Valve manufacturing process

Valve manufacturing process is extremely complex and technically difficult. On the surface, valves have a small number of parts, a simple structure, and general precision requirements. They are relatively simple parts in the machinery industry. However, the manufacturing of the core sealing part of the valve requires extremely high standards, and a zero-to-zero seal must be achieved to meet the zero leakage requirements of the airtight test. Therefore, the valve manufacturing process is actually quite complex and technically difficult, with the following characteristics:

1. The material selection requirements are demanding.

Due to the wide range of valve applications, valves need to be used under harsh working conditions such as high temperature and high pressure, low temperature and deep cold, flammable and explosive, highly toxic, and highly corrosive, which places extremely high demands on materials. In addition to commonly used cast iron, carbon steel, etc., high-alloy materials such as stainless steel, alloy steel, and titanium alloy are also widely used. The casting, welding, and processing properties of these high-alloy materials are poor, which brings great difficulties to the manufacturing process.

2. The casting process is complex.

Most valves use thin-shell castings with complex structures. Not only do they have high requirements for appearance quality, but the internal quality and metallographic structure must also meet very high standards, and there must be no defects such as pores and shrinkage holes. Therefore, its casting process is much more complicated than that of general mechanical parts.

3. Machining is difficult.

Most high-strength, high-hardness, and high-corrosion-resistant valve materials have poor cutting performance and it is difficult to achieve the required dimensional accuracy and finish. In addition, the machining accuracy, matching angle, and finish requirements of the valve sealing surface are also very high, which brings great challenges to machining.

4. It is also difficult to clamp valve parts on machine tools.

The main parts of the valve, such as the valve body and the gate, have complex structures and shapes. Some parts are thin-walled and slender parts with poor rigidity. It is difficult to position and clamp them during machine tool processing, and more complex special tooling fixtures are required.

5. The process arrangement is complex.

On the surface, the valve has a small number of parts and a simple structure, but the "three degrees" (flatness, finish, and hardness) of the core sealing part are extremely high, and the fit of the two sealing surfaces must reach zero to zero. This requirement of ensuring precision sealing with a rough reference is the biggest technological difficulty in valve manufacturing.

6. There are great hidden dangers in testing and inspection.

As the opening and closing and regulating element of the pressure pipeline, the valve needs to be used under various harsh working conditions. However, the test and inspection can only be carried out under normal temperature conditions, which cannot fully simulate the actual working conditions and poses major hidden dangers.

In summary, the complex manufacturing process and high technical difficulty of valves are a major challenge in the field of mechanical manufacturing. Only by fully recognizing these characteristics and adopting targeted manufacturing technologies can the quality and reliability of valve products be ensured.