US2394345A - High-pressure closing device - Google Patents

Description

Feb. 5, 1946. K. WERNER HIGH PRESSURE CLOSING DEVICE Filed March 5, 1941 4 Sheets-Sheet 1 t, K" 1H A Feb. 5, 1946. K. WERNER HIGH PRESSURE CLOSING DEVICE Filed March 5, 1941 4 Sheets-Sheet 2 Feb.,5,1946.. K, W RNER 2,394,?11-1 HIGH PRESSURE CLOSING DEVICE Filed March 5, 1941 4 Sheets-Sheet 3 fFeb. 5, 1946. K.- WERNER 2,394,345

HIGH PRESSURE CLOSING DEVICE Filed March 5, 1941 4 Sheets-Sheet 4 Patented Feb. 5, 1946 HIGH-PRESSURE CLOSING DEVICE Karl Werner, Kiel-Wilt, Germany; vested in the Alien Property Custodian Application March 5, 1941, Serial No. 381,815

, In Germany March 9, 1940 1 Claim.

This invention relates to an improved high pressure closing device.

It is a fact well-known with high-pressure valves, particularly with those used for compressed air, and in which, in the closed state, scaling is effected by pressing metallic surfaces and edges upon each other, that they remain airtight for a short period only, even if they be finished according to the best methods and the material be carefully-selected. This is mainly due to the fact that'the air passes along the seating surfaces at a very high velocity, especially when the valve cone is but slightly open, so that the sealing surfaces and edges quickly become scored by the action of solid particles, or, as experience has shown, even of water droplets, carried along by the compressed air.

To avoid this, the attempt has already been made to obtain the necessary tight sealing by seating the valve cone or disc on a somewhat softer or elastic material, such as special alloys of white metal, ebonite, cellon, and the like, and by pressing such cone or disc against such material by means of a high closing pressure. But

even this method has proved unsatisfactory in the long run, because in this case the afore-v mentioned scoring of the seating surfaces also takes place, quite apart from the fact that the seating surfaces finally become crushed as a consequence of their frequent and excessive compression. Most of the high pressure valves, therefore, present the disadvantage of becoming leaky in use after a certain period of service. The economic emciency of the plant therefore suffers as a consequence of the constant loss of compressed air which in certain cases must absolutely beavoided.

Now, the construction of the device forming the subject of my invention follows a line deviating from the methodsused heretofore. It consists in that, when closing the device, first a preliminary shut-off of the high-pressure line is accomplished by means of a slide valve which, on its own account and as experience has shown, does not produce a reliable seal. Furthermore,

- a lipped seal, e. g. a Simmerit grooved ring sleeve packing, which, while inadequate as a direct packing for high-pressure valves yet has given highly satisfactory results with high pressure stufing boxes, is'provided at the points of leakage in question, located between the inlet and the outlet side, and is so arranged, similarly to the sealing surfaces of the preliminary shut-oil, as to lie outside the current of the high-pressure medium, thus eliminating damage due to the unrestrained action of said medium, and securely retaining the pressure medium penetrating thereto.

In the drawings: Fig. 1 is a vertical section of the device. Fig. 2 is an enlarged vertical section of the slide valve in open position.

Fig. 3 is a view similar to Fig/ 2, the valve being in closed position.

Fig. 4 is a view similar to Fig. 1, showing an other embodiment of the invention, the valve being open.

Fig. 5 shows the valve of the embodiment of Fig. 4, in closed position.

Fig. 6 is a view similar to Figs. 1 and 4, showing another embodiment of the invention, the valve being in open position.

Fig. 7 shows the valve of the embodiment 0 Fig. 6, in closed position.

Fig. 8 is a view similar to Figs. 1, 4 and 6, showing another embodiment of the invention, the valve being in closed position.

Fig. 9 shows the valve of the embodiment shown in Fig. 8,-in open position.

The embodiment according to Figs. 1 to 3 comprises a straight guided, tubular slide valve i closed at the bottom and having two rows of ports 2 and 3. In Figs. 2 and 3 the same valve is represented on a larger scale. This tubular slide valve has an internal thread engaging with the thread of a spindle t which can be turned by a hand-wheel s but cannot be displaced axial- 1y. By turning the hand-wheel i, the tubular slide valve I may thus be screwed up and down in the stationary bushing t fitted into the threepart housing i. The bushing 6 has ports 6 with which the ports 3 of the tubular slide valve may be brought to coincide.

