DE2345689A1 - DISTRIBUTION OUTLET FOR HIGH PRESSURE MEDIUM SYSTEMS - Google Patents

Description

V.i

September 7, 1973 Wa./K

Wilmot Breeden (Truflo) Ltd. Witton, Birmingham / England

¹¹ Distributor outlet for high pressure fluid systems "

The invention relates to a distributor outlet for high pressure pressure medium systems for delivering a low pressure supply from a high pressure source. Such distributor outlets can, for example can be used to provide a low pressure gas supply (e.g. 2.1 atm) from a high pressure gas system in which

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the pressure many times higher than the required manifold pressure is (e.g. 17.5 atü). The distributor outlet must therefore contain a pressure regulator. Pressure regulators are known themselves and are not further described here. They essentially consist of a controllable throttle valve that operates automatically is regulated according to the pressure on the outlet side.

The invention is based on the object of an improved To create the form of a manifold outlet that is ready. in case of a defect in the normal flow path in use to be used.

According to the invention, a manifold outlet for supplying a low pressure medium supply from a high pressure pressure medium source is characterized by a first pressure medium path and a second pressure medium path from the high pressure supply source to an outlet, the first pressure medium path comprising a first pressure regulator for lowering the pressure to a set point P. and further a first flow control valve between the high pressure source and the first regulator, which can be actuated to shut off the pressure medium flow to the regulator, wherein the second pressure medium path comprises a second regulator for lowering the pressure to a value Pp which is below the value P ₁ , and wherein the second pressure medium path furthermore a second passage

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having flow control valve between the second regulator and the supply source, which is used to shut off the flow to the second Regulator can be actuated, furthermore a first device responsive to the pressure and an actuator which is in an operative connection is connected to the first pressure flow control valve in such a way that the first flow control valve is closed, when the pressure in the outlet exceeds a set point P ^, which is higher than P., and a second pressure responsive Einrichtun and an actuator which is in operative connection with the second flow control valve and for closing the second flow control valve is set up when the pressure in the outlet exceeds a target value P ^ which is higher than P ^ is.

In normal operation, both flow control valves are open, and so the high pressure goes to both regulators. The regulator in the first fluid path allows a higher pressure to the outlet, and thus the flow normally passes through the first fluid path to give a regulated pressure of substantially P ^ in the outlet. At this pressure, the pressure regulator in the second pressure medium path, which is set to a pressure P ^ which is below P ₁ , does not allow any pressure medium through. The flow thus only goes through the first pressure medium path, and for this reason the first pressure medium path is used as the main flow

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denotes, while the second pressure medium path is the supply flow. If for some reason the pressure in the outlet is below P _? decreases, for example due to excessive consumption of pressure medium from the outlet or due to some malfunction in the first regulator or, as described below, as a result of closing the first flow control valve, the second regulator allows pressure medium to flow through the second pressure medium path. If this state is only the result of a drop in pressure, both pressure medium paths can let pressure medium through. The second pressure medium path, however, ceases to let pressure medium through when the pressure subsequently rises to a value above Pp. The distributor outlet thus provides a provision option in the event of a low pressure at the outlet.

If the pressure in the outlet increases as a result of some malfunction, then when it reaches the value P i, the first one closes device responsive to pressure is the first flow control valve. No pressure medium reaches the first pressure regulator. As mentioned above, during normal operation there is a high pressure up to the regulator in the second pressure medium path or in the supply flow, and this pressure medium path is therefore still there functioning. Therefore, if as a result of closing the first flow control valve the pressure in the outlet drops, e.g. as a result of the pressure medium from the outlet being consumed,

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the second pressure regulator lets pressure medium through and regulates the pressure in the outlet in order to keep _{it at P 2.} In this way, if any malfunction of the first pressure regulator occurs which allows excessive pressure in the outlet, the flow is automatically transferred to the supply stream. If, however, when the flow is transferred in this way to the supply flow, the pressure continues to rise and reaches the value P., the second device responsive to the pressure and the actuator close the flow control valve in the second pressure medium path. In the simple system which has been described so far, the supply to the outlet is then completely shut off. However, an automatic reset is preferably provided for the actuator for the first flow control valve in order to open this valve again when the pressure in the outlet falls below a setpoint value P ₅ which is lower than Pp. This ensures that when, after both flow control valves have been shut off and the pressure has dropped, the first pressure medium path is put back into operation. If the high pressure at the outlet is the result of an error in the controller in the second pressure medium path, the first pressure medium path is blocked because of the high pressure at the outlet, and then the second pressure medium path is blocked. Because of the automatic reset, however, the flow control valve in the first pressure medium path is opened again in order to keep the flow control valve in the second pressure medium path closed.

