Hdpe Tube Other Instructions

Plastic pipes have achieved great development and improvement in the design theory and construction technology of buildings, and accumulated rich practical experience, which has promoted plastic pipes to occupy a very important position in the construction of water supply and drainage pipeline engineering, and form a first An unstoppable development trend. In our country, most plastic pipes used in water supply pipelines mainly include PVC-U water supply pipes, PP-R pipes, aluminum-plastic composite pipes (PAP), steel-plastic composite pipes (SP), HDPE pipes, etc. HDPE pipe adopts advanced production technology and technology and is formed by hot extrusion. It has the characteristics of corrosion resistance, smooth inner wall, low flow resistance, high strength, good toughness, and light weight. After PVC-U drainage pipes, HDPE pipes have become the second most consumed plastic pipe variety in the world.

1. The development of HDPE water supply pipes

In the water supply and drainage piping system, plastic pipes have gradually replaced traditional pipes such as cast iron pipes and galvanized steel pipes as the mainstream pipes. Compared with traditional pipes, plastic pipes have significant advantages such as light weight, corrosion resistance, low water flow resistance, energy saving, simple and rapid installation, and lower cost. They are favored by the pipeline engineering community. At the same time, with the rapid development of the petrochemical industry and the continuous advancement of plastic manufacturing technology, the output of plastic pipes has increased rapidly, and the types of products have become more diversified.

After PVC-U drainage pipes, HDPE pipes have become the second most consumed plastic pipe variety in the world. PE80 and PE100 grade medium or high-density polyethylene pipes should be used for gas transportation; PE80 and PE100 grade medium or high-density polyethylene pipes are usually used for water supply pipes, and PE63 has gradually been eliminated. In terms of water delivery, the fastest growing is the PE100 pipeline system, and the growth rate in the next five years is expected to reach more than 10%.

In Europe, HDPE pipes have been developed and used more rapidly. HDPE pipes have gradually replaced PVC-U pipes and become the main consumer pipes. At the same time, HDPE pipes are gradually being used outside Europe.

2. HDPE pipe specifications and connection methods

The diameter of HDPE pipe ranges from DN32 to DN1000, and is divided into 26 levels. The pressure level is between 0.6Mpa ~ 1.6Mpa, a total of 5 levels.

HDPE pipe will be melted between 190℃n240℃. With this feature, the two melted parts of the pipe (or pipe fittings) can be fully contacted and maintained at proper pressure. After cooling, the two can be firmly integrated. Therefore, the connection method of PE pipe is different from that of U-PVC pipe. It usually adopts two methods of electric hot melt connection and hot melt butt. According to the size of the pipe, it can be divided into: when DN≤63, injection hot melt socket connection is used; When DN≥75, use hot melt butt connection or electrofusion socket connection; when connecting with different materials, use flange or threaded connection.

In the pipeline repair method, there are pipe expansion construction method and lining HDPE method.

Three, the application field of HDPE

HDPE pipes are mainly used for: municipal engineering water supply systems, building indoor water supply systems, outdoor buried water supply systems and residential communities, factory areas buried water supply systems, old pipeline repairs, water treatment engineering pipeline systems, gardens, irrigation and other industries. Water pipes, etc.

But it should be noted that HDPE pipes cannot be used for hot water pipes.

Fourth, the advantages of HDPE water supply pipeline in application

HDPE water supply pipelines are widely used, mainly because they have advantages that other pipelines cannot match:

1. It is easy to butt welding and electrofusion welding to form a closed anti-seepage system. When laying along the trench, it can reduce the amount of trench excavated earthwork and reduce the amount of accessories.

2. Light weight and easy to install and handle;

3. With strong wear resistance and excellent hydraulic performance, no external protection is needed for buried pipelines. It can be applied to earthquake and soil settlement areas in mining areas, and it can also be laid at the bottom of rivers by the sinking method.

4. Resistant to chemical corrosion, internal, external and microbial corrosion, strong corrosion resistance, and healthy. It is suitable for transporting acidic and alkaline substances, sewage, natural gas, coal gas and other substances;

5. Good environmental adaptability and frost resistance. Can be used for indoor and outdoor water supply pipelines.

6. Long service life, with a service life of more than almost 50 years;

7. Easy to recycle.

V. Matters needing attention in the application of HDPE water supply pipeline

1. It is recommended to take sheltering measures for outdoor laying in the open air and places exposed to sunlight.

2. Buried HDPE water supply pipelines, pipelines with DN≤110 can be installed in a serpentine shape in summer, pipelines with DN≥110 have sufficient soil resistance and can resist thermal stress, so there is no need to reserve a pipe length; in winter, there is no need Reserve the tube length.

3. When installing HDPE pipelines, if the operating space is too small (such as: pipeline wells, ceiling construction, etc.), electrofusion connection methods should be used.

4. When connecting hot-melt sockets, the heating temperature should not be too high or too long, and the temperature should be controlled at 210±10℃, otherwise it will cause too much squeeze out of the fittings and reduce the inner diameter of the water; the pipe fittings are inserted. Or the pipe interface should be clean, otherwise it will cause the socket to escape and leak; at the same time, pay attention to control the angle and direction of the pipe to avoid rework.

5. When connecting hot melt butting, the voltage is required to be between 200~220V. If the voltage is too high, the temperature of the heating plate will be too high and the voltage will be too low, and the docking machine will not work normally; when docking, keep the interface aligned, otherwise It will cause insufficient butt joint area, insufficient weld strength, and improper crimping; when the heating plate is heated, the pipe interface is not cleaned, or the heating plate has impurities such as oil and sand, which will cause the joint to detach and leak; heating time It must be controlled well. The heating time is short and the pipe heat absorption time is not enough, which will cause the welding edge to be too small, and the heating time will be too long, which will cause the welding edge to be too large and may form a false weld.