Therefore, there are three main categories of pipes currently in use. The first category is the metal pipe, such as plastic-lined hot-plated cast iron pipe, steel pipe, stainless steel pipe, etc.. The second category is plastic composite metal pipe, such as plastic composite steel pipe, aluminum-plastic composite pipe, etc. The third category is the plastic pipe, such as PP-R (cross-linked polypropylene high-density mesh engineering plastics). Also provides for a variety of pipes and fittings involving drinking water pipes, must have the approval of the health department, before sales.
Commonly used plastic code and meaning in water supply pipes.
PP-R cross-linked polypropylene high-density mesh engineering plastics PE high-density polyethylene PP polypropylene PB poly PEX cross-linked polyethylene comprehensive performance requirements for water supply piping: as water supply piping, health, safety, energy saving and convenience are required. Therefore a pipeline, should be checked from four aspects. That is, hygiene: pipes and fittings shall be free from any damage to human body.
Safety: sufficient strength and excellent mechanical properties as well as anti-aging, heat resistance and other properties.
Energy saving: smooth inner wall, corrosion resistance, low resistance to fluid and good heat preservation performance. Convenient: convenient coupling, construction, reliable, with the possibility of promoting the use of. If the above four requirements are not met, it will damage the health of the user and the safety of property.
Several kinds of water supply pipe profile.
1, aluminum-plastic composite pipe Aluminum-plastic composite pipe is an early alternative to cast iron pipe water supply pipe, its basic composition should be five layers, that is, from the inside out, in order of plastic, hot melt adhesive, aluminum alloy, hot melt adhesive, plastic. Aluminum-plastic composite pipe has better heat preservation performance, the inner and outer wall is not easy to corrode, because the inner wall is smooth, the resistance to fluid is very small; and because it can be bent at will, so the installation and construction is convenient. As a water supply pipe, aluminum-plastic composite pipe has enough strength, but if the lateral force is too large, it will affect the strength, so it is suitable for open pipe construction or buried in the wall, but not buried in the ground. The connection of aluminum-plastic composite pipe is ferrule type, so one is to pass strict test pressure in construction, whether the connection is firm. Second, to prevent frequent vibration, so that the ferrule loose. Third, the length of the direction should leave enough installation volume, so as not to pull off.
2, plastic composite copper pipe plastic composite copper pipe to pure copper (purple copper) for fittings, PE plastic outside, from a comprehensive performance, plastic composite copper pipe slightly aluminum-plastic composite pipe. For example, the strength is better, longer life, heat-resistant performance is also better. But the insulation performance is slightly worse. Pure copper has a very high corrosion resistance, after a period of time, the inner surface will appear a layer of green oxide. But the life of the tube, the flow, and the resistance to fluid, basically nothing. Copper green is not harmful to human health, and has the ability to kill. Plastic compound copper pipe installation methods are ferrule type and welding type two, welding type is more reliable.
Copper, stainless steel pipe: This type of pipe in addition to poor insulation performance, other indicators such as strength, life expectancy on the resistance of the fluid are very good, set up suitable for cold water piping. If used for hot water transmission, should add insulation sheath. The connection method is mainly tube type, copper pipe can also be welded. Galvanized cast iron pipe with internal plastic coating: that is, a layer of plastic coating on the inner wall of ordinary galvanized pipe, so that it has the performance of corrosion resistance, low resistance, good insulation, while having the characteristics of galvanized pipe itself with high strength. This pipe is connected by ribbing.
Plastic pipe: Plastic pipe can have sufficient strength, longevity, safety and hygiene as long as the material selection meets the standard requirements. It is the good insulation performance of all pipes. Plastic pipe adopts heat fusion welding, high reliability, as long as the construction is correct, by the test pressure of normal pipe welding, there will be no leakage off.