RU2238468C2 - Automatic device for closing valve in main gas conduits - Google Patents

Abstract

FIELD: fitting manufacture, namely automatic closing of gas duct in case of possible breakage and leakage at gas transportation in main gas conduit.

SUBSTANCE: device for automatic closing of valve includes distributor. The last has slide valve in the form of piston arranged in housing of distributor, first and second control chambers communicated with gas conduit. The last has shut-off organ joined with hydraulic drive unit. Piston is arranged in housing between first and second control chambers and it is secured to stepped rod with annular turning. Length of annular turning is equal to spacing between opening of housing communicated with vessel for emergency storage of gas and opening of housing communicated with hydraulic vessel for closing valve joined with shut-off organ of gas conduit. First control chamber is arranged under lower end of lid; second control chamber is arranged under piston. Protective hood is placed in upper portion of housing. Explosion-proof switch is placed on said hood.

EFFECT: enhanced operational reliability, simplified design, easy maintenance of device.

1 dwg

Description

The invention relates to valve engineering and can be used in the transportation of gases through gas pipelines, for automatic shutdown of the pipeline in the event of possible breaks and gas leaks.

There are known automatic machines for emergency shutdown of a gas pipeline when it is damaged (Andreev G.S. Shutoff valves of main gas pipelines. - L. Nedra, 1968, - p. 73-76, RF patent No. 2138720), including a gas distribution device for controlling a shut-off actuator body on the gas pipeline and sensors that respond to changes in the rate of pressure drop, containing cylinders associated with the gas pipeline through a small section.

The disadvantages of these devices are the lack of reliability, since it is possible for the gas to flow slowly through the shut-off element, due to its insufficient tightness and the formation of microcracks during long-term operation, which leads to a false response.

A well-known automatic shutdown of the pipeline when it is damaged, we have chosen for the prototype (RF patent No. 2029191, IPC F 16 K 17/34, publ. 02.20.1995) The machine contains a distributor with a spool installed in its housing in the form of a spring-loaded first piston, installed in the lower end of the housing, at the upper end of which a second piston is mounted, connected to a hydrodefer piston located in the housing bore, loaded with a spring connected through a plate to the first piston. The first piston is supported on a thin metal membrane sandwiched between the lower end of the housing and mounted on this flange to ensure that the membrane ruptures in the lower position of the first piston.

The main disadvantage of this device is the design complexity, as it has three pistons and two rods, several ring seals, a complex system for regulating the annular channel of the hydrodefer, which requires disassembling the emergency shut-off valve on the day it is set up, and after the device is triggered, it is necessary to replace the membrane to restore the output chamber . Additional use (along with the pneumatic system) of a hydraulic system with non-freezing fluid. This leads to the complexity of the manufacturing technology and tuning of the emergency shutdown machine, as well as its operation, which, ultimately, is reflected in the main indicator of reliability.

The technical solution of the proposed device is to increase reliability, simplify the design and operation of the crane closing machine. High reliability of operation is ensured by the absence of intermediate working fluids (fluid, springs) and the exclusion of false positives, because the gas closing valve is connected to the atmosphere. Compared with the prototype, the proposed device does not require disassembly when setting up for work.

The technical solution is achieved by the fact that in the emergency shut-off valve on gas pipelines containing a distributor with a spool in the form of a piston installed in its body, the first and second control chambers connected to the gas pipeline, in which a shut-off element connected with the hydraulic actuator is installed, according to the proposed solution the piston is installed in the housing between the first and second control chambers and is mounted on a stepped rod with an annular groove of a length equal to the distance between the hole in the housing, with running along with a container for emergency gas supply and an opening in the housing that connects to a closure valve attached to a shut-off element in the gas pipeline, with the first control chamber located under the lower end and the second control chamber located under the piston, and a protective cap installed in the upper part of the housing on which the explosion-proof switch is located.

An example of a specific implementation.

