PRESSURE TANK

Abstract

A pressure tank includes a metallic vessel, a plastic liner received in the metallic vessel, a flexible diaphragm, two connectors and a nozzle coupled to the nipples respectively. The metallic vessel includes upper and lower shells. The upper shell defines a first planar area on a side thereof and a second planar area on a top thereof. The lower shell defines a third planar area thereunder. The flexible diaphragm divides the metallic vessel into a storage space and a pneumatic room. Each of the connectors includes a nipple and an anti-leak assembly. The nipples of the connectors are mounted on the side and top of the upper shell respectively and are in communication with the storage space. The two anti-leak assemblies provide leakproof connection between the nipples and the plastic liner. Additionally, the nozzle is mounted on the third planar area to be in communication with the pneumatic room.

Claims

1. A pressure tank, comprising: a metallic vessel having an upper shell and a lower shell joined together; a plastic liner received in the upper shell of the metallic vessel; a flexible diaphragm disposed inside the plastic liner, wherein the flexible diaphragm and the plastic liner co-define an upper storage space therebetween, the flexible diaphragm and the lower shell co-define a lower pneumatic room therebetween; a fixing ring provided to hold the flexible diaphragm against an inner peripheral wall of the plastic liner; a nozzle mounted on the lower shell of the metallic vessel and being in communication with the lower pneumatic room; a through-wall connector mounted on the lower shell of the metallic vessel upper and being in communication with the storage space, wherein the through-wall connector comprises an inner tubular portion and an exposed tubular portion including a cylindrical section welded to the metallic vessel, a threaded section for connection with a pipe, and a polygonal section formed between the cylindrical section and the threaded section, wherein the polygonal section has a plurality of flat sides, wherein the cylindrical section is made with an external diameter smaller than that of the polygonal section and larger than that of the inner tubular portion, wherein the cylindrical section includes an end located against an external surface of the metallic vessel, wherein the inner tubular portion passes through the upper shell of the metallic vessel and the plastic liner, and has a base section and a bendable neck section extending from an end of the base section; a seal washer placed around of the base section of the inner tubular portion of the through-wall connector and placed in between the upper shell and the plastic liner, wherein the seal washer is made with an external diameter larger than that of the polygonal section of the through-wall connector; a retainer ring having a flat annular disk placed around the inner tubular portion of the through-wall connector, a circumferential wall extending outward from an outer periphery of the flat annular disk, and a flat ring flange extending outward from a peripheral end of the circumferential wall, wherein the flat annular disk and the circumferential wall together define an annular recession; and upon being bent, the neck section of the inner tubular portion of the through-wall connector presses against an outer surface of the flat annular disk of the retainer ring, an inner surface of the flat annular disk of the retainer ring faces the end of the cylindrical section of the through-wall connector, and an inner surface of flat ring flange is in face-to-face contact with a first annular face of the plastic liner and faces an end of the polygonal section of the through-wall connector; and an O-ring placed around the inner tubular portion of the through-wall connector, received in the annular recession of the retainer ring, and having a thickness greater than a depth of the annular recession, wherein once the neck section of the inner tubular portion of the through-wall connector is bent to form an annular expanded portion to abut against the flat annular disk of the retainer ring, the thickness of the O-ring becomes smaller and no longer greater than the depth of the annular recession, and the O-ring has a bottom surface abutting against the inner surface of the flat annular disk of the retainer ring, an outer peripheral surface abutting against an inner surface of the circumferential wall of the retainer ring, an inner peripheral surface abutting against the inner tubular portion of the tubular body, and a top surface being in face-to-face contact with a second annular face of the plastic liner; wherein the flat annular disk, the O-ring, a portion of the plastic liner, a portion of the washer and a portion of the metallic vessel extend around the inner tubular portion and are clamped between the annular expanded portion of the neck section and the end of the cylindrical section.

2. The pressure tank of claim 1, wherein the circumferential wall of the retainer ring extends obliquely outward from the flat annular disk, and a portion of the circumferential wall between the circumferential wall and the flat annular disk is arc-shaped.

