Electrofusion fittings are special pipe fittings that connect fittings to pipes through electrical heating. They are usually used to connect plastic pipes such as PE (polyethylene), PPR (polypropylene), and PVDF (polyvinylidene fluoride). The design of electrofusion fittings includes a built-in resistance wire, which is heated by electricity, and the heat is used to melt the contact surface of the pipe and the fitting, and finally form a strong connection.
Construction of electrofusion fittings
1. Resistance wire: Located on the inner wall of the electrofusion fitting, it serves as a heating element.
2. Connection interface: One end of the electrofusion fitting is usually the interface for connecting the pipe, and the other end is connected to the current through the heating wire.
3. Shell: The shell is usually made of high-temperature resistant material to ensure that the heating will not affect other parts of the fitting.
Features of electrofusion fittings
1. Strong connection: The strength of the molten joint produced by the electrofusion connection is the same as or even higher than that of the pipe material.
2. No risk of water leakage: The electrofusion joint is completely integrated with the pipe material, eliminating the gap and water leakage risk that may be caused by traditional welding.
3. Strong applicability: It can be applied to a variety of plastic pipes, especially PE pipes, and is widely used in municipal, water supply and drainage, gas, chemical and other fields.
4. Safe and reliable: Using professional equipment for connection and matching with a suitable temperature control system can ensure the accuracy and safety of the connection.
5. Convenient and fast: Compared with traditional welding methods, electric fusion connection does not require too much mechanical operation, and only needs to be heated to complete the connection, which greatly saves time and labor intensity.
Installation steps of electric fusion pipe fittings
1. Preparation: Check whether the specifications and models of the pipeline and electric fusion pipe fittings match. Clean the connection surface of the pipeline and pipe fittings to ensure that there are no impurities such as oil, dust, etc.
2. Pipe cutting: Use a pipe cutting tool to cut the pipeline to the appropriate length and ensure that the cut is flat.
3. Install the pipe fittings: Install the electric fusion pipe fittings to the pipe port to ensure that there is no gap at the connection and the connection is in place.
4. Heating electric fusion: Use special electric fusion welding equipment to pass the current through the resistance wire and start heating. The heating process requires precise control of temperature and time to ensure the quality of the connection.
5. Cooling and solidification: After heating is completed, wait for the joint to cool and solidify naturally, and the connection is completed.
Application of electrofusion pipe fittings
Water supply network: used for urban and rural water supply system construction, especially high-pressure water pipeline system.
Gas pipeline: suitable for the connection of gas transmission pipelines to ensure sealing performance and safety.
Chemical pipeline: used for pipeline systems with corrosive media, electrofusion pipe fittings have strong corrosion resistance.
Agricultural irrigation: In agricultural irrigation systems, electrofusion pipe fittings can ensure the efficiency and durability of pipeline connections.
This connection method solves the quality problems that may occur in traditional welding connection methods through efficient and stable electrofusion technology, so it is very popular in modern pipeline systems.
Welding of electrofusion pipe fittings
The welding of electrofusion pipe fittings is to heat the resistance wire inside the electrofusion pipe fittings through electric current, and use the heat to melt the contact surface between the pipe and the fittings, and finally form a firm connection. This process is called electrofusion welding, which requires strict temperature control and operating specifications to ensure the quality and safety of the connection. The following are the steps and precautions for welding electric fusion pipe fittings:
Welding steps for electric fusion pipe fittings
1. Preparation
Check materials and equipment: Make sure that the size and material of the pipe and pipe fittings match and the welding equipment works properly. Check the specifications and markings of the electric fusion pipe fittings to confirm the applicable voltage and current requirements.
Clean the contact surface of the pipe and pipe fittings: Use tools to cut the pipe end flat to ensure that there are no burrs, cracks, or impurities on the cut. Use appropriate detergents or solvents to clean the connection surface of the pipe end and the electric fusion pipe fitting to ensure that there is no oil, moisture or other contaminants.
2. Install the electric fusion pipe fittings
Align the electric fusion pipe fittings with the pipe end to ensure that the joint surface is tight and there is no gap or misalignment. Check whether the pipe is fully inserted into the pipe fitting.
Make sure that the terminal (electrode end) of the electric fusion pipe fitting is correctly connected to the welding equipment.
3. Heating welding
Start the electric fusion welding equipment to conduct the current to the resistance wire inside the pipe fitting through the set current. The resistance wire generates heat to heat the contact surface of the pipe fitting and the pipe.
The heating temperature and heating time should be strictly controlled. Too high a temperature will cause excessive melting or damage of the material, while too low a temperature may cause the welding to be weak. The heating process should be set according to the material, size and equipment specifications of the pipe fittings and pipelines.
4. Cooling and curing
After the heating is completed, turn off the power supply to ensure that the welded part cools naturally. The cooling time is determined by the material, size and ambient temperature of the pipe and pipe fittings.
The cooling time is usually between 5 and 30 minutes, depending on the size of the pipe fittings, ambient temperature and other factors.
5. Check the welding quality
After welding, check whether there are cracks, bubbles or leaks in the connection. A pressure test can be performed to verify the sealing of the joint.
Make sure that the molten surface of the connection is flat, smooth and free of obvious defects.
Precautions for welding of electric fusion pipe fittings
1. Matching of pipes and fittings
Make sure that the selected electric fusion pipe fittings match the material and specifications of the pipe. Pipes of different materials (such as PE, PPR, etc.) need to use corresponding electric fusion pipe fittings.
Check the size and model of the pipe fittings to ensure that they are suitable for the intended piping system.
2. Cleaning and cutting
Before welding, be sure to clean the contact surface of the pipe and the electrofusion pipe fittings to remove all impurities such as dirt, grease, dust, etc. A clean contact surface helps to weld better.
When cutting the pipe, make sure the cut is flat and burr-free to avoid uneven cuts that cause the pipe fittings to not fit tightly.
3. Current and temperature control
During the welding process, the control of temperature and current is very critical. Excessive current will cause overheating, and the pipe and pipe fitting materials may melt too much, resulting in insufficient joint strength; too low current may cause insufficient melting and affect the quality of the connection.
According to the specifications of the pipe and pipe fittings, choose the appropriate current, heating time and cooling time.
4. Avoid excessive pressure
When heating, avoid applying excessive mechanical pressure to the pipe and pipe fittings, otherwise it may cause deformation or damage to the pipe.
5. Cooling time
After the electrofusion welding is completed, do not rush to operate the joint part, and be sure to let it cool completely. Applying external force too early may cause the joint to deform or crack.
6. Equipment inspection
Before welding, check the electrofusion welding equipment to ensure the normal operation of the equipment, especially whether the temperature control system and current output are stable.
7. Welding environment
Ensure that the welding operation environment is clean and well ventilated, and avoid construction in extreme temperatures or humid weather to avoid affecting the welding effect.
When performing electrofusion welding in a high humidity environment, avoid moisture or short circuits in electrical equipment.
Quality inspection of electrofusion pipe fittings
Appearance inspection: Check whether the welding part of the electrofusion pipe fitting is flat, without bubbles, cracks, shedding and other problems.
Pressure test: The sealing of the connection point can be tested by air pressure or water pressure to confirm whether there is leakage.
Hot melt test: The welding strength is evaluated by tensile testing of the joint to ensure that the connection part has the same strength as the pipeline.
These precautions can help ensure the quality of electrofusion pipe welding, avoid leakage, breakage and other problems caused by improper operation, and thus improve the overall reliability and safety of the pipeline system.