The drawing shows a diagram of an emergency shutdown crane. The device consists of a distributor assembled in a cylindrical housing 1 with a cover 2 and a clamping nut 3, a closed protective cap 4 with a drainage hole 5. Inside the housing 1 there is a spool consisting of a piston 6, in which calibrated holes 7 and a rod 8 with an annular groove are made 9 and O-rings 10. The rod 8 is made stepwise with a large diameter above the piston 6. The first control chamber 11 is located under the lower end of the cover 2, and the second control chamber 12 is located under the piston 6. The first control chamber 11 the cut hole 13 is connected to the receiver 14 and through calibrated holes 7 to the second control chamber 12. The second control chamber 12 through the hole 15 is connected to the main gas pipeline 16. An annular groove 9 through the hole 17 is connected to the emergency gas supply capacity 18. The hole 20 is connected to the hydraulic cylinder closing 21 of the shut-off member 22 of the gas pipeline 16. The length of the annular groove 9 is 29 mm A drainage hole 23 connects the working area of the closure valve 21 to the atmosphere. The locking element 22 is connected to the hydraulic actuator 24. An explosion-proof switch 25 is installed on the protective cap 4 and the upper part of the rod 8, which controls the position of the emergency shut-off valve. Explosion-proof switch 25 is connected to the telemechanics system. Gas is supplied to the emergency shut-off valve from the gas line 16 through the valve 26 and the hole 15, and to the emergency gas supply capacity 18 through the valve 26 and the check valve 27. The emergency shut-off valve operates as follows. Bringing to working condition.

When connecting the emergency shut-off valve to the gas line 16, the gas hole 15 is supplied to the second control chamber 12, the rod 8 together with the piston 6 moves to its original upper position, then the first control chamber 11 is filled through the calibrated holes 7 and the receiver 14 is filled through the hole 13. emergency gas supply 18 is filled through the valve 26 and the check valve 27. In this case, the pressure in the chambers 11 and 12 is equalized and equal to the gas pressure in the gas pipeline 16.

If the gas line 16 is damaged, the pressure in the first control chamber 11 drops more slowly than the pressure in the second control chamber 12, which leads to a pressure drop between the chambers on the piston 6. When a pressure drop of sufficient value (~ 0.4 kg / cm) is reached due to receiver 14 and calibrated holes 7, the movable piston system 6 is moved to its lowest position. The piston together with the rod 8 moves down and the annular groove 9 in the rod 8 connecting to the hole 19 forms an outlet chamber. Gas from the emergency reserve tank 18 through the hole 17, the annular groove 9 and the hole 20 is supplied to the closing valve 21, in which pressure is created to actuate the shut-off element 22. The shut-off element 22 closes and closes the gas pipeline 16. When the working pressure of the gas in the gas pipeline is restored after liquidation rupture of the piston 6 with the rod 8 automatically returns to its original position due to the fact that the rod 8 is made in steps, and due to the difference in area are suppressed technological operating pressure fluctuations in the gas pipeline. In addition, the rod 8 is made integral, which allows for accurate alignment.

The crane emergency shutdown machine was tested at the Yurginsky linear production department of Tomsktransgaz LLC and showed high operational properties. Sustainable operation and reliability in emergency situations. After eliminating gusts in the gas pipeline, the proposed machine does not require disassembling the machine components, and is automatically brought into operation by returning the piston 6 and the rod 8 with the gas pressure in the second control chamber 12 to its upper initial position. Thus, the proposed machine emergency closure of the crane in comparison with the prototype has a simpler design and high reliability, it does not require disassembly for configuration. The machine is industrially applicable and easy to manufacture.

Claims (1)

An emergency shut-off valve on main gas pipelines, comprising a distributor with a spool in the form of a piston installed in its housing, first and second control chambers connected to the gas pipeline, in which a shut-off element connected to the hydraulic actuator is installed, characterized in that the piston is installed in the housing between the first and the second control chambers and is mounted on a stepped rod with an annular groove, the length of which is equal to the distance between the hole in the housing, which is connected to the tank for emergency gas supply a, and a hole in the housing that connects to the valve closing valve associated with a shutoff member in the gas pipeline, the first control chamber located under the lower end of the cover, and the second control chamber under the piston, and a protective cap is installed in the upper part of the housing explosion protection switch.