10 kinds of welding plugging methods

In general, we commonly used welding plugging methods are: 1. Wedge plug welding repair method This method is very simple, with good toughness of the metal such as: nails, welding rod made of tapered wedge, wedge into the leakage of the hole, through the leakage or reduce leakage; It can be repaired in the same way as normal welding operations. 2. Hammer, twist and welding repair This method is also relatively simple operation, twist, squeeze, press is to use external force, such as: with a hammer, flat chisel, the leakage twist pressure closed part, to create weldable conditions, welding (also known as chisel block method or riveting welding method). The specific method is: first in the edge of the leakage welding part of the welding meat, and then use a hammer, flat head chisel, etc. to squeeze the metal around the leakage into the hole, so that the hole is reduced by the leakage. Or with good plastic wire, welding wire, welding rod core, etc., the crack plug and riveting welding, welding while hammering extrusion until the leakage stop. Then, the first use of acid electrode, AC welding power supply, using a small current for shallow welding, fast welding. This is because, compared with alkaline electrode, acid electrode is less sensitive to oil, water, rust and other oxides. Finally: the use of high strength, toughness and good crack resistance of alkaline electrode evenly covered a layer. Because the whole welding repair process needs to hammer the weld. Therefore, it is called hammer twist welding repair method. This method is suitable for pressure welding of cracks, pores or shrinkage holes of low pressure vessels and pipelines, water, steam and other media with low pressure, and carbon steel pipelines with pipe thickness above 3.5mm or other leakage parts of vessels. When welding, small diameter electrode should be used as far as possible. The welding current is about 10% larger than the normal welding current. The welding operation should adopt the fast welding method. 3. Blocking welding repair method When some cracks are wider or the diameter of trachoma and porosity is larger, it is difficult to use the hammer twist welding method. The crack or hole can be plugged with the appropriate wire or electrode head to reduce the pressure and flow of leakage, and then the rapid welding is carried out. When the periphery of some cracks is irregular, the electrode head, thin iron sheet and so on can be used to plug in and then quickly weld. The main points of this method operation are: one can only plug a section, and then quickly weld a section, that is, plug a section of welding a section, until the whole weld welding. 4. Top flow welding repair method This method is to make use of the principle of heat expansion and cold contraction of the object, using the method of discontinuous welding operation from both sides of the crack to the middle, relying on the thermal stress inside the weld to reach the local temporary closure of the leakage. It is suitable for metal fatigue crack, welding crack and so on. Specific methods are as follows: High-temperature heat caused by arc burning, the use of long arc, arc length L 1.5 times that of the electrode diameter lower or higher) heating stretch toward leakage and leakage in earnest observation, at this time to crack due to arc heat and expansion on the edge of the leaks appear instantly closed after a short while, immediately return to depress arc short arc arc (arc length L electrode diameter phi) or less for discontinuous welding. And so on and so forth, until the welding repair work is completed. For the leakage caused by corrosion and wear, do not weld directly to the leakage site at this time, and avoid greater welding difficulties caused by the burning through of the leakage site. Should be in the leakage of the surrounding like the swallow bit mud base nest, can also be called the method of surrounding the city in the countryside; Bit by bit weld to the center until it is filled. Gradually reduce the area of the leakage, in the final arc of the point, with a small diameter electrode, a larger welding current to fill the arc pit, sealing the arc of the arc; And immediately hammer it down. In order to avoid the weld arc at the appearance of loose and porosity. 5. Diversion welding repair method This method is applied to the workpiece which cannot be welded by twisting, squeezing and pressing, or the occasion of high pressure, thin wall of tank (tube) and high material strength. You can first weld a section of pipe with a valve or its method to guide the pressure medium away from the welding area, after the welding work is completed, then close the valve or tighten the screws, to stop leakage (some people will also call this method drainage method or venting method). When the machine is shut down for maintenance, the welding repair should be carried out again. Can also be based on the leakage of the welding area, in order to ensure that the welding process smoothly, welding three sides of the U-shaped first, the remaining narrow mouth with asbestos rope and so on after the death of the welding. This method is used on the plane and cambered surface with large abrasion or corrosion area. 6. Casing welding repair method When a large area of leakage occurs due to corrosion or wear, a pipe with the same diameter or just holding the diameter of the leakage pipe is composed of a sleeve tube. The length of the sleeve tube depends on the area and length of the leakage place. Cut the sleeve into two halves symmetrically and weld a guide pipe. The specific welding method is the same as the guide welding method. In the welding sequence, the ring seam of pipe and sleeve should be welded first, and the longitudinal weld of sleeve should be welded finally. 7. Pressure welding repair method When the area of the leakage is large but the pressure is not large, the pipe with the same diameter as the leakage pipe can be cut into the plugging plate, and the leakage surface is lined with tin, lead, aluminum and other soft and plastic metals; The leakage will be tightened and blocked by hand pulling the hoist, jack, karan and other machine fixtures. Then use the normal welding method to weld the plugging plate and the leakage pipe into one. 8 rubber leakage welding repair method After welding fasteners at the leakage place, first cover the leakage place with rubber, and then add the repair welding block, and use the method of fasteners with mechanical fastening to stop leakage. Then, it is repaired by welding. This welding repair method is often used in some shipyards to repair the large area of leakage in the side wall of the ship cabin. This method is especially suitable for large area of wear, corrosion defects and the leakage of liquid and gas medium, also can be used for cracks and other situations. When welding, it is also necessary to pay attention to the temperature of the welding seam part of the repair welding block can not be too high to prevent burning rubber. For the pipelines with difficult welding and low requirements, pipe clips can also be made to temporarily stop leakage. Reweld and repair when it is shut down for maintenance. 9. Adhesive repair welding repair method Sometimes in the leakage due to too many cracks, welding up is time-consuming and laborious, we simply use the adhesive will be welded object and the material of the same welding plate together bonding (also known as plugging agent welding repair method). Then, according to the normal welding technique for welding. 10. Direct welding repair method For sand holes, pores and other small leakage or leakage at the pressure is relatively low, you can also use small specifications, small current, according to the normal welding method directly on the leakage of the welding.铜焊丝,Copper Welding Rods,铝焊丝,aluminium welding wire,镍焊条,Nickel electrode,药皮焊条,Flux Coated Brazing Welding Rods