Precautions for replacing the valve core
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The valve core is the valve component through whose movement the valve body carries out its basic functions of direction control, pressure control, or flow control. The valve core is the component of a valve through whose movement the valve carries out its basic functions of direction control, pressure control, or flow control; it is usually made of bronze or stainless steel, but can also be made from plastics, nylon, ceramics, glass, and other materials. Determine the material of the valve core, which must be appropriate for the medium. It can be considered from the following aspects: if it is a non-corrosive medium such as water, it can be made of 45 steel or other structural steels. If it is a corrosive medium, it is necessary to understand factors such as the nature of corrosion, temperature, and concentration. Under normal conditions, corrosion in acidic environments is more severe than that in alkaline environments. Acids that cause corrosion include various types such as hydrochloric acid, sulfuric acid, nitric acid, and organic acids. There are many more. Alkaline corrosion such as sodium hydroxide, potassium hydroxide, etc. In an acidic environment, it is necessary to know the properties of the acid, temperature, pH value, etc.; otherwise, corrosion can occur even if stainless steel is used. Pure hydrochloric acid is usually made of Hastelloy. Sulfuric acid is usually selected from materials such as 316, 904, 841, 20# alloys and high-silicon cast iron. Nitric acid is usually selected from materials such as 304 and 2Cr13. Organic acids are usually selected from materials such as 304 and 316. In an alkaline environment, carbon structural steel can be used at room temperature, while stainless steel can be used at high temperatures and high concentrations. Valves used in fluid control systems range from the simplest stop valves to highly complex automatic control systems for various sizes and applications. Valves can be used to control the flow of various types of fluids, such as air, water, steam, various corrosive substances, mud, oil, liquid metals, and radioactive materials. According to the materials, valves are also classified into cast iron valves, cast steel valves, stainless steel valves (201, 304, 316, etc.), chromium-molybdenum steel valves, chromium-molybdenum-vanadium steel valves, duplex steel valves, plastic valves, and valves made from custom materials. The valve core is a component of the valve body; through its movement, it enables the basic functions of direction control, pressure control, or flow control. Based on the motion pattern, it is divided into rotational types of 45°, 90°, 180°, 360°, and translational types (radial, directional). Based on its shape, it can generally be divided into spherical (ball valves), conical (plug valves), disc-shaped (butterfly valves and gate valves), domed (globe valves and check valves), and cylindrical (directional control valves). Typically, it is made mainly of bronze or stainless steel, and it also includes plastics, nylon, ceramics, glass, etc. The valve core in a pressure relief valve is one of the main components used to control pressure.
Precautions when replacing the valve core are crucial, as they directly affect the performance and service life of the valve. Here are some key points to keep in mind: 1. **Choose the appropriate valve core material**: The suitable valve core material must be selected based on the medium flowing through the valve (liquid or gas), as well as temperature, pressure, and corrosivity. For example, using a stainless steel valve core is suitable for corrosive media, while for ordinary water-based media, copper or copper alloy valve cores may be more economical and appropriate. 2. **Power off and depressurize**: Before replacing the valve core, it is essential to ensure that the entire system has been powered off and that the internal pressure has been completely released to guarantee the safety of the maintenance personnel. 3. **Clean the working environment**: Before removing and replacing the valve core, it is necessary to clean the area around the valve to prevent dust and debris from entering the valve body and affecting its proper operation. 4. **Proper disassembly and installation**: When removing the old valve core, care should be taken to avoid damaging the valve body or other components. Similarly, when installing a new valve core, it is also necessary to ensure proper alignment and a smooth installation to avoid damaging the sealing surfaces. 5. **Replace seals and gaskets**: When replacing the valve core, it is recommended to replace the seals and gaskets at the same time, as the old seals may have worn out or become deformed, failing to ensure a proper seal. 6. **Prevent over-tightening or under-tightening**: When installing a new valve core, use moderate force to avoid tightening it too much or too little, as this can affect the valve’s sealing performance or cause leaks. 7. **Inspection and Testing**: After installation, it is necessary to check for any incorrect installations or omissions, followed by leak tests and performance tests to ensure that the valve meets the design requirements and can function properly. 8. **Use professional tools and technicians**: Replacing the valve core should be carried out by professional technicians, using appropriate tools and equipment, and in compliance with relevant safety procedures and operating guidelines. 9. **Consult the manufacturer’s instructions**: Before replacing the valve core, it is advisable to consult the valve manufacturer’s instructions to understand the specific requirements and recommended procedures for that particular model of valve. Please use appropriate methods and preventive measures to replace the valve core, depending on the specific type of valve and its operating environment. Safety should always come first. .