How to improve the sealing performance of PPR Fitting under high temperature and high pressure conditions?

In modern building water supply systems, PPR Fitting is widely used in hot and cold water pipe connections due to its good corrosion resistance, weldability and environmental protection performance. However, under high temperature and high pressure conditions, such as central heating systems or high-rise building hot water circulation systems, PPR pipe fittings often face problems such as sealing failure, thermal expansion deformation and interface leakage. In order to improve its sealing performance and connection reliability under such conditions, it should be comprehensively improved from aspects such as material modification, structural optimization, installation process improvement and system design.

Optimizing high-performance PPR raw materials is the basis for ensuring sealing. Ordinary PPR materials are prone to creep under long-term high temperature, resulting in loosening or even leakage of interfaces. Therefore, it is recommended to use special PPR raw materials with high molecular weight and low melting temperature, and add appropriate amounts of antioxidants and stabilizers to enhance its heat aging resistance and long-term mechanical stability. Some high-end products can also use nano-modified PPR composite materials to enhance the fit and pressure resistance between sealing surfaces by improving the density of the material.

Optimizing the structural design of pipe fittings is crucial to improving the sealing effect. Traditional PPR pipe fittings mostly adopt straight-mouth docking, but axial displacement is prone to occur under high-pressure environment. By introducing a tapered socket structure or a double-layer sealing step design, a tighter contact surface can be formed after the pipe is inserted, and a stronger fusion zone can be formed during the hot melt process, thereby effectively preventing micro-leakage caused by pressure fluctuations.

Strict control of the hot melt connection process is a key link to ensure sealing performance. During the construction process, a constant temperature hot melt welding machine should be used to ensure that the heating temperature is stable within the range of 260±5℃, and the heating time and insertion depth should be accurately controlled according to the pipe diameter. Avoid carbonization of the material or insufficient welding due to overheating, which will lead to a decrease in interface strength. In addition, after welding, the interface should be kept still and cooled to avoid external force disturbance affecting the welding quality.

Installing auxiliary sealing elements at key locations is also an effective technical means. For example, using high-temperature resistant EPDM rubber gaskets or PTFE sealing rings at flange connections or valve interfaces can establish a double sealing barrier between the PPR pipeline system and metal parts, further improving the sealing stability and adaptability of the overall system.

Reasonable system design and installation and maintenance should not be ignored. In high temperature and high pressure environments, the thermal expansion coefficient of the pipeline should be fully considered, and the expansion joints and fixed brackets should be reasonably set to avoid loose interfaces due to stress concentration. At the same time, regular inspection of the operating status of the pipeline system and timely detection and treatment of potential leakage points will help extend the service life of PPR Fitting.

By selecting high-performance materials, optimizing structural design, standardizing hot melt processes, introducing auxiliary sealing technology, and strengthening system design and maintenance, the sealing performance and connection reliability of PPR Fitting under high temperature and high pressure conditions can be significantly improved, providing modern buildings with safer and more stable water supply solutions.