Manufacturing process and quality control points of Chinese standard flange globe valves

Manufacturing process and quality control points of Chinese standard flange globe valves

1、 Introduction

The Chinese standard flange globe valve, as a common pipeline valve, is widely used in industries such as petroleum, chemical, power, and metallurgy. Due to its simple structure, good sealing performance, and long service life, it has been favored by the market. However, in the manufacturing process, how to ensure the quality of flange stop valves and improve product competitiveness has become the focus of attention for production enterprises. This article will explore the high-quality production of Chinese standard flange globe valves from two aspects: manufacturing process and quality control points.

2、 Manufacturing process of Chinese standard flange globe valves

1. Material selection

Material is the key factor affecting the quality of flanged globe valves. When selecting materials, the materials of the main components such as the valve body, valve cover, and valve disc should be reasonably selected based on the operating conditions, medium type, temperature and pressure parameters of the valve. At the same time, attention should be paid to the chemical composition, mechanical properties, welding performance and other indicators of the material to ensure its quality.

2. Valve body casting

The valve body is the main pressure bearing component of a flanged globe valve, and its quality directly affects the safety of the valve's use. In the process of valve body casting, reasonable casting techniques should be adopted, such as sand casting, lost foam casting, etc., to ensure that there are no defects such as sand holes, pores, and slag inclusions inside the valve body. At the same time, it is necessary to strictly control parameters such as temperature and cooling rate during the casting process to avoid casting stress that affects the dimensional accuracy and mechanical properties of the valve body.

3. Mechanical processing

Mechanical processing is a key process to ensure the accuracy and smoothness of flange globe valves. During the machining process, high-precision and high rigidity CNC machine tools should be selected to ensure machining accuracy. At the same time, reasonable setting of processing parameters, such as cutting speed, feed rate, etc., can improve processing efficiency and reduce costs. In addition, it is important to pay attention to quality control during the processing process, strictly inspect key dimensions, and ensure product qualification.

4. Valve assembly

Valve assembly is a crucial step in ensuring the sealing performance and service life of flanged globe valves. During the assembly process, the cleanliness of the parts should be ensured to avoid impurities, oil stains, and other factors that may affect the sealing performance. At the same time, it is necessary to strictly follow the assembly process to ensure the fitting accuracy of sealing surfaces such as valve discs and valve seats. In addition, attention should be paid to the selection of sealing gaskets, and suitable gasket materials should be selected according to the operating conditions of the valve to improve the sealing effect.

5. Welding process

The welding process has a significant impact on the strength and sealing performance of flange globe valves. During the welding process, suitable welding methods and materials should be selected, such as argon arc welding, electric arc welding, etc. At the same time, it is necessary to control parameters such as welding speed and welding current to ensure the quality of the weld seam. In addition, heat treatment should be carried out after welding to eliminate welding stress and improve the mechanical properties of welded joints.

3、 Key points for quality control of Chinese standard flange globe valves

1. Design quality control

In the design phase, it is necessary to fully consider factors such as the operating conditions and medium characteristics of the valve, optimize the valve structure, and improve the safety and reliability of the valve. At the same time, attention should be paid to the strength calculation and sealing performance calculation of the valve to ensure that it meets the usage requirements within the design life.

2. Material quality control

Material quality control is the foundation for ensuring the quality of flanged globe valves. We need to strengthen the inspection of raw materials, auxiliary materials, welding materials, etc., to ensure that the materials comply with national and industry standards. At the same time, attention should be paid to the quality stability of materials to avoid product quality instability caused by material quality fluctuations.

3. Processing quality control

During the processing, it is necessary to strictly follow the process specifications to ensure machining accuracy. Strengthen quality control of key processes, such as valve body casting, mechanical processing, welding, etc., to ensure product quality. At the same time, regular maintenance and upkeep should be carried out on the equipment to improve its accuracy and ensure product quality.

4. Assembly quality control

Assembly quality control is the key to ensuring the sealing performance and service life of flange stop valves. During the assembly process, it is necessary to strictly follow the assembly process to ensure the cleanliness and fitting accuracy of the parts. Strengthen the inspection of the sealing surface to ensure that there are no scratches, wear or other defects on the sealing surface. In addition, attention should be paid to the selection and installation of gaskets to improve the sealing effect.

5. Inspection quality control

Inspection is an important step in ensuring the quality of flanged globe valves. We need to strengthen the inspection of finished and semi-finished products to ensure that they meet national and industry standards. At the same time, attention should be paid to the training of inspection personnel to improve their inspection level and avoid product quality problems caused by human factors.

4、 Conclusion

The manufacturing process and quality control points of Chinese standard flange globe valves are key to ensuring product quality. By optimizing design, selecting high-quality materials, strictly controlling the processing and assembly process, and strengthening inspection, the quality of flange globe valves can be improved and product competitiveness can be enhanced. Enterprises should continuously explore new technologies and processes, provide users with higher quality and more reliable products, and contribute to the development of China's valve industry.