DE3411576C1 - Safety valve - Google Patents

Abstract

A safety valve for pneumatically or hydraulically operated devices, which, in the case of fire, must be brought into a predetermined state or held in a predetermined state, particularly for fire protection doors, has a valve element (2, 4) which can be moved onto a valve seat (20) and the surface of which which faces the valve inlet (1) is smaller than its surface facing the valve outlet (18). The safety valve contains a trigger element (8) which can be destroyed by heat and upon the destruction of which a control cavity (22) connected to the valve element (2, 4) is vented, thereby moving the valve element (2,4) into its sealing position. <IMAGE>

Description

To solve this problem, a safety valve of the initially mentioned type according to the invention designed in such a way that the valve seat adjacent, from the inlet to acted upon with working fluid area of the valve element smaller is more remote than the valve seat, through the valve element from the inlet Area to be acted upon with working fluid, which absorbs a working fluid Control cavity limits that the control cavity is limited by an insert, which has a through hole connected to the control cavity at the inner end, whose cross-section is significantly larger than the minimum cross-section of the connection between the inlet and the surface of the valve element remote from the valve seat, and that the through-hole at the outer end with the help of a release element that can be destroyed by heat is sealed.

In the valve according to the invention, the one that occurs at the inlet of the valve exercises Compressed air as a result of the surface dimensions of the valve element on the control cavity facing surface exerts a greater force than on the one adjacent to the valve seat Area so that the valve element is normally in the open state and compressed air can pass from the inlet to the outlet and thereby to the control device.

The safety valve according to the invention has a heat-destructible Trigger element on, which at the temperatures occurring in fires, which up to 1100 ° C can be reliably destroyed, the destruction preferably should occur at temperatures between 100 ° C and 120 ° C. As a result of the destruction of the release element, the control cavity is vented via the through hole and thereby brought the valve element into its sealing position. In this sealing position the valve element is held by the compressed air at the inlet, and in In this position of the valve element, the outlet of the valve is vented via the vent, d. H. it is ensured that the downstream No facility even if the temperature rises further as a result of the fire More compressed air is supplied, which can be ensured even further, that both the valve seat and at least that which is brought into contact with it Part of the valve element are made of stainless steel, i.e. due to the high temperatures cannot be damaged or leak as a result of the fire.

In order to make the safety valve according to the invention functional, However, it is surprisingly necessary that the per se usually one Small cross-section having connection through the valve element a smaller one Has cross-section than the through hole of the closure element, because only then when the cross section of the through hole is larger than the minimum cross section the connection results in a safe and reliable function in the event of destruction of the release element.

Around the through hole in the normal state through the release element to keep it sealed reliably and independently of material aging and the like the trigger element be pressed by a spring against a sealing plug, the causes a seal of the through hole in this position.

A liquid with a trigger element is particularly suitable closed glass ampoule containing a low boiling point, which if sufficient Heating bursts and so does the displacement of the stopper and thus the closing movement of the valve element allows. Such ampoules were, for example, in sprinkler systems used.

As already mentioned above, the minimum cross-section must be the Connection must be smaller than the cross section of the through hole. Preferably the minimum cross-section of the connection is not greater than half the cross-section the through hole.

The safety valve according to the invention is used for pneumatically operated Facilities, so the trigger element can the through hole against the ambient air seal, d. H. if the release element is destroyed, compressed air is released into the ambient air the end.

If the safety valve according to the invention is to be operated hydraulically Facilities used so the hydraulic fluid should of course be included Destruction of the release element, if possible, do not leak into the environment. That Trigger element can therefore the through hole against a collecting container for Seal hydraulic fluid, d. H. the hydraulic fluid flows in the event of destruction of the release element in the collecting container.

