Patent Number: 046738142
Section: description

DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION Referring to the drawing, FIG. 1 shows a metal container 22 of the invention. The container 22 includes a vessel 1 and a cover 4 seated in the open end of the vessel. FIG. 2 is an enlarged view of the upper portion of the container 22 and shows that the inner bore 2 of the vessel 1 is conically widened at its upper end to define a conical seating surface 3. The sealing cover 4 is pressed into the vessel at its open end and lies with its conical outer peripheral surface 5 on the seating surface 3 of the inner bore 2 of the vessel 1. The upper portion of the outer peripheral surface of the sealing cover 4 has a cylindrically beveled surface 6 so that a wedge shaped gap 7 is formed between the inner wall of the vessel 1 and the sealing cover 4. The sealing cover 4 is so positioned in the vessel 1 that its upper edge 23 lies beneath the rim 8 of the vessel and is tightly welded with the vessel wall by a fillet weld 9 at the open end of the vessel 1. A protrusion 11 is centrally located on the outer side of the cover 4 and is provided with a threaded bore 12. Beneath the bore 12, the cover 4 is penetrated by a connecting bore 13 of smaller diameter. A cover knob 14 threadably engages the threaded bore 12 of the protrusion 11 of the cover 4. The knob 14 is provided with a recess 15 in the form of a blind bore lying along the longitudal axis of the knob 14. The knob 14 and protrusion 11 are welded to each other at their connecting joint. The base 16 of the recess 15 is provided with a centrally disposed through-bore 17 through which the valve body 18 of a check valve extends. The valve body 18 is secured in the manner of a bolt to the base 16 of the recess 15. The valve body 18 and its pressure-means connection 19 projects into the recess 15 of the knob 14, the recess 15 defining a protective chamber for the valve. The recess 15 is closed at its upper end with a plug 20 which threadably engages the knob. The plug 20 lies with its flange 21 on the knob 14. The rim of the flange 21 and the knob 14 are welded to each other. After the vessel 1 is filled to a specific level, the sealing cover 4 having a conical outer peripheral surface is guided into its open, conical end and pressed therein. The conical seating surface 3 of the vessel 1 has the same taper as the conical outer peripheral surface of the cover. By pressing the conical sealing cover 4 into the inner cone 3 of the vessel 1, a radial force is exerted on the vessel wall. At the region of the conical seating surface 3, the wall of the vessel 1 is of a thickness which permits the wall to respond to this radial force and fit approximately evenly to the peripheral outer surface 5 of the sealing cover 4 thereby contributing to an improvement in the seal therebetween. The sealing cover 4 is pressed into the vessel cone 3 so deep that sufficient space remains between the upper sealing cover edge 23 and the vessel rim 8 to accommodate a fillet weld 9. While the valve 18 is held open, the sealing cover 4 can be joined to the vessel 1 by means of a gas-shielded arc-welding process. The stream of shielding gas is directed into the wedge-shaped gap 7 between the vessel wall and the sealing cover 4. Subsequently, a suitable test gas is injected into the space formed by the sealing cover 4 and the vessel 1 via the valve 18. With the aid of this gas, the impermeability of the sealing of this space can be tested and this test can be repeated. During the test, the gas pressure in the container is measured via the valve 18. If the gas pressure is too low or if the measured value falls off, this indicates that a leak of the closed off container is present so that appropriate measures can be taken to remove the leak. The integrity of the seal of the closed off container can be tested and this test can be repeated. If the test is satisfactory, the plug 20 on the cover knob 14 is welded tight in order to tightly close off the valve chamber 15. In the event that a new test is to be made after a large amount of time has passed since the container has been sealed off, it is merely necessary to destroy the weld-seam of the plug 20. Then either a new test gas can be applied or a test of the pressure within the container can be made. Other modifications and variations to the embodiments described will now be apparent to those skilled in the art. However, the aforesaid embodiments are not to be construed as limiting the breadth of the invention. The full scope and extent of the present contribution can only be appreciated in view of the appended claims.