Views:137 Author:Site Editor Publish Time: 2019-01-22 Origin:Site
HDPE is a highly crystalline, non-polar thermoplastic resin. The original HDPE has a milky white appearance and a semi-transparent shape in a thin section. HDPE has excellent electrical properties, especially high dielectric strength. Medium to high molecular weight grades have excellent impact resistance, both at ambient temperatures and even at low temperatures of -40F.
HDPE pipe applications range from small-section yellow tubes for natural gas to thick-walled black tubes for industrial and urban pipelines up to 48 in. diameter. Large diameter hollow wall tubes are used as an alternative to rainwater drains and other sewer lines made of concrete to grow rapidly.
So how do we install HDPE Pipe?
There are more and more pipeline structures and types with HDPE as the main raw material on the market, the pipeline interface structure produced by the manufacturer according to the requirements of its geographical geological conditions is different, so there are also various connections between the pipelines. In the current way, the main connection methods on the market currently exist in the following categories:
1. Hot-melt connection
Hot-melt butt joint: a joint method in which two pipes are heated by a heating plate and butt welded together. The connection mode is simple in operation, high in strength, stable in connection quality, and fast in construction.
Heat-shrink connection: double-layer connection, heat-shrink tape is made by cross-linking polyolefin and reinforcing fiber, the inner layer adopts heat shrinkable tape as sealing layer, and the outer layer acts as reinforcing layer to ensure the sealing and strength of the joint. The connection has strong waterproof and anti-aging ability, good sealing performance and strong tensile resistance, and is suitable for poor geological environment.
2. Electric hot melt connection
Socket-type electric hot-melt connection:
Pre-fabricated sockets and sockets before the pipe is delivered, embedded in the inner wall of the socket, using special electricity when connecting The welding machine energizes the resistance wire, and the resistance wire heats up to melt the joint portion, and connects the resin on both sides of the resistance wire interface under the action of the resin melting pressure, and cools to achieve the connection purpose. This connection method has good sealing performance, large sealing strength, and uniform strength between the joint and the pipe.
3. Clamp connection:
Clamp-type elastic connection: This connection integrates rigid connection and flexible connection, the inner layer is sealed, and the outer layer is made of stainless steel clamp to increase the strength of the interface.
This type of connection is suitable for engineering in various environments. It is not affected by the groove water level on the construction site. It is convenient for maintenance and repair, but it requires a high degree of responsibility from the construction personnel. The material factor should be relatively high.
The general hot-melt connection mode is simple to operate, suitable for non-pressure drainage and small-diameter pipelines; large-diameter pipelines have large heat-receiving area and long warm-up time due to the large weight of the pipe itself. Inconvenient inconvenience and other disadvantages, it is recommended to use the connection operation professional, high heat sealing and clamping connection with high sealing rate.
In addition to the above factors, the connection method of the pipeline will be affected by geological effects. The uneven settlement will occur due to the ground in the collapsed land. The gravity of the pipeline itself and the water in the pipeline will cause the joint at the joint of the pipeline. It is recommended to use flexible connection: Heat shrinkable tape (set) connection, electric hot melt ribbon connection, or socketed connection with sealing ring.
In addition, there are many other connection methods:
1. Threaded connection method (suitable for various prefabricated installations where it is easy to remove the joints, as well as connection with underwater traps and forest tubs).
2. Socket type telescopic short pipe connection method (installation connection) When using the anchor pipe clamp, it must be fixed to prevent the position of the socket in the thermal expansion and contraction.
3. Flange connection method (this connection method is usually used as a detachable connection on the low-pressure transmission line, and also The simplest connection method between cast iron pipe and steel pipe).
4. HDPE pipe anti-telescoping casing (for anti-flat, irregular, special pipe connection, anti-telescoping casing is a convenient method, can also be used in HDPE pipe Connection with a variety of different ceramic equipment).