Since the safety valve according to the invention in normal operation always is open, d. H. the valve element due to the pressure in the control cavity in its Is held in the open position and only comes into its sealing position when the If the release element is destroyed, it is particularly useful to provide a possibility to be able to check the functionality of the safety valve without doing this a destruction of the release element would be necessary. To this end, the control cavity or the through hole of the safety valve with an opening for connection be connected to a test tap. The test cock is normally closed when it is but open to test the function of the valve, so that a condition results which corresponds to that which occurs when the release element is destroyed. if then the valve element is moved into the closed position, it has been demonstrated that the safety valve is functional. If the test cock is then closed again, so the valve element builds up again in the control cavity in the open position moving pressure on.

The invention is illustrated below with reference to the schematic exemplary embodiments showing figures explained in more detail.

F i g. 1 shows a section through a safety valve for a pneumatically controlled device.

F i g. 2 shows a section through a safety valve for a hydraulically controlled device.

The safety valve according to FIG. 1 has one of a part 3 and a part 13 existing valve body.

The parts 3 and 13, which are preferably made of stainless steel, are in In a manner not shown with the interposition of an O-ring sealingly with one another tied together. In part 3, an inlet 1 is provided to which a compressed air line is connected can be. From the inlet 1 extends a cylindrical opening coaxially, the is connected to an outlet 18 via an opening in its side wall. In the A valve element 2 made of stainless steel is arranged coaxially in the cylindrical opening exists and has a frustoconical sealing surface at its lower end, in the illustrated sealing position of the valve element sealingly on an im Transition from the inlet 1 to the cylindrical opening formed valve seat 20 flat and fits tightly. Between the valve element 2 and the wall of the cylindrical Opening is an annular space formed with a side vent opening 17 is connected to which a throttle 19 can be connected. As a result of this In the illustrated state, the outlet 18 is also connected to the connection Vent 17.

At the upper end in the figure, there is a sealing body on the valve element 2 4 attached, which has a ring seal 16 on its lower surface and on its outer surface has an annular seal 15. The connection between the sealing body 4 and the valve element 2 is carried out by a screw 5, the head of which is on the upper surface of the sealing body 4 and the one connecting the inlet 1 with the space above the screw head Has bore 14. The lower end of the bore 14 ends at a continuous one Inner bore of the valve element 2.

The part 13 has a recess that coincides with the top surface of the sealing body 4 forms a control cavity 22 from which a threaded hole runs upwards, into which an insert 12 is screwed.

The insert 12 has a blind hole at its upper end and takes in this a plug 11 on.

Furthermore, on the free end of the insert 12 is a cap element 10 screwed on, which has lateral openings. In the upper end of this cap element a spring 9 is supported, the lower end of which on the neck area of a closed, a glass ampoule 8 containing a liquid with a low boiling point rests and this presses against the plug 11 so that the insert 12 extending through hole 23 with the help of the in the bottom surface of the plug 11 receiving blind holes arranged O-rings 7 is sealed.

Laterally in part 13 there is a threaded opening 6, which with the control cavity 22 is connected and in which a not shown in operation The test tap is screwed in so that the opening 6 is normally sealed off is.

The in Fig. 1 shown safety valve can be in the compressed air supply line be installed for the control device of a pneumatically operated fire door, such a compressed air supply line usually connected to a main ring line that supplies compressed air to the control devices of various fire doors.

If compressed air is supplied to the inlet 1 of the safety valve, so first presses this onto the lower surface of the valve element 2 and in FIG. 1 holds the valve element in the position shown or brings it into this position. By the central opening of the valve element 2 and the very small cross-section Bore 14 of screw 5 gradually enters the control cavity 22 compressed air, whereby the same pressure is built up in the control cavity as at inlet 1.

However, as the area subjected to pressure is the surface of the head of the screw 5 and the surface of the surface area delimiting the control cavity 22 of the sealing body 4 is larger than the lower annular surface of the valve element 2 the valve element from the position shown down into its open position moves, in which the frustoconical sealing surface is at a distance from the valve seat 20 is located and in which the ring seal 16 rests sealingly on the surface 21 and so that the continuation of the inlet 1 forming the central opening closes. In this Inlet 1 is connected to outlet 18, but the connection between Outlet 18 and vent 17 interrupted. The control device will therefore from outlet 18 supplied compressed air.

