Sealing with pressure is a widely used pipeline maintenance technology, which can effectively solve the problems of pipeline leakage and damage. The realization of sealing with pressure needs to master certain theoretical knowledge and practical experience. This paper will introduce the technology of expanding sealing with pressure in detail from the following aspects.

First, the concept of sealing with pressure

Sealing with pressure is a kind of use of expansion cylinder and sealing tape and other materials to block the pipe mouth to prevent the effect of pipeline leakage. The technology can be applied to various types of pipelines, including water, gas, chemical, etc. Compared with the traditional pipe sealing method, pressure sealing has the advantages of simple operation, low cost and short maintenance time, so it is widely used in various occasions.

Second, the principle of sealing with pressure

(1) Expansion cylinder

The most core component in the pressure sealing, its role is to expand the pipe opening through the internal elastic control structure, so that it is fully fitted to the inner wall of the pipeline. Before plugging, the expansion cylinder needs to be placed in the plugging position and expanded by compressed air or hydraulic pressure. Once the expansion cylinder is expanded, it can effectively seal the pipe opening and prevent the pipe from leaking.

(2) Sealing belt

The sealing belt is another important part of the pressure sealing, which is used to ensure the tightness of the pipe opening. Before plugging, the sealing tape needs to be wrapped around the outside of the expansion cylinder and pressed tightly to ensure that the gap between the sealing tape and the inner wall of the pipe is as small as possible. The sealing belt is usually made of elastic materials such as rubber or silicone rubber, which has good corrosion resistance and high temperature resistance.

(3) Valves

When performing pressure plugging, valves need to be set before and after the pipe plugging to control the pressure in the pipe. When blocking, it is necessary to close the inlet and outlet valve of the pipeline and control the pressure within a certain range to ensure that the expansion cylinder and sealing belt can work normally. After the sealing is complete, the pressure in the pipeline needs to be gradually restored to ensure a stable and reliable sealing effect.

3. Operation steps with pressure sealing

1) Preparation

Adequate preparation is required before a pressure plug is carried out. The first inspection of the pipeline is required to confirm the extent and location of the damage to the pipeline. Then the appropriate expansion cylinder and sealing tape need to be selected and placed in the sealing position. At the same time, it is also necessary to set the inlet and outlet valves and pressure control devices to ensure the stability and smooth progress of the sealing process.

(2) Plugging operation

After the preparatory work is complete, the plugging operation can begin. The specific steps are as follows:

1. Open the pipe inlet and outlet valve and adjust the pressure control device to the appropriate pressure range.

2. Place the expansion cylinder in the position that needs to be blocked, and expand it by compressed air or hydraulic pressure.

3. Wrap the sealing belt around the outside of the expansion cylinder and press it tightly to fit it tightly with the inner wall of the pipeline.

4. Close the pipe inlet and outlet valve, stop the fluid flow, and gradually increase the pressure in the pipe.

5. Monitor the sealing effect to ensure that the pipe opening is completely sealed and stable within a certain pressure range.

(3) Treatment after completion of plugging

After the closure is complete, the normal use of the pipeline should be gradually restored. The specific steps are as follows:

1. Gradually reduce the pressure in the pipeline, and open the pipe inlet and outlet valve to restore the fluid flow.

2. Check the blocked position and ensure that there is no water leakage or other problems in the pipeline.

3. Remove the expansion cylinder and sealing tape and other materials, and clean.

4. Check and compare the pipes before and after plugging to confirm the plugging effect, and make corresponding records and reports.

4. Applications with pressure plugging

Pressure plugging technology can be applied to various types of pipeline maintenance and plugging work, including the following aspects:

A) water pipe maintenance

Pressure sealing can be used for the maintenance of water pipe leakage and damage, which can quickly, simply and economically solve the problem of water pipe leakage and avoid water resource waste and environmental pollution.

(2) Gas pipeline maintenance

Pressure sealing can also be used for the maintenance and sealing of gas pipelines, which can effectively prevent gas leakage and stabilize the occurrence of accidents. Due to the flammable and explosive properties of gas, it is necessary to be extra careful when carrying out gas pipeline maintenance.

(3) Chemical pipeline maintenance

Chemical pipelines are vulnerable to corrosion and damage when transporting and storing chemicals, so they need to be repaired and plugged regularly. The sealing technology with pressure can be applied to the maintenance and sealing of chemical pipelines, which can ensure the stable transportation and storage of chemicals.

(4) Other occasions

Pressure plugging technology can also be applied to other types of pipeline maintenance and plugging work, such as oil pipelines, underground pipe networks, etc. As long as the principle and operation method of the writing tape sealing technology are mastered, it can be flexibly applied in various occasions.

In short, the pressure sealing technology is an economical, practical and efficient pipeline maintenance technology, which has a wide application prospect. In actual operation, it is necessary to pay attention to stability and quality assurance to ensure that the sealing effect is stable and reliable.