how to solve the leakage problem of high pressure flange?
The sealing structure of the high pressure flange lens pad is such that the sealing surfaces on both sides of the lens pad are spherical surfaces, and the inclined surface of the tube end is in contact with the tapered sealing surface, and the angle between the ends is about 20 degrees for the tube end and the lens pad. The initial state is a complete circular line. Under the pre-tightening force of the bolt, the lens pad is plastically deformed at the contact point, and the loop wire becomes an endless belt, ensuring a reliable sealing of the high-pressure pipe.
Although such high pressure flanges leak more during use, such high pressure flange leaks are more common and the methods seen today can appropriately reduce this.
First, the leakage method
The most basic way to repair a sealing element to eliminate leakage is to increase the preload of the flange bolt and repair or replace the sealing element. The high-pressure lens pad is easy to remove and inexpensive, and is usually machined by removing the light knife or replacing it. For high-pressure pipelines, especially large-diameter high-pressure pipelines, replacement and disassembly, transportation and production are difficult, and economically uneconomical, it is recommended to take on-site maintenance methods. If the tube end sealing surface is partially damaged, it can be repaired by first spot welding the damaged portion and then grinding the sealing surface and performing coloring or magnetic particle inspection.
Second, leakage measures
Most of the leakage of the lens pad seal is an interface leak that occurs at the interface between the sealing surface of the lens pad and the tapered sealing surface of the tube end, mainly due to tube vibration, poor assembly, and corrosion. Medium, process fluctuations, etc. According to the cause of the leak, take effective preventive measures in light of the actual situation. Reducing vibration and vibration is the main cause of damage to the high pressure weld neck flange lens pad seal. The vibration of the pipeline is mainly caused by the vibration of adjacent equipment, the pulsation of the airflow generated by the fluid flowing in the pipeline, and the vibration of the pipe fittings (such as elbows and valves). Therefore, in the case where the pipe direction and structural size cannot be changed due to the conditional constraints, most of the pipes are reinforced, and pipe racks and pipe clamps are added at corners, valves, short sections and large spans of different diameters. Use basic pre-embedded iron to repair welding and pipe joint welding, reinforce the original pipe frame with angle steel or channel steel to increase its rigidity; replace all pipe clamps and bolts, and use double nuts to prevent loosening.