G SCHOESSOW 2,789,721
T FOR HIGH PRESSURE FLUID T EXCHANGE APPARATUS Filed July :5 1951 pril 23, 1957 CLOSURE FIG.
 INVENTOR r clzoessow ARY 4 max.
CLOSURE FITTING FOR HIGH PRESSURE FLUID HEAT EXCHANGE APPARATUS Glen J. Schoessow, Barberton, Ohio, assignorto The Babcock & Wilcox Company, Rockleigh, N. 3., a corporatlon of New Jersey Application July 3, 1951, Serial No. 235,076
6 Claims. (Cl. 220-24) This invention relates to fluid pressure apparatus, and
more particularly to apparatus of this type which is in volved in the subjection of fluids under high pressure to heat exchange.
 In a more specific sense the invention relates to an expanded closure for non-circular openings in a header.
Such openings are formed in the sides of headers opposite surface against which an expander is operated to expand the closure element into pressure tight relationship with the walls of the non-circular access opening in the header. By way of explanation and not by way of limitation, the following description will refer to the particular constructions shown in the drawings.
In the drawings:
Fig. lis an end elevation of the closure element shown in its expanded condition;
 Fig. 2 is a section on theline 22 of Fig. 1, looking in the direction of the arrows;
 Fig. 3 is a section on the line 3-3 of Fig. 1 and looking in the direction of the associated arrows;
 Fig. 4 is a partial view of a header showing the manner in which tubes are arranged along one side of the header and the manner in which the illustrated closure elements are arranged in access openings along the opposite side of the header; and
Fig. 5 is a partial plan of the structure shown in Fig. 4.
 Theheader 10 is a pressure part of fluid heat exchange apparatus andtubes 12 and 14 are arranged in a row along one side of the header with their ends expanded into tube seats in the header. The opposite side of the header has a row of substantially oval access openings such as indicated at 16. Cup-shaped closure members orcap members 18 are constructed so as to be readily movable into the access openings with the dome-shaped part 20 of the closure member within the header. Each closure member is formed with a circular or hollow cylindricalinterior surface 22.
 'It is the main body portion of the closure member which has a hollow cylindrical inner surface. The outer surface of this main body portion has diametrically opposite parts such as 24 and 26, which are of a wall thickness greater than the wall thickness of the remainder of the main body portion. Thus, it might be said that the periphery of the closure member is somewhat elliptical or oval in form.
 The main body portion of the closure member is, of course, a tubular structure, and in the embodiment indicated in the drawing the closure member has at one end a dome-shaped portion 20 integral with the main body portion and closing one end of the tubular member. This dome-shaped portion forms circumferential shoulders such as 28 and 30 at positions where it meets the main body portion.
 In the operative use of the illustrative closure member, it is so positioned within apressure part 10 that the main body portion extends through the non-circular access opening in the pressure part. Thereafter, the closure member is expanded against the seat formed by the sides of the access opening. This seat has two annular grooves such as 21 and 23 in which the metal of the closure member is caused to flow when it is expanded. The expanding operation is effective in successive narrow circumferential zones of the main body portion, progressing toward the open end of the closure member. This expanding operation brings the entire main body portion of the closure member into pressure tight contact with the grooved walls of the access opening, and tightens theshoulders 28 and 30 against the interior surface of thepressure part 10.
 Whereas in accordance with the revised statutes the invention has been described with reference to certain preferred embodiments, it is to be appreciated that the invention is not limited to all of the details thereof, but that it is rather of a scope corresponding to the scope of the subjoined claims.
