• Categories:Industry Information
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• Time of issue:2011-07-29 22:27
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(Summary description)The spring type quick closing butterfly valve is mainly composed of butterfly valve, hydraulic-spring drive device, hydraulic station and electric control box. When the valve is opened, the system issues a command (the electric control box is set to remote control), the hydraulic station works, and the hydraulic oil enters the bottom of the cylinder to push the piston to drive the butterfly valve to open, and the spring in the spring cylinder is compressed and stored. When an emergency occurs in the working system, the butterfly valve will receive an accident signal and will be closed quickly under the action of the spring. The closing time is 013～015s, thus protecting the working system and pipeline equipment. Since the working medium of the quick-closing butterfly valve is a medium-high temperature gas, a special structure is adopted when the butterfly valve is designed. (1) Butterfly plate The butterfly plate adopts a triple eccentric structure, so that during the opening and closing process of the butterfly valve, the sealing surface of the butterfly plate will immediately leave the sealing surface of the valve body at the moment of opening. During the closing process, only at the moment of closing, the sealing surface of the butterfly plate It will contact and compress the sealing surface of the valve body to ensure the seal, which completely eliminates the wear and abrasion between the two sealing surfaces. At the same time, the inclined cone structure has a self-positioning function to ensure the neutrality of the butterfly plate. (2) The metal-graphite sandwich sealing ring of the floating sealing ring butterfly plate adopts a floating sealing form. When the temperature change of the butterfly valve occurs during installation or use, the floating sealing ring can compensate for the slight deformation of the valve body to make the butterfly valve seal Always keep it in the best condition. (3) Shaft end temperature compensation mechanism due to the high operating temperature of the butterfly valve, taking into account the thermal expansion effect of the valve shaft, in order to prevent the valve shaft from being held up and the valve cannot be opened normally, a temperature compensation mechanism is added at the upper and lower shaft ends at the same time. Several sets of support gaskets with the same function as the disc spring are used to automatically adjust the size of the valve shaft caused by temperature to compensate for the unfavorable factors caused by excess deformation, so as to ensure that the butterfly plate does not deviate, the shaft end does not leak, and the tail The end is not damaged. The normal working state (power-on state) of the quick-closing butterfly valve is normally open. Only when the system fails (power-off state) can it be quickly closed. According to this feature, the drive device must have an automatic reset function, that is, the drive device makes the butterfly valve open when the power is turned on, and the drive device automatically resets to close the butterfly valve when the power is off. There are many types of automatic reset drive devices. Considering the high safety performance requirements of butterfly valves, the structure of shift fork transmission and spring reset is adopted, which is mainly composed of box, shift fork, oil cylinder, piston, piston rod, spring and spring cylinder, etc. composition. Since the fast closing time of the butterfly valve is required to be within 015s, considering the performance, the pin in the shift fork is made of alloy steel, and the contact part of the shift fork is equipped with a cylindrical roller bearing, which transmits the piston force of the cylinder to the shift in a rolling manner. Fork, in this way, not only reduces friction, increases life span, but also improves torque transmission efficiency. Due to the use of the spring action mechanism, the safety of the spring has been carefully considered. The independent safety protection screw makes it unnecessary to install and remove the spring on site, and to ensure the personal safety of the operator. The spring loading and disassembly are safe and convenient.