Main specification of technical performance of valve

Strength performance
Valve strength performance refers to the ability of the valve to bear medium pressure. Valves are mechanical products that bear internal pressure, so they must have sufficient strength and stiffness to ensure long-term use without rupture or deformation.
Sealing performance
The sealing performance of valves refers to the ability of each part of the valve to prevent leakage of the medium. It is the most important technical performance index of valves. There are three sealing parts of the valve: the contact between the opening and closing and the two cover of the valve seat; the matching of the filler to the stem and the filling letter; the connection between the valve body and the valve cover. The leakage in the former part is called internal leakage, which is usually referred to as lax. It will affect the ability of the valve to cut off the medium. For cut-off valves, internal leakage is not allowed. The latter two leakage is called external leakage, that is, the medium leaks from the valve to the valve. Leakage will cause material loss, pollute the environment, and cause accidents in severe cases. For flammable, explosive, toxic or radioactive media, leakage is not allowed, so the valve must have a reliable sealing performance.
Flow medium
When the medium flows through the valve, the pressure is lost (the pressure difference before and after the valve), that is, the valve has certain resistance to the flow of the medium, and the medium will consume a certain amount of energy to overcome the resistance of the valve. From the point of view of energy conservation, when designing and manufacturing valves, reduce the resistance of valves to flowing medium as far as possible.
Opening and closing force and opening and closing moment
The opening and closing force and the opening and closing moment are the forces or moments that must be applied when the valve is opened or closed. When the valve is closed, a certain seal ratio should be formed between the opening and closing and the two cover of the hair seat. At the same time, the friction between the stem and the filler, the thread of the stem and the nut, the support of the stem end and the other friction parts must be overcome, so a certain closing force and closing moment must be applied, and the valve is in the process of opening and closing. The opening and closing force and opening torque are varied, and the maximum value is the final instantaneous or open initial instant. When designing and manufacturing valves, efforts should be made to reduce the closing force and closing torque.
Opening and closing speed
The opening and closing speed is expressed by the time required for the valve to complete an opening or closing operation. There are no strict requirements for the opening and closing speed of the valve, but some conditions have special requirements for the opening and closing speed, such as the demand for quick opening or closing, in order to prevent accidents, and some requirements are slowly closed to prevent water shock, which should be taken into consideration when choosing the type of valve.

Action sensitivity and reliability
This refers to the sensitivity of valves to corresponding changes in media parameters. For valves, such as throttle valve, pressure relief valve, regulating valve and other valves which are used to adjust the medium parameters, as well as valves with specific functions such as safety valves and traps, its functional sensitivity and reliability are very important technical performance indicators.
Service life
It indicates the durability of valves, is an important performance index of valves, and has great economic significance. Usually it can be expressed by the number of opening and closing which can ensure the sealing requirements, and it can also be expressed with the use time.