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The system thus continues to function despite the malfunction in the pressure regulator in the second pressure medium path, because the flow through the second pressure medium path is now shut off. It should be noted that P ^ _{must be lower than P 2} , so that the first pressure medium path is not put back into operation when the second pressure medium path is working satisfactorily in order to regulate the outlet pressure at the value P ~.

If, after the return to the first pressure medium path, the pressure again rises above P ^, the first pressure medium path is again locked. The second pressure medium path is still closed, and the pressure can then be at the outlet when it is consumed fall off. Repeated opening and closing of the first fluid path can then occur, and it is therefore preferable to provide a counting device which limits the number of automatic resets of the first flow control valve .

In which the automatic resetting of the first flow control valve is provided, the system is switched in a sequence in the event of a high pressure in the outlet, to first switch on the second 'pressure medium path, the first pressure medium path being blocked, and then the first Switch on pressure medium path, wherein the supply pressure medium path is blocked if the high pressure error is still

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is available. Each of the two paths is thus checked alternately, with the other path being blocked off. If one way or the other works satisfactorily, the system will remain in this state. There is thus no need to provide any automatic return for the valve in the second pressure medium path. If an automatic reset is provided in the second pressure medium path, for example at a pressure Pg which is below P ₅ , the two pressure medium paths are alternately switched on and off if there are malfunctions that lead to a high pressure in both pressure medium paths.

The flow control valves are on / off valves, and they will preferably switched quickly by the actuator in question. For this reason they can be referred to as "surcharge" valves. Fast operation is desirable to quickly shut off a pressure medium path in the event of a high pressure failure is available.

The actuators can be fluid actuated actuators be. The pressure responsive device may comprise relay pressure switches. The pressure medium for actuating the Actuators and for control by the relay pressure switch can expediently from the high pressure pressure medium source shut off by means of a check valve and a pressure regulator

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be in charge. Appropriately, the relay pressure switches each set actuator control valves in function, for example Four-way control valves used to reverse the connections between the two ends of an actuator cylinder and the source of pressurized fluid and the drain can be set in function. With such a Arrangement can be an automatic reset easily by a spring return of the actuator control valve for Reach the appropriate actuator for which an automatic reset is required. If, as described above, only the actuator for the first flow control valve automatically is reset, manual reset means can be provided for the second flow control valve. With these manual resetting means for the second flow control valve are expediently manual resetting means of the actuator control valve for the actuator for the second flow control valve.

If necessary, more than one delivery route can be provided be. In this case, the pressure regulators for the various successive paths are arranged in such a way that they are successively lower Pressing work. The flow control valves for the various successive paths are successively higher Press closed. With such an arrangement all flow control valves are normally open, flow goes

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however, through the pressure medium path, the pressure regulator of which is set to the highest pressure. When the pressure in the Auslal3 drops, let the various supply pressure medium paths successively through pressure medium while the pressure on the values to which the corresponding controllers are set. If a high pressure fault arises anywhere in the system, will the various pressure medium paths are successively blocked, starting with the one for which the device responding to the pressure is set to the lowest pressure. After the faulty pressure medium path or the faulty pressure medium paths are locked, the system then remains in function with the next pressure medium path. By providence an automatic reset takes place on at least one of the successive pressure medium paths with the exception of the last one a transfer back to the pressure medium path with the automatic reset if the error occurs on the last of the successive ones Pressure medium paths is available.

The invention is explained in more detail below with reference to the drawings. In the drawings are:

1 shows a schematic representation of an exemplary embodiment of a distributor outlet from a high pressure gas pipeline system and

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Figs. 2, 3 and. 4 the representation of control arrangements

for three further embodiments of a distributor outlet.

Although specific reference to a manifold outlet for a It is understood that the system is used for liquids as well as for gases can be.

