How do I eliminate cavitation in my valves? 5

Here are some of the well-known brands recognized in the valve industry, which are widely recognized and have a high reputation. While rankings may vary depending on time and market conditions, the following brands are generally considered to be among the top brands in the valve industry:

The following influential first-line brands of water system valves and industrial valves can be used as a reference, but for reference only: Suzhou Neway Valve, Shanghai Guanlong Valve, Shanghai Qizhong Valve, Sanhua, Su Yan, Shentong, Su Valve, Nanfang, Jiang.

First, the word Yao. The above manufacturers are only estimates and references, and the specific situation may vary or fluctuate at any time due to changes in a series of factors such as changes in the market, the size of the competition pattern, and the stability of product quality. As an indispensable key device in industrial production and civil facilities, the quality and reputation of the valve brand directly affect the satisfaction and trust of users.

These brands are known in the valve industry for their innovative technology, high-quality products and reliability. It is important to note that the market and industry are evolving rapidly, and different rankings may vary depending on time and region. For the most up-to-date ranking information, it is recommended to refer to industry reports, professional organizations or market research data for more detailed and accurate information.

The pressure difference of the valve is very important, and the key is that the internal parts of the valve need to be surfacing and sprayed with cemented carbide, which is anti-erosion and cavitation-resistant.

What kind of valve are you?

1. According to the causes of cavitation, solutions: 1. Reduce the pressure difference and flow rate of the fluid at the cavitation so that cavitation cannot occur. Measures such as not to open the valve opening too small, if you have to get a large pressure drop, you can take multi-stage pressure reduction, you can also take labyrinth spool, porous spool, etc.

2. Reasonably design the shape of the fluid channel or valve core, and try to avoid the structure that makes the flow direction of the fluid abrupt change or throttle and block.

Second, if cavitation is inevitable, then we can only find a way to increase the cavitation resistance at the valve material to increase the cavitation resistance, that is, to increase the hardness of the material. For example, cemented carbide materials, surface hardening, etc., to prolong the service life of the valve.

For high-pressure low-flow control valves, a series of problems caused by the main high pressure and high differential pressure must also be considered. For example, the actuator must have sufficient output force to overcome the unbalanced force of the medium, the strength of the valve parts, the high-pressure sealing problem, and the most critical thing is the material and processing of the valve core and valve seat.

The causes of damage to the valve core and valve seat of the high-pressure control valve are very complex, and the theories in this are not the same, but the general attention is the scouring phenomenon (also known as the velocity effect) caused by the movement of the high-speed liquid (gas) flow relative to the valve core and valve seat and the cavitation phenomenon of the liquid medium under the high pressure difference. The former is damaged in the form of scouring marks that have a certain relationship with the flow line, and the latter is a spongy hole.

In the case of cavitation, if the spool and seat material are not selected properly, the valve will be scrapped for a few days or a few months.

To solve the problem of cavitation, we should start from the methods to avoid cavitation and materials resistant to cavitation, and there are several ways to avoid cavitation.

1. Improve the design of the valve core and valve seat to make it have a reasonable liquid flow velocity distribution and pressure distribution. For example, the small flow control valve adopts a narrow channel type spool and valve seat. The spool and seat bore have a small taper for precise flow control at constant upstream pressure.

Due to its ability to absorb energy and reduce cavitation, it has been reported to have been used for a pressure drop of 4200 kg cm2.

2. When the conditions are allowed, inflate in the liquid flow to partially or completely eliminate the low pressure area.

3. The valves are used in series to reduce the pressure drop of each valve.

4. The pressure difference between the front and back of the valve is lower than the maximum allowable pressure difference of the medium cavitation phenomenon at the inlet temperature of the regulating valve.

5. The medium works in the "flow open" state, and the allowable pressure difference is more than three times larger than that in the "flow closed" state.

1. The corrosion of the valve is usually understood as the damage of the metal material of the valve under the action of chemical or electrochemical environment.

2. The method of anti-corrosion of metal valves is determined by the required protection period, transportation and storage conditions, valve construction characteristics and materials, and of course, it is suitable to consider the economic effect of lifting anti-corrosion.

3. The anti-corrosion of metal valves can be understood as coating the metal valve with a protective layer (such as paint, pigment, lubricating materials, etc.) to protect it from corrosion, so that the valve is not corroded in the whole process of manufacturing, storage, transportation or its use.

4. Because the chemical corrosion of the metal depends on the temperature, the mechanical load of the friction parts, the sulfide contained in the lubricating material and its acid-resistant stability, the duration of contact with the medium, the catalytic effect of the metal on the nitriding process, the conversion rate of the molecules of corrosive corrosive substances to the metal, etc.

Therefore, the anti-corrosion methods (or measures) of metal valves and the application of synthetic material valves have become one of the research topics in the valve industry.

5. As we all know, the corrosion damage of metal has a considerable impact on the service life, reliability and service life of the valve. The action of mechanical and corrosive factors on the metal greatly increases the total wear of the contact surface.

The total amount of wear on the surface of the friction during the operation of the valve. During the operation of the valve, the friction surface is worn and damaged due to the simultaneous mechanical action and the chemical or electrochemical interaction between the metal and the environment.

For valves, the working climatic conditions of the pipeline are complex; The presence of hydrogen sulfide, carbon dioxide and certain organic acids in media such as oil, natural gas and oil layer water increases the destructive power of their metal surfaces, which quickly loses their ability to work.