During the installation of PVC high-pressure pipes, the connection quality of pipes and fittings is directly related to the stability and safety of the entire pipeline system. With the wide application of PVC high-pressure pipes in industry, construction and other fields, ensuring the connection quality has become the top priority of the installation process.

Cleaning and inspection of pipes and fittings prior to connection is essential. The connection parts of pipes and fittings must be free of oil, dust, moisture and other impurities, otherwise it will seriously affect the connection effect. The installation personnel shall carefully wipe the connection surface with special cleaning agent to ensure that the surface is clean. At the same time, it is necessary to conduct a comprehensive inspection of the pipes and fittings to see if there are defects such as cracks, blisters, and deformation. Even minor flaws can cause serious problems in a high-pressure environment. For example, in the pipeline installation of chemical enterprises, if the pipe has cracks that are not easy to detect, leakage may occur when transporting corrosive media, endangering production safety and the environment.

The operation specification in the connection process is the core of quality assurance. At present, the common connection mode of PVC high pressure pipe is hot melt connection, electric fusion connection and adhesive connection. Hot melt connection, to strictly control the heating temperature and time. Generally speaking, the heating temperature should be kept at 260 ℃ - 280 ℃, and the heating time depends on the specifications of the pipe and the pipe fittings. Usually, the pipe with smaller diameter is heated for 10 - 15 seconds, while the pipe with larger diameter needs 30 - 60 seconds. Insufficient heating, pipe and pipe fittings can not be fully integrated; excessive heating, the material will decompose carbonization, will reduce the connection strength. Taking the installation of building water supply and drainage pipeline as an example, if the temperature control of hot melt connection is improper, water leakage may occur after passing water. Electrofusion connection also requires strict setting of equipment parameters, and appropriate voltage, current and power-on time should be set according to the product specification. When the adhesive is connected, the adhesive should be applied evenly and appropriately. After application, the pipe should be inserted into the pipe fitting to the specified depth quickly and kept for a certain period of time to make the adhesive fully cured. In the installation of PVC high-pressure pipe for home decoration, if the adhesive is applied unevenly, it may lead to poor local sealing and affect the use.

After the connection is completed, quality inspection is indispensable. Appearance inspection is the first step to observe whether there are obvious defects such as gaps and wrong sides in the connection parts. Qualified connection parts shall have smooth surface and natural transition. For important piping systems, pressure testing is also required. The test pressure is generally 1.5 times of the working pressure, but not less than 0.6MPa, and the pressure stabilization time is not less than 30 minutes. During the test, if there is no obvious drop in pressure and no leakage at the connection part, the connection quality can be determined to be qualified. For example, in large-scale water conservancy irrigation projects, after the installation of PVC high-pressure pipes, they must pass strict pressure tests to ensure safety and reliability in long-term operation.

To ensure the connection quality of PVC high-pressure pipes and fittings, it is necessary to start with the preparation before connection, the standardized operation of the connection process and the strict inspection after connection. Only in this way can we create a safe and stable PVC high-pressure pipe system to meet the needs of various industries.