Title of Invention

"CONNECTABLE CHAMBER FOR PORTHOLE TESTING"

Abstract

The invention relates to shipbuilding and can be used for strength and leakage tests of the portholes of low-volume submersible vehicles. A connectable chamber is used for increased external pressure testing of the submersible vehicle portholes (1) which are arranged in a cylindrical body (socket welded connection) (2) provided with a supporting flange (11). The body of a chamber (4) is embodied at least partially in the form of a spherical surface and comprises a joining flange (9) which is provided with an internal annular collar (10) embodied in such a way that it encompasses the porthole (1). A device (14) for pressing the body (4) against the socket welded connection (2) is embodied in the form of a banding ring (15) provided with a sectional annular insert (16) arranged thereinside the contact surfaces of the ring and insert being embodied in the form of the surface a truncated cone. The annular insert (16) is provided with an annular slot for simultaneously embracing the supporting (11) and joining (9) flanges. The ring (15) is tightened by bolts (17), whereby the perfect junction thereof to the annular insert (16) and the tight crimping of the spherical body of the chamber (4) through a sealing ring are maintained. A working medium is supplied inside the body (4) by an internal pressure source. The inventive device reduces the test duration, increases the reliability thereof and can be used directly during the submersible vehicle operation.

Full Text

FIELD OF THE INVENTION The present invention relates to shipbuilding and may be used for strength and leakage tests of portholes of low-volume submersible apparatuses. BACKGROUND OF THE INVENTION There has been known an installation for strength tests of portholes (see, Stegiv I.G., Grey K.O., Designing Safe Portholes for Elevated Pressure Chambers, Transactions of the American Society of Mechanical Engineers, No. 4,1971, pp. 61-72). The known installation comprises a strong pressure vessel with a pressure gauge, a thermometer, an instrument for measuring displacements along a porthole thickness and a TV camera to continuously record displacements of the end of a porthole to be tested based on the instrument readings. The known installation allows high-precision determination of a quantity of porthole strains under the influence of pressures equal to 6.9 MPA over a long period of time (10-20 hours) and at an ambient temperature up to 65 °C, and also determination of a necessary reserve strength factor (scaling factor) Kr to ensure porthole strength. Porthole dimensions selected with a reserve strength factor Kr = 10 allow for the porthole capability not to destroy and withstand an operating pressure, which makes it possible to check portholes in actual practice only for leakage and strength. The drawback to the known installation resides in its complexity, necessity to employ a great number of instruments and equipment having a considerable weight and sizes and intended to be applied in stationary conditions of a measuring laboratory, not in low volumes of submersible apparatuses, which adversely affects a test duration and restricts functionalities only to strength tests, said strength is judged indirectly - by the presence or absence of cracks in the porthole material. Testing portholes for leakage to be judged by the availability of leaks of the working fluid under elevated pressure, involves the use of a separate installation. There has been known a device for strength and leakage tests of dead portholes of submersible apparatuses for internal pressure (see, USSR Inventor's Certificate No. 307,936, Bulletin of Inventions No. 21, 1971). In the known device, a casing with glass simulating a porthole is fastened on the inside of a submersible apparatus body, whereas under operating conditions the porthole undergoes pressure on a port glass on the outside of a submersible apparatus body. It is well known that a body made to the shape of a socket welded connection in which the porthole is fastened, differently influences a casing with glass given an internal or external pressure of the medium. That is why insufficient accuracy and reliability are likely to be expected from the known device when studying desired characteristics. There has been known a connectable chamber for testing portholes (see, USSR Inventor's Certificate No. 689,882, Bulletin of Inventions No. 37, 1979) comprising a body with a pipeline brought out thereto from a water pump, said chamber being packed with a large cavity for receiving a working medium, which envelopes the porthole, with a stepped piston, a small cavity with a connectable chamber cover and a screw press mounted on the cover, wherein the large cavity is provided with a pipeline with a valve to the small cavity, said large and small cavities being separated by the stepped piston. The device is made demountable at the expense of a threaded connection of the chamber body, said connection enveloping the great cavity, and a porthole cylindrical body constituting a socket welded connection in a submersible apparatus body. The possibilities for dismantling the test chamber provide for carrying out porthole tests under operating conditions with a minimum expenditure of time and means. However, the known device fails to ensure hermetic sealing of the connection in full measure when carrying out tests under conditions of elevated external pressure, which is caused by peculiarities of interaction of heterogeneous materials of which contacting elements are made, since in sea water those elements of the device that are made of steel materials and a submersible apparatus body made of a special alloy form galvanic couples in threaded connections, which gives rise to the mass transfer (outboard water leakage). Furthermore, in order to attach the chamber to the porthole body (submersible apparatus body) along a threaded connection, it is necessary to rotate the chamber having large weight and sizes, which complicates tests with low volumes of the submersible apparatus. The known connectable chamber for testing portholes for external