As shown in Fig. 1 is a high pressure gas line system 1o via a connection 11 with a valve 12 with a first pressure medium path 13 and a second pressure medium path 14 connected. These two pressure medium paths ultimately lead to as will be described below, to a common outlet 15 through which the gas supply with the required low pressure is delivered. The first pressure medium path 13, hereinafter sometimes referred to as the active flow is referred to, includes a first flow control valve 18 and a first pressure regulator 19. The valve 18 sits between the pressure regulator 19 and the high pressure source. The second pressure medium path 14 contains a second flow control valve 2o and a second pressure regulator 21. The flow control valve 2o sits between the pressure regulator 21 and the high pressure source. The first pressure regulator 19 is in this particular embodiment

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for example to lower the pressure to 2.1 atmospheres, and normally the flow control valve 18 is fully open. The second pressure regulator 21 is for lowering the pressure to 1.96 atü and normally the second flow control valve 2o is fully open. In normal operation, the The pressure of the outlet is essentially regulated to 2.1 atmospheres by the first regulator 19. The second regulator leaves at this pressure 21 no gas through because it is set to a lower pressure. If for any reason, e.g. as a result of a Excessive consumption of gas at the outlet or, as a result of a failure in the first pressure regulator, the pressure at the outlet below 1.96 atü falls, the second pressure regulator is activated and the gas flows through both pressure medium paths.

The flow control valves 18 and 2o are each actuated by pressure medium Actuators 22 and 23 operated. The medium pressure for the actuator 22 is derived from a feed line 24 and fed via a four-way control valve 25 to one or the other end of the actuator 22, depending on the required direction of movement. Correspondingly, the actuator 23 is actuated by medium pressure from a supply line 26 comes, which is connected via a four-way control valve 27 to one or the other end of the actuator 23, depending on the required direction of movement of the flow control valve 2o. The valves 1ö and 2o are expediently so fast

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operated as possible and, as mentioned above, these valves are referred to as "supplementary" valves. The actuation of the pressure medium for the actuators 22, 23 comes from the inlet supply 11 via a filter 28, a pressure regulator with a
Pressure gauge 29 and a check valve 3o which feeds a collecting tank 31. This collecting container has a block valve 32 at its outlet in order to enable the control device to be separated from the pressure medium source. From the block valve 32 the pressure medium outlet goes iom the collecting tank through a further pressure regulator 33, which lowers the pressure to 5.6 atmospheres, which is the target operating pressure for the actuators, and then through an oiler to said lines 24, 26 Oiler 34 is required in a natural gas system, but is not required, for example, if the pressure medium is a liquid.

The four-way control valves 25, 27 are actuated by pressure medium, specifically by pressure relay switches 35 and 36, respectively. These pressure relay switches withdraw their pressure medium via a pipe 37
from the pressure medium supply source described above. The relay pressure switch 25 responds to the pressure in the outlet 15, which is measured by a probe 4o, the
connected to the relay switch 35 via a block valve 41
is. A vent valve 42 is provided between the block valve 41 and the relay 35. The outgoing pressure medium from the relay switch 35 is the control valve 25 via an automatic

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table counting manifold 43 supplied, which is only a certain limited Number of circuits of the control valve 25 allows. The counting bus 43 has a manual reset 44 so that it can be reset to a count of zero. Usually, the metering bus line 43 enables only three functions. It then blocks the service line to the control valve 25 so that the actuator 22 does not control the flow control valve 18 can open again.

The relay pressure switch 36 responds to the pressure in outlet 15 measured by a probe 45 connected to the pressure switch 36 is connected via a block valve 46. A vent valve 47 is provided to allow communication between the block valve 46 and the relay switch 36 to ventilate. Of the Relay pressure switch 35 is set to operate at 2.38 atmospheres while relay pressure switch 36 is set to operate at 2.56 atmospheres is set. The relay pressure switch has a dead band between 1.75 and 2.38 atmospheres. The relay pressure switch 36 has a wider dead band with the higher upper limit value, e.g. 2.66 atm.

The operation of the device described so far is as follows. Under normal 'conditions the flow control valve is 18 opened, and the pressure regulator 19 regulates the pressure at outlet 15 to a value of 2.1 atü. The second pressure regulator 21 is set to a lower pressure of 1.96 atmospheres and

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thus prevents a flow through the supply path 14, although the flow control valve 2o is open. Of the The entire gas flow therefore goes through the active path 13. When the pressure at outlet 15 falls below 1, ii6 atmospheres, this is possible the regulator 21 a flow rate, and thus the preparation path in the event of any functional error is in operation which causes a low pressure fault, or even in the event of the low pressure rising for any reason other reason.

