Basic methods for repairing sealing elements include increasing the pre-tension of the flange bolts and modifying or changing the sealing elements. The cost of the national standard lens pads is low after removal. Typically, this is done by using a removal knife or by replacing it with a new one. For national standard pipelines, especially large-diameter national standard pipelines, it is difficult to modify, dismantle, transfer, and manufacture.

Economically speaking, it is not cost-effective. It is recommended to use on-site calibration methods. If the sealing surface of the pipe end is damaged, it is advisable to first spot-weld the damaged area, then grind the sealing surface, and stop the color or magnetic particle inspection. The method of reducing the leakage of the lens pad seal indicates that most of it is interface leakage.

At the interface between the sealed spherical surface of the lens pad and the conical sealing surface of the pipe end, this is primarily caused by pipeline vibration, substandard equipment, medium corrosion, and process fluctuations. Based on the disclosure of the causes, we have separated field practices and implemented effective preventive measures to reduce oscillation and vibration, which are the main reasons for destroying the sealing integrity of the national standard flange lens pads.

Vibration in pipelines is primarily caused by adjacent equipment vibration, air pulsation due to fluid movement within the pipeline, and excitation vibration from pipeline components such as elbows and valves. Therefore, when it is not possible to alter the pipeline's direction and structural dimensions due to constraints, it is typically chosen to reinforce the pipeline. This involves adding pipe supports and clamps at elbows and valves, reducing short joints and large spans.