pressure comprising a body with a pipeline for supplying the working medium from an external pressure source, a device for pressing the chamber body against the porthole body and a sealing to suit an area of fitting the chamber body, has been chosen as the closest prior art to the present invention. OBJECTS OF THE INVENTION It is an object of the present invention to decrease the working volume of a connectable chamber and increase reliability of the results of testing the portholes for external pressure directly on a submersible apparatus body. SUMMARY OF THE INVENTION The above object has been achieved by the fact that in the known connectable chamber for testing the portholes for external pressure comprising a body with a pipeline for supplying the working medium from an external pressure source, a device for pressing the chamber body against the porthole body and a sealing to suit an area of fitting the chamber body, in accordance with the invention said chamber body is embodied at least partially in the form of a spherical surface and provided with a joining flange having an internal annular collar embodied in such a way that it envelopes a body of a porthole to be tested. In so doing, said porthole body is embodied in the form of a cylindrical body with a bearing flange around the perimeter, and a device for pressing the body against the socket welded connection is embodied in the form of a tread ring provided with a sectionalized annular insert arranged thereinside to ensure perfect junction between said tread ring and annular insert along their contact surfaces, said contact surfaces being embodied in the form of the surface of a truncated cone and said annular insert being made profiled to envelop the bearing and joining flanges. Furthermore, the surface of the joining flange and the internal annular collar is provided with circular grooves to accommodate said sealing. Moreover, said sealing is made in the form of resilient circular gaskets. In addition, the tread ring is made to ensure its joining with the sectionalized annular insert by means of clamping bolts. Furthermore, the chamber body is made of material, whose elastic modulus is equal to the elastic modulus of a porthole body material. The technical effect of the present invention consists in the improvement of hermetic sealing of portholes for a submersible apparatus, said porthole having a special body shape (a cylindrical socket welded connection with a bearing flange) when testing for external pressure, by ruling out leakages through joining of elements in conditions of deformation under pressure, and when ensuring a uniform pressing of a porthole body, thereby increasing accuracy and reliability of test results with a decreased working volume of a single-cavity chamber. BRIEF DESCRIPTION OF THE DRAWINGS The essence of the invention is explained by the following drawings, in which: FIG. 1 is a sectionalized schematic view of a connectable chamber joined to a porthole to be tested; FIG. 2 is a schematic top view of a connectable chamber; FIG. 3 is a sectionalized schematic view of a chamber fragment with elements of pressing thereof against a porthole body; FIG. 4 illustrates a scheme of carrying out a porthole tests for external pressure. DETAILED DESCRIPTION OF THE INVENTION A connectable chamber for testing a porthole 1 having a cylindrical body 2 in the form of a socket welded connection (hereinafter referred to as a "socket welded connection 2") in a submersible apparatus body 3, comprises (FIG. 1) a body 4, which is embodied at least partially in the form of a spherical surface and has a pipeline 5 for supplying a working medium (sweet water) from an external pressure source (not shown in FIG. 1), said pipeline having a pipe seal 6, and also a pipeline 7 for draining the air from the volume of the body 5, said pipeline having a pipe seal 8. The body 4 is provided with a joining flange 9 having an internal annular collar 10 whose diameter is lesser than the diameter of a spherical part of the body 4. A cross-section of the internal annular collar 10 exceeds in dimensions the sizes of the porthole 1, thus ensuring the envelopment of the latter. The joining flange 9 corresponds to a return bearing flange 11 located on the socket welded connection 2. The surface of the joining flange 9 and the internal annular collar 10 is provided with circular grooves 12 to accommodate a sealing 13 between the joining flange 9 and the bearing flange 11 of the socket welded connection 2, which are made in the form of resilient circular gaskets to enable hermetically sealed attachment of the demountable chamber body 4 to a body of the socket welded connection 2 under the action of a pressing device 14 (FIG. 2). A pressing device 14 is made in the form of a tread ring 15 with a sectionalized (cut) annular insert 16 (FIG. 2) joined between each other by means of clamping bolts 17. The tread ring 15 and the annular insert 16 are made to ensure perfect junction along their contact surfaces during clamping with the clamping bolts 17, thereby ruling out leakage of the working medium under elevated pressure through the regions of loose fit of joined elements. Continuity of joining of contact surfaces is achieved by their accomplishment in the form of the surface of a body of revolution, namely in the form of a truncated cone with its upper base being disposed under the clamping bolts 17, thus ensuring the fit of the tread ring 15 onto the sectionalized annular insert 16 along a cone generator when tightening the bolts 17 fitted in threaded holes. When the chamber body is embodied, if only partially, in the form of a spherical surface, the tread ring 15 with the annular insert 16 tightly, without gaps, crimp the body. The sectionalized annular insert 16 is made profiled (FIG. 3) - with an annular slot - to envelop and engage simultaneously the joining flange 9 and its return bearing flange 11, at the expense of which the pressing device holds securely1 the chamber body 4 above the portholevl. The annular insert 16 (FIGS. 2, 3) is centered in relation to the tread ring 15 by means of pins 18 located in blind centering holes 19 of the