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| Valve sealing performance and service life |
| Valve sealing performance and service life |
Sealing performance
Valve valve sealing performance is part of the sealing ability to prevent media leaks, it is the most important technology valve performance. Sealing valve has three parts: opening and closing pieces and valve seat sealing surface between the two contact points; packing and stem and stuffing the distribution and office; body and bonnet connection. Which is called before a leak within the leak, also known as loose relationship, it will affect the ability of the valve cut off media. For the truncated valve, the internal leakage is not allowed. Leakage after the two called the leak, that media leaks from the valve to the valve outside. Leakage will result in material losses, environmental pollution, will result in serious accidents. The explosive, toxic or radioactive medium, leakage is allowed, and thus the valve must have a reliable sealing performance.
Mobile Media
Medium flow through the valve will produce a pressure loss (both before and after the valve pressure difference), that is, the flow valve on the media have a certain resistance, medium to overcome the resistance of the valve, it takes some energy. From the conservation of energy considerations, the design and manufacture of valves, to minimize the resistance of the valve on the flow media.
Stop force and the opening and closing torque
Stop force and the opening and closing torque is necessary for the valve to open or close the force or torque applied. Close the valve, the need to open and close the two pieces with the fat seat sealing surface of the seal formed between certain specific pressure, but also to overcome the stem and the packing between the stem and the nut thread between the stem end of the Bearing friction and other friction parts, which must exert closing force and closing moments, the valve in the opening and closing process, the need to stop force, and opening and closing moments of change, and its maximum is close to the final instant or open the initial transient. Design and manufacture of valve closing force should seek to reduce and close the moment.
Hoisting speed
Opening and closing speed is an opening or closing the valve action to complete the time required to represent. Generally open and close the valve speed without strict requirements, but some conditions on the hoist speed with special requirements, if any, required to open or close rapidly to prevent accidents, and some asked slowly shut down to prevent water hammer and other produce , which used to be considered when the valve type.
Sensitivity and reliability of action
This refers to the valve for the medium parameters, and make the appropriate degree of sensitivity. The throttle valve, reducing valve, regulating valve used to adjust the valve and safety valve medium parameters, the trap has a specific function such as valves, its function is very important to the sensitivity and reliability of technical performance indicators.
Life
It said that the durability of the valve, the valve is an important performance indicators and has great economic significance. Usually guarantee the number of seals required to open and close that can also be used to indicate the use of time.
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ICP: 06003029