Ten Leak Repair Techniques for Welding
1. Wedge塞焊接法
This method is quite simple: using metals with good toughness, such as nail heads and welding rod tips, to make conical wedges, which are then inserted into the leaking holes to plug or reduce the leakage.
2. Hammering, bending, welding, and repairing
This method is also relatively simple to operate. Twisting, squeezing, and compressing utilize external force, such as using chisels or flat chisels, to twist and compress a portion of the leak hole into a weldable state, and then proceed with the welding (some may refer to this technique as chiseling or riveting welding).
This method is applicable to low-pressure vessels and pipelines, water, steam, and other low-pressure media, as well as cracks, blow holes, or shrinkage cavities in carbon steel pipelines with thicknesses of 3.5mm and above.
3. Leak Sealing and Welding Techniques
When cracks are wider or when blisters and pores have larger diameters, it's difficult to weld with hammering and twisting. First, use suitable wire or welding rod to block the cracks or holes to reduce the pressure and flow of leakage, and then perform a quick weld.
4. Top-tier Welding Repair Techniques
This method employs the principle of thermal expansion and contraction of objects, utilizing a discontinuous welding operation from both sides of the crack to the center, and relies on the internal thermal stress of the weld to temporarily seal local leaks. Suitable for metal fatigue cracks, weld cracks, and the like.
5. Drainage Welding Repair Method
This method is suitable for workpieces that cannot be welded using twisting, squeezing, or pressing techniques, or for those with high pressure, thin tank (pipe) walls, and high material strength. You can weld a section of pipe using a valve or direct the pressurized medium away from the welding area. After the welding is complete, close the valve or tighten the screws to prevent leakage. During shutdown for maintenance, perform the welding repairs again.
6. Tubular Welding Repair Technique
When pipelines experience large-scale leaks due to corrosion or wear, pipes of the same diameter can be used or a sleeve can be formed by simply embracing the leaking pipe diameter. The length of the sleeve depends on the area and length of the leak.
The tube is symmetrically cut in half and the flow guide is welded. In the welding sequence, the annular seam between the tube and the sleeve should be welded first, followed by the longitudinal seam of the sleeve.
7. Pressure Welding Repair Method
When the leakage area is large but the pressure is low, the pipe with the same diameter as the leakage pipe can be cut into a sealing plate. The inner lining of the leakage surface is made of tin, lead, aluminum, etc., which are relatively soft and have good plasticity. The sealing is achieved by tightening the metal hand扳, jacks, and clamps, and then the sealing plate and the leakage pipe are welded into a single unit using normal welding methods.
8. Leak-proof Welding Method for Rubber Housings
After adding welding fasteners to the leaky area, cover it with a rubber cap, then weld a weld block and mechanically secure it with fasteners to prevent leakage. This welding method is commonly used in shipyards to repair large-scale water leaks in the side walls of ship compartments. This method is also particularly suitable for large-scale wear, corrosion defects, and leaks of liquid and gas mediums, and can also be used for cracks and other situations.
9. Soldering Repair Technique
Bond the welding object and the weldment plate of the same material with an adhesive. Subsequently, weld using the standard welding method.
10. Direct Weld Repair Method
For minor leaks such as bubble or pinholes, or areas with low pressure, small specifications and low currents can be used. Leaks can be directly welded using standard welding methods.