If, considering normal operation, the pressure at the outlet 15 becomes higher, for example when the regulator 19 has a If this pressure reaches 2.38 atm, the relay pressure switch 35 is activated and causes an error switches the control valve 25 so that the actuator 22 closes the flow control valve 18. This is the pressure medium flow blocked by the active path 13. If there is gas at the outlet is consumed, there is a drop in pressure at the outlet. A drop in pressure to 1.96 atm causes the pressure regulator 21 is set in the provision path in. Function. The flow control valve 2o is open, and thus the gas flows through the supply path 14 to the outlet 15, the pressure from the regulator 21 is regulated so that it is 1.96 atm. The function is thus transferred to the provision path and this path remains in function as long as there is no malfunction leading to

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a bend in the discharge pressure. leads. A return to the main path which will be described later, can be done manually, e.g. if any error in the main path has been corrected has been.

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If there is an overpass on the. Provision path has been effected, this path supplies the. Outlet 15 continues as long the downstream pressure does not rise to 2.66 atmospheres. If the If the pressure in the outlet rises above this value, e.g. as a result of an error in the controller 21, the relay pressure switch 36 sets this Control valve 27 in function to the actuator 23 in function to set, whereby the flow control valve 20 is closed. Then both pressure medium paths are closed. The pressure in outlet 15 can now fall, for example as a result of Gas consumption. When the outlet pressure drops to 1.75 atm, it switches the relay pressure switch 35 to thereby the supply to shut off the control valve 25. This control valve 25 has a spring return, which is shown schematically at 50, so that the valve returns to its normal state, which leads to that the actuator 22 opens the flow control valve 18. A Opening the flow control valve 18 allows one. Flow to pressure regulator 19 · The high pressure as a result of a malfunction in the supply path thus causes a shut-off the supply route and a return to the main route. To return to the main path, one takes the energy to switch the Control valve 25 via the counting manifold 43, which has a certain Number (e.g. 3) of opening processes. A flameproof one Limit switch (not shown) is switched by the flow control valve 18 or its actuator 22,

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to provide a remote indication when the active path is blocked is.

Returning to a consideration of the provision path, this is put into operation, for example as a result a malfunction of the regulator in the active path causing the downstream pressure to increase to 2.58 a "tu. How As mentioned above, if the downstream pressure continues to rise to 2.66 atm as a result of, for example, a malfunction of the regulator 21, the relay pressure switch 36 will operate to a function of the control valve 27 to the actuator 23 To supply energy. When energized in this manner, the four-way control valve causes the actuator 23 closes the control valve 20. At the end of the closing stroke of the actuator is a flameproof limit switch (not shown) from the actuator 23 on the flow control valve 20 in function, set to provide a remote indication, that the supply route is closed. No automatic reset is provided for the control valve 27. One manual reset 51 is provided, and thus the supply path can only be put back into operation by the valve 27 is reset by hand. It can only be postponed when the pressure measured by the probe 45 has fallen sufficiently, so that the relay pressure switch 26 the Valve 27 does not work again. If the active path works, this reduction in pressure under the back

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control value through the use of the block valve 46 and the ventilation valve 47 reach.

Each of the actuators 22, 23 has flow controllers 52, which Regulate the closing and opening speed of the valve.

In normal operation, the flow goes through the active pressure medium path 13 as described above. Let us now assume that the controller 19 causes an error, and that the pressure increases downstream to 2.38 atm. As mentioned, switch on this pressure the pressure relay switch 35 the control valve 25, around a. Close to effect the flow control valve 18, and thus to transfer the flow to the supply path Η. The system then continues with the provision path until the error in the active path is corrected.

