DE8414555U1 - ARMATURE TO OPEN AND / OR LOCK - Google Patents

Description

Valve to open and / or shut off

The invention relates to a valve for opening and / or Shutting off the conveying path of a medium conveyed by means of a pump, with a passage for the medium releasing or blocking shut-off device, in particular a pipe fitting with a non-return valve.

It is well known that fittings of this type are of great importance in many areas of technology, since the problem above all of blocking the conveying path of a medium in great variety. As a special As an example, reference is made to a pumping station in which the medium forms water in the conveying path Pipelines is transported. The aforementioned shut-off device is usually located on the Pressure side of the pump and is designed as a non-return valve, which is known e.g. from DE-OS 3 125 029 has become.

In the case of such pumping stations, it is necessary to shut off the pipeline using the non-return valve, to prevent the water from flowing back when the pump supplying the water is switched off. Without that

The presence of the non-return valve could namely allow the water conveyed under pressure to pass through the pump flow back and damage them in the process. Therefore, the check valves must also be in their closed seat get before a retrograde water flow starts after the pump has been switched off.

Even if the well-known non-return valve in the sense of the above-mentioned requirement is a blocking of the conveying path can prevent backflow of the water column or the pumped water, so is but it should be noted that the associated closing process of the Check valve is associated with significant problems.

In practice it can be observed that when switching off the pump and when closing the non-return valve significant pressure surges occur, namely an overpressure on the side facing away from the pump the non-return valve and a negative pressure on the other side of the non-return valve. These extreme pressure differences which strive to balance each other, have the effect that the non-return valve forcibly under enormous force gets into the closing seat or hits.

The opening of the non-return valve makes itself felt with the

known pumping stations acoustically disturbing noticeable. More serious, however, is the disadvantage that is caused by the high mechanical stress on the valve and, above all, also on the pump, and the high mechanical load on the valve when it hits it creates the risk of associated damage.

The above-mentioned large pressure differences not only have |; the flap of the non-return valve result. More serious are the adverse effects that result from the high Pressure surges can result within the valve itself.

In practical use, it can be seen again and again that they form the conveying path for the medium Pipelines cannot withstand the high pressure surges that occur during shut-off and are destroyed. Especially in the area of the pump-valve arrangement with the shut-off device, but also up to the reflective parts The pipelines are special because of the pressure waves that occur and also at more distant weak points endangered.

It should be pointed out that the damage and consequential costs caused by the pressure surges are considerable are. The vibrations caused by the pressure surges can damage buildings and buildings occur in the system, e.g. at a power plant.

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Despite these disadvantageous effects known in the specialist field, however, it has so far not been more satisfactory We succeeded in completely eliminating the negative consequences of the known fittings during the closing process to eliminate.

In the German utility model G 83 32 918.8 has already been proposed, parallel to the shut-off device to provide a bypass at whose. Mouth on the side of the shut-off device facing away from the pump there is a pressure-dependent closing element, through which the bypass is dependent on the prevailing Pressure is permeable switchable or lockable.

This older proposal is in itself very elegant, because it is made possible with simple means that At least partially suppress the occurrence of the harmful high pressure surges. In the dangerous phases in which pressure surges can build up in the system, the bypass creates a certain pressure equalization brought about if the prevailing pressure is large enough to open the pressure-dependent closing element and so release the bypass. When a pressure equalization is established in this way, the closing element arrives under the action of a spring back into its closing seat, so that the bypass is closed again.

However, it has been found in tests that this older proposal compared to the prior art Although it can enable a noticeable pressure equalization, the pressure peaks that occur are still so great that the above-mentioned risk of damage can still not be ruled out can. The solution according to the earlier proposal mentioned thus brings a technical advance, In many cases, however, this is not to be regarded as sufficient.

It should be noted that the previous explanations limited to the medium water, which is conveyed in pipelines, but is this should only be seen as an example, because the same problem generally occurs with other media on, which are transported in conveyor routes, where there is a need to have a valve with a Provide a shut-off device to shut off the conveying path.

The invention is based on the object of creating a valve to avoid the disadvantages described, which makes it possible with simple means to avoid the harmful effects that occur when the conveying path is shut off To reduce pressure peaks to such a level,

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^r that the risk of damage is excluded.