3. The pressure tank of claim 2, wherein the circumferential wall of the retainer ring extends obliquely outward to the flat ring flange, and a portion of the circumferential wall between the circumferential wall and the flat ring flange is arc-shaped.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0009] The invention is illustrated by the accompanying drawings in which corresponding parts are identified by the same numerals and in which:

[0010] FIG. 1 is an exploded view of a pressure tank in accordance with the preferred embodiment of the invention;

[0011] FIG. 2 is a cross section of the pressure tank of FIG. 1;

[0012] FIG. 3 is a fragmentary exploded view of the pressure tank, showing an arrangement among an upper shell and a first through-wall connector;

[0013] FIG. 4 is an assembled view of the parts shown in FIG. 3;

[0014] FIG. 5 is a fragmentary exploded view of the pressure tank, showing an arrangement among an upper shell and a second through-wall connector;

[0015] FIG. 6 is an assembled view of the parts shown in FIG. 5;

[0016] FIG. 7 is a fragmentary exploded view of the pressure tank, showing an arrangement between a nozzle assembly and a lower shell; and

[0017] FIG. 8 is an assembled view of the parts shown in FIG. 7.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0018] Referring now to the drawings, the pressure tank according to the present invention comprises a metallic vessel 1, a plastic liner 2, a flexible diaphragm 3, a fixing ring 4, two through-wall connectors and a nozzle 9. The first through-wall connector including a first nipple 5 and a first anti-leak assembly 6; and the second through-wall connector includes a second nipple 7 and a second anti-leak assembly 8.

[0019] As shown in FIGS. 1 and 2, the metallic vessel 1 includes an upper shell 10 and a lower shell 11 joined together, and preferably is made of stainless steel to conform to the requirements of Food and Drug Administration (FDA). The upper shell 10 is formed of a circular plate 12 and a hollow cylinder 13 extending from the periphery of the circular plate 12. The hollow cylinder 13 defines a recessed first planar area 14, as depicted in FIG. 2. A second planar area 15 is defined in the center of the circular plate 12 of the upper shell 10. Moreover, the lower shell 11 defines a third planar area 16 thereunder and formed with an inward tubular protrusion 17 extending inwardly from the third planar area 16, as depicted in FIGS. 7 and 8. The inward tubular protrusion 17 is provided with a hole 18 including a lower hole 181 and an upper hole 182 of diameter smaller than the lower hole 181 and thereby provides a projection 183 in the hole 18. It should be noted that opposite inner and outer surfaces of each of the planar areas 14, 15, 16 are flat and even in order to be easily and firmly weld/connected with the first, second nipples 5, 7 and a third nipple 90 of the nozzle 9.

[0020] As shown in FIG. 2, the plastic liner 2 is received in the upper shell 10 and is formed with an inward protrusion 21 on a top thereof. As best seen in FIG. 6, the inward protrusion 21 of the plastic liner 2 defines an annular recession 23 therein.

[0021] Referring again to FIG. 2, the flexible diaphragm 3 is made of a rubber material and is disposed inside the plastic liner 2. The flexible diaphragm 3 and the plastic liner 2 co-define an upper storage space 30 therebetween. Likewise, the flexible diaphragm 3 and the lower shell 11 co-define a lower pneumatic room 31 therebetween. The fixing ring 4 is provided to hold the flexible diaphragm 3 against an inner peripheral wall of the plastic liner 2. Further, the flexible diaphragm 3 and the plastic liner 2 are tightly sandwiched between the fixing ring 4 and the upper shell 10 by applying rolling depression upon an exterior periphery of the upper shell 10 of the metallic vessel 1.