The temperature in the vicinity of the safety valve rises as a result a fire strongly, so the liquid evaporates in the glass ampoule 8, whereby the glass ampoule is destroyed. As a result of this destruction, the compressed air causes in the through hole 23, the cross section of which is at least twice as large as the cross section of the bore 14 in the screw 5, a displacement of the plug 11 in Fig. 1 upwards, whereby the sealing effect of the O-ring 7 is canceled. Thus, there is a pressure drop in the control cavity 22, which is due to the different Dimensions of through hole 23 and hole 14 are not different from that supplied by inlet 1 Compressed air ii ',. Glit.hcn werdell kallll. I) ie on the lower izlilelle of the valve element 2 acting compressed air therefore moves the valve element into the position shown in Fig. 1, whereby by means of the frustoconical sealing surface of the valve element 2 and the Valve seat 20, the connection between inlet 1 and outlet 18 is interrupted, so that the outlet 18 is no longer supplied to compressed air. Rather, it becomes the inlet 18 is now vented via the vent opening 17 and so any compressed air that is still present removed from the control device for the fire door. The control device can therefore do not open the fire door under any circumstances, even if within the control device leaks in valves etc. occur due to heating.

Since both the valve element 2 and the valve seat 20, in particular the entire part 3 as well as most of the other parts of the safety valve Stainless steel cannot, even if the valve heats up as a result of the fire Leakage occur, but the sealing effect is also at temperatures of 1 1000C still maintained. If a leak occurs anyway, this will result insufficient compressed air supply to the control device to open a door, because the outlet 18 is connected to the vent 17.

Since through the hole 14 of the screw 5 only relatively little Compressed air per unit of time through and then through the through hole 23 into the Ambient air escapes, there are compressed air losses when the safety valve is closed, but these are so low that there is sufficient operating pressure in the main ring main is maintained, i.e. other fire doors that are not in the area of the fire can still be opened and closed pneumatically.

To the safety valve shown in the open state on his To check functionality, the connected to the opening 6, can not The test tap shown must be opened briefly. This opening of the test tap leads to a pressure drop in the control cavity 22, that is to say to a state like him occurs when the glass ampoule 8 is destroyed. If the valve is in functional condition, as a result of this pressure reduction, the valve element 2 is in the context of the above with the destruction of the glass ampoule 8 described manner in the illustrated closed position moved, whereby the functionality of the safety valve is verified.

After the test cock is closed, overbuilding builds up in the control cavity 22 the bore 14 again the same pressure as supplied to the inlet 1, and the Valve body 2 is moved back into the open position, so inlet 1 with it connected to the outlet 18 and the outlet 18 by means of the ring seal 16 opposite the vent opening 17 sealed.

The in Fig. 2 represented safety valve corresponds in his Structure and its function essentially the safety valve from FIG. 1, serves but for use in hydraulically controlled facilities.

As shown, the safety valve according to FIG. 2 a valve body from a part 25 and a part 36 serving as an insert. The two parts are in a manner not shown with the interposition of an O-ring sealingly with one another tied together. In part 25 there is an inlet 24 for the supply of hydraulic fluid, which is in the same way as with the safety valve according to FIG. 1 in one concentric central bore continues, with an opening Zlll- connection in the wall liii <1cm outlet 45 is provided is. In the center hole is a corresponding to the valve element 2 from FIG. 1 assembled valve element 26 with arranged frustoconical sealing surface, the sealing surface on a valve seat 46 is present. Here, too, there are valve element 26 and valve seat 46, that is to say part 25 made of stainless steel. At the upper end of the valve element 26 is the sealing body 4 from F i g. 1 corresponding sealing body 41 with lower ring seal 43 and outer ring seal 42 by means of one of the screw 5 from FIG. 1 corresponding screw 28 with a central hole 27 attached. Laterally in part 25 there is a vent 44 to which a line, not shown, is connected via the hydraulic fluid can be passed into the collecting container 49.

