DK171282B1 - Servo operated stop valve installation - Google Patents

Description

DK 171282 B1 i

The present invention relates to a servo-operated stop valve installation, in particular for use in underground pipe systems such as district heating systems, comprising a valve with associated switching motor and a power or operating station located at an easily accessible location away from the valve.

In district heating pipe systems, a number of stopcocks are usually mounted, often located below street level, where they may be accessible for manual operation, provided with a valve spindle projecting to just below an upper cover of a surrounding well ring. This installation requires a lot of work and it will be inconvenient for the traffic when the stopcock is to be operated, as there is a need to arrange some blockage of the street.

Therefore, for some taps, the first mentioned installation is selected, where the cock / motor unit may be completely buried and simply be connected to said control station through a power or hydraulic line, which may be mounted in a nearby pavement cabinet. The tap can then be operated without the inconvenience of traffic. However, there can also be an almost inverted problem, namely that the cock is almost never operated, whereby the swivel part can get very stuck, and it is therefore a further advantage of the motor-operated taps that one can work with a greater operating power than manual operation.

25 In the case of the fully buried valve units in question, it may be a problem that it is not immediately possible to observe that a given changeover order has been fully executed, which in practice is an important condition, since the taps are usually not designed to be able to left in 30 a position only almost completely closed or almost fully opened. Therefore, it would be desirable to establish some form of sensor monitoring that the actuation effect is actually completed with the full conversion of the tap, and there have been many considerations and suggestions regarding. this. It goes without saying that for management and control experts there will be an immense number of theoretically possible solutions, but they have had to be discarded due to the special mounting conditions and the requirement for full functionality for a very long time, e.g. . 30-40 years. It is not relevant here to further elaborate on the possibilities and advantages in question, but it should be mentioned that it is customary, however, to methodically make a kind of safety operation of the taps approx. once a year to counteract 5 overpowering tenets.

The invention provides a special motion and notification system which has been able to meet the extreme security requirements imposed on the functionality of the system.

The invention has chosen to work with a hydraulic actuator, since very large operating forces can be used relatively cheaply and safely, e.g. at the pressure of a few hundred bar, which will probably loosen fixed faucets. The associated pumping equipment may be located in the pavement cabinet and below the tap may be mounted a hydraulic cylinder having a piston body which, by displacement, respectively, acts on the male spindle by co-operation between a toothed rod on the piston body and a toothed rim on the spindle. .

In connection with this cylinder, a special 20 notification system is provided, from which, at the end of each switching movement of the tap, a message pressure is delivered which is returned to a hydraulic indicator unit in the operating station.

This is explained in more detail below with reference to the drawing, which shows in schematic sectional views and an accompanying diagram a device according to the invention.

The dotted transverse line a shows the ground level below which is fitted a stopcock with male spindle 2, which is formed with a dental ring 4. This cooperates with a tooth 6 on a slider body 8, which at the ends constitutes 30 piston parts 10 cooperating with respective cylinder parts 12 and 14, which are firmly attached to a joint, not shown substrate. The two cylinder portions 12 and 14 have a head 16 in which a central bore 18 is formed and a breakthrough channel connected thereto. In addition, these head pieces have a breakthrough channel 22 outside the central bore 18.

At the ends of the piston parts 10 is formed an protruding piston pin 24 which fits in the respective central bores 18.

The slider body 8 is shown to be located in a left-hand position, with the possibility of an offset towards the right corresponding to what is necessary for turning the spindle 2 through 90 °, i.e. for operating the stopcock between open and closed positions.

The two ducts 20 and 22 at each end of the system are connected to a common hydraulic line 26 and 28, respectively, connected to an adjustable hydraulic valve unit 30 in the pavement cabinet. Through this unit, these lines can be interchangeably connected to the pressure side, respectively, of a hydraulic pump 32 with suction reservoir 34 and the same or preferably a separate receiver reservoir 36. It will be seen that in the illustrated situation the pump 32 can thus be started to obtain , that the slider body 8 is pushed to the right for adjustment of the stopcock, while it is subsequently possible, after adjustment of the valve unit 30, to induce a reset of the tap.

At both ends of the cylinder system, a check valve 38 is provided between the connections to the ducts 20 and 22, which permits the flow of hydraulic fluid from the conduits 26 and 28 to the ducts 22, but prevents flow the opposite way, and the channels 22 are at the stop side of these check valves. connected through respective wires 40 and 42 to a separate section of switching unit 30, through which these wires are alternately connected to one and the other of wires 44 and 46 leading to a display element 48 disposed in the pavement cabinet, respectively to an associated receiving reservoir 50.

