China Scratch Mat

Natural oxidation and corrosion of the valve stem, because the surface of the valve stem packing is oxidized, and ferroferric oxide (rust) is formed, which will cause the valve stem to become thin and cause leakage; For example, the use temperature of pure PTFE must be 150℃, filled with PTFE250℃, and PTFE particle filler The compensation performance is poor, and it is only suitable for low-pressure valves, PTFE fiber, carbon fiber or the mixed filler of the two, and the price is too high to be unfavorable for promotion.

A valve that relies on exteal force to rotate and drive to open and close is designed with a sealing device that is used to install a certain number of packing seals in the packing culvert to achieve a sealing effect, but how about the sealing? Leakage at the PTFE fiberglass fabric high temperature cloth packing of the valve is one of the most prone to leakage failure in the valve, but there are roughly two reasons for it.

Synthetic resins and synthetic fibers, some of these products are restricted in the scope of use. Corrosion problems can also be caused by one aspect., serious threats to personal safety, property safety and environmental pollution accidents. Asbestos, because the asbestos material has chloride ions that corrode the valve stem, and the asbestos contains carcinogens, which are harmful to human health.

The country has banned or seldom used the parts of the product; 2. Expanded graphite will cause severe electrochemical corrosion. If the water valve leaks, it will lead to serious consequences, such as poisonous, harmful, flammable, explosive and Corrosive media leakage, etc. Reasons for fillers The main fillers currently used are:  Corrosion situations include: 1.Valve leakage is very common in life and production, and it will cause waste or danger to life at the slightest. Leakage caused by chloride ion corrosion of asbestos packing;

The pipeline is relatively fixed. Except for the coal slurry pipeline which is still in the brewing stage, other pipelines for conveying media have been successfully constructed and operated in China. 5. The characteristics of long-distance pipelines Long-distance pipelines are one of the five major transportation industries of railways, highways, shipping, civil aviation and long-distance pipelines. In-service pipelines pose a long-term threat to ground structures or areas, especially natural gas, coal gas, LPG and other flammable gas pipelines, which pose a greater threat. Continuity of transportation.

The construction unit has no ability PTFE BBQ Mesh Mats to choose an ideal construction site..1. Except for special terrain, long-distance pipelines are generally laid underground, and it is not easy to find potential hazards during operation, especially defects that have not been detected during construction. In addition to the common petroleum and natural gas, the transportation medium also includes industrial gases such as oxygen, CO2, etc. The construction operation points are constantly moving along with the construction progress. 2. That is, the pipeline is buried in the ground. Except for reasons such as reconstruction and laying of new lines, the pipeline will generally not be displaced. The topography has a direct impact on welding, so it must be adapted to local conditions.

Therefore, pipeline welding quality is an extremely important factor affecting pipeline quality. Compared with the production of factory products, the difficulty of construction management, quality management, safety management, etc. is increased; because the welding operation is in a flow state, it is relatively difficult to ensure quality. A long-distance pipeline may encounter a variety of terrains? For example, the West-East Gas Pipeline Project will pass through Gobi, deserts, loess plateaus, mountains, plains, water networks, etc. Characteristics of welding in the construction of long-distance pipelines 1．

The influence of fluidity construction on welding quality. As a separate system in the transportation industry, the pipeline differs from other transportation systems in the following aspects: 1. That is, once the pipeline is completed and put into production, it should be operated continuously under normal circumstances, which correspondingly increases the difficulty and danger of continuous transportation and maintenance under pressure., ethylene, liquid ammonia, mineral slurry, coal slurry and other media.

Choose different welding methods to meet the needs of the project. 2. from west to east. The pipeline and the conveying medium flow relatively, which requires the inside of the pipeline to be as smooth as possible to reduce abrasion resistance; in addition, considering the corrosiveness of the medium, a corresponding margin should be increased in the design. The influence of topography on welding quality. 2. The above analysis shows that the quality of the pipeline is very important for its safe operation and service life. 3