Safety shut-off valve

Abstract

The invention discloses a safety shut-off valve. The safety shut-off valve comprises a valve body, an upper valve body and a shut-off mechanism. The valve body is provided with a first channel and a second channel, the upper valve body is connected with the upper end of the valve body through a screw and used for sealing the valve body, and the shut-off mechanism is arranged in the middle of the valve body and used for connecting or disconnecting the first channel and the second channel. The safety shut-off valve is characterized in that the shut-off mechanism comprises a shut-off part and a cam connecting device which are separated from each other; the valve body is integrally formed by forged steel in a turn milling mode. The independent cam connecting device is adopted, so that separated repair is facilitated, and the situation that the shut-off valve cannot work normally due to maintenance assembly errors is avoided; the internal structure of the valve body is simple, the forged steel integration valve body is adopted, the internal organizational structure of the valve body is improved, grains are refined, the mechanical properties, such as shock resistance, plasticity and toughness, of the forged steel integration valve body are superior to those of a cast steel valve body, and the safety performance of the valve is improved.

Description

technical field [0001] The invention relates to a safety cut-off valve, in particular to a safety cut-off valve for a gas transmission system. Background technique [0002] Safety cut-off valves are used in gas transmission and distribution systems for emergency cut-off protection. When the pipeline pressure controlled by the shut-off valve is higher or lower than the cut-off set pressure, the safety shut-off valve can cut off the pipeline air flow urgently to protect the downstream equipment. [0003] The Chinese patent application number 200920170968.3 discloses a safety shut-off valve such as figure 1 As shown, it mainly consists of housing 001, air inlet 002, air outlet 003, cut-off chamber 004, release mechanism 005, cut-off valve 006, cut-off spring 007, cut-off valve stem 008, piston 009, pressure regulating spring 0010, connecting rod 0011 , Feedback signal tube 0012 and so on. When this type of cut-off valve is in the open state and reset operation, the trip mech...

AI Technical Summary

Problems solved by technology

The closing element of this patent adopts the sealing method between the valve disc and the valve port, and the sealing part of the valve port has a raised design, which reduces the service life of the valve disc; the closing components of these two cut-off valves require springs to provide a large force , to help the closing element to achieve sealing, which increases the force of the shut-off valve during manual reset operation; at the same time, when the shut-off valve is open, the O-ring at the valve plate has no protection measures and will be washed by the inflowing gas, so that it cannot Play a good sealing effect, causing loss and safety problems

[0005] The safety cut-off valves in the prior art all use sleeve-guided positioning valve discs, which have high requirements for concentricity and occupy a large space ( figure 1 Cutting cavity 004 and figure 2 Shut-off valve body II), complex structure, difficult manufacture, high cost, and many disassembled parts during maintenance; at the same time, due to the casting shell, the structure is complex, difficult to manufacture, many material defects, and low safety

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