In modern industry, pressure sealing technology is an important pipeline maintenance and repair technology. It ensures pipeline integrity and stability under high pressure conditions. Whether in the oil, gas, power or chemical industries, pressure plugging plays a vital role. This paper will discuss four commonly used pressure sealing installation methods in detail, and analyze their principles, advantages and disadvantages, and application scenarios.

#### 1. Mechanical sealing with pressure

Mechanical belt sealing is to seal the pipeline by mechanical device. The main principle is to use a mechanical device to form a sealed area to prevent fluid leakage. This method usually uses rubber seals, metal gaskets and other materials, and relies on adjusting the pressure and position of the device to achieve the sealing effect.

##### 1. Principles

Mechanical plugging devices are usually composed of several key components, including sealing rings, pressure regulators, fixtures, etc. When working, the sealing ring is compressed to the wall of the pipeline, forming a close contact with the pipeline, so as to achieve the effect of sealing.

##### 2. Advantages and disadvantages

- ** Advantages ** :

- Simple installation and easy operation;

- Can be used back and forth, high economy;

- Smaller on the pipe.

- ** Disadvantages ** :

- Limited range of applicable pressures and temperatures;

- For corrosive media, the durability of the sealing material may be insufficient;

- Under high pressure conditions, there may be a risk of seal failure.

##### 3. Application scenarios

Mechanical sealing with pressure is suitable for general liquid and gas pipelines, especially in the case of low pressure and stable medium properties, the effect is remarkable.

#### Two, expansion type with pressure plugging

Expansion tape sealing uses high-pressure gas or liquid to expand the sealing material to seal the pipeline. This method usually uses expandable rubber or plastic material, relying on the action of external pressure to expand it, close to the inner wall of the pipe.

##### 1. Principles

The expansion plugging device consists of multiple air sacs or fluid sacs. When the pressurized medium is injected into the capsule, the capsule expands and forms a seal against the inner wall of the pipe. This method can adapt to the diameter change of the pipe in a large range.

##### 2. Advantages and disadvantages

- ** Advantages ** :

- Strong adaptability for pipes of different diameters;

- Can withstand high pressure, good sealing performance;

- Short operation time, suitable for emergency situations.

- ** Disadvantages ** :

- Need to replace the material after a single use, the cost is higher;

- For high temperature, highly corrosive media, material selection should be careful;

- The expansion process may cause damage to the pipe.

##### 3. Application scenarios

The expansion sealing is suitable for high pressure and high flow rate liquid and gas pipelines, especially in the case of rapid sealing, which can effectively reduce the risk of leakage.

#### three, welded type with pressure sealing

The welding type pressure sealing is to fix the sealing device on the pipeline by welding to form a solid sealing point. This method is usually used for sealing large pipelines or high temperature and high pressure environments.

##### 1. Principles

Welded plug first requires cleaning and preparation of the pipe, and then welding the plug device to the specific location of the pipe. After the welding is completed, a pressure test is performed to ensure the tightness of the welded joint.

##### 2. Advantages and disadvantages

- ** Advantages ** :

- Good sealing performance, can withstand high temperature and high pressure;

- Suitable for lasting plugging in long-term use;

- Enhanced structural integrity of the pipeline.

** Disadvantages ** :

- The installation process is complicated and requires technical personnel to operate;

- The pipeline is large and cannot be reused;

- Once welded, generally cannot be disassembled and repaired.

##### 3. Application scenarios