Flange is a kind of disk part, common in pipeline engineering, flanges are used in pairs. In pipeline engineering, flanges are mainly used for connecting pipelines. In the pipeline that needs to be connected, a flange should be installed. Wire flange can be used for low-pressure pipeline, and welding flange can be used for pressure over 4 kg. Add a gasket between the two flanges and tighten with bolts. Flanges with different pressures have different thicknesses and use different bolts. Pumps and valves, when connected with pipes, parts of these devices and equipment are also made into corresponding flange shapes, also known as flange connections. In the case of two planes in the periphery of the use of bolts together closed connection parts, are generally called “flange”, such as the connection of ventilation duct, this kind of parts can be called “flange parts”. But this connection is only part of a device, such as the connection between the flange and the pump, it is not good to call the pump “flange parts”.
The flange gasket has been replaced by a sealing ring to ensure that the sealing face matches the sealing surface. Only a small amount of pressure is required to tighten the cover. As the required pressure decreases, both the specification and the required number of bolts can be reduced accordingly. The end describes a new product that is small in size and light in weight (70 percent 80 percent less than conventional ANSI flanges. The principle of interest efficiency, environmental protection, and optimal health and safety assurance are the three major issues facing operators and contractors in the 21st century. Therefore, we initially considered new flange sealing methods. ANSI flange sealing principle pole simple: the two sealing face of the bolt knead each other flange gasket and constitute a seal (large diameter flange). In order to adhere to the sealing, you have to adhere to a large bolt effect force. To do this, the bolts have to be made bigger. Larger bolts have to fit larger nuts, which means larger diameter bolts are needed to create conditions for tightening nuts. The larger the diameter of the bolt, the more curved the flange will be. The only way is to increase the wall thickness.
Preparation before welding, check and debug equipment to ensure normal operation of equipment; It is best to prepare φ4.0J402 electrode in 300℃-350℃ drying for one hour. Welding process, assemble the vertebral body and the large flange together according to the drawing requirements, and then evenly distribute the large flange in 8 equal parts. Welding because the flange is thicker and the groove is larger, so the piecewise symmetric and multi-layer welding is selected. Weld quality, weld strength is required to reach the base metal strength at least. The weld surface is flat and lubricated, without burning through, porosity, welding leakage, slag inclusion, edge biting, not fully welded and other shortcomings. The residual height is less than 2mm. Precautions: J506 welding electrode technology must be used for surfacing when laying the bottom, and small current welding is selected. Strictly follow the welding process welding. After each welding of a bearing, a level should be used to clamp the deformation of the flange plane. While welding, hammer the weld with an air hammer to achieve the effect of eliminating stress.
Flanges in the process of use due to improper connection of flanges or long years of use, there is no need to panic users in this case. First of all, check the leakage part. In the leakage part, it is generally impossible to eliminate the leakage by injecting sealant through the gap because the flange connection gap is very small. Sealing construction method according to the leakage site survey, in order to achieve limited plugging, the fixed fixture method is used to contain the leakage point to form a sealing cavity, and the sealant is injected, so as to eliminate the leakage. And the side of the fixture are customized, the first fixture to meet the inclusion of leakage points, establish the valve body flange and pipe flange connection between the short flange sealing cavity for the first point. In order to prevent re-leakage in the potential leakage place between the valve body and flange due to pressure suppression, a ring cavity is set at the anastomosing place between the fixture and the flange of the valve body. Because the clamp is easy to move to the small flange side in the process of injection, the limiting measure of tooth contact clamping is adopted. During the operation, after the sealant curing, after the effect of observation, local injection compression, to prevent stress relaxation, and then closed the injection hole.
Post time: Sep-30-2022