How to distinguish between valve inlet and outlet

How to distinguish between valve inlet and outlet

Nowadays, as a rapidly developing industry in China’s manufacturing industry, the types of valves are also increasing, and the quality and requirements of manufacturing materials for valves are also improving. Valve * * * is used in various fields, so more and more people choose the origin of the valve. We need to consider more when choosing the valve. How to distinguish the import and export of the valve? What is the difference between valve inlet and outlet? In this issue, like valve will answer the selection of inlet and outlet valves for you!
1、 How to distinguish the inlet and outlet of the valve
Import refers to products from research to production in strict accordance with foreign standards. Domestic products are designed and manufactured by Chinese people and use national standard products.
After years of efforts, China’s valves have achieved good results in production and use. However, when enterprises purchase, more people will give priority to imported valves and lack trust in domestic valves.
When buying valves, more people pay attention to the quality of valves. The working environment of the valve is relatively poor, so the quality and service life of the valve are very important.
Due to the early start of the research on instrument valves abroad, the processing equipment and R & D level are more advanced than those in China.
But in recent years, China’s valve quality has also been greatly improved. After decades of absorption and digestion, the manufacturing technology and quality of instrument valves in China have been greatly improved.
At the same time, it is important for China’s valve industry * * to further improve product quality and technical content, cooperate with foreign valve manufacturers for win-win results, and constantly improve and grow in the learning process.
2、 Difference between valve inlet and outlet
1. Life and reliability
In 2021, I participated in the research of major control valve manufacturers on key enterprises of Sinopec. Listened to the opinions and suggestions of key enterprises of Sinopec on domestic imported control valves.
The main gap between domestic and imported control valves is reflected in service life and reliability. In the past, the major maintenance cycle of China’s petrochemical industry and power industry was 1-1.5 years. At present, the major maintenance cycle has been extended to 4-5 years.
In some special cases, maintenance is not allowed as long as the control valve is started. If the quality problem of the control valve leads to shutdown, it will bring immeasurable losses to users, and the daily losses can reach hundreds of millions or even billions. Therefore, users would rather spend millions or even tens of millions of yuan to buy imported products with high service life and reliability.
2. Basic materials and processes
At present, the processing technology level of domestic control valve manufacturers has been greatly improved. NC lathes and machining centers are generally used for processing, and the processing equipment is almost the same as that of foreign valve manufacturers.
However, many key components in the control valve, from spring, diaphragm to sealing ring (rubber or metal), have a certain gap with foreign products. In particular, there are several or even more than a dozen products abroad, while there are generally only two in China.
There is a certain gap between domestic large die forgings, high-pressure castings, tungsten carbide molded parts, hard alloy surfacing, spray welding technology, heat treatment technology, especially the application of special materials and foreign technology.
3. Archives Management
Foreign professional control valve manufacturers attach great importance to user file management. Each control valve has a sound database, including complete files such as users, service conditions and digits, factory date, driving date, maintenance records and spare parts replacement. When users need it, they can transfer all historical data of products within a few minutes.
4. Selection software
Foreign professional control valve manufacturers (with Fisher as * *) have a production history of 140 years since the advent of * * * control valve in 1880, and have accumulated rich experience in design, manufacturing, installation and use.
Fisher not only has strong test equipment and instrument support, but also has * * * product varieties and specifications. The selection software has powerful functions, clear and complete prompts, so that users can perfectly accept Fisher products.
5. Test equipment
The laboratory equipment of foreign professional control valve manufacturers (with Fisher as * *) is very complete. Their laboratory can complete CV (kV) test, FL test, CG test, XT test, dynamic torque test, dynamic tensile test, cycle life test, dynamic high and low temperature test, etc.
Domestic control valve manufacturers generally only have water flow test devices, and most of them have not yet adopted dynamic data acquisition and storage. In addition, some professional control valve manufacturers do not even have a flow laboratory to accurately calibrate the rated flow coefficient and flow characteristics of the valve.
6. Process depth
Foreign professional control valve manufacturers have many professional and part-time technical support personnel, who are very familiar with the production process of power, petrochemical, steel, cement and other industries.
Most of these people are engaged in the practical work of the above industries. They understand the type, specification and material application of the control valve on site pressure, temperature, differential pressure, scouring, corrosion, corrosion, gas corrosion and flash, and communicate with the design unit and user * * * before purchase.
Select * * the control valve suitable for the user’s working conditions, and form a formal contract after being approved by the designer and the user. The technical support personnel of domestic control valve manufacturers are almost lack of personnel with this comprehensive quality level, which makes the manufacturers unable to communicate with users.
7. Standard implementation
The production and manufacturing standards of domestic and foreign control valves are basically the same, but foreign control valves are produced beyond the standard, while domestic control valves are produced after the standard.
The standard GB / t4213-2008 pneumatic control valves that we currently implement has been applied for 12 years, and some contents are not applicable to the current production and field application.
Here, I suggest that the “research group in the field of” control valve “should organize relevant personnel to revise the standard of GB / t4213-2008 pneumatic control valve in the near future.