Precautions for forged steel valves, precautions for cast steel gate valves

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 the user's stove.

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 changing rapidly, and the rankings may vary by time and region. For the latest ranking information, it is recommended to refer to industry reports, professional institutions or market research data for more detailed and accurate information.

Handwheels, handles and transmission mechanisms are not allowed to be used for lifting, and collisions are strictly prohibited.

The double gate valve should be installed vertically (i.e., the stem is in a vertical position and the handwheel is at the top).

Gate valves with bypass valves should be opened before opening (to balance the pressure difference between the inlet and outlet and reduce the opening force).

The gate valve with transmission mechanism shall be installed according to the provisions of the product instruction manual.

If the valve is opened and closed frequently, lubricate it at least once a month.

Forged steel valves are mainly used in the pipelines of various systems of thermal power stations, and can be used to control the flow of various types of fluids such as air, water, steam, various corrosive media, mud, oil, liquid metal and radioactive media.

Compared with other valve products, forged steel valves are characterized by high temperature and high pressure resistance, unique self-sealing design, the higher the pressure, the more reliable the sealing. Due to the special performance, technical characteristics and working conditions, the product has also formed a characteristic that cannot be replaced by other products.

Forged steel valves often ignore the issue of grease injection. After the grease injection gun is refueled, the operator selects the valve and the grease injection connection method at the low temperature stop valve, and then carries out the grease injection operation. There are two situations for forged steel gate valves:

On the one hand, the amount of grease injection is small, the grease injection is insufficient, and the sealing surface accelerates wear due to the lack of lubricant. On the other hand, excessive grease injection causes waste. The reason is that there is no precise calculation of the sealing capacity of different valves according to the type of valve type.

The sealing capacity can be calculated according to the size and type of valve, and then the appropriate amount of grease can be injected reasonably.

Forged steel gate valves often ignore the pressure problem. During the grease injection operation, the grease injection pressure of the regular semi-free float® steam trap changes regularly in peak and valley. The pressure is too low, the seal leaks or the safety valve fails, the pressure is too high, the grease port valve manufacturer is blocked, the lipin hardens in the seal, or the seal ring locks up with the valve ball or valve plate.

Usually, when the grease injection pressure is too low, the injected grease mostly flows into the bottom of the valve cavity, which generally occurs in small gate valves. The pressure of the grease injection flow control valve is too high, on the one hand, check the grease injection nozzle of the insulation gate valve, and replace it if the grease remote control float valve hole is blocked, and the spring closure with the wrench is fully open; On the one hand, the plunger globe valve is grease hardening, and cleaning fluid is used to repeatedly soften the failed sealing grease and inject new grease to replace it. In addition, the sealing type and sealing material also affect the grease pressure, different sealing forms have different grease pressure, and the grease pressure of hard seal is generally higher than that of soft seal.

Forged steel globe valvePay attention to the problem of the valve in the switch position. The ball valve is generally in an open state during maintenance, and it is closed for maintenance under special circumstances. Other valves should not be treated as open.

Forged steel globe valves must be closed during curing to ensure that the grease fills the sealing groove along the sealing ring, and if it is open, the sealing grease will fall directly into the flow channel or valve cavity, resulting in waste. When the valve is greased, the grease injection effect is often ignored. The pressure, amount of grease injection, and switch position are normal during the grease injection operation.

However, in order to ensure the grease effect of the valve, it is sometimes necessary to open or close the valve, check the lubrication effect, and confirm that the surface of the valve ball or ram is evenly lubricated.

First of all, the general small-caliber valve needs to be forged, the general situation is less than DN50, and there are some situations that need to be forged, such as power stations, which are generally high temperature and high pressure, PN>100, the pressure bearing performance of forging is better, and specific problems can be communicated with me.

Yongjia Baiye Valve Factory specializes in forging steel.

Natural gas pipelines with relatively high sulfur content.

High-temperature fields, such as power plants, heat transfer oil, high-temperature steam pipelines, etc., high-pressure fields, such as petroleum, chemical industry, etc.

The selection principle is: 1. Globe valves should be selected on the pipelines or devices of high-temperature and high-pressure mediums. Such as thermal power plants, nuclear power plants, petrochemical systems of high temperature, high pressure pipelines.

2. Pipelines with lax requirements for convection resistance. That is, where pressure loss is not considered much. 3. Small valves can be selected needle valves, talking about Qinji instrument valves, sampling valves, pressure gauge valves, etc.

4. There is flow adjustment or pressure adjustment, but the adjustment accuracy is not high, and the diameter of the pipeline is relatively small, such as the nominal through 50mm pipeline, it is advisable to choose. 5. Small fertilizers and large fertilizers in synthetic industrial production should choose high-pressure first-attack angle globe valves or high-pressure angle throttle valves with nominal pressure PN160 nominal pressure of 16MPa or PN320 nominal pressure of 32MPa. 6. In the desilization workshop in the production of alumina Bayer method, and on the pipeline that is easy to coke, it is easy to choose the direct flow stop valve or direct flow throttle valve with separate valve body, valve seat can be removed, and cemented carbide sealing pair.

7. In the water supply and heating projects in urban construction, the nominal passage through the smaller pipeline can be selected, such as the nominal through-passage of the pipeline less than 150mm, such as the nominal through-passage of the pipeline less than 150mm.

2.The sealing packing is checked and replaced regularly to prevent the aging and leakage of the packing;

3.Before the valve is installed, it is necessary to purge the welding slag, rust and other foreign objects in the pipeline to prevent the sealing surface from being damaged when the valve is closed;