What is claimed is:
 1. In a high fluid pressure apparatus of the type having a thick wall steel header formed with a row of tube seats along one side and having expanded therein heavy -wall tubes for withstanding high fluid pressures, said header having at its side opposite the tube seat openings a row of substantially oval access openings; the combination therewith of a closure fitting of cup-shaped design, said fitting having a smooth hollow cylindrical bore of circular cross section and an exterior surface which is oval in correspondence with the shape of the header opening to be closed by the fitting, said fitting also having a dome-shaped portion of a wall thickness much less than the main body portion of the fitting, said domeshaped portion being adapted to be passed through said opening, said dome-shaped portion also being disposed within the header when the fitting is placed within the header access opening for subsequent expanding of the fitting against the sides of said opening, the dome-shaped portion being of greater maximum diameter than the main body portion with the dome-shaped portion joining said main body portion at a position adjacent the plane of the interior surface of the header and forming an external rib at that position, the juncture zone of the dome-sh aped portion and the main body involving an abrupt transition from the thin section of the dome to the much thicker wall section of the main body, and an external rib seal contacting the internal surface of the pressure vessel after the expanding of the fitting within said access opening.
 2. In a high fluid pressure apparatus of the type having a thick wall pressure vessel said pressure vessel having a substantially oval access opening adapted to be closed by heavy pressure resistant and correspondingly oval metallic closure element i-nsertable through said opening into the pressure vessel, the combination therewith of a more permanent closure fitting of cup-shaped tubular design, said fitting having a smooth hollow cylindlrical bore of circular cross section and having an exterior surface of oval cross section in correspondence with the shape of the access opening to be closed by the fitting, said fitting also having a dome-shaped portion of a wall thickness much less than the main body portion of the fitting, said dome-shaped portion being disposed within the pressure vessel when the fitting is placed within the access opening for subsequent expandingof the fitting against the sides of said opening, the dome-shaped porthe plane of the interior surface of the header with the juncture zone of the dome-shaped portion and the main body involving an abrupt transition from the thin section of the dome to the much thicker wall section of the main body.
 3. In a high fluid pressure apparatus of the. type having a thick wall pressure vessel, said pressure vessel having asubstantially oval access opening adapted to be closed by pressure resistant and correspondingly oval closure member insertable into the pressure vessel through said access opening by reason of the oval outlines of the opening and the closure, the combination therewith of a more permanent closure fitting of cup-shaped design, said fitting having a smooth hollow cylindrical bore of circular cross section and an exterior surfacewhich is oval in correspondence with the shape of the access openingto be'closed by thefitting, said fitting also having a dome-shaped portion of a wall thickness less than the wall thickness of the main body portion of the fitting, said dome-shaped portion being disposed within the-pressure vessel when the fitting is placed withinthe acoess opening for subsequent expanding of the fitting against the sides of said access opening, the domeshaped portion joining said main body portion at a position adjacent the plane of the interior surface of the pressure vessel, juncture zone of the dome-shaped portion and the main body involving an abrupt transition from the thin wall section of the dome to the thicker wall section of the main body.
 4. The combination expressed byclaim 3 further characterized by said fitting having a circumferential extension of the dome-shaped portion forming a shoulder for engaging the internal surface of the pressure vessel after expanding of the fitting within said opening, whereby with increase of fluid pressure within the vessel the fluid seal effectiveness is increased.
 5. A unitary cup-shaped steel closure fitting for an access opening of a thick walled header for high pressure apparatus, said fitting having a normally expandable tubular portion with a smooth hollow cylindrical bore of circular cross section, said tubular portion also having an exterior surface of substantially oval cross section whereby the tubular portion has dilferent radial thicknesses at the circumferenttially spaced positions around its perimeter, the fitting also having one end closed by an outwardly convex dome shaped portion having a base of transverse dimensions greater than thoseof the tubular portion toform a pressure part engaging shoulder.
 6. A normally expandable hollow cup-shaped metallic closure fitting for a substantially oval opening inya pressure vessel, said fitting having a main tubular, portion with a smooth hollow cylindrical bore of circular cross section and an exterior surface of substantially oval cross section whereby the tubular portion has varying radial wall thicknesses around its perimeter, one end of the fitting being closed by a dome-shaped portion joined to the tubular portion, said dome-shaped portion having a wall thickness less than that of saidtubular portion, and the transverse dimensions of the base thereof being greater than those of said tubular portion to form a pressure part engaging shoulder.
References Cited in the file of thispatent UNITED STATES PATENTS Condon et a1. Nov. 20, 1951