Fishplate Joint Sealing Design and Track Leakage Prevention
What are the key points of the sealing structure design of national standard fishplates?
National standard fishplates will be provided with sealing grooves on the joint contact surfaces, with the groove width controlled at 8-10mm and the groove depth at 3-5mm for embedding rubber gaskets. The gasket should be made of aging-resistant nitrile rubber with a Shore hardness of 60-70A, balancing sealing performance and compression resilience. Annular sealing protrusions with a height of 1-2mm will be added around the bolt holes of the fishplate to prevent water vapor from seeping through the bolt holes. The sealing structure must be compatible with the installation gap of the fishplate, and the compression amount of the gasket after installation should reach 30%-40% to ensure the sealing effect. In addition, the edges of the sealing groove should be chamfered to avoid scratching the gasket during installation.
What are the advantages of foreign standard integrated sealed fishplates?
The foreign standard integrated sealed fishplate die-casts the sealing structure and the fishplate body into one piece, eliminating the need for additional installation of gaskets, simplifying the construction process and improving installation efficiency. Its sealing structure has a higher fit with the fishplate, without the risk of gasket displacement, and the sealing stability is stronger. The sealing layer of this type of fishplate is made of weather-resistant polyurethane material, which has stable performance in the temperature range of -50℃ to 70℃ and is suitable for extreme climates. The integrated sealing design can cover all contact gaps between the fishplate and the rail, with a wider anti-leakage range, which can effectively isolate salt spray and sand dust. At the same time, the service life of its sealing structure is synchronized with that of the fishplate, and there is no need to replace the seals separately, reducing the operation and maintenance cost.
Why is it necessary to strengthen the anti-corrosion synergy of the sealing design of fishplates in coastal areas?
The salt spray in coastal areas will invade through the joint gaps, which will not only rust the rail joints but also corrode the fishplates and bolts. Strengthening the seal can block the invasion path of salt spray. The sealing design is coordinated with the anti-corrosion coating to form a double protection of "physical sealing + chemical anti-corrosion", improving the overall anti-corrosion level of the joint. The gasket is prone to aging and failure in the salt spray environment. The strengthened sealing design will use salt spray-resistant fluororubber material to extend the service life of the seal. The coordinated anti-corrosion design will fill the sealing groove with anti-corrosion paste. Even if the gasket is slightly damaged, the anti-corrosion paste can play an emergency protection role. In addition, strengthening the synergy can reduce the maintenance frequency of the joint, adapting to the operation and maintenance difficulty of the lines in coastal areas.
What are the low-temperature resistance design points of the fishplate sealing structure in alpine regions?
The gasket of the fishplate in alpine regions should be made of cold-resistant silicone rubber with a glass transition temperature below -60℃ to avoid low-temperature brittle fracture. The compression amount of the sealing structure should be appropriately reduced to 25%-30% to prevent the gasket from being over-squeezed and failing due to low-temperature shrinkage. The sealing groove of the fishplate needs anti-freezing expansion treatment, and an elastic buffer layer is added to the groove wall to resist the frost heave stress at low temperatures. Low-temperature special adhesive should be used at the bonding place between the gasket and the fishplate to ensure no degumming at low temperatures. In addition, the surface of the sealing structure should be treated with a hydrophobic coating to prevent rain and snow from freezing at the joint and damaging the sealing structure.
How to detect whether the sealing performance of the fishplate joint meets the standard?
The water pressure test method can be adopted: build a sealed cavity outside the joint, pass water pressure of 0.3MPa, and observe whether water seeps inside the joint after 30 minutes. No water seepage means the seal is qualified. The fitting state of the gasket is detected by an ultrasonic flaw detector. If there is a large area of void, the seal is not up to standard. Spray soap solution on the joint and pass compressed air into the gap. If no bubbles are generated, the seal is good. Regularly check the appearance of the seal. If there are aging phenomena such as cracking and hardening, it should be replaced in time. In addition, the corrosion of the joint area can be monitored. If there is no obvious corrosion of the joint, it indirectly indicates that the sealing performance is in an effective state.