Strength properties

The strength of the valve performance is the ability to under medium pressure valve. Within the valve is under pressure of mechanical products, and therefore must have sufficient strength and rigidity, so as to ensure the long-term use without cracking or deformation.

The sealing performance

Valve sealing performance refers to the sealing parts of valve's ability to prevent leakage of medium, it is the most important technical performance index of the valve. Sproul valve sealing part three: open-close part and seat the contact point between the two sealing surface; Packing match and with the stem and packing gland; The joint of the body and bonnet. One former place called internal leakage of leakage, known as the closed lax, it will affect the valve truncation medium capacity. For block valve type, the internal leakage is not allowed. After the two called the leakage of leakage, the medium from leaking to the outside of the valve from the valve. Leakage would cause material loss, environmental pollution, serious when still can cause accidents. For flammable and explosive, toxic or radioactive medium, leakage is not allowed, so the valve must have a reliable sealing performance.

The flow of medium

After medium flow through the valve pressure loss (both before and after the valve pressure difference), namely the valve has a certain resistance to the flow of medium, medium to overcome the resistance of the valve will consume a certain amount of energy. From the consideration on the energy saving, design and manufacture of valves, to reduce the resistance of valve for liquid medium as much as possible.

Open/close force and moment of opening and closing

Open/close force and open-close torque is to point to open or close the valve must be imposed by force or torque. Close the valve, the need to make the open-close part and send a form a seal between the two sealing surface pressure, sypv also overcome between stem and packing, the valve stem and between threads of the nut, valve rod end bearing friction and other parts of the friction force, and therefore must exert closing force and close moment, in the process of opening and closing, the valve is required for opening and closing force and the open-close torque changes, its maximum is in the closed end transient or open the initial transient. Design and manufacture of valves should strive to reduce the closing force and close moment.

Opening and closing speed

Valve opening and closing speed is to use the time needed to complete the open or close a action. Typically on the valve opening and closing speed without strict requirements, but some of the operating mode of opening and closing speed have special requirements, such as some requirements quickly turned on or off, in case of an accident, slowly closing some requirements, to prevent to produce water hammer, etc., it should be taken into consideration when selecting valve type.

Sensitivity and reliability

This refers to the valve for medium parameters change, make corresponding response sensitivity. For throttle valve, relief valve, regulating valve used for adjusting the parameters of the medium, such as valve and relief valve, steam trap valve has a specific function, its function sensitivity and reliability is an important technical performance index.

The service life of the

It said the valve durability, is one of the important performance index sproul valve, and has great economic significance. Usually to ensure the sealing requirements of opening and closing times, use time can also be used to say.