Self-operated safety shut-off valve with pneumatic reset axial flow structure

Abstract

The invention discloses a self-operated safety shut-off valve with a pneumatic reset axial flow structure. The self-operated safety shut-off valve comprises a valve body. A pneumatic reset mechanism used for achieving quick opening of the valve body is installed on the valve body, and the pneumatic reset mechanism is connected with a self-operated controller used for controlling the valve body to be automatically closed. The valve is reasonable in structural design, rapid and stable resetting of the valve is achieved without the help of external force or balance of pressure in front of and behind the valve, meanwhile, rapid and automatic cutting off of the valve is achieved, and efficient sealing of the valve is achieved.

Description

technical field [0001] The invention relates to the technical field of valves, in particular to a self-operated safety cut-off valve with axial flow structure and pneumatic reset. Background technique [0002] The safety shut-off valves used in natural gas high-pressure occasions mainly have the following two driving modes: [0003] The first is the flap structure, which is typically represented by the 711 series of the German RMG company. It uses a hook to hang the flap. When the feedback air pressure reaches the set value, the hook falls off and the flap falls to play a sealing role, thereby realizing Cut off, the advantage is that it is self-operated, does not require any external power source, and can be adjusted by the pipeline pressure. It can be used in unattended stations. The action is fast, the structure is simple, and the reset time is short. It has a blocking effect on the instantaneous movement of the medium flow, and it will produce water hammer. The vibration...

AI Technical Summary

Problems solved by technology

[0003] The first is the flap structure, which is typically represented by the 711 series of the German RMG company. It uses a hook to hang the flap. When the feedback air pressure reaches the set value, the hook falls off and the flap falls to play a sealing role, thereby realizing Cut off, the advantage is that it is self-operated, does not require any external power source, and can be adjusted by the pipeline pressure. It can be used in unattended stations. The action is fast, the structure is simple, and the reset time is short. It has a blocking effect on the instantaneous movement of the medium flow, and it will produce water hammer. The vibration caused by the water hammer phenomenon has an impact on the safety of pipeline instrumentation equipment. After cutting off, it is necessary to balance the pressure before and after the valve before it can be reset and opened. In addition, because the valve flap is also relatively heavy, the largest valve diameter is generally DN300, and the pressure is generally CL600, and it is difficult to reset it no matter how large it is

The other is the axial flow structure, represented by MOKVELD in the Netherlands and Ningxia Aikefu. The valve body adopts the valve body of the electric axial flow valve, which is a pure axial flow structure. The spring return hydraulic actuator is used to drive the valve. The lower valve is fully opened, and the hydraulic thrust presses against the spring in the cylinder to fully open the valve. When the pressure behind the valve is overpressured, the pressure transmitter sends a signal to the central control room, and the central control room sends a signal to the solenoid valve of the hydraulic system, and the solenoid valve Reversing, the hydraulic discharge of the lower chamber of the spring, the valve is closed under the action of the spring, the advantages are quick action, high reliability, large caliber and high pressure, the disadvantage is that the reset time is long, the reset is laborious, and the cost is low. High, need external power source

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