The indicator unit 48 has a cylinder part 52 in which is inserted a slide 54 which can be pushed from side to side by introducing pressure fluid through the respective lines 44 and 30 46. The slide 54 is formed at a center region with an inwardly extending ring 56 which can be cooperating with one or the other of two spring-loaded balls 58 connected to respective protruding arm portions 60 having an outer projection 62 which will clearly indicate visually whether the slider 54 is in one or the other outer position , depending on whether the protruding portion 60.62 is more or less protruding from the unit 48.

If it is assumed that the tap is in the open position and is wanted to close, then you simply need to start the pump 32, whereby through the fluid 26 pressure fluid is sent through the ducts 20 and 22 to the entire cylinder compartment in the left cylinder part 12. In the control valve 30, For example, a very large opening torque can be exerted on the male spindle 2, so that it can be expected that 5 will even be able to switch even the most solidly-grown cock. So it will only be quite exceptional that it may be necessary to excavate a tap for repair or replacement.

During the adjustment of the slider body 8, the hydraulic fluid in the right cylinder chamber 14 will be able to evade through the central 10 channel 20 and the line 28 back to the tank 36. This can occur without significant resistance, while a flow through the channel 22 to the connecting line 42, 44 to the indicator 48 will meet. resistance in that the indicator slide 54 is subjected to a locking effect upon the residence of the ball 58 in the groove 56.

However, towards the end of the shifting movement, the central bore 18 will be blocked by the piston pin portion 24, whereby it will only be the liquid in the space 18 that can eventually escape to the tank 36, while the liquid in the surrounding space is forced out to the conduit 42,44 and thus induce 20 a change of the indicator slide 54. The length of the piston pin 24 is adjusted such that at the final migration of the slide 8, just as much liquid will be expressed that a safe adjustment of the indicator slide is carried out, the liquid at its other end avoiding through the conduit 46 to the tank 50 .

Thus, a clearly visible indication of the fully guided male adjustment is obtained by the arm portions 60 and 62 shifting position between the more and the less protruding position, and this indication will only appear during the very last few degrees of rotation of the male spindle 2.

30 In view of the diagram blocks shown in the switch valve 30, there will be no further explanation here that a subsequent reopening of the tap will take place in quite the same way, only with switch valve 30. It is essential that the indicator's acknowledgment for full recovery aperture first appears at the actual establishment of the full aperture; a far and sufficient opening could very well be detected already upon the reappearance of the hot water to the section behind the valve, but due to the special tap construction it would normally be damaging to the tap if it was not reset to full opening during all circumstances.

It will be natural that after each use of the device or at least after every open / close operation, the hydraulic fluid contained in tanks 36 and 50 is collected and disposed of and replaces this 'old' fluid with new fluid added to it. tank 34.

The invention will not be limited to the embodiment shown, and especially not with regard to the manner in which the actual indication of the conversion is obtained. Also, the arrangement of the working cylinder can be modified to obtain that the pressure adjusting the indicator first appears in the very last phase of the male adjustment.

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Claims (3)

A servo-operated stop valve installation, in particular for use in underground piping systems such as district heating systems, comprising a valve with a hydraulic switching motor and an associated operating station disposed at a readily accessible location away from the valve, comprising installation means (48) for remote control of the valve assuming a fully open or fully closed position, respectively, 10, characterized in that the switching motor is a double-acting cylinder unit (16) with a piston rod (8), which is connected to the operating part (2,4) of the valve to rotating it to fully open and close the valve by hydraulically depressing the piston (10) of the cylinder unit in one and the other, respectively, and the indicating means (48) being adapted to be adjusted depending on the piston (10) during the latter part of its switching movement causes a shut-off of the hydraulic return flow (28) and a subsequent television anxious expression of the remaining hydraulic fluid (18) for releasing the indicating means (48). Installation according to claim 1, characterized in that the piston is constructed as a free piston block (10), the opposite ends of which are accommodated in respective cylinder head portions 25 (12,14) and that the hydraulic drive and return connection (26,28) for these are passed through local cylinder bores (20) in the inner end faces of the cylinder heads, the piston block having at both ends an protruding pin portion (24) which, when moving towards the associated cylinder bore, closes it in a position of the piston from which the piston is terminated. - movable through a volume containing just as much hydraulic fluid as is required for proper alignment of the indicating means. Installation according to claim 1, characterized in that the indicating means are constituted by a hydraulically actuated slide (54) provided with mechanical sensors (60,62) for displaying the slide position.