1、 The oil and natural gas transmission pipeline is an energy supply line. The emergency cut-off valve on the line is a fully welded valve body pipeline pneumatic ball valve, which requires a service life of more than 30 years without maintenance. But the service conditions are very bad: from the Arctic Circle to the equator, from the plateau to the seabed, from the desert to the wilderness; It passes through seismic zones, marshes, permafrost, rivers, lakes and hillsides; Some are erected or directly buried underground; In the field, nobody operates and maintenance is difficult. It bears both internal pressure of the pipeline and external loads, such as foundation settlement, debris flow and earthquake, pipeline temperature stress, as well as potential corrosion and stress corrosion of groundwater.

Pay close attention to internal quality of pneumatic butterfly valve
The raw materials of pneumatic butterfly valves are crucial to the production of the products of the company, and are the basis for ensuring the quality of the company. However, with the increasingly fierce competition in the pneumatic butterfly valve market, there are always some mercenary manufacturers or illegal traders who push fake and inferior pneumatic butterfly valve products to the market. Even some standardized manufacturers may make some defective products flow into the market due to their own disposal gaps or other reasons. These fake and inferior commodities constitute serious quality or safety hazards in the process of production and application, and become the main culprit of commodity production quality accidents or safety accidents. In addition, if the purchased raw materials are not properly manipulated, the quality of the goods produced will also be directly affected. How to prevent fake or degenerated raw materials from flowing into the production line is a subject that every company needs to discuss. Tongfeng pneumatic butterfly valve needs to control the purchase quality of the company's raw materials, and stop the operation from the evaluation and selection of raw material suppliers, strengthening the inspection of raw materials before warehousing, and improving the quality of warehousing and disposal.
1、 Classification of raw materials and evaluation and selection of suppliers
1. The produced raw materials shall be classified and disposed to highlight the key points
In order to stop the key control of purchasing quality, the raw materials shall be classified and disposed according to the different impact levels of raw materials on the production quality of commodities. It is generally divided into three categories:
Class A raw materials: refer to the raw materials that may have a direct and serious impact on the production quality of commodities (for example, may have a direct impact on the key functions and functions of commodities) in the process of production and application.
Class B raw materials: refer to the raw materials that may have a direct or major impact on the quality of suppliers in the process of production and application.
Class C raw materials: refer to the raw materials that are usually auxiliary parts and have a common or subtle impact on the quality.
The practice shows that whether the quality of purchased raw materials is stable depends on the quality disposal degree of suppliers. Therefore, before purchasing, the quality assurance ability of suppliers of various raw materials should be evaluated.
2. Selection and determination of raw material suppliers
Qualified raw material suppliers shall be determined through selection. The acquisition of a qualified raw material supplier depends on the above evaluation results of the quality assurance ability of each supplier, as well as the production and application, quotation, promise and other factors. Therefore, Tongfeng pneumatic butterfly valve selects several suppliers of the same raw materials to stop comparison, especially when the production and application conditions and the quality assurance ability of each supplier are basically appropriate.