[0022] Referring to FIG. 3, the first nipple 5 of the first through-wall connector is mounted on the first planar area 14 and includes an exposed tubular portion 50 and an inner tubular portion 51. The exposed tubular portion 50 is formed with a threaded section 52, a polygonal section 53 and a cylindrical section 54. The threaded section 52 is formed with external thread for connection with a pipe (not shown). In this embodiment, the polygonal section 53 is hexagonal and extends from the threaded section 52. The cylindrical section 54 extends from the polygonal section 53 and is weld to an exterior surface of the first planar area 14 of the hollow cylinder 13 of the upper shell 10. The inner tubular portion 51 includes a base section 55 and a neck section 56. The base section 55 extends from the cylindrical section 54 of the exposed tubular portion 50. The neck section 56 extends from the base section 55. Referring to FIGS. 2 and 4, the inner tubular portion 51 passes through the first planar area 14 of the upper shell 10 and the plastic liner 2 and is in communication with the storage space 30.

[0023] Referring again to FIGS. 3 and 4, the first anti-leak assembly 6 of the first through-wall connector provides leakproof connection between the first nipple 5 and the plastic liner 2, and includes a seal washer 60, an O-ring 61 and a retainer ring 62. The seal washer 60 is placed around the inner tubular portion 51 of the first nipple 5 and placed in between the hollow cylinder 13 of the upper shell 10 and the plastic liner 2. The O-ring 61 is also placed around the inner tubular portion 51 of the first nipple 5 and is placed in between the plastic liner 2 and the retainer ring 62. As best seen in FIG. 4, the retainer ring 62 includes a ring body having a flat annular disk 63 and an inclined circumferential wall 64, and a flat ring flange 66 extending from the inclined circumferential wall 64. The flat annular disk 63 is placed around the inner tubular portion 51 of the first nipple 5. The inclined circumferential wall 64 extends outwardly from the periphery of the flat annular disk 63 and an arc connecting portion is formed between the flat annular disk 63 and the inclined circumferential wall 64 to connect the flat annular disk 63 and the inclined circumferential wall 64. The flat ring flange 66 extends and flares outward from the outer periphery of the inclined circumferential wall 64 and another arc connecting portion is formed between the inclined circumferential wall 64 and the flat ring flange 66 to connect the inclined circumferential wall 64 and the flat ring flange 66. The flat ring flange 66 has a flat surface which abuts against a planar area of an inner wall surface of the plastic liner 2. The flat annular disk 63 and the inclined circumferential wall 64 co-define an annular recession 65 for receiving the O-ring 61. It is noted that the neck section 56 of the inner tubular portion 51 is thinner than the base section 55 and is bent to hold the first anti-leak assembly 6 and the plastic liner 2 against an interior surface of the first planar area 14 of the hollow cylinder 13 of the upper shell 10. Additionally, the O-ring 61 has a thickness slightly larger than a depth of the annular recession 65 of the retainer ring 62 in such a way that the O-ring 61 can be tightly held against the planar area of the inner wall surface of the plastic liner 2 and provides a better leakproof effect.

[0024] As shown in FIG. 5, the second nipple 7 of the second through-wall connector is substantially identical to the first nipple 5 in construction and is mounted on the second planar area 15 of the circular plate 12. Specifically, the second nipple 7 includes an exposed tubular portion 70 and an inner tubular portion 71 joined together. The exposed tubular portion 70 is formed with a threaded section 72, a polygonal section 73 joined to the threaded section 72 and a cylindrical section 74 joined to the polygonal section 73. The threaded section 72 is provided for connection with another pipe (not shown). The cylindrical section 74 of the exposed tubular portion 70 is weld to an exterior surface of the second planar area 15 of the circular plate 12 of the upper shell 10. The inner tubular portion 71 is formed with a base section 75 and a neck section 76 extending from the base section 75. Referring to FIG. 6, the inner tubular portion 71 passes through the second planar area 15 of the circular plate 12 and the inward protrusion 21 of the plastic liner 2 and is in communication with the storage space 30.

