Spring-type quick closing butterfly valve structure

Butterfly valve structure: 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) and the hydraulic station works. Hydraulic oil enters the bottom of the cylinder and pushes the piston to drive the butterfly valve to open. At the same time, 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 quickly close under the action of a spring. The closing time is 013-015s, thus protecting the working system and piping equipment.

Since the working medium for the rapid closing of the butterfly valve is a medium-high temperature gas, a special structure is used in designing the butterfly valve.

(1) 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 instant of opening. In the closing process, only at the closing moment, the butterfly plate sealing surface It will contact and press the sealing surface of the valve body to ensure the seal, completely eliminating the wear and scratches between the two sealing surfaces. At the same time, the tapered cone structure has a self-positioning function to ensure that the butterfly plate is neutral.

(2) The metal-graphite sandwich seal of the floating seal disc adopts a floatable seal type. When the temperature of the butterfly valve changes during installation or use, the floating seal can compensate for the slight deformation of the valve body and seal the butterfly valve. Always stay in top condition.

(3) Shaft end temperature compensation mechanism Because of 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 against the normal opening of the valve, a temperature compensation mechanism is additionally provided at the upper and lower shaft ends. Through several sets of supporting washers with the same function as the disc spring, the temperature change of the valve shaft caused by the automatic adjustment, to compensate for the unfavorable factors caused by the excess deformation, so as to ensure that the disc does not offset, the axis does not leak, tail The end is not damaged.

The normal operation state (power-on state) of the butterfly valve is quickly closed. The normally open state is only required when the system fails (power-off state). According to this feature, it is required that the drive device must have an automatic reset function, that is, the drive device causes the butterfly valve to open when the power is turned on, and the drive device automatically resets to close the butterfly valve when the power is turned off. There are many kinds of drive devices for automatic reset. Taking into account the high safety requirements of the butterfly valve, the structure of the shifting fork drive and the spring return is adopted. The structure is mainly composed of a box, a shift fork, a cylinder, a piston, a piston rod, a spring and a spring cylinder. composition.

Due to the quick closing time of the butterfly valve is within 015s, considering the use performance, the pin in the shift fork is made of alloy steel, and the cylindrical roller bearing is mounted on the contact portion of the shift fork to transfer the piston force of the cylinder to the dial in a rolling manner. The fork, in this way, reduces friction, increases lifetime, and increases torque transmission efficiency. Due to the adoption of the spring action mechanism, careful consideration has been given to the safety of the spring. The independent safety protection screw makes it unnecessary to install and disassemble the spring when it is needed in the field, and does not require special tools and guarantee the safety of the operator. It is safe and convenient to load and remove the spring.