\ This task is solved by the senior

■ handle of claim 1 mentioned valve characterized in that

A relief path is provided parallel to the shut-off element, which above and below the shut-off element opens into the conveying path, with the mouth above of the shut-off element permeable through a closing element

, 'is switchable and lockable, which is in his

Rest position is located in a seat that closes the mouth, and that the closing element is controlled by an external control can be brought into its open position at a selectable point in time for a selectable period of time, before the shut-off element has taken its closed seat.

The invention thus takes the new and surprising route of opening the closing element of the relief path in an externally controlled manner - that is, independently of the prevailing pressure in the area of the closing element - even before the shut-off element has reached its closing seat. This important feature is based on the idea of providing a relief path even before the conveying path is completely blocked, in order to counteract dangerous pressure peaks.

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In a series of experiments it has been confirmed that with such a premature opening of the relief path a considerable reduction of the pressure peaks actually occurs is made possible. In several test arrangements it was possible to reduce the pressure peaks by up to 80% can be determined, which means a remarkable reduction in harmful pressure surges, such as they have not yet been considered possible in the professional world (e.g. from 12 bar to 2.4 bar).

The advantage achieved with the invention is all the more surprising and to be rated higher than the measures for realizing the new type of valve just simple Include steps. It is sufficient to use an inexpensive piston, which is e.g. can be moved by compressed air within the piston housing and relieves the pressure when it is moved via a rod sweg releases.

The advance - i.e. the point in time at which the foreign S.

j control starts and releases the relief path before the shut-off device has taken its closed seat - $

depends to a certain extent on the given circumstances.

differ in the fitting. In I

Within a certain range, advances of about |

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According to an expedient development of the invention the closing element reaches its open position against the force of a spring. Therefore, if the external control has been "switched off", the closing element can nonetheless get into its open position and Release the relief path when the prevailing pressure in the area of the closing member is sufficiently high is to move the closing element against the force of a spring.

So while the actual advance is the release of the conveying path by the external control, After switching off the external control, the prevailing pressure takes over this function. To the with To achieve the drastic reduction in pressure surges striven for by the invention, the external control is at least as long as it is effectively switched on and the relief path is forcibly released until the shut-off device has closed the conveying path.

From the above explanation, it can be seen that the point in time at which the shut-off device has reached its closed seat, a fixed reference point for the advance is. Therefore, in an advantageous embodiment of the invention, the external control can be switched on as a function the closing movement of the shut-off device

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gen, e.g. by the fact that the external control via a mechanical proximity switch is switched on just before the shut-off device reaches its Schilaßsitz Has.

However, it is also possible to use switching off the pump as a criterion for the external control, since that The shut-off element starts the closing process after the pump has been switched off. The Switch on external control for a selectable period of time before the shut-off device completely shuts off the conveying path.

Other advantageous refinements and developments of the invention are specified in the subclaims and to be taken from the drawing.

The invention is described below with reference to the in the drawing illustrated embodiments explained in more detail. Show it:

Fig. 1 is a schematic partial representation of a valve with a partially still open shut-off device as well as with an external control,

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Fig. 2 shows the valve according to FIG. 1, shortly before the shut-off element Closing seat reached and with already effective external control,

Fig. 3 several diagrams to illustrate the pressure occurring

r come close to the shut-off of the conveying

'So with a friend

Fitting,

4 time diagrams to illustrate the point in time of opening of the relief path, and

5 shows a detailed cross-sectional view of a fitting according to FIGS. 1 and 2.

The valve 10 shown in the drawing comprises, according to FIGS. 1 and 2, a non-return valve 12 designed as a non-return valve Shut-off device. In the open position of the non-return valve 12 can be a medium - here water - under the action of a for reasons of clarity the drawing, not shown pump along the conveying path 14 in the direction of the dashed arrow

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In Fig. 1 and 2 it can also be seen that there is a parallel relief in the area of the non-return valve 12 path 16 is located, which is below the (closed) non-return valve 12 over the mouth 20 and above the (closed) non-return valve 12 is connected to the conveying path 14 via the hound 18.

The upper opening 18 is closed in FIG. 1 by a valve disk 22, so that the relief path 16 is blocked or ineffective. For the closed position of the valve disk 22, a spring 28, which located in a piston housing 36 and between a Piston 40 and a rear end plate 42 is stretched. The piston 40 is connected to the valve disk via a rod 24 22 in connection, so that the force of the spring 28 presses the valve disk 22 into the closing seat.

