RU56536U1 - UNLOADING DEVICE OF PNEUMATIC HYDRAULIC DRIVES OF BALL VALVES - Google Patents

Abstract

The pneumatic hydraulic actuator of figure 1 is equipped with a piston pressure compensator 12, containing in the housing 12A a piston 13 with a stem 15 with an emergency poppet valve 14 fixed on it, in contact with the seat 16, a hand pump 19, which interacts with the hydraulic cavities B, D of the hydraulic cylinders 1.37 through a pressure regulator 21, distribution hydraulic valves 29,30, controlled by a key control 47 (FIGS. 1, 3), a fixed threaded connection 42 on the control levers 26, 27, held by a retainer plate 56 (FIG. 4) during operation of the hand pump 19, and the operation pneumohydro cylinders 1.37 from gas 40, 41 provide: an overflow valve 23, a pneumohydro block 5 (Figs. 1, 2) in which a two-chamber pneumohydrocylinder 5A is placed by gas chambers D, C in communication with the gas pressure relief valves with one-way conductivity 51, 52 (Fig. 2 ) and the gas cavities A, B of the hydraulic cylinders 1.37, acting with its pistons 7, 8 from the gas pressure 40, 41 through the plate 9 on the spools 6, 6A of the shut-off hydraulic valves 24, 25.

Description

The utility model relates to valves used for pumping gas in the gas industry and can be used for pumping liquid petroleum products in the oil refining industry.

The known design of pneumatic actuators, which are produced by foreign companies and domestic factories that do not meet the modern requirements of operating organizations.

The closest in design and manufactured in large series are pneumatic actuators manufactured at the leading Russian plant Tyazhpromarmatura, Aleksin, Tula region.

A description of the operation of such a hydraulic actuator is given in the attached operating instructions. Working on the gas pipelines of the Russian Federation and a number of foreign countries during operation, a number of shortcomings were identified that lead to breakdown of components and parts, which are caused by the following factors.

1. The hand pump can pass pressure in hydraulic cylinders over 150 atm. (experiments were carried out) This occurs for the following reasons: an expansion tank with a one-way valve connected to the atmosphere. The hydraulic fluid enters the suction part of the pump, it pumps the hydraulic fluid from one cavity to the other of the hydraulic cylinders and plus the hydraulic fluid, which is in the expansion tank, creating excessive pressure, this is facilitated by a one-way valve.

2. The hand pump has a complex design and is difficult to repair in the field. In addition, the hollow is equipped with two rubber o-rings. When turning the spool, there were cases of jamming, in all likelihood this happens because the rings work on collapse.

3. When working from main gas, the shut-off ball is in the free position in the hand pump; it cuts off under the influence of hydraulic fluid pressure, the channel connecting the hand pump from the expansion tank. Perhaps it works the same way as described in another case. When the operator works with the hand pump and creates pressure, see point 1, after

during the opening-closing operation of the tap, the pump handle is switched from manual control to remote control, at this moment hydraulic fluid is injected, which forces the cutting ball to lock the message channel: manual pump-expansion tank. Hydraulic fluid under pressure remains in the cavity of the pneumatic cylinder, which expands when heated from ambient temperature, creating increased pressure in a confined space.

The expansion tank ceases to fulfill the function of adjusting the pressure in the hydraulic system depending on the ambient temperature.

4. The handle of the pump for switching from manual control to remote control for some reason is not transferred, the hydraulic fluid remains locked in a closed space in one of the cavities of the pneumohydrocylinders, creating a pressure exceeding 150 atm when heated. (empirically)

5. Lack of information about hydraulic fluid leakage from the hydraulic system can lead to dynamic loads - impact of the piston on the adjusting stop.

6. According to some data, an external energy source (air pressure from the compressor, compressed air cylinder) with high pressure can be connected to the gas chamber of the pneumatic cylinder on the highway. In this case, the air pressure is not discharged into the atmosphere and the movement of the piston reaches the adjusting stop with a dynamic load.

7. Pneumohydraulic cylinders are manufactured with a margin for high pressure and dynamic loads, which leads to an increase in metal consumption and a complicated technological process for manufacturing pneumohydrocylinders. All these factors lead to a breakdown of the pneumohydrodrive. The proposed utility model is intended to solve these shortcomings.

PURPOSE OF DEVELOPING A USEFUL MODEL.

I. Improve the quality and reliability of the operation of pneumatic-hydraulic drives.

II. Extend service life.

III. Reduce metal consumption and the complexity of manufacturing and assembly.

To fulfill these requirements, the utility model solves the following technical problems:

1. The unloading device constantly maintains a hydraulic fluid pressure close to zero in the hydraulic system and does not depend on the ambient temperature.

2. The hand pump can create pressure on the pistons of the pneumatic cylinders no more than that set by the manufacturer.

3. The simplicity of the design of the hand pump with the possibility of repair in the field.

4. The unloading device provides control and information in case of a drop in the volume of fluid in the hydraulic system, in case of leakage.