sectionalized annular insert 16, said holes being made in the insert 16 (FIG. 3). Furthermore, the tread ring 15 mates with the annular insert 16 by means of squeezing bolts 20 arranged between clamping bolts 17 (FIG. 1). For ease of transportation of the connectable chamber to the place of tests, the outer surface of the body 4 is provided with handles 21 (FIG. 2). Since tests for elevated external pressure involve subjection of contacting joining and bearing flanges 9 and 11, the chamber body 4 and the socket welded connection 2 respectively, as well as the pressing device 14 to static loads, in order to rule out non-uniform stress distribution within these elements, said distribution being capable of disturbing hermetic sealing of a connectable chamber cavity, these elements are made of materials with the same elastic modulus or of the same material. Tests in relation to a submersible apparatus porthole for elevated external pressure using a connectable chamber are carried out in the following manner. A chamber body 4 is mounted (FIG. 1), with a joining flange 9 fitted with a sealing 13, onto a return bearing flange 11 of a socket welded connection 2. Sections of an annular insert 16 are located on the joining flange 9 while enveloping the latter and, simultaneously with it, enveloping the bearing flange 11. A tread ring 15 is fitted over sections of the annular insert 16, while joining and centering those sections by means of pins 18. Clamping bolts 17 are introduced into the holes of the tread ring 15 to join successively parts of a pressing device 14 followed by pressing the body 4 against the socket welded connection 2. The device is ready for tests as a part of installation (FIG. 4). From external ends of a pipeline 5 for supplying a working medium and a pipeline 7 for draining the air, there are removed pipe seals 6 and 8 respectively. The pipeline 5 is connected, by means of a pipeline 22 through a pressure gauge 23, a stop valve 24, a pump 26 and in parallel-connected safety valve 25, to a working medium external source, said medium may be in the form of sweet water, to a reservoir 27, as shown in FIG. 4. On trials the safety valve 25 is shut off, the stop valve 24 is opened, the pump 26 is actuated and the working medium (water) is supplied through the pipelines 22 and 5 to the chamber body 4. As water appears in the pipeline 7 for draining the air, thus witnessing to complete displacement of air from the chamber, the pipe seal 8 covers the pipeline 7 following which , in accordance with the test program, the pressure in the pipeline 22 and 5 for supplying the working medium is raised in a stepwise fashion while controlling the system state using a pressure gauge 23. At each step the preset pressure is kept for at least 10 minutes. After testing the porthole 1 for elevated external pressure, by which the porthole leak-proofness and strength can be judged, the pump 26 is turned off, the safety valve 25 is opened and the pressure in the pipeline line 22 is released gradually. In the absence of overpressure in the pipeline line 22, the latter is detached from the pipeline 5, on which the pipe seal 6 is fitted over, and a pressing device, that is the tread ring 15 with the annular insert 16, is removed by means of squeezing bolts 20, whereupon the chamber body 4 with the sealing 13 is detached from the socket welded connection 2. The porthole is considered to withstand a test for elevated external pressure if at a maximum pressure of the working medium, no leakages, droplets and the availability of moisture as viewed from the bearing flange 11 of the socket welded connection 2 through sealing elements 13 have been detected, which is demonstration of the porthole leak-proofness. If in the process of tests at a maximum pressure, no cracks have been detected on the glass of the porthole 1, it is deemed that the porthole ?has withstood strength tests. The proposed device allows efficient tests of portholes of submersible apparatuses under any conditions, including operating conditions, monitoring (periodic inspection) of the state of portholes of submersible apparatuses and also tests of portholes at external pressures corresponding to a submerged depth of submersible apparatuses in excess of 7000 m. We claim: 1. A connectable chamber for testing the portholes (1) for external pressure comprising a body (4) with a pipeline (5) for supplying the working medium from an external pressure source, a device for pressing (14) the chamber body (4) against the porthole body (1) and a sealing (13) to suit an area of fitting the chamber body (4), characterized in that said chamber body (4) is embodied at least partially in the form of a spherical surface and provided with a joining flange (9) having an internal annular collar (10) embodied in such a way that it envelopes a body of a porthole (1) to be tested, said porthole body (1) is embodied in the form of a cylindrical body with a bearing flange (11) around the perimeter, and a device for pressing (14) the body against the socket welded connection is embodied in the form of a tread ring (15) provided with a sectionalized annular insert (16) arranged there inside to ensure perfect junction between said tread ring (15) and annular insert (16) along their contact surfaces, said contact surfaces being embodied in the form of the surface of a truncated cone and said annular insert (16) being made profiled to envelop the bearing (11) and joining (9) flanges. 2. A connectable chamber as claimed in claim 1, wherein the surface of the joining flange (9) and the internal annular collar (10) is provided with circular grooves (12) to accommodate said sealing (13). 3. A connectable chamber as claimed in claim 1, wherein said sealing (13) is made in the form of resilient circular gaskets. 4. A connectable chamber as claimed in claim 1, wherein the tread ring (15) is made to ensure its joining with the sectionalized annular insert (16) by means of clamping bolts (17). 5. A connectable chamber as claimed in claim 1, wherein the chamber body (4) is made of material, whose elastic modulus is equal to the elastic modulus of a porthole body (4) material.