On the side of the piston 40 facing away from the spring 28, there is a canister 39 in the piston housing 36, which via a passage opening 41 with an external control 70 communicates. Thus, a medium - e.g. compressed air or a hydraulic fluid - be guided into the chamber 39 in order to move the piston 40 to the right.

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The external control 70, shown only schematically as a block diagram in principle in FIG. 1, comprises a compressed air container 72 which is connected to a control unit 74 so that when the control unit 74 is active, the compressed air can pass through the passage opening 41 into the chamber 39.

The control unit 74 is subject to the influence of a proximity switch 76 through which the control unit 74 can be activated.

For the actuation of the proximity switch 76, the respective local position of the non-return valve 12 can be used during the closing movement can be used. By the German Offenlegungsschrift 31 25 029 it is has already become known, on the outside of the valve on a lever connected to the non-return valve Helle to provide a pointer, which shows the position of the non-return valve and which corresponds to the Moving the closing movement of the non-return valve. The position of this pointer gives the position of the non-return valve 12 on, and when a desired position of the non-return valve 12 is reached, just before this is theirs Close (has taken a seat, the proximity switch 76 can be switched on by means of the known pointer.

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Alternatively, it is also possible to control unit 74 by means of a delay switch shown in dashed lines 78 to drive. In this case, the criterion for triggering the external control 70 is Shutdown of the water along the conveying path 14 pump used. After switching off namely, the pump moves the check valve 12 in the direction of its closed seat. Therefore, if after the Switching off the pump via a time delay by means of the delay switch 78 activates the control unit 74 is, it can be achieved that the external circuit 70 becomes effective shortly before the non-return valve 12 got into their shooting seat. All it takes is that Delay time to be set accordingly.

In both cases - that is, both when the control unit is activated by the proximity switch 76 as also by the delay switch 78 - is achieved, that the external control 70 is activated to release the relief sweg 16 in the sense of an advance, shortly before the non-return valve 12 completely blocks the conveying path 14.

With reference to FIGS. 2 and 4, the mode of operation of the valve 10 is explained below. In Fig. 1 is the arrow C already indicates the closing movement of the non-return valve 12 after the pump has been switched off.

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indicates, and Fig. 2 shows the non-return valve 12 in a position shortly before reaching the closing

Js seat. As can be seen in the graph in Fig. 4 above

can, where the closing curve 58 of the saddle flap 12 is shown along the time axis 52, the return

% flap flap 12 in the closed position at time t _Q.

The opening curve 59 of the valve disk 22 is below the closing curve 58 in FIG. 4 along the time axis 61

; _: shown. As can be seen, the valve disk 22 already opens at the time ty _{due to an advance At 1.} , ·

At the time ty the external control 70 is e.g. has been switched on by the proximity switch 76, so that compressed air via the passage opening 41 into the Chamber 39 arrives. As a result, the piston 40 - and via the rod 24 also the valve disk 22 - is shown in FIG. 2 moved to the right so that the relief path 16 is released before the check valve 12 is closed has fully achieved. The dashed arrow B indicates that in this position Returning water to flow through the relief path 16 can. This considerably reduces the occurrence of the large pressure peaks described at the beginning,

because over the relief path 16 can already flow back Drain water, with the result that rUe pressure surges at

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fully closed non-return valve 12 are reduced.

Through the external control 70, the relief path '16 is thus advanced with respect to the reaching of the closing seat of the non-return valve 12 from the point in time ^;

t forcibly released. The period of time during which the valve disk 22 is inevitably brought into its open position is at least At

point t_ free, i.e. at least until the

Non-return valve 12. However, it is also possible to use the |

I forced open position of the valve disk 22 to hold shortly after time t.

If after the selectable period of time 4t. the external control 70 is shut off, the valve disc 22 of the spring ■ 28 passes by the action of force back into £ its closing seat. The external control 70 remains ineffective from now on, but the relief path 16 can nevertheless still be released again.

Despite the premature opening of the valve disk 22 builds namely, there is still pressure in the area of the muzzle, and as soon as this is sufficient to increase the force

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of the spring 28, the valve disk 22 2 moved to the right and the relief path 16 released again. After switching off the external control 70, so to speak, the spring 28 takes over the opening function if there is sufficient pressure in the area of the mouth 18. Depending on the pressure conditions prevailing there so the relief path 16 is released or closed again, so that it continues in this way pressure equalization is guaranteed.

For a better understanding of the invention and for clarification of the achievable advantages, the emergence of the is again below, based on the diagrams in FIG harmful pressure surges in a known valve explained.