5. The pneumatic hydraulic drive system is hydraulically closed and there is no connection with the external environment.

6. Provides the ability to connect an external energy source (air from the compressor, compressed air cylinder, etc.) to the gas chamber, limiting the pressure to that authorized by the manufacturer, and also creates the possibility of bleeding air into the atmosphere with the inhibitory effect of the piston in another cylinder .

7. The ability to connect an electric pump to the hydraulic system in parallel with a hand pump.

In Fig.1 shows a diagram of the operation of a pneumatic actuator and unloading device. Pneumohydraulic actuator consists of the following units: rocker mechanism 43; pneumatic cylinders 1, 3, 7; adjusting stops 3, 3A; pistons 2-38 and is designed to control the ball valve 39, by rotating the ball plug located in it at an angle of 90 degrees from the gas pressure supplied to the cylinders of the pneumatic actuator or from the hydraulic fluid pressure created by the hand pump and works as follows:

From the control unit of the crane 33, the standard valve 34, the main gas 40 enters the gas cavity A of the cylinder 1, presses on the piston 2 with the rod 42, which, moving

to the rocker mechanism 43, turning the ball plug in the valve 39 through an angle of 90 degrees, while the hydraulic fluid flows through the open bypass valve 23 into the cavity G of the cylinder 37. At the same time, the gas 40 enters the piston cavity D of the pneumatic unit 5, presses the piston 7 of FIG. 1, 2, moving the stem 44 of the piston 8, the plate 9 with the stem 45, squeezing the spring 46, moves the spools 6, 6A, cutting off the spool valves 24-25. The hydraulic lines 32, 36, 4, 31 overlap, preventing hydraulic fluid from entering the hand pump 19 and the piston pressure compensator 12.

The piston 38 of FIG. 1 reaches the adjusting stop 3A — it stops, the gas supply 40 to the cavity A of the pneumohydraulic cylinder 1 is stopped with some advance. The valve 39 is in the open position.

Gas 40 from the cavity A of the pneumatic cylinder 1 and the cavity D of the pneumatic unit 5 is vented to the atmosphere through a standard exhaust valve.

The closing of the valve 39 occurs in the reverse order. Gas 41 from the control unit of the valve 33 through the standard valve 35 enters the cavity B, moving the piston 38 with the rod 42, at the same time into the cavity C of the pneumatic unit 5 of FIG. 2, blocking the flow of fluid into the hand pump 19 and piston pressure compensator 12. The fluid has a very high by the coefficient of volume expansion, and depending on the ambient temperature, heating expands, creating a significantly greater pressure in the cavities B, D of the pneumohydrocylinders 1, 37 or when it cools, it compresses. To compensate for this pressure, a piston pressure compensator 12 is used, which works on the principle that, when it expands, the fluid flows from cavities B and D along lines 4, 36 through open channels of shut-off hydraulic valves 24, 25 of line 31, 32 and then open channels of hydraulic distribution valves 29 , 30, the control levers are in position 26, I, 27 — III line 10 into the piston cavity E of FIG. 1 of the piston pressure compensator 12. Under hydraulic fluid pressure, the piston 13 rises, forcing air out of the cavity K into tmosferu. When cooling the fluid in the cavities B, G of the pneumatic cylinders 1, 37, the piston 13 drops down, returning the hydraulic fluid back to the cavity B, G. These cycles

are repeated depending on the ambient temperature, maintaining the pressure in the hydraulic system close to zero. In case of emergency failure of the pneumatic unit 5 at the time of operation of the pneumatic actuator from the main gas, the hydraulic fluid under pressure lifts the piston 13 to its highest position, the poppet valve 14 is pressed against the seat 16, interrupting the connection of the cavity K with the atmosphere, maintaining a hermetically closed system, while the rod 15 is raised mounted on the piston 13, acts on the lever of the limit switch 18, closes the electrical circuit of the alarm "alarm" in it. An alarm is provided in case of fluid leakage from the hydraulic system. With a decrease in the level of hydraulic fluid, the piston 13 will lower to its lowest position, the rod 15 acts on the lever of the limit switch 17, closes the electrical circuit for switching on the alarm signal about the decrease in the volume of hydraulic fluid in the hydraulic system. During the absence of main gas pressure, the hydraulic actuator is controlled by the manual pump 19. For this, it is necessary to carry out the operation procedure with the strictly provided design of the utility model in order to maintain the hydraulic control valves 29, 30 constantly in the open position, otherwise the pressure compensator will not work.

