Overview of three ways to assemble valves: selection, interchange and repair, accurately and efficiently meeting different needs

Valves commonly used assembly method can be three kinds, namely, complete interchangeable method, repair method and selection method.

(1) Matching method
1. Overall assembly: Assemble the various parts of the valve (such as valve body, valve cover, ball, valve stem, sealing ring, etc.) in sequence to form a complete device. It is generally used for the standard assembly process before leaving the factory and for the manufacture of new products.
2. Segmented assembly: The components of the valve (such as sealing structure, drive device, etc.) are first assembled independently into sub-modules, and then integrated. It is convenient to improve assembly efficiency and replace modules during maintenance.
3. On-site assembly: The various parts of the valve are transported to the installation site and then assembled. It is suitable for large-caliber, heavy-duty or specially customized valves, which is convenient for transportation and installation.
The valve assembly adopts the matching method. The parts are processed according to the economic accuracy requirements. After assembly, the size with adjustment and compensation functions is selected to achieve the required assembly accuracy. The principle of the matching method is the same as the repair method, and the only difference is the method of changing the size of the compensation ring.
(2) Complete interchangeability method
When the valve assembly adopts the complete interchangeability method, the valve parts can be assembled without any trimming and matching, and the assembled product can meet the specified technical requirements. At this time, valve parts should be processed completely according to the design requirements to meet the requirements of dimensional accuracy and shape tolerance.
The advantages of the full interchangeability method are: the assembly work is simple and economical, the workers do not need a high level of technical skills, the assembly process has high productivity, and it is easy to organize assembly lines and organize specialized production. However, relatively speaking, the full interchangeability method requires higher processing accuracy for parts. It is suitable for valves with relatively simple structures such as stop valves and check valves and small-diameter valves.
(3) Repair method
The valve assembly adopts the repair method. The parts can be processed according to the economic accuracy requirements. After assembly, the size repair with adjustment and compensation functions is carried out to achieve the specified assembly purpose. For example, the gate and valve body of the gate valve have too high processing costs to achieve the requirements of interchangeability. Most manufacturers use the repair method. That is, when the gate sealing surface is finally ground, its opening size is controlled to match the opening size of the valve body sealing surface to achieve the final sealing requirements. Although this method adds the "matching" process, it greatly simplifies the dimensional accuracy requirements of the previous processing process. The "matching" process is skilled in operation and generally does not affect production efficiency.