When it is intended to close the device represented in the opened state in Figs. 1 and 2, the tubular slide valve i is raised by turning the hand-wheel i. In doing so, its row of ports 3 moves away from the formerly coinciding row of ports 6 01 the bushing 5, passing the upper portion of the, latter, which is not broken by openings. From this moment onwards, the cur rent of high-pressure air which is admitted laterally through the branch of the housing i and escapes at the bottom end of. the valve, is cut off, and only very little air is still allowed to penetrate between the bushing 5 and the periphery of the slide valve, which may be sup-v posed to move therein with a sliding fit, as well as through the threaded connection between the slide valve and the spindle, and thus to pass on to the outlet side. This leakage air which would escape and be lost if only the preliminary shutoII existed, is prevented from escaping according to my invention by the provision of a sleeve III of the grooved-ring type, encircling the tubular slide valve. This stufling-box packing, which is in itself well-known, is fitted between the lower and the medial part of the housing I with a small axial play. When closing the slide valve (Fig. 3), the air pressure firmly presses the inner edge of the lips of the sleeve III to the outer cylindrical surface of the lower part of the slide valve, thus creating a reliable seal.

During the closing operation, i. e. while the tubular slide valve I is moving upward, the row of ports 2 passes through the grooved ring III, and care has to be taken not to injure the lip edge of the latter, as this is made of indie-rubber and therefore easily damaged. For this purpose, the surface of the tubularslide valve I is recessed conically over its entire circumference above and below the row of ports 2, and the edges of the ports 2 are rounded 0115. Furthermore, for the same reason the ports 2 are drilled in an angle to the axis, rising towards the outer side, i. e. in a direction coinciding with the position of the packing-lips. This ensures that the leakage air continuing to escape during the closing operation tends to separate the delicate lip-edge of the grooved ring from the tubular slide valve, which action also protects the grooved ring against damage.

The lower end of the tubular slide valve I is designed in the form of a valve cone I2 which, by turning the hand-wheel 4, can be screwed down to the seating I3 arranged in the housing. Thus, in case of emergency, the second seal between the inlet and the outlet side can also become operative at least for a short period, and the installation be kept working temporarily if, at any time, the grooved ring should exceptionally happen to fail, whereupon it will have to be replaced at the next opportunity.

Since the life of grooved-ring sleeves of such design has in numerous cases been tested and found satisfactory when applied to stufllngboxes, their application, as described above, creates a shut-oif'device suitable for opening and closing, which distinguishes itself advantageously from the conventional types of valves, particularly on account of its reliability under very high pressures. It is also suitable for special conditions where the time allowable forrepairs is frequently short, and only simple auxiliary means can be resorted to.

The second embodiment illustrated in Figs. 4 and 5 also comprises the straight guided tubular slide valve I which is provided with an internal thread and can be screwed up and down by means of the hand-wheel I. With the slide valve I fully open (Fig. 4), the compressed air coming from the container-in this case from belowflows through the stationary bushing 5, which projects into the tubular Slide valve I, and passes out laterally through the openings 2 to the place of consumption. On screwing down the tubular slide valve I, the bushing 5 covers the range of holes 2, constituting a. preliminary shut-off of the current of compressed air (Fig. 5). Any leakage air escaping from between the tubular slide valve I and the bushing 5 as well as through the thread of said valve, thus putting the housing under internal pressure, is prevented from reaching the space in direct communication with the outlet pipe by the grooved ring III sealing below, and by a second grooved ring II sealing above said space. In this case the compressed air once again presses the edges of the lips of the grooved rings tightly against the outer surface 01 the tubular slide valve I, sealing said surface. In the examples according to Fig. 1 to 5, the tubular slide valves I have lugs 8 guided in grooves I5 cut in the cap I6 of the housing I, which lugs '8 serve to prevent turning of the tubular slide valve I during its vertical movement.

The arrangement adopted for preventing damage to the grooved ring I0 during the passage of the row of ports 2 is similar to that of the first embodiment.

In the third embodiment, illustrated in Figs. 6 and 7, the current once more follows the direction shown in the example first described, namely from top to bottom. The slide valve serving as a preliminary shut-off oi the compressed air, is however of a somewhat difierent design as it has a piston-shaped part I4 fitted with two grooved rings III and II, the lips of which face each other, while itslower end is fitted with a short tubular part I, open at the bottom and provided with ports 2. In addition, this example differs from the two others in that the slide valve, on turning the hand-wheel 4, rotates with the spindle 9 which, in turn, engages with the thread of the housing I, in which it moves up and down.

