Water heater tank construction

Abstract: A water heater tank having a tank shell (10) and a tank top (12) and bottom (14) member welded therein to provide a water tight space inside the shell. A cold water outlet (48) is mounted in the lower portion of the tank. The tank top member (12) has an upwardly extending flange (16) welded to the tank shell. The flange (16) has a deformed portion (58) extending inwardly from the main body of the flange to provide a space between the shell and the deformed portion. The hot water outlet (52) is mounted in the upper portion of the tank with at least a portion of the outlet extending into the space provided by the deformed portion of the flange. The axis of the hot water outlet (52) is thereby positioned at approximately the same level as the face of the tank top member.

Description: The present invention relates to a water heater tank construction of the type as outlined in the preamble of claim 1. A water heater tank construction of this type is known from AU-B-500 476. The known water heater tank has a shell and a tank top member curved into the tank interior in order to withstand pressure. The top member is welded to the shell by means of an upwardly extending flange which flange is parallel to the shell over its entire circumference. The location of the hot water outlet opening is shown in the figures as being essentially flush with the lowermost portion of the top member leaving a relatively large air space above the water level which may cause corrosion problems to occur. EP-A-126 801 describes a water heater tank construction having a shell and a disk-shaped top member which is welded to the shell by an upwardly extending flange. The flange over its entire circumference is parallel to the shell. The hot water outlet of the known tank is arranged below the top member. The water level of known tanks is shown in dotted lines in Figure 1 of the present specification. With such a design, the water level of the tank provides a relatively large air space above such level in which the exposed portions of the tank interior are subject to corrosion. It will, therefore, be appreciated that there has been a significant need to reduce corrosion problems of a water heater tank construction. A water heater tank construction fulfilling this need comprises the features of Claim 1. The design of the present invention contemplates the location of the hot water outlet at a distinctly higher level in the tank to thereby reduce the amount of exposed portions of the tank in the space above the water level. Corrosion of the exposed portions of the tank interior is thereby reduced. A preferred development of the water heater tank construction of the present invention is described by Claim 2. A preferred embodiment of the present invention will hereinafter be described by reference to the drawings, wherein: FIG. 1 is a fragmentary cross sectional elevational view of the water heater equipped with an improved hot water outlet construction; FIG. 2 is a fragmentary top plan view of the tank top member of the water heater shown in Fig. 1; and FIG. 3 is a fragmentary side elevation view taken along line 3--3 of FIG. 2. Referring to FIG. 1, the water heater is comprised of a tank shell 10 having a top tank member 12 and a bottom tank member 14 mounted therein. Top and bottom members 12 and 14 are fastened to shell 10 by welds 18 and 22 to provide a water tight space in the tank. Top member 12 has an upwardly extending flange 16 fastened to shell 10 by a weld 18. Tank bottom member 14 has a downwardly extending flange 20 fastened to shell 10 by a weld 22. A plurality of flue tubes 24 (one shown) are mounted in tank top and bottom members 12 and 14 by means of collar members 26 and welds 28 and 30. A jacket member 32 is mounted around tank 10 and has a jacket top member 34 and a jacket bottom member 36. Jacket bottom member is provided with a plurality of legs 38 and the space 40 directly below tank bottom 14 serves as a combustion chamber in which a burner (not shown) is mounted. Cold water is introduced into the bottom portion of the tank through nipple 42 threaded into a spud 44 of conventional design. Spud 44 is welded to tank shell 10 by weld 46. In water heater tank of conventional design the hot water outlet 48 is located in the top portion of the tank as shown in dotted lines in FIG. 1. With such design, the water level in the tank as indicated by reference numeral 50 will provide a relatively large air space above such level in which the exposed portions of the tank interior are subject to corrosion. The design of the present invention contemplates the location of the hot water outlet at a distinctly higher level in the tank. Such design includes an outlet nipple 52 and spud 54 assembly mounted with the axis 56 of nipple 52 at approximately the same level as the face of tank top member 12. To accommodate such location of the hot water outlet, the flange 16 of the tank member 12 is provided with a deformed portion 58 which extends inwardly from the main body of flange 16 to thereby provide a space 60 between shell 10 and the deformed portion 58 of flange 16. In such improved constuction the water level can be maintained at a relatively high level as indicated by reference numeral 62 to thereby materially reduce the air space above level 62 which in turn materially reduces the portions of the tank interior which are exposed to air. Corrosion of the exposed portions of the tank interior is thereby reduced.

Claims: A water heater tank construction comprised of a tank shell (10) having a tank top member (12) and a tank bottom member (14) mounted therein to provide a water tight space therein, a hot water outlet (52) mounted in the upper portion of said tank shell (10) and a cold water inlet (42) mounted in the lower portion of said tank shell (10), said tank top member (12) having an upwardly extending flange (16) welded to said tank shell (10), at least a portion of the face of said tank top member (12) extending below the level of the uppermost portion of said hot water outlet (52), characterized in that said flange (16) has a deformed portion (58) locally limited to the region of said hot water outlet (52) and extending inwardly from said main body of the flange (16) to provide a space between said shell (10) and said deformed portion (58) and in that said hot water outlet (52) is arranged with at least a portion of said outlet (52) extending into said space provided by said deformed portion (58) of said flange (16) with the face of said tank top member (12) outside said deformed portion (58) being below the level of the uppermost portion of said hot water outlet (52). A water heater tank construction according to claim 1 in which the axis (56) of said hot water outlet (52) is at approximately the same level as the face of said tank top member (12).

Inventors: VATO OTTO Z, VATO, OTTO Z.
Applicants: STATE IND INC, STATE INDUSTRIES, INC.
Application year: 1988
Main classification: F24H1
IPC codes: F24H1, F24H9