If, again, normal operation is considered, in which the Flow through the. active path I3 is the control valve 2O for the. The delivery route is open and there is a high one Gas pressure in the supply path H up to the supply regulator 21. Assuming that this regulator causes an error, or enables one. Downstream flow, which causes the pressure to increase to 2.38 atmospheres, becomes the active path as before locked, and the supply path is then switched on. If so, the malfunctioning regulator causes the Pressure increases downstream to 2.66 atmospheres, the pressure relay switch 36 puts the control valve 27 into operation, which is controlled via the

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member 23 the. Flow control valve 20 closes. The activation of the four-way control valve 2? puts one, manual. Reset mechanism 21 in puncture, and the closing stroke of the actuator 23 switches a flame-proof switch, the one Remote indication provides that the delivery route except puncture is set. This display shows that the delivery route is being checked and / or postponed manually, got to. If in the meantime, both paths are now closed if gas continues to be consumed at the outlet, the pressure decreases downstream. When the pressure drops to 1.75 atmospheres, it switches the relay pressure switch 35 to, and the four-way control valve 24 with its spring return 50 enables a Reopen the control valve 18 of the active path to thereby to put the active route back into operation. A. Error in regulator 21, which causes high pressure at the outlet, therefore leads to the fact that the control valve 20 of the supply path is closed and that only the main path is in function.

If the control systems develop errors on both routes, a state is reached in which, following a malfunction, first the active. Regulator of the supply path in function, set and this does not work either, like this that the feed is returned to the active path. Until maintenance has been carried out, the provision path remains permanent isolated, as there is no automatic reset on control valve 27 is available. As mentioned above, it falls with consumption

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of gas is the pressure at outlet 15, and thus becomes the active path put in! puncture again. If the active controller is still not working to incur undue pressure and a pressure builds up again downstream, this is measured by the probe H and the flow control valve 18 will be closed again. The pressure in the outlet drops, and so on. cyclical operation. The counting manifold 43 however, limits the number of work cycles. When this limit is reached, deliver / the flame-proof limit switches, associated with the two flow control valves or their actuators, a remote indication that the system is now complete is disabled.

The arrangement of the various. Components, which are shown in Fig. 1, depend on the construction site conditions and on the requirements, away. In an expedient arrangement, the collecting container 51 with the associated filter 28, the manometer 29 and the check valve 50 together with drain connections what can conveniently be called a collection unit, and the remaining part of the control device to control the actuators 22, 25 is in one or more Tax rates arranged, which are arranged at the collection unit could be. It is therefore expedient to describe further exemplary embodiments of the invention in relation to the control device to be regarded as a unit.

According to the division in. Fig. 1, each of the two pressure

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middle way a regulator. In. in practice you work. for security sgrundη with two regulators, in. each Druekmittelweg. One the controller known as the active controller has one. Set point that is lower than that of the other than that Safety controller is known. For example, in the active. Pressure medium path the active controller has a set point of. 2.1 atü, and the safety controller can have a. Set point of 2.24 atmospheres. The active controller can use a. Set point of 1.96 atm and the The safety controller can have a set point of 2.1 atm. The safety controller in the active path is normally whole opened. When a. Mistake arises, the one. Causes pressure increase, the safety controller is set to function. Only if both regulators have errors that lead to high pressure lead in the outlet, the surcharge valve 18 closes. The system works as described above, has been, is except that two regulators and not one must develop faults leading to high pressure before overpass takes place on the delivery route. Accordingly, in the Provision path both controllers will be faulty before the valve 20 is put into operation.

In practice, for safety reasons, pressure reducing valves are also used for each of the two. Pressure medium paths provided, before they converge in the distributor outlet 3 1 ^. The pressure medium valves act as a backup when the pressure increases

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and both the active and the safety controllers fail, and when, the pressure rises before the slap valve close, can;

One form of regulator element is shown in FIG. This Element is essentially the same as the corresponding one. Part off 1, and the same reference numerals as in FIG. 1 are used used to indicate corresponding components. However, the element shown in FIG. 1 contains certain modifications in comparison to Fig. 1. The element shown in Fig. 2 is as a Unit formed, the only corresponding pressure medium connections requires. The inlet 60 is the feed line from the collecting container 31 'and the gas goes through a filter 61 through Pressure control valve 33 and an oiler 34 to supply pressure medium for the two control valves 25, 27 and also for the relays 35 and 36 to deliver. Inlets 62 and 63 lead from. the pressure probes. 40, 45 and supply control signals for the relays 35, 36. Each relay has a pressure medium inlet 64 and an outlet 65, via a check valve to a common discharge

66 leads. Each relay also has a transfer opening

67, from which the pulse signal comes, to the corresponding Set valve 25 or 27 in. Function.