[0025] Referring back to FIG. 5, the second anti-leak assembly 8 of the second through-wall connector is placed around the inner tubular portion 71 of the second nipple 7 in order to provide a leakproof connection between the second nipple 7 and the plastic liner 2. Specifically, the second anti-leak assembly 8 includes a seal washer 80, an O-ring 81 and a retainer ring 82. The seal washer 80 is placed around the inner tubular portion 71 of the second nipple 7 and placed in between the circular plate 12 and the plastic liner 2. The O-ring 81 is also placed around the inner tubular portion 71, placed in between the inward protrusion 21 of the plastic liner 2 and the retainer ring 82, and lodged in the annular recession 23 of the inward protrusion 21 of the plastic liner 2. Likewise, the O-ring 81 has a thickness slightly larger than a depth of the annular recession 23 of the inward protrusion 21 of the plastic liner 2. As shown in FIG. 6, the neck section 76 of the inner tubular portion 71 is thinner than the base section 75 of the same and is bent to hold the second anti-leak assembly 8 and the plastic liner 2 against an interior surface of the second planar area 15 of the circular plate 12 of the upper shell 10.

[0026] Referring to FIGS. 2, 7 and 8, the nozzle 9 is mounted on the third planar area 16 of the lower shell 11 of the metallic vessel 1 and is in communication with the pneumatic room 31. Specifically, the nozzle 9 includes the third nipple 90, a third anti-leak assembly 96 and a one-way valve 99. The third nipple 90 is inserted in the hole 18 of the inner tubular protrusion 17 and has an exposed tubular portion 91 and an inner tubular portion 92. The inner tubular portion 92 has a protruding section 93, a cylindrical section 94 extending from the protruding section 93 and a threaded section 95 extending from the cylindrical section 94. The protruding section 93 of the inner tubular portion 92 is lodged in the lower hole 181 of the hole 18 of the inward tubular protrusion 17 of the lower shell 11. The inner tubular portion 92 of the third nipple 90 passes through the third planar area 16 as well as the inward tubular protrusion 17 and is in communication with the pneumatic room 31.

[0027] Moreover, the third anti-leak assembly 96 of the nozzle 9 is placed around the inner tubular portion 92 of the third nipple 90 to provide leakproof connection between the third nipple 90 and the lower shell 11. The one-way valve 99 of the nozzle 9 is received in a passage formed in the third nipple 90, through which outside air or gas can be injected into the pneumatic room 31 to drive the flexible diaphragm 3. Specifically, the third anti-leak assembly 96 includes an O-ring 97 and a connecting member 98. The O-ring 97 of the third anti-leak assembly 96 is placed around the inner tubular portion 92 of the third nipple 90. And, the O-ring 97 is lodged in the lower hole 181 of the hole 18 of the inward tubular protrusion 17 of the lower shell 11 and is sandwiched between the projection 183 of the inward tubular protrusion 17 and the protruding section 93 of the inner tubular portion 92. The connecting member 98 of the third anti-leak assembly 96 defines a through hole 980 having an screw hole 20 and a receiving hole 19 for receiving the third nipple 90 and the inward tubular protrusion 17 of the lower shell 11. The screw hole 20 of the through hole 980 of the connecting member 98 is adapted for engaging the threaded section 95 of the inner tubular portion 92 of the third nipple 90, and thus a surface of the connecting member 98 abuts against an end face of the inner tubular protrusion 17 of the lower shell 11. The receiving hole 19 of the through hole 980 of the connecting member 98 includes an annular groove 191 defined in an inner peripheral wall surface of the connecting member 98 for reception of the inner tubular protrusion 17 of the lower shell 11. In particular, the receiving hole 19 of the through hole 980 of the connecting member is tapered in diameter from outside to inside of the lower shell 11, and the inner tubular protrusion 17 of the lower shell 11 is mated with the annular groove 191 of the receiving hole 19 of the through hole 980 of the connecting member 98. In such a way, the inner tubular protrusion 17 can be snugly wedged into the connecting member 98. In such a fashion, the nozzle 9 can be easily assembled and provides excellent leakproof function.

[0028] From the forgoing description, the present invention includes at least two connectors to connect with pipes. One of two connectors may serve as an inlet and the other as outlet for water or liquid so as to prevent the upper surface of the flexible diaphragm from accumulation of residue dust or dirt.

[0029] It will be appreciated that although a particular embodiment of the invention has been shown and described, modifications may be made. It is intended in the claims to cover such modifications which come within the spirit and scope of the invention.