Hardware spring type quick closing butterfly valve is mainly composed of butterfly valve, hydraulic spring driving device, hydraulic station and electric control box. When the valve is opened, the system sends a command, and the hydraulic station works. The hydraulic oil enters the bottom of the oil cylinder to push the piston to open the butterfly valve. At the same time, the spring in the spring cylinder is compressed to store energy. In case of emergency in the working system, the butterfly valve will receive the accident signal and close quickly under the action of spring. The closing time is 013 ~ 015s, thus protecting the working system and pipeline equipment.
Because the working medium of quick closing butterfly valve is medium and high temperature gas, special structure is adopted in the design of butterfly valve.
(1) Floating seal ring the metal graphite sandwich seal ring of butterfly plate adopts the floating sealing form. When the temperature changes during the installation or use of butterfly valve, the floating seal ring can compensate the slight deformation of the valve body and keep the sealing of butterfly valve in the best state all the time.
(2) Due to the high service temperature of butterfly valve, considering the thermal expansion effect of valve shaft, in order to prevent the valve from opening normally due to the valve shaft jacking, a temperature compensation mechanism is added at the upper and lower shaft ends at the same time, and several groups of supporting gaskets with the same function as the disc spring are used to automatically adjust the size change of valve shaft caused by temperature, Compensation for the adverse factors caused by redundant deformation, so as to ensure that the butterfly plate is not offset, the shaft end is not leaked, and the tail end is not damaged.
(3) The butterfly plate adopts a three eccentric structure, so that the sealing surface of butterfly plate will immediately leave the sealing surface of the valve body at the moment of opening and closing. In the process of closing, the sealing surface of butterfly plate will contact and compress the sealing surface of the valve body to ensure sealing, and completely eliminate the wear and scratch between the two sealing surfaces. At the same time, the inclined cone structure has self positioning function to ensure the butterfly plate to be neutral.
Since the fast closing time of butterfly valve is required to be less than 015s, considering the service performance, the pin in the fork is made of alloy steel, and the contact part of the fork is equipped with cylindrical roller bearing, which transfers the piston force of the oil cylinder to the fork in a rolling way. In this way, the friction is reduced, the service life is increased and the torque transmission efficiency is improved. Due to the use of spring mechanism, the safety of the spring has been carefully considered. The independent safety protection screw makes it unnecessary to install and disassemble the spring on site without special tools and ensure the personal safety of the operator. The spring loading and disassembling is safe and convenient.