In part 36 there is a recess, which together with the upper Surface of the sealing body 41 and the screw head 28 delimits a control cavity 46, from which a through hole 39, corresponding to the through hole 23 extends from Fig. 1 upwards into a blind hole. This blind hole is located a stopper 32, which is from a glass ampoule 35, corresponding to the glass ampoule 8 from FIG. 1 due to the action of the cap element 33 provided in the openings arranged spring 34 is pressed against the plug 32, so that this rests firmly on the O-ring 38 with its lower surface. In the peripheral wall of the Closure plug is a sealing on the wall of the blind hole O-ring 37.

An outlet opening 31 in part 36 is via a line 30 with the Collecting container 49 connected, and the outlet opening 31 is via a transverse bore with the interior of the blind hole in connection, this transverse hole in itself sealing plug 32 located above the O-ring 38 of the O-ring 37 opens into the blind hole.

The through hole 39 is connected to an opening 29 into which a schematically indicated test tap is screwed, its outflow into the collecting container 49 opens.

As already mentioned, the functionality of the safety valve is the same according to FIG. 2 that of the safety valve from Fig. 1. Is therefore the safety valve according to FIG. 2 is supplied with hydraulic fluid via inlet 24, so brings or holds this due to the pressure on the lower surface of the valve element 26 this initially in its sealing position. However, the hydraulic fluid occurs as a result of the overpressure through the central bore 27 into the control cavity 48 and there gradually builds up a pressure corresponding to the pressure at inlet 24. However, since the surface of the screw head 28 and sealing body 41 which is subjected to pressure is larger than the lower surface of the valve element 26, the valve element moves 26 in its open position, in which the inlet 24 is connected to the outlet 45 and the vent opening 44 as a result of the ring seal 43 resting on the surface 47 is sealed against the outlet 45.

If the glass ampoule 35 is destroyed, it causes the pressurized Hydraulic fluid in the control cavity 48 and the through hole 39 a shift of the plug 32 in Fig. 2 upwards until it rests against the in the blind hole protruding annular surface of the cap element 33 comes. In this position is located the O-ring is located above the cross hole, so that hydraulic fluid from the control cavity 48 via the through hole 39, the cross hole, the outlet opening 31 and the Line 30 in the Collecting container 49 can drain. This reduces the pressure in the control cavity 48, and the pressure on the lower surface of the valve element 26 moves it into the in F i g. 2, in which the ventilation device 44 Drain hydraulic fluid from the control device connected to the outlet 45 can.

Of course, the cross-section of the through hole must also in this case 39 must be significantly larger than the cross section of the bore 27 in order for it to be effective Pressure drop in the control cavity 48 comes.

In order to ensure the functionality of the safety valve according to FIG. 2 without To be able to check the destruction of the glass ampoule 35, there is a threaded hole 29, which is connected to the through hole 39 via a bore and to which a Test tap is connected. By opening this test tap, as in connection with the safety valve from FIG. 1, the pressure in the control cavity 48 are lowered to determine whether the valve element 26 is then in the Moved closed position, so the safety valve is functional.

It should be mentioned that the connection between inlet 1, 24 and control cavity 22, 48, that is to say in particular the bore 14 from FIG. 1 and the bore 27 from FIG. 2 should have the smallest possible cross-section so that when the safety valve responds, so when the glass ampoule 8, 35 is destroyed, as little working fluid as possible from the inlet 1 or 24 exits through this hole. If too large a quantity escapes Working fluid would result in a significant pressure drop in the main fluid line come what is undesirable. On the other hand, the cross-section of these holes must of course sufficient to achieve the required operating pressure within a reasonable period of time build in the control cavity. It has been shown that, for example, when used of safety valves according to FIG. 11 in pneumatic actuators for fire doors on ships, a minimum diameter of the connecting hole between Inlet 1 and control cavity 22 of 0.2 mm to 0.5 mm is appropriate - Blank page -

