HDPE pipe & accessories

Sun Rise uses new HDPE raw materials of PE100 grade, and the recommended operating temperature range is -60°C to +60°C. Within this range, HDPE pipes can maintain good physical and mechanical properties without significant performance degradation due to temperature changes.

Above +60°C it will result in a decrease in the material's strength and rigidity, as well as a decrease in its ability to withstand pressure, and accelerates the aging process of HDPE, thereby shortening its service life.

In environments below -60°C, HDPE pipes may become more fragile and more likely to break when impacted. Therefore, when using HDPE pipes in extremely low temperature environments, special attention needs to be paid to the protection of the materials and installation methods to reduce the risk of damage.

Welding methods are quite diverse. Visual inspection and on-site inspection are usually performed at the construction site. When third-party sampling is performed, tensile test and sampling inspection are more commonly used.

1. Visual inspection
   Appearance inspection:check whether the appearance of the welded joint is smooth and uniform, and whether there are obvious defects such as bubbles, cracks, inclusions, etc.
   Dimension inspection:measure the width and height of the weld to ensure it meets relevant specification requirements.
2. On-site inspection
   On-site observation and measurement:real-time monitoring of the welding process at the construction site to ensure that personnel operate in accordance with specifications and that welding parameters such as temperature, time, pressure, etc. are within the allowed range.
3. Destructive test
   Tensile test:do the test on the welded joints to measure its tensile strength and ensure that it meets the specification requirements.
   Bend test:bend the welded joints to check its performance and ensure that no cracks or breaks occur.
4. Pressure test
   Hydrostatic test:fill the welded pipe with water and pressurize it to test its sealing and strength under a certain pressure, and observe whether there is leakage or deformation.
   Air pressure test:similar to hydrostatic test, but using gas for testing. Also check the sealing and strength of the welded pipes.
5. Sampling test
   Sampling:take samples from the welded pipe and conduct detailed laboratory testing, including melt index, density, tensile strength etc., to ensure that the welding materials and processes meet the specification requirements.
6. Non-destructive test
   Ultrasonic inspection:use ultrasonic equipment to detect whether there are defects inside the weld, such as incomplete fusion, inclusions, cracks, etc.
   X-ray inspection:use X-ray equipment to inspect the internal structure of the weld to ensure there are no defects.

These test methods can be used comprehensively to ensure that the welding quality of HDPE pipes meets specification requirements. Specific testing methods and standards should be carried out according to relevant national or industry standards (such as ISO, ASTM, etc.).

There are 6 welding types:

Butt Fusion Welding
It uses a heating plate to heat the two pipe ends and butt them together and apply a certain amount of pressure until the joint cools and solidifies. Suitable for larger diameter HDPE pipes.

Electrofusion Welding
Use electric welding sleeves with embedded heating wires to connect the pipes to the fittings. The electric heating wire is heated by electric current, to melt HDPE and connect together. Suitable for small diameter pipe or in limited construction space.

Socket Fusion Welding
Heat the outside of the pipe and the inside of the fitting simultaneously, then insert the pipe into the fitting until the joint cools and solidifies. Suitable for smaller diameter pipes.

Flange Connection
Flange connections can be used when pipes of different materials need to be disassembled or connected. Weld the flange to the end of the HDPE pipe, and connect the two flange pieces with bolts to connect the pipes.

Compression Fittings
Use special screw coupling to connect HDPE pipes together. Mainly used in small diameter pipe systems, such as household water supply systems.

Mechanical Connection
Use special mechanical connectors, such as compression joints, clamps, etc., to mechanically connect HDPE pipes. Often used for temporary connections or situations that require frequent disassembly.

Each of these welding types has pros and cons. The site conditions and pipe diameters should be considered to decide which one is the most suitable.

The outer diameter and thickness can be customized. At present, the common outer diameter is 20mm (min.) and 1600mm (max.), and the common thickness is 1.8mm (min.) and 88.2mm (max.). If the pipe wall is too thin, it can easily cause the pipe to deform and collapse. It is recommended to refer to SDR (standard size ratio). For the pipe specification, please visit Domestic Pipe.

Black HDPE pipe withstands UV the best.

