PE Pipe for Water Supply Specification

No matter in China or other developed countries, pe pipe for water supply is very commonly used in urban water supply systems, we are a professional manufacturer of pe pipe for water supply, we can do 16mm-1600mm pe pipe for water supply, and we can also According to the needs of customers, the products are modified. Our factory currently exports the most pe pipe for water supply. Customers who need to order pe pipe for water supply can refer to the parameters in the following table. Among them, the material of pe100 has new national standard parameters. Customers who need it can contact us or leave a message to get it.

Construction of PE pipe for water supply in urban water supply projects

Advantages of PE pipe for water supply

Ductile ink pipes have been widely used in the construction of China's water supply pipe network, and plastic pipes (mainly PVC pipes and PE pipes) are also used in a certain amount. The material of PE pipe for water supply is non-toxic, so most of the plastic water supply pipes used in developed countries such as Europe and the United States are PE pipes. Now compare the PE pipe for water supply with the ductile ink tube to illustrate the superiority of the PE tube.

1.1 Physical and chemical properties

a. Light weight, hygienic and non-toxic materials, long-term use does not scale, does not rust, the inner wall of the pipeline is smooth and does not change with the use of time, and can maintain good water quality for a long time;

b. It has good flexibility and is easy to bend and shape; the length of the pipe can be supplied according to the user's requirements (small-diameter pipes are coiled), the number of interfaces is small, and the installation speed is fast;

c. The joint is integrated with the pipe material, has good thermal melting property, high interface reliability and good sealing performance;

d. Anti-vibration, high impact strength; strong applicability to ground changes;

e. It has stable chemical properties, corrosion resistance, wear resistance and long service life; it is easy to recycle, and does not produce substances that damage the environment.

1.2 Comprehensive cost of pipelines

The cost of PE pipe for water supply is usually equivalent to about 70% of that of ductile ink pipe. In practical applications, using the

Substituting small-sized PE pipe for water supply for ductile pipes with the same water delivery capacity can further reduce the cost.

PE water supply pipeline construction

2.1 Pipe groove section and pipe foundation treatment

The size of the trench excavation section has a great influence on the construction schedule and cost. Usually a longer pipeline is prefabricated on the ground to reduce the excavation width B of the pipe trench. Generally, the width of the pipe trench can be determined according to B=D+0.3m (D-pipeline outer diameter) to meet the requirements. The foundation of the pipeline is required to be flat and have sufficient strength, and the trench must be excavated to prevent disturbing the undisturbed soil of the base. When the base is in a relatively soft soil layer below the groundwater level, it can be treated by laying 15cm thick gravel with a particle size of less than 50mm thick, and then laying a 5cm thick sand cushion, so that the pipeline can obtain long-term stable support.

2.2 Pipe connection

2.2.1 Select the connection method

The connection of PE pipe for water supply mainly includes thermal fusion connection, mechanical connection, electric fusion connection and other methods. The hot-melt connection method has the advantages of low cost, good pipe joint quality, and no need for pipe fittings, so it is widely used. Due to the unfavorable factors such as the need for welding equipment, long time-consuming interface hot-melt operations, and high technical requirements, it is recommended to use it under the conditions of relatively concentrated pipeline engineering, long straight pipes with few branches, relatively concentrated machinery, and no water accumulation in pipe trenches. Otherwise, PE pipes and fittings with socket flexible interface can also be considered. Currently, there are few manufacturers producing such products. The flange connection is suitable for the connection between PE pipes of different materials and the connection between PE pipe for water supply and pipe accessories, and steel-plastic joints are used for small-diameter metal pipes. Electrofusion connection is easy to operate and reliable, and can be used for the connection of pipes of the same material, but the price of pipe for water supply fittings is high, and it is usually only used in special locations and when construction is difficult.

2.2.2 Main points of quality control of hot melt connection

The quality defects and preventive measures that are prone to occur during the hot-melt connection process are as follows:

a. Cracks appear on the pipes at or near the joints: Due to the set temperature being too high, the surface of the pipes is carbonized, and the melt flow rates of the materials at the two ends of the joint are different.

b. There is a gap in the weld: the welding pressure is insufficient, the heat absorption time or cooling time is too short, and the cutting of the nozzle is not parallel.

c. Pipe end misalignment: due to the different axes of the machine tools and fixtures, the PE pipe for water supply section is not erected horizontally, and the operation error is large.

d. The curling is not standardized: too narrow means that the welding pressure is too high, and too wide means that the heat absorption time is incorrect.

e. Insufficient welding produces false welding: the end face of the connected pipe is polluted, the conversion time is too long, hot plate temperature is too low.

f. Angle deformation: uneven force on the pipe end caused by improper installation of the fusion machine and the pipe.

g. Pores and sand holes appear on the connection surface: insufficient welding pressure and insufficient cooling time.

h. Voids caused by external impurities: the heating plate is not cleaned or there is water solvent on the heating plate.

2.3 Pipe laying

When the pipeline changes direction, the good flexibility of the pipeline can be used for bending and laying, and the bending radius must meet the requirements. For example, when the nominal outer diameter of the pipeline D (mm) ≤ 50, the allowable bending radius R (mm) = 30D; otherwise, an elbow must be used . When the pipe passes through the well chamber, a steel pipe or steel ring with a diameter one to two larger than the PE pipe for water supply is built in the well wall as a casing, and rubber or clay is filled in the middle to form a natural connection.

2.4 Trench Backfill and Pipeline Protection

After the pipeline is installed, it should be backfilled as soon as possible, and the pressure test should ensure that the filling height at the top of the pipeline is not less than 0.5m. And the method of laying warning tape and tracer line is used for pipeline protection.

2.5 Pipeline pressure test

The hydrostatic test of PE pipe for water supply is a comprehensive inspection of the pipe joints, pipe materials, and construction quality. Referring to the "Code for Construction and Acceptance of Water Supply and Drainage Pipeline Engineering", it is required that the length of each section of the pipeline pressure test should not be greater than 1.0km, and the joints should not leak for 1h under the test pressure of 1.5 times the design working pressure and not less than 0.6Mpa, that is, the strength The test is qualified; if the pressure drop is not greater than 0.05Mpa within 1 hour of voltage stabilization, it can be judged as tight and the test is qualified. Since PE pipe for water supply is a kind of thermoplastic material, the pipe itself has the characteristics of creep and stress relaxation, which is different from traditional material (such as ductile iron, steel, etc.) pipes. During the hydraulic test, the creep of PE pipe will cause For a period of time, it shows a continuous downward trend, and the pressure test takes a long time. Water injection is required to replenish the pressure. The pipeline should not be considered to be leaking. Therefore, the hydraulic pressure test of pipe for water supply is consistent with the hydraulic pressure test of pressure pipelines in GB 50268 Water Supply and Drainage Pipeline Engineering Construction and Acceptance Specifications Different methods and standards for judging hydrostatic tests are also different, and the pressure drop phenomenon of PE pipes during pressure tests should be fully understood.

In short, PE pipes for water supply have unique properties. The use of PE pipes in projects can not only reduce engineering costs, but also help protect water quality and save operating costs. It has good economic and social benefits and is worthy of promotion and application in water supply pipe networks.