In the arrangement shown in Fig. 1, these control signals from the relay directly to the control valve 27 and via a counter

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Manifold applied to valve 25. In the one shown in FIG Arrangement, the two control valves 25 »27 both reset by springs, and a manual control valve is provided that a change of the connections from the Ütierführungöffnungen of the two. Relays 35, 36 to the two. Control valves. 25, 27, in order to enable the two currents to be exchanged by the respective probes. 40, 45 should be measured. The change takes place through the manually operable valve 68. The control valves 25, 27 have, respectively eils an outflow 69, which via a check valve to the common Discharge 66 leads, and also two outlet connections 70, di§ & over adjustable flow regulators 71 and outlets 72 to the. relevant pilot openings of the actuators 22, 23 lead.

In the arrangement shown in Fig. 2, the set point of each probe is above the pressure settings for both (or all) of the controllers and the reset point is below the. Controller settings. The operation of this arrangement is essentially the same as that shown in FIG. Normally one route is active, depending on the controller settings. If the pressure drops, the second route is activated. When a mistake arises that leads to a high. Pressure leads, a route is first switched off, the choice of route is determined by the reversing valve 1 68. The first path to be blocked off is the one connected to the probe, which is the lower setting

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point has. If the high pressure still persists, the second way is blocked. If so, then the pressure is lower the first path that is blocked off will be reopened. If. a. Error on. both. Because there is, there is a cyclic switching., with the system as a. On / off regulator functions. A counting manifold can be provided to the The number of switching operations should be limited, as in that shown in FIG. Arrangement. The reversing valve 68 thus enables one or the other path to be selected as the main path Requirement.

As mentioned above, the invention can be used in connection with Systems that are used that have more than two fluid paths to have. It can therefore in some. Cases be expedient of. to make use of separate elements, one per fluid path, and one. such element for one, only one. Pressure medium path is shown in FIG. 3. This element has a feed connection 75 which leads from the container 3I. The supply line goes through a. Filter 76, a self-adjustable pressure regulator 77 and an oiler 78 to feed the line to a relay pressure switch 79 and also to a pilot operated one Supply spring force resettable control valve 80. Drain from. the relay 79 and from. the valve 80 go via lines 81, 82 and check valves 83 to one common. Respiratory / Filter outlet 84 · The relay 79 has an input connection 85 of a probe and a transfer port that a pilot

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signal on a line 86 supplies to the control valve 80 to operate. The control valve 80 enables the application of pressure on one or the other of the actuator connections 87 »88. Each of these set in. Puncture. links includes a flow regulator 89 to which a. check valve 90 is connected in parallel.

In a two-way system, two of the ones in Pig. 5 shown Elements are used, one in each of the fluid paths. The corresponding setting points of the Various punctures are those as they are related to Pig. 2 have been described. The working method is in essentially the same as related to Pig. 2 has been described. In the event of low pressure errors, the Regulator the choice of the pressure medium path. For high pressure errors the control element controls the selection of the pressure medium path. if If a Pehlef occurs in the active pressure medium path, a Change to the delivery route. If this is incorrect, the supply route is blocked and the system returns to the active one. Druckraittelweg back. If there is also a Pehler is located, the system acts as an on / off controller with cyclical operation, since, after shut-off, both pressure medium paths, the pressure drops. Finally, there is a pressure medium path (determined by the reset settings.) set in puncture. With the further increase in pressure as the pole of the

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Error this is locked. The corresponding probe settings are preferably those as described in connection with FIG. 1 have been described, so that both pressure means away are alternately put into operation. A counting bus can be provided to keep track of the number of cyclic operations to limit.

With a three-way system it is possible to add three elements each of which has the structure shown in FIG. However, Fig. 4- shows a preferred form of element arrangement for a three-way selective surcharge system in which a single element controls all three pressure medium paths.