Three diagrams are shown in each case. The closing curve 58 results in the closing process along the upper time axis 52 the non-return valve shown. Is along the second time axis 54 by means of the pressure curve 60 Pressure above the non-return valve - where there is in the valve according to the invention according to FIGS. 1 and 2 the dog 18 is located - shown, and along the The third time axis 56 shows the pressure curve 62 for the pressure below the non-return valve.

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Although reference is also made below to FIGS. 1 and 2, it is expressly to avoid misunderstandings it should be noted that the curves in Fig. 3 belong to the prior art; so it is with the description of the diagrams in FIG. 3, it is assumed that the mouths 18 and 20 and the relief path 16 1 and 2 are not present.

The upper closing curve 58 in FIG. 3 shows how the non-return valve 12 changes depending on the time t Closing seat is approaching. During the closing process, in the assumed example, something conveyed by a pump flows Water in the direction of arrow A in Fig. 1, and above and below the non-return valve 12 the pressure curves 60 and 62 are measured. The corresponding pressures are relatively low.

At t, the check valve 12 is in its closed seat arrives (Fig. 2), the conveying path for the medium water is thus interrupted. What matters now is how that Pressure curves 60 and 62 run. Initially, the pressure values hardly change within a time period A t; whereby At in Fig. 3 is about 1/10 second.

At t ₁ , however, a considerable pressure build-up begins. As the middle curve in Fig. 3 shows, large pressure peaks 64 arise, with these pressure peaks according to Art

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of an oscillation only slowly decrease. As long as the curve 60 runs above the time axis t / it is an overpressure.

In the lower pressure curve 62 it can be seen that after t ₁ a pressure peak 66 builds up as a negative pressure / follows the pressure peaks 68 (overpressure) until the pressure below the non-return valve 12 oscillates after a long time.

j'rend goes to zero.

The pressure curves 60 and 62 mean absolute pressure values,

so that for the time after t ₁ with respect to the load

ί the pressure difference between pressure peaks 64 and 66

must take into account, this pressure difference assuming extreme values. This then results in the above-described negative consequences that lead to a burst of pipes or used the valve: may ^cause.

ο After closing the non-return flap 12 at a

known valve resulting pressure surge leads to a

r expansion or bulging of the valve body,

which mostly consists of steel. If the steel case

t cannot withstand this pressure surge, the arm

ti door burst.

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In the invention, this risk is simple Means encountered. Because of the advance, the non-return valve is already closed before it is finally closed 12 of the relief path 16 released, so that already at this point in time measures for a relief the dangerous pressure surges are hit. But also after the non-return valve has been closed completely 12, pressure compensation is still possible, since the relief path is also possible when the external control is switched off 16 is released when the pressure in the area of the mouth 18 is large enough, the force of the spring To overcome 28 and bring the valve plate 22 into its open position.

Another advantage of the invention is that Because of the considerable reduction in pressure surges, the extreme impact noises of the non-return valve 12 are also reduced so that pumping stations with the valve according to the invention can work much quieter.

In the case of the valve according to FIG. 1 and described so far, only a single relief path 16 was assumed. But it is also easily possible with larger pipe diameters for the conveying path 14 on the Scope distributed several such relief paths with valve plates which can be influenced by the external control 70 22 to be provided.

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In the cross-sectional view according to FIG. 5, a fitting 10 - based on the basic representations in FIG 1 and 2 - shown in more detail, without the external control 7O. The same parts are made 1 and 2 are provided with the same reference numerals.

Around the relief path 16 in the normal operating state, that is, with the non-return valve 12 fully open to seal in the area of the mouth 18, the valve disk 22 has a sealing ring 26 which is attached to the Inner wall of. Relief path 16 is applied.

The end of the rod 24 facing the valve disk 22 is embodied as a rod head 34 that is crowned or spherical and held in a recess of the valve plate 22, with the result that articulated movements of the Valve disk 22 relative to rod 24 are possible. The rod 24 is attached to the valve disk by means of a disk 32 22 held.

The spring 28 located in the piston housing 36 presses against the piston 40 and against the end plate 4 2 and acts via the rod 24 in the desired manner on the valve disk 22, which is in the normal operating position is held in the closing seat by the spring force of the spring 28.

