesive is relatively cheap. 4. Fiberglass downpipe, downspout fiberglass downpipe, downspout with unsaturated polyester resin as adhesive, glass fiber products as reinforcement materials, generally made by hand paste forming method. The product has the characteristics of light quality, high strength, no rust, corrosion resistance, high and low temperature resistance, bright color and simple construction, maintenance, maintenance, etc., suitable for all kinds of buildings roof drainage, but also for industrial, domestic wastewater, sewage drainage. There are other plastics, such as polystyrene (PS), acrylonitrile-butadiene-polyethylene (ABS), but they are not usually used in drainage pipes.