In Fig. 4, the pressure medium inlet from the container 3I is shown at 100, and this leads via a filter 10i, a pressure control valve 102 and an oiler 103 to a supply line 104, the pressure medium to three relays 105, 106, 107 and to the pressure medium inlet of three Four-way control valves 108, 109, 110 conducts. The relays 105, 1o6, 107 each have an inlet connection 111 that leads from the associated pressure sensor, and each having a drain connection 112 II5 lead via a return 'seiilagventil to a common bleed 114 ..- The transfer openings 115 of the three Relays are each connected to the pilot inlets of the three control valves via a unit 116. This unit 116 is a selection unit for enabling a selection with regard to the connection between the relevant relay and the relevant control valve.

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Mechanically, the unit is a triple rotary switch unit with three poles, of openings. The control valves 108, 109, 110 each have two outlets 117, 118 with associated adjustable. Flow regulators 119 to Delivery of the outputs to the actuators for the supplementary flow control valves in the. three pressure medium paths. The three control valves 108, 109, 110 are in this exemplary embodiment all reset by spring force, it can, but as with a two-way system, one of them can be reset manually depending on the form of operation required.

The sequence of operations and the system function of a three-way system are similar to those of a two-way system, except that one more probe and one more pilot operated through. Pressure force reset control valve are provided, the pressure medium to the actuator for the third. Druckmittelweg supplies. By appropriate selection of the dead band values, the set point values and the reset point values of the probes, a choice of the three pressure medium paths can be achieved. For example, in one arrangement the normally active supplement pressure fluid path has a probe with a set point of. 2.38 atm, a dead band of. 0.35 atm and one. Reset point of 2.03 atm. The second active pressure medium path has a set point of 2.52 atmospheres, a T _o tband of 0.63 atmospheres and a reset point of 1.89 atmospheres. The third return path or loading

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The equestrian path has a setting point of 2.66 atmospheres Dead band of 0.9 "* atm and a reset point of 1.75 atm.

With this arrangement, the surcharge valve closes in the first active pressure medium path first, but also resets itself first. The supplement valve in the second active pressure medium path closes second and also opens second. The supplementary valve in the pressure medium path, which is normally used as a supply path closes as the third and resets itself as the third. If so, an error in the first active pressure medium path arises, which leads to a high pressure in the outlet, the surcharge valve closes in this pressure medium path, and that Valve prevents further flow through this path. The pressure at the outlet drops, and the second active pressure medium path is put into operation. This builds up the pressure at the outlet, and the first active pressure medium path is reset. If a fault, which leads to high pressure in the outlet, arises in the second active pressure medium path, the first active pressure medium path is closed first, and then the second active pressure medium path is closed. The pressure drops from, and the pressure medium path normally provided as provision is put into operation. If so, he works up the pressure on, and the first and the second pressure medium path are reset. If. a. faulty condition im normally as a supply serving pressure medium path in advance

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that leads to high pressure, become the first and the second pressure medium path is closed, as described above, and the supply path is then closed. The pressure drops "to the reset point value of the first normally active pressure medium path, and the surcharge valve in this pressure medium path opens again. This reopening takes place slowly. The second active pressure medium path is available on demand to reopen when the pressure in the manifold outlet has passed through the first active pressure medium path itself are not maintained, can and if the pressure there if necessary up to the reset point value of the second active one. Pressure medium path drops. The third Pressure medium path or the pressure medium path used for provision remains isolated because it is reset by hand will. If in all three pressure medium paths, one. Error arises, are all three pressure medium paths through the surcharge valves isolated, and the first active pressure medium path acts as an on / off regulator which is at its set point or opens or closes at its reset point.

For maintenance reasons, it may be necessary with a three-way system be able to choose specific fluid paths and ensure that a. Pressure medium path disabled will. For this reason, a key-operated three-way control valve can be provided in each pressure medium path

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be that through. Spring force is reduced. This valve is connected between the transfer opening of the relay pressure switch and the pilot connection to the control valve. Each of these When the key is inserted and turned, the valve is used to supply a continuous medium pressure to the Pilot connection of the control valve, so that the associated actuator removes the additional control valve from the corresponding pressure medium path shut off. As long as a key is inserted and turned, the associated pressure medium path remains blocked. When the key is pulled out, the Spring return reconnects the relay output to the pilot input to the control valve, allowing normal operation gets going again.