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The piston housing 36 is closed by a housing cover 38 through which a threaded bolt is in the center 30 is performed. The threaded bolt 30 is screwed into the rod 24. By means of an adjusting screw 44 is it is possible to act on the end plate 42 in order to be able to adjust the spring force of the spring 28. the Adjusting screw 44 thus forms a tensioning device which influences the pretensioning of spring 28 permitted. By turning the screw 44 on the threaded bolt 30, the distance between the piston 40 and the end plate 42 are influenced to each other, and thus it is possible to set the spring 28 in a desired manner Way to spaa. en. There is also a lock nut 50 on the adjusting screw 44.

On the outer end of the threaded bolt 30 is a Adjusting nut 46 screwed on, when actuated or rotated via the rod 24 and the threaded bolt 30 a Influence on the local position of the valve disk is possible. If you wish, use the conveyor path 14 To empty above the closed non-return valve 12, this can be done in a simple manner by turning the adjusting nut 46 by moving the valve disk 22 into its open position. As a consequence of this the relief path 16 is released so that the desired emptying can take place.

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f. Above, the invention was based on a

Embodiment of a faucet with a rear 'f> flip flap described as in promoting

J of water is used, however, the invention is

'not limited to this. Rather, under the

Invention, modifications are possible without departing from the inventive concept.

; The invention can be used anywhere with advantage

• Set where a medium prefers along a conveying path

wise is conveyed under pressure, and where the need arises, the conveying path by means of a shut-off device to be able to interrupt or shut off if necessary. The resulting damaging pressure surges are through the invention with simple means degraded to such an extent that harmful side effects are no longer to be feared are.

Claims (14)

DIPL-ING.'UWE THOMEN EUROPEAN PATENTATTORNEy Strate GmbH ... 446/18 SnhutzansPrüche 1. Fitting for opening and / or shutting off the conveying path of a medium conveyed by means of a pump, with a shut-off element which releases or shuts off the passage of the medium, in particular a fitting of a pipeline with a non-return valve, characterized in that a relief path (16 ) is provided, which opens into the conveying path (14) above and below the shut-off element (12), the opening (18) above the shut-off element (12) being permeable switchable and closable by a closing element (22) which is in its rest position is located in a seat closing the mouth (18), t - 2 - and that an external control (70) to open the closing % organes (22) is provided. £ 2. Fitting according to claim 1, characterized in that ,;, net that the closing organ (22) one in the area of fs mouth (18) located in the relief path (16) valve plate included. j 3. Fitting according to claim 2, characterized in that net that a spring (28) in a piston housing (36) between a piston (40) and an end plate (42) '; is arranged, and that the piston (40) has a Rod (24) is connected to the valve plate (22). 4. Fitting according to claim 3, characterized in that at the end of the piston housing (36) on the side of the piston (40) facing away from the spring (28) a passage opening (41) is provided in the housing wall, via which the spring (28 ) facing away from the side of the piston (40) can be acted upon by a medium. 5. Fitting according to claim 4, characterized in that net "that the passage opening (41)" lit the external control f (70) is connected. I. 6. Fitting according to one of the preceding claims 1-5 / characterized / that the external control (70) comprises a compressed air generator (72) which can be connected to the passage opening (41) at the selectable time. 7. Fitting according to one of the preceding claims 1-6, characterized in that the external control (70) can be effectively switched on. 8. Fitting according to one of the preceding claims 1-7, characterized in that the external control (70) comprises a control unit (74) which can be switched on via a delay switch (78). 9. Fitting according to one of the preceding claims 1-7, characterized in that the control unit (74) can be switched on by means of a proximity switch (76) which is controlled by a pointer indicating the angular position of the shut-off element (12). 10. Fitting according to one of the preceding claims 2-9, characterized in that the valve disk (22) has a sealing ring (26) which, in the closed position, rests against the wall of the relief path (16). 11. Fitting according to one of the preceding claims 3 - 10, characterized in that the valve disk (22) is articulated to the rod (24), the other end of which is in communication with the piston (40). 12. Fitting according to one of the preceding claims 2-11, characterized in that the spring (28) is adjustable by means of a clamping device (38; 44). 13. Fitting according to one of the preceding claims 2-12, characterized in that the valve plate (22) with a threaded bolt (30) is in connection to the valve plate (22) by means of an adjusting nut (46) externally against the spring force from the closing seat to move, for the purpose of emptying the conveying path 14. Fitting according to one of the preceding claims 2-13, characterized in that the threaded bolt (30) is screwed into the rod (24).