The procedure is as follows:

The key control 47 is screwed into the rod 49 A of the latch 49 (Fig.3), which under the action of the spring 48 is in the locking state, and lift up. Insert the handle 20A of the pump 19 with the keyway 53 into the plug 20 of the hand pump 19 along the keyway 50. Release the key control 47, the rod 49A of the latch 49 under the action of the springs 48 will go into the socket 57 of the handle 20A, fixing it. Unscrew key control 47 from rod 49A. Next, turn the control key 47 into the control lever 27 of FIGS. 1, 4 of the hydraulic distribution valve 30, turn on the axis 55 from position IV to position III and fix it with a plate 56 (figure 4), while the control lever 27, acting on the valve spool 30, closes the low pressure line 10 and opens the high pressure line 22. Pumping the hydraulic fluid from cavity B to cavity G of the pneumohydraulic cylinders by hand pump 19

1, 37, when the bypass valve 23 is closed, it enters through line 4, through the open channel of the shut-off valve 25, line 31, the open channel of the distribution hydraulic valve 29 is closed, the high-pressure channel is interrupted, interrupting the fluid flow through the high-pressure lines 31-22 of Fig. 1 and the control knob 26 is in position 1, then along the low pressure line 10 it flows into the suction part of the hand pump 190, from it the hydraulic fluid under pressure enters through the pressure regulator 21 into the discharge line 22, is open Channel high pressure hydraulic distributor valve 30, line 32, open channel clipping hydraulic valve 24, manifold 36 into the cavity 37. G pnevmogidrotsilindra piston 38 moves under the pressure of hydraulic fluid to an adjusting 3A stops. The ball valve 39 will fully open. After that, open the control key 47 from the plate 56 (Fig. 4), the control lever 27 together with the key control, release the spool of the hydraulic distribution valve 30 from pressing, and open the low pressure channel by connecting lines 10, 32. The key - turn the control out of the control lever 27 and screw it into the rod 49A (Fig. 3), lift it up and disengage it from the socket 57 of the handle of the pump 20A. Remove the pump handle from the keyway 50. Release the key control by inserting it into the pump handle. The reverse process of pumping the hydraulic fluid from G to the cavity B is similar to the above, with the difference that the control key 47 is screwed into the control lever 26. In this case, the control knob 26 is locked in position II. The channel of the hydraulic distribution valve 29 closes the message of the low-pressure lines 10, 31 and opens the communication channel of the high-pressure pipes 22, 31, and the control lever 27 is depressed in position IV, opening the channel of the hydraulic distribution valve 30, connecting the low-pressure pipes 10, 32 and closing the message high-pressure lines 22, 32.

The manual pump by design consists of the main components: a cylinder, a piston, a suction valve, a valve forcing a pressure regulator connected to each other, which is a pressure reducing valve adjusted to a certain

pressure at which the pump starts to work on its own.

For gas routes, during the absence of gas pressure, the operator uses an external pressure source acting on a 2.38 piston in 1.37 pneumatic cylinders, which can come from a compressed air cylinder or compressor with a pressure of over 120 atm, to open or close the valve. can cause a dynamic impact of 2.38 pistons against adjusting stops 3, 3A. This is especially dangerous during partial or complete leakage of hydraulic fluid from the hydraulic system. For this purpose, in the pneumatic unit 1, 2 there are valves for gas pressure relief with one-sided conductivity 51, 52, adjusted by the manufacturer to the desired pressure and operate as follows: air from the gas cavity A of the hydraulic cylinder 1 enters the gas chamber D of the hydraulic cylinder 5, acting on the piston 7 simultaneously presses on the ball 52A of the valve 52, the gas pressure exceeding the resistance of the spring 52B enters the cavity C and is discharged through the channel C2 into the atmosphere through the standard exhaust valve of the valve control unit 33. Ana the valve 51 is logically triggered exceeding the resistance of the spring 51 B by the incoming air from the gas cavity B of the pneumatic cylinder 37.

For the purpose of universally installing the actuator on cranes working for pumping oil and oil products into a hydraulic circuit, an electric pump 58 can be installed. It will work in the same way as a hand pump with the difference that the opening and closing of the distribution hydraulic valves 29, 30 will be carried out by 58A electromagnets 58B.

Claims (1)

A pneumatic hydraulic actuator containing a turning mechanism made in the form of a rocker mechanism, driven by two pneumohydraulic cylinders that interact with the solenoid valves of the valve control unit and a hand pump, which includes a suction and discharge valve in its design, a spool that changes the direction of pumping the fluid, communicating through the shut-off a ball with an expansion tank, characterized in that the pneumatic actuator is equipped with: a piston pressure compensator containing a piston with a rod with an emergency poppet valve fixed on it, in contact with the seat, a hand pump interacting with the hydraulic cavities of the pneumohydrocylinders through a pressure regulator, distribution hydraulic valves controlled by a key control, a screwed connection on the control levers, and a retaining plate that is held during the operation of the manual pump, and the operation of the pneumatic and hydraulic cylinders from gas is ensured by a bypass valve, a pneumatic and hydraulic unit, in which a two-chamber pneumatic and hydraulic cylinder with gas chambers, -rotating with gas pressure relief valves unidirectional conductivity, and gas cavities pnevmogidrotsilindrov acting their pistons on the gas pressure through the shut-off plate on spools hydraulic valves.