Documents:

2915-DELNP-2006-Abstract-(01-10-2008).pdf

2915-delnp-2006-abstract.pdf

2915-DELNP-2006-Claims-(01-10-2008).pdf

2915-delnp-2006-claims.pdf

2915-DELNP-2006-Correspondence-Others-(01-10-2008).pdf

2915-delnp-2006-correspondence-others.pdf

2915-delnp-2006-description (complete).pdf

2915-DELNP-2006-Drawings-(01-10-2008).pdf

2915-delnp-2006-drawings.pdf

2915-DELNP-2006-Form-1.pdf

2915-delnp-2006-form-18.pdf

2915-DELNP-2006-Form-2-(01-10-2008).pdf

2915-delnp-2006-form-2.pdf

2915-DELNP-2006-Form-26-(01-10-2008).pdf

2915-DELNP-2006-Form-3-(01-10-2008).pdf

2915-delnp-2006-form-3.pdf

2915-DELNP-2006-Form-5-(01-10-2008).pdf

2915-delnp-2006-form-5.pdf

2915-DELNP-2006-PCT-304-(01-10-2008).pdf

2915-DELNP-2006-PCT-373-(01-10-2008).pdf

2915-delnp-2006-pct-search report.pdf

2915-DELNP-2006-Petition-137-(01-10-2008).pdf

2915-DELNP-2006-Petition-138-(01-10-2008).pdf