The original color of PE pipes is generally milky white. Now, most pipes on the market are available in various colors such as white, gray and green for customers to choose from.

2. Can the PE pipe be exposed to the outside?

Yes, but it will shorten the service life of PE pipes, because ultraviolet rays and wind and sun will accelerate the aging of PE.

3. Can PE pipes be used in winter?

The theoretical temperature of PE pipe is -40℃-40℃. It is not damaged by freezing when used outside in winter. The toughness of PE pipe is very good. Even if it freezes, it will not be damaged. This is a very large performance of PE pipe. freeze!

4. Is the PE pipe toxic?

The PE pipe is divided into two types: new material pipe and recycled material pipe. The new material pipe has good hygienic performance: no heavy metal salt stabilizer is added during the processing of PE pipe, the material is non-toxic, no scaling layer, and does not breed bacteria. Solve the secondary pollution of urban drinking water. Because PE pipes are clean and hygienic, they are widely used in urban water supply, food and other industries. But adding the return quality will not work.

5. Can PE pipes (or fittings) with different wall thicknesses be directly hot-melted?

can not. For hot-melt butt joint, the heating temperature of the hot plate is the same, and the welding pressure applied is the same. If the cross-sectional area of ​​the hot-melt zone of the pipe and the pipe (or pipe fitting) is different, the bonding effect between the two cannot be guaranteed, which will greatly affect the butt joint. quality. Therefore, it is best not to heat-melt pipes with different wall thicknesses.

6. Are the pipe connections of PE pipes all hot melt?

There are two main connection methods for PE pipes: electrothermal fusion and hot fusion butt connection.

7. What are the advantages of polyethylene pipes over metal pipes?

①Low energy consumption, light weight, recyclable, is a new generation of environmental protection products with long service life;

② The installation (connection) is reliable and convenient, which can meet the requirements of various special occasions, and the requirements for the pipe base are low;

③Good flexibility and strong ability to resist geological movement;

④Excellent corrosion resistance.

8. What is the nominal pressure (PN), working pressure, design pressure and their relationship of pipes?

Nominal pressure refers to the working pressure of the pipe to continuously deliver water at 20°C. If the water temperature is between 25°C and 45°C, the working pressure should be corrected according to different temperature drop coefficients.

Working pressure refers to the maximum continuous motion pressure acting on the inner wall of the pipe under normal working conditions of the pipe, excluding the fluctuating pressure of water.

Design pressure refers to the maximum instantaneous pressure that the piping system acts on the inner wall of the pipe. Generally, the sum of working pressure and residual water hammer pressure is used.

The relationship between the three: nominal pressure ≥ working pressure

Design pressure=1.5×working pressure

The working pressure is derived from the hydraulic calculation of the pipe network.

9. Why should an exhaust valve be installed in the pipeline? How to set it up?

During the operation of the pipeline, the gas in the water will accumulate in the high position of the pipeline, and even form a gas block. When the water flow in the pipe fluctuates, the bulging part forms an airbag, which will be continuously compressed and expanded. After the gas is compressed, a great pressure will be generated, which is dozens of times or even hundreds of times stronger than the pressure generated by the compressed water. At this time, the pipeline is prone to rupture, so consider installing an exhaust valve when designing the pipeline.

10. What is color masterbatch? Why use masterbatch in tubing?

A substance that changes the color of plastic when melted at high temperatures. The purpose of adding color masterbatch is to make the pipe opaque and prevent the foreign body from being generated in the pipe due to ultraviolet radiation.

11. The reason for the bend or oval of the pipe? How to exclude?

Possible reasons: ①The die core is not concentric; ②The temperature around the machine head is uneven, and the material is unevenly discharged; ③The supply of cooling water is uneven; ④The rubber conveyor belt of the tractor has a small gap and the clamp is too tight.

Removal methods: ①Adjust the gap of the die core mold to make it concentric; ②Adjust the heating temperature to be uniform; ③Appropriately adjust the cooling water volume and flow direction; ④Adjust the conveyor belt gap.

12. What do the numerical values ​​of S12.5, S6, S10 mean? What does SDR mean? What is the relationship between the two?

Pipe series S: Infinite number of steels related to nominal outer diameter and nominal wall thickness. Available and guide the selection of pipe specifications!

SDR: Standard Size Ratio. Refers to the ratio between the outer diameter and the wall thickness. For example, SDR11 is the outer diameter divided by the wall thickness equal to 11.

The relationship between S and SDR: S=(SDR-1)/2