Claims (8)

Claims: 1. Safety valve for pneumatic or hydraulic devices to be operated, which in the event of a fire in a predetermined Brought state or must be kept in a predetermined state, in particular for fire doors, with an inlet and an outlet for the working fluid, one between these arranged valve seat, on which a between a sealing position and an open position movable valve element can be brought into sealing contact is, as well as with a vent opening, which is located in the sealing position Valve element connected to the outlet and when in the open position Valve element is sealed against the inlet and the outlet, characterized in that that the valve seat (20; 46) adjacent to the inlet (1; 24) with working fluid to be acted upon surface of the valve element (2, 4; 26, 41) is smaller than the the valve seat (20; 46) further away, through the valve element (2,4; 26,41) from the inlet (1; 24) to be acted upon with working fluid surface, which is a working fluid receiving control cavity (22; 48) limits that the control cavity (22; 48) of an insert (12; 36), one at the inner end with the control cavity (22; 48) connected through hole (23; 39), the cross-section of which is substantially is greater than the minimum cross-section of the connection (14; 27) between the inlet (1; 24) and the surface of the valve element (2,4; 26,41), and that the through hole (23; 39) at the outer end with the help of a through Heat destructible trigger element (8; 35) is sealed. 2. Safety valve according to claim 1, characterized in that the release element (8; 35) by a spring (9; 34) against a sealing plug (11; 32) is pressed, which in this position seals the through hole (23; 39) causes. 3. Safety valve according to claim 2, characterized in that the trigger element made of a liquid containing a low boiling point, closed glass ampoule (8; 35). 4. Safety valve according to one of claims 1 to 3, characterized in that that the minimum cross-section of the connection (14; 27) is not greater than half of the cross section of the through hole (23; 39). 5. Safety valve according to one of claims 1 to 4, characterized in that that the control cavity (22) or the through hole (39) with an opening (6; 29) is connected to the connection of a test tap. 6. Safety valve according to one of claims 1 to 5 for pneumatic Devices to be operated, characterized in that the release element (8) the through hole (23) seals against the ambient air. 7. Safety valve according to one of claims 1 to 5 for hydraulic devices to be operated, characterized in that the release element (35) the through hole (39) against a collecting container (49) for hydraulic fluid seals. 8. Safety valve according to one of claims 1 to 7, characterized in that that the valve seat (20; 46) and at least that in engagement therewith coming part of the valve element (2; 26) are made of stainless steel. The invention relates to a safety valve for pneumatic or hydraulically operated devices which, in the event of a fire, are installed in a brought to a predetermined state or held in a predetermined CONDITION must, especially for fire doors, with an inlet and an outlet for the working fluid, a valve seat arranged between these, on which a between a sealing position and an open position movable valve element for sealing System can be brought, as well as with a vent opening, which is in the sealing position located valve element connected to the outlet and in the open position located valve element is sealed against the inlet and the outlet. Such valves are used, for example, in systems for operation from fire doors used on ships to the control devices for the to pressurize individual fire doors with compressed air. The valve element is located in the sealing position, there is the compressed air connection between inlet and outlet interrupted, and the outlet is connected to the vent so that the Compressed air located in the connection area between the outlet and the control device can escape through the ventilation opening. A major problem with the actuators for such Fire doors, for example on ships, but also on other pneumatic or hydraulic doors to be operated devices is to ensure that in the event of a Brandes results in a predetermined state or a movement in a predetermined State takes place, so for example the fire doors remain closed and do not open automatically as a result of fire damage to the associated components. This could happen, for example, when the compressed air supply to the control device for the fire door interrupting valve due to excessive heating, for example leaks due to damage to its rubber seals and then lets compressed air through. This compressed air could cause a fire door to open and thus completely eliminate the intended effect of the fire door. It is the object of the invention to create a safety valve, in the event of a fire, it is reliably and permanently brought into such an operating position is that the pneumatically or hydraulically operated device in a predetermined State comes or is held in this predetermined state.