US2857073A - High pressure closure - Google Patents

Description

Oct. 21, 1958 T. TINKER 2,357,073

HIGH PRESSURE CLOSURE I Filed Sept. 26, 1955 mmvrox TOWNSEND 77/VKER United States Patent HIGH PRESSURE CLOSURE Townsend Tinker, Orchard Park, N. Y., assignor, by mesne assignments, to American Radiator & Standard Sanitary CorporatiomNew York, N. Y., a corporation of Delaware Application September 26, 1955, Serial No. 536,696

1 Claim. (Cl. 220-39) This invention relates to closures for pressure vessels and more particularly to covers or closure members for high pressure heads for heat exchangers and similar apparatus.

The problem of sealing vessels against high internal pressures by means of removable closure heads or covers presents many problems and has been the subject of much 2,857,073 PatentedO'ct. '21, 1958 Ct:v

7 present invention is set forth in detail herein by way of development and experimentation. The extremely high internal pressures frequently encountered presents a considerable problem in maintaining an adequate seal and transmitting and distributing the stresses resulting from such high internal pressures.

Because of the complexity and difliculty of the general problem, such closure or cover members have become increasingly complex. It is recognized as advantageous to separate or divorce, to some extent, the fluid seal means from the structural load-bearing portion of the closure means, so that the main hydrostatic pressure load against the latter does not act against the fluid seal means.

In recognition of this desirability and in providing high pressure closures with that end in view it is frequently proposed and practiced to employ multiple closures wherein, generally speaking, an inner closure member provides a hermetic seal against leakage and a separate outer closure member bears the hydrostatic load applied to the closure means by the internal fluid pressure forces in the vessel.

With the foregoing approach to the problem and numerous other approaches and proposals the design of high pressure closure heads for vessels of this general class has become increasingly complex and the very complexity inevitably introduces other vexatious design problems and progressively increases the cost of such closure arrangements.

The present invention is characterized by extreme simplicity and economy of construction and still provides a high pressure closure arrangement wherein the hydrostatic load against the closure is transmitted to the body of the vessel without thereby stressing the fluid seal portion of the closure means. In the construction of the present invention this is accomplished without the usual multiple cover plate construction and without the use of relatively fragile and delicate diaphragm arrangements often employed in present day high pressure closures.

Furthermore, the present invention provides a welded closure which entirely dispenses with the usual screw deor bolt .devices.

{-In the closure of the present invention the fluid seal is effected by a welded seam at the outside of the closure which is broken or removed to open the closure, when necessary. A novel seal arrangement is provided whereexample it is to be understood that the scope of the invention is not necessarily limited thereto or otherwise than as defined in the appended claim.

The single figure of the drawing is a fragmentary cross sectional view taken longitudinally through a corner of a pressure vessel provided with one form of the closure of the present invention.

The drawing shows what may be considered to be the upper left hand corner of a cylindrical pressure vessel which extends vertically as viewed in the drawing. The vessel has a main hollow cylindrical body portion 10 and a head member welded to the upper end thereof, the head member being designated generally by the numeral 11 and comprising a radial wall portion 12 which in the present instance provides a tube sheet for a tube-type heat exchanger. Head member 11 further includes a cylindrical portion 13 which extends axially outwardly from the pressure vessel proper (upwardly as viewed in the drawing).

Pressure fluid such as high pressure water or superheated steam may enter the head space 14 by way of an inlet conduit 15 and the numeral 16 designates, merely by way of example, one of the usual plurality of tubes fixed in tube sheet 12; A conventional pass plate 17 is welded within the head space 14 as at 18, to divide the head space into inlet and outlet portions, the division of the head space being completed by a marginally welded semi-circular pass rib or pass plate cover 19, all of the foregoing being generally conventional construction in high pressure heat exchanger vessels of this general class and well known to those skilled in the art to which the present invention relates.

The novel high pressure closure means in the form illustrated herein'by way of example will now be described in detail. The interior of the head member 11 outwardly of the head space 14 is provided with internal buttress threads as at 20 and a rigid cover member 21 is peripherally externally threaded to engage the internal threads 20. An internal flange 24 on head member 11 serves to limit inward threading movement of cover 21 and locate the same relative to the outer end of the cylindrical portion 13 of head member 11.

The outer end of the cylindrical portion 13 of head member 11 and the outer surface of cover 21 are preferably co-planar and are provided with axially projecting annular flanges 27 and 28, respectively, which define a space therebetween for cooperation in providing a welded pressure seal at the external edge of cover 21. In the illustrated embodiment a metallic ring 30 of U-shaped cross section is inserted in this recess and the outer terminal edges of the U-shaped ring 30 are welded to the upper edges of the flanges 27 and 28 as indicated at 31 and 32, respectively.

To remove cover 21 the welds 31 and 32 are displaced by chipping or otherwise. The extreme simplicity and eifectiveness of the foregoing closure arrangement more than compensates for the slight inconvenience incurred ,in thus breaking the welded seal to gain access to the moving the welded seal since this element may be re 3 plaeed whenever circumstances require removal and ren asementqf. he. eal:

What is claimed is: Pressure vessel means comprising a hollow cylinder haying an openend-and a clos11re memberv therefor, said 5 hollow cylinder being internally, threaded at its open end saidclosure member having complementary external peripheral threads, the endzof said cylinder and theouter face of said closurqmernber having axially extending concentric flangelformationss forming a channel at the externaljunetureof said cylinder end and said closure member, and :a. complementary channel shaped sealing ring 4. disposed in said channel and welded at its upper terminal edges to said closure member'flanger and. said cylinderend flange, respectively.

References Cited in the file of this patent UNITED STATES PATENTS 1,902,494 Emmet Mar. 21, 1933 1,958,582 Kerr et al. May 15, 1934 2,352,583 Zetterquist June 27, 1944 2,797,017 Tangard June 25, 1957

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