Valves The use is extensive
Valve little common sense
The purpose of the valve is wide, so it is also very useful. For example, valves in power plants can control the operation of boilers and turbines; In petroleum and chemical production, valves also control the normal operation of all production equipment and processes. The same is true in other departments. Nevertheless, the comparison of valves with other products is often overlooked. When installing machine equipment, people tend to focus on the main machine equipment but ignore the valve. This will reduce or halt production efficiency, or cause other accidents. Therefore, the selection, installation and use of valves must be carefully and responsibly. The most commonly used domestic general points gate valve, cut-off valve, throttle valve, instrument valve, plunger valve, diaphragm valve, plug valve, ball valve, butterfly valve, check valve, pressure reducing valve, safety valve, drain valve, regulating valve, bottom valve, filter, drain valve etc.
The sealing performance of the valve is the ability of the valve seal to prevent the leakage of the medium. It is the most important technical performance indicator of the valve.
There are three sealing parts of the valve: the contact between the closing part and the two sealing surface of the seat; Packing and stem and stuffing box; The connection of the valve body to the bonnet. The first leak is called an internal leak, which is often said to be lax, and it will affect the valve's ability to truncate the medium. For truncated valve classes, internal leakage is not allowed. The latter two leaks are called external leakage, that is, the medium leaks out of the valve to the outside of the valve. Leakage can cause material loss, environmental pollution and serious accidents. For flammable, toxic or radioactive media, leakage is not allowed, so the valve must have reliable sealing performance.
Test requirements, test items, test methods, etc. The life test of valve electric device type test is still under the standard. Jbz247-85 series JB/t8528-1997 reference standard for the technical conditions of ordinary valve electric device.
The electrical installation is based on the following:
1.. Operation thrust: the main structure of valve electric device is two kinds: one is not to configure thrust plate, direct output torque; The other is the configuration thrust disc, which is converted to the output thrust through the stem nut in the thrust plate.
Operating moment: the operating moment is the main parameter to select the valve electric device. The output torque of the electric device shall be 1.2 ~ 1.5 times of the maximum torque of the valve operation.