When the device is open (Fig. 6), the compressed air can flow from the cylinder to the place of consumption, passing through the ports 6 of the stationary bushing 5' and the ports 2 01 the tubular slide valve I. On screwing down the piston I4, the non-perforated wall located in the lower part of the bushing 5 provides a preliminary shut-oif for the ports 2. In this final position of the slide valve, the grooved rings In and II are situated on both sides of the ports 6 of the bushing 5. Consequently, when the compressed air has reached the piston I4 it cannot escape either towards the top or the bottom of the valve, as the air firmly presses the outer lips of the grooved rings against the inner wall of the bushing 5, thus ensuring an entirely reliable seal.

The application of a like arrangement ensuring particular and reliable cooperation between the slide valve and the grooved ring packing, is also possible in connection with automatic valves. Thus, as the fourth embodiment, Figs. 8 and 9 show a safety valve, the reference numbers of which correspond, in part. to those 01 the embodiments already described. In the housing 1 is mounted a slide valve II designed as a hollow diiierential piston, which onboth sides of its shoulder I8 and within range of the smaller and greater diameters is provided each with a series of slots I9, 20 and surrounded each by an elastic grooved ring III, II. Communicating with an annular space 2 I, encircling the slide valve I1, is on the one side the connecting branch 22 of the pressure line, and on the'other a bore 23 the wall of which in the opposite direction tapers down to edge-like form. Between the latter and an identical edge located a. certain distance apart therefrom, but in opposite direction, of a coaxial bore 24 open to the atmosphere, there is a membrane 25 which by the action of a tensioned spring 26 lies against the edge of the bore 23. Extending to the outer end of the bore receiving the greater step of the slide valve I1, and arranged thereon, is a longitudinal groove 21 connected with a bore 28 bifurcating one each branch to either side of the membrane 25.

So long as the pressure to be controlled "in the the groove 21 with the atmosphere, so that the slide valve I1 is subjected to the action of the pressure medium at its shoulder l8 only and is thereby held in closed position.

As, however, the pressure on the'valve becomes excessive, the membrane 25, against the action of the adjustably loaded spring 28, is brought into the position according to Fig. 9, in which the groove 21 is shut off from the bore 24 open to the atmosphere, and is, in exchange, connected with the bore 23 being under pressure. The pressure medium now can also impinge upon the greater face of the slide valve ll, pushing the same to the left into its opened position, in which the annular shoulder serves as a stop for limiting the stroke. At this point, however, the slide valve l'I will only remain until thepressureof the medium, owing to its issuing into the atmosphere by way of the slots 20, I9, has decreased to an amount somewhat below the admissible maximum limit. The preponderance of the spring load acting upon the membrane 25 then re-establishes the state shown in Fig. 8. The facesarranged in the interior of the slide valve I1 are acted upon by the pressure medium with equal force in opposite directions.

Inversely, a valve'of this character may also be used in closing a normally open connection, when the pressure falls below an admissible lower limit. In such a case, the valve only seals upon the occurrence of an undesired working condition. It may then in certain circumstances be useful in the design of the slots in the slide valve to take cognisance of the necessity of adapting the throttling effect due to the passage of the air through the slide valve. to the conditions prevailing in each case. Furthermore, an arrangement of substantially similar character may likewise be used in automatic closing and automatic opening, upon surpassing, or falling below, a predetermined pressure. It is only necessary to this effect to modify the arrangement of the slots, bores, etc. in a suitable manner. Finally, in order to protect the inner sealing lips of the two grooved rings, similar measures may be taken as in the case of the other embodiments.

slide valve i1 is relieved by the communication of ,The combination of a main and an auxiliary regulating member, of which the latter only is spring-pressed, is well-known in itself with other types of valves., The advantage it offers and which resides in the-fact that the opening and the closing movements of the main regulating member, which movements should be accomplished at the critical moment with the greatest possible ceierity, are not restrained by an increasing spring tension, still enhances the suitability of the present device. But even if for some reason .or other, for example in order to avoid the stepped arrangement of the slide valve, its normal position is more conveniently maintained or re-established by a tensioned spring rather than by the pressure medium acting upon its shoulder,

. selves (for example in the nature of the wellknown "Simmerit grooved ring sleeve packing"). All the elements are so arranged that the surfaces and/or parts contributing to effect tightness, lie outside the main path followed by the pressure medium. Provisions are also made to prevent the delicate edge of the lips of the grooved rings from being damaged on ports.

What I claim anddesire to secure by Letters Patent is:

In a high-pressure valve. a valve casing having fluid inlet means and fluid outlet means. a slide valve movable longitudinally in said casing. a tubular guide and conduit between said inlet and outlet means upon which said slide valve is guided. ring packing means in said casing surroundingand packing against said slide valve and located between the extremities of said tubular guide. said slide valve having 'an aperture located so as to be positioned beyond the outlet extremity of said tubular'guide in one position of the slide valve and to move pastsaid outlet passing the

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