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Claims (1)

Claims 1 / distributor outlet for supplying a low pressure pressure medium supply from a high pressure pressure medium supply source, characterized by a first pressure medium path and a second pressure medium path from the high pressure supply source to an outlet, the first pressure medium path having a first pressure regulator for lowering the pressure to a setpoint P ₁ and furthermore a comprises first flow control valve between the high pressure source and the first regulator, which can be set to shut off the pressure medium flow through the regulator, and the second pressure medium path a second regulator for lowering the pressure to a value P ₂ , which is lower than P ₁ , and further a second flow control valve between, the second. Regulator and the supply source, which can be set for shutting off the flow to the second regulator in puncture, a first device responsive to the pressure and a. Actuator in operative connection with the first flow control valve for closing the first. Flow control valve when the pressure in the outlet exceeds a target value P, which is higher than P ₁ , and a second device responsive to the pressure and an actuator in operative connection with the second flow control valve for closing the second flow control valve when the pressure by doing - 32 4098 13/0885 Outlet exceeds a setpoint P- which is higher than P ~ is. 2. Y Teilerauslaß according to claim 1, characterized that an automatic reset for the actuator for the first flow control valve to reopen this valve is provided when the pressure in the outlet falls below a setpoint P, -, the is lower than Pg. 3. distributor outlet according to claim 2, characterized in that a manual reset is provided on the actuator for the second control valve. 4 · distributor outlet according to one of claims 1 Ms 3> characterized in that a counting device provided for limiting the number of automatic resetting operations of the first flow control valve is. 5. distributor outlet according to claim 2, characterized that an automatic reset on the actuator for the second flow control valve is provided, which is intended to work at a pressure Pg which is lower than P, -. - 33 409813/0885 6. distributor outlet according to one of claims 1 to 5, characterized in that the flow control valves On / off valves are. 7 · Distributor outlet according to one of Claims 1 Ms 6, characterized in that the actuators Pressure medium-operated actuators are. 8. distributor outlet according to claim 7, characterized that the device responsive to the pressure are relay pressure switches. 9. distributor outlet according to claim 8, characterized that the pressure medium for actuating the actuators and for control by the relay pressure switch from the high pressure pressure medium supply source via a. Check valve and a pressure regulator is derived. 10. Distributor outlet according to one of claims 7 to 9, characterized in that the relay pressure switch Operate actuator control valves in each case. 11. Distributor outlet according to claim 10, characterized that the actuator control valves are four-way control valves that are used to reverse the connection - 34 A 0 9 8 1 3/08 8 5 fertilize between, the. both. Ends, of an actuator cylinder can be set in function with the pressure medium source and the drain. 12. Distributor outlet to. Claim. 1 0 or 11, characterized by an automatic reset for at least one. Actuator, the automatic Reset by spring return means on the actuator control valve is provided for this actuator. 13 · Distributor outlet according to claim 10 or 11, characterized by a manual reset for at least one actuator, the manual reset is provided by manual means for resetting the actuator control valve for that actuator. H · Vertexler outlet according to one of Claims 2 to 5, characterized by a third. Pressure medium path with a pressure regulator for lowering the pressure to a value P ", which is lower than P ₁ and P ₂ and higher than I, wherein the third pressure medium path comprises a third Durchflußrege lventil between, the high pressure source and the regulator that is used to shut off the pressure medium flow to the controller in function, can be set, with a third device responsive to the pressure and a. Actuator in operative connection - 35 409813/0885 dung mit.dem third flow control valve for closing the third flow control valve are provided when the pressure in the outlet exceeds a target value P _Q , the higher than P, is.
4th 15. Manifold outlet according to claim 14, characterized ge. This shows that an automatic reset is provided for the actuator of the second flow control valve to reopen this valve when the flow rate in the outlet falls below Pg, which is lower than P ₅ . 16. Distributor outlet according to claim H or 15, characterized marked that a manual reset for the actuator for the third flow control valve is provided- 17 · Distributor outlet according to claim 15, characterized in that an automatic reset is provided for the actuator for the third flow control valve to reopen this valve when the pressure in the outlet falls below a setpoint P _q which is lower than Pg. 18. Distributor outlet according to one of claims 1 Ms I7, g e - - 36 -409813/0 8-8 5 characterized by means of changing, the connections between the pressure responsive devices and the actuators. 19 · Distributor outlet according to one of Claims 1 to 18, characterized by key-operated Means for effecting a function of one or more particular actuators such that one or more of the The flow control valve can be closed independently of the pressures present in the system. 409813/0885