What are the inspection procedures for control valve castings

The first step in the inspection process is the visual inspection. This step mainly relies on the naked eye or a magnifying glass to evaluate the surface quality of the casting, focusing on surface finish, crack-free, deformation-free and rust-free conditions. At the same time, the nameplates and logos on the castings must be carefully reviewed to ensure that their information is clear and accurate, including the name, model, specification, nominal pressure, applicable medium and temperature of the valve. In addition, it is necessary to verify whether the structural dimensions of the valve body meet the design requirements, covering key parameters such as length, diameter, thickness, etc., to ensure product compliance.

Subsequently, material analysis is an important part of the inspection process. This step conducts a detailed analysis of the composition of the casting material to ensure that it meets the requirements of relevant standards. Advanced detection methods such as spectral analysis can be used to accurately detect the content of the main elements in the casting to verify whether its material meets the design specifications. This process is crucial to ensure the performance and service life of the casting, and can effectively avoid potential risks caused by unqualified materials.

Mechanical property testing is also an integral part of the inspection process. This link includes multiple indicators such as hardness test, tensile strength test and impact toughness test, aiming to comprehensively evaluate the mechanical properties of casting materials, so as to judge their reliability and durability in actual work. For example, the hardness test can use Rockwell or Brinell hardness tester to accurately measure the hardness value of the material, thereby providing a scientific basis for the application of castings.

Sealing performance detection is one of the key links in the inspection process. For control valve castings, their sealing performance directly affects whether they can effectively prevent the leakage of the medium. Therefore, it is necessary to conduct a systematic sealing test on the sealing surface of the casting to ensure that there is no leakage during use. This process is usually carried out using an air tightness detection instrument or a hydraulic testing machine. By applying pressure to the sealing surface and observing whether leakage occurs, the reliability of its sealing performance is evaluated.

Pressure resistance test is also a crucial link in the inspection process. This step is mainly used to detect the pressure bearing capacity of castings under high pressure conditions to ensure their safety in actual use. Pressure resistance test is generally carried out using a hydraulic testing machine. By applying a certain water pressure to the casting, observing whether it leaks or deforms, its pressure resistance performance is comprehensively evaluated.