Co-Extruded White HDPE Pipes details description:

HDPE is white on the outside and black on the inside, using high-density polyethylene as raw material. The outer and inner layers are formed simultaneously during the extrusion process, but the material and function are independent. The outer layer of the pipe is usually white for reflection or UV protection, while the inner layer of black is usually used to reduce light transmission, prevent algae growth and improve corrosion resistance of the pipe.
Outer layer (white) :
Strong reflection: suitable for use in high temperature environment under sunlight, can effectively reflect solar radiation, reduce temperature rise, extend the service life of the pipe.
Anti-ultraviolet: The outer white layer is usually added with anti-ultraviolet additives, so that the pipe is not easy to age in the exposed environment, and the anti-ultraviolet ability is strong.
Good visibility: Excellent reflective performance, easier to identify at night or in dim environments.
Inner layer (black):
Low light transmission: the black inner layer can effectively isolate light, reduce the possibility of light through the pipe wall, thereby reducing the growth of algae and bacteria, and maintain the internal environmental health of the pipe.
Strong corrosion resistance: the black material of the inner layer often adds corrosion resistance to resist chemical corrosion, wear resistance, aging resistance, and adapt to a variety of complex drainage environments.

Co-Extruded White HDPE Pipes material characteristics and advantages:

Strong corrosion resistance: HDPE material has high chemical stability, good corrosion resistance to acid, alkali, salt, etc., can adapt to different chemical environments, can be used to transport corrosive media, extend the service life of pipelines.
Excellent mechanical properties: with high impact strength and tensile strength, ring stiffness is good, can withstand greater external force and pressure, not easy to break or deformation, suitable for use in a variety of complex engineering environments.
Wide temperature range: can be used normally in the temperature range of -60 ° C to 60 ° C, can withstand certain temperature changes, and can also operate stably in some areas with large temperature differences.
Smooth inner wall: the inner wall of the pipe is smooth and flat, the roughness is low, the fluid transmission resistance is small, and it is not easy to scale, which can effectively improve the transportation efficiency, reduce energy consumption and reduce maintenance costs.
Reasonable color design: the color combination of white outside and black inside, the white outer layer makes the pipe appearance clean and beautiful, and the surrounding environment is highly coordinated; The black inner layer can effectively absorb ultraviolet light, prevent the aging effect of ultraviolet light on the pipeline, and enhance the weather resistance.
Environmental hygiene: HDPE material is non-toxic and tasteless, will not pollute the transported water or other media, meet environmental protection and health standards, and can be used in drinking water transportation and other areas with high health requirements.
Easy installation: hot melt connection, electric melt connection or socket connection can be used, simple connection operation, high construction efficiency, can effectively shorten the project cycle.
Long service life: under normal conditions of use, the service life of HDPE outer white black tube can reach more than 50 years, and it has a high cost performance.

HDPE outside white inside black tube construction method:

Hot melt connection: The hot melt machine is used to heat the connection part of the pipe and pipe fittings to a molten state, and then the two are quickly bonded, cooled and solidified under a certain pressure to form a solid connection. Suitable for the same material, nominal outer diameter ≥63mm pipe and pipe, pipe and pipe fittings connection.
Electric fusion connection: the electric fusion pipe is set on the pipe, and the resistance wire in the electric fusion pipe is electrified through the electric fusion welding machine, so that the resistance wire heats up and the contact surface of the pipe and the pipe is melted, and the body is formed after cooling. Suitable for various specifications of HDPE pipe connection, especially suitable for nominal outer diameter < 63mm pipe or can not use hot melt connection occasions.
Socket connection: First heat one end of the HDPE pipe to soften it, and then insert the other end into the softening end, and then heat and apply pressure to make the two closely combined. This connection method is suitable for small-caliber HDPE pipes, convenient installation, fast connection speed, but the connection strength is slightly lower than that of hot melt butt and electric melt connection.
Flange connection: The HDPE pipe and flange are connected together by hot melt or electric melt, and then the two flanges are connected by bolts, and the sealing gasket is installed in the middle to realize the connection and sealing of the pipeline. The flange connection is suitable for the connection of HDPE pipes with valves, flowmeters and other equipment, as well as the parts that need to be disassembled frequently, which is easy to maintain and overhaul.
PE quick joint connection: This joint has an internal cavity into which the PE pipe can be inserted, sealed and fixed by sealing rings or elastic clasp and other components, suitable for small and medium diameter PE pipe connection.

Hot melt connection	Electric fusion connection

Socket connection	Flange connection

PE quick joint connection