Yes, except for fluorescent colors, Sun Rise can do over 180 colors in RAL Classic Color K7.

The production of HDPE pipes is mainly completed through the extrusion molding process, which usually involves the following 8 steps. Sun Rise is the largest HDPE pipe factory in Taiwan, and all machines used are originally from Austria. Compared with machines imported from China that are common in the Taiwan market, Austrian machines produce faster, more environmentally friendly, and more stable.

A. Material preparation:
HDPE particles are used as the main raw material, and color masterbatches are sometimes added to produce other colors.

B. Auto-feeding:
HDPE particles enter the auto-feeding section of the extrusion machine.

C. Melting:
In the extrusion machine, HDPE particles are gradually heated and melted, forming a uniform flow of molten plastic. The heating zone of the extrusion machine is usually divided into multiple temperature zones, and each temperature zone is controllable to ensure uniform melting of HDPE.

D. Extrusion and forming:
HDPE is extruded from the molding on the extrusion machine to form a tubular shape. The shape and size of the molding determine the outer diameter and wall thickness of the pipe.

E. Vacuum forming and cooling:
The pipe passes through a vacuum forming device to rapidly cool down and take shape. There is cooling water in the device, which can quickly cool the pipe to ensure dimensional stability and roundness.

F. Traction:
After cooling and shaping, the pipe is pulled out by a tractor to ensure that the pipe passes through the entire production line at a uniform speed to avoid stretching or shrinking.

G. Cutting:
Then the pipe is cut to the required length by an automatic cutting device.

H. Inspection & Packing:
Finally, the pipes need to undergo quality inspection, including size, wall thickness, appearance, etc., to ensure compliance with standards. Qualified pipes will be packaged and ready to be shipped.

HDPE pipes are used in many applications because they are more resistant to acid and alkali corrosion than iron pipes or PVC pipes, have higher flexibility and are not easy to break. HDPE pipes are light in weight, environmentally friendly and can be fully recycled, have low water flow resistance, high transportation efficiency. No leaking risk when welded together, also they have a service life of more than 50 years, so they’re widely used, especially in water supply, drainage and gas delivery systems.

Anti-corrosion:
HDPE pipe: has excellent corrosion resistance, can resist a variety of chemicals, and is not easily corroded by acids, alkalis and salts.
Iron pipes: prone to rust and corrosion and require frequent anti-corrosion treatment.
PVC pipe: corrosion resistance is also very good, but it may not be as good as HDPE pipe in certain kinds of chemicals.

Flexibility:
HDPE pipe: has high flexibility, can remain intact during earthquakes, and is not easy to break.
Iron pipe: has high rigidity, but lacks flexibility and is easy to break under external force.
PVC pipe: compared with HDPE pipe, less flexible and easy to break.

Light in weight:
HDPE pipe: light in weight, low installation and transportation costs, and easier installation.
Iron pipe: heavy in weight, high transportation and installation costs. It requires the use of special equipment.
PVC pipe: Also lighter in weight, but usually slightly heavier than HDPE pipe.

No leaking risk:
HDPE pipe: welding technology can be used to ensure the strength and sealing of the joint and almost no leakage.
Iron pipes: usually use threaded or flanged joints, which may cause leakage risks.
PVC pipes: usually sealed with glue or rubber rings, the joints may age with time and cause water leakage.

Durability:
HDPE pipe: long service life, usually more than 50 years.
Iron pipes: The service life is greatly affected by corrosion and usually requires regular replacement or maintenance.
PVC pipes: have a relatively long lifespan but may age with exposure to sunlight and high temperatures.

Eco-friendliness:
HDPE pipe: recyclable and has less impact on the environment.
Iron pipe: can also be recycled, but the production process may have a greater impact on the environment.
PVC pipe: the recycling rate is relatively low, and harmful substances may be produced during processing.

Transportation efficiency:
HDPE pipe: The inner wall is smooth so the water flow resistance is small, and the transportation efficiency is high.
Iron pipe: The inner wall may be rusted, which increases the chance of blocking water flow and affects the transportation efficiency.
PVC pipe: The inner wall is also relatively smooth, but may not be as good as HDPE pipe.