Varieties of water supply pipe fittings

In the past, the pipes used for water supply were mainly cast iron pipes. Outdoor mainly used sand cast iron pipe, indoor use is galvanized cast iron pipe, and can be divided into cold (electric) galvanized and hot-dip galvanized two. China has stipulated that from June 1, 2000, the sand mold casting pipe and cold galvanized cast iron pipe will be eliminated, and the use of hot plated cast iron pipe will be gradually restricted, and the use of aluminum-plastic composite pipe and plastic pipe will be promoted.

Therefore, there are three main categories of pipelines currently in use. The first type is metal pipes, such as hot plated cast iron pipes, steel pipes, stainless steel pipes and so on. The second type is plastic clad metal pipe, such as plastic clad steel pipe, aluminum-plastic composite pipe and so on. The third type is plastic pipe, such as PP-R (cross-linked polypropylene high-density mesh engineering plastic). The State also stipulates that all kinds of pipes and fittings involving drinking water pipelines must have the approval of the health department before they can be sold.

Code and meaning of plastics commonly used in water supply pipelines:

Pp-r crosslinked polypropylene high density mesh engineering plastic PE High density polyethylene PP polypropylene PB polybutene PEX crosslinked polyethylene water supply pipeline comprehensive performance requirements: as a water supply pipeline, it requires health, safety, energy saving and convenience. Therefore, the inspection of a pipeline should start from four aspects. That is, hygiene: pipes and accessories must not cause any damage to the human body.

Safety: It has 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, good thermal insulation performance. Convenient: easy connection and construction, reliable, with the possibility of promotion and use. If the above four requirements are not met, it will damage the physical health and property safety of the user.

Introduction of several water supply pipes:

1, aluminum-plastic composite pipe aluminum-plastic composite pipe is the earliest replacement of cast iron pipe water supply pipe, its basic composition should be five layers, that is, from the inside out, plastic, hot melt adhesive, aluminum alloy, hot melt adhesive, plastic. 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 fluid resistance is small; And because it can be bent at will, it is convenient for installation and construction. As a water supply pipeline, the aluminum-plastic composite pipe has enough strength, but if the lateral force is too large, it will affect the strength, so it should be constructed as an open pipe or buried in the wall, but it should not be buried underground. The connection of the aluminum-plastic composite pipe is sleeve type, so the construction is to pass strict pressure test to check whether the connection is firm. The second is to prevent frequent vibration, so that the sleeve loose. Third, the length direction should be left enough to install, so as not to pull off.

2, plastic composite copper pipe plastic composite copper pipe with pure copper (copper) as pipe fittings, covered with PE plastic, from the comprehensive performance point of view, plastic composite copper pipe is slightly better than aluminum-plastic composite pipe. For example, the strength is better, the life is longer, and the heat resistance is better. But the insulation performance is slightly worse. Pure copper has very high corrosion resistance, and after a period of use, a layer of green oxide will appear on the inner surface. But it has basically no effect on the life of the pipe, the flow rate, and the resistance to the fluid. Patina is not harmful to human health, and has a certain ability to kill bacteria. The installation method of plastic clad copper pipe has two kinds of card type and welding type, and the welding type is more reliable.

Copper pipe, stainless steel pipe: in addition to the poor insulation performance of this kind of pipe, other indicators such as strength, life resistance to the fluid are very good, should be used as cold water pipe. If used for hot water transportation, should add insulation sheath. The connection mode is mainly sleeve type, and the copper pipe can also be welded. Lining galvanized cast iron pipe: that is, lining the inner wall of the ordinary galvanized pipe with a layer of plastic, so that it has corrosion resistance, low resistance, good thermal insulation performance, and has the characteristics of high strength of the galvanized pipe itself. The tubes are connected with ribbed joints.

Plastic pipe: Plastic pipe as long as the material selection meets the standard requirements, it can have enough strength, life, safety and health. It has the best insulation performance of all pipes. Plastic pipe using hot melt welding, high reliability, as long as the construction is correct, the normal pressure test of the pipe welding, there will be no leakage.