US3718571A

US3718571A - Anode fitting

Info

Publication number: US3718571A
Application number: US00158431A
Authority: US
Inventors: A Bidwell
Original assignee: MAGNODE PROD Inc
Current assignee: MAGNODE Corp A CORP OF OH; MAGNODE PROD Inc; MAGNODE PROD INC US
Priority date: 1971-06-30
Filing date: 1971-06-30
Publication date: 1973-02-27
Anticipated expiration: 1990-02-27

Abstract

An anode fitting for protecting metallic surfaces such as water heaters, water tanks, and the like which are in contact with an electrolyte, from corrosion, the fitting including a connector member adapted to be secured to the metallic surface in electrical contact therewith and having a fluid passageway therethrough, the connector member including a hollow nipple portion having a depending tubular portion. The tubular porion includes an annular flange porion therein which is positioned so as to form a socket at the distal end of the tubular portion, the socket being adapted to receive an electrode formed of a metal which is higher in the electromotive series than the metal forming the metallic surface. The electrode includes a core wire secured in electrical contact to the annular flange portion and a coating of insulating material lines the fluid passageway, and covers the outside of the tubular porion and substantially fills the space between the electrode and the socket.

Description

Fb. 27, 1973 A. w. BIDWELL ANODE FITTING Filed June 50, 1971 2 Sheets-Sheet l F ig.

Feb. 27, 1973 A. w. BIDWELL 2 Sheets-Sheet l Filed June Z50, 1971 azi/14247513.44?

Fig. 7

Fig. 6

Fig. 5

[NVE N' TOR` ARTHUR W BDWELL United States Patent O 3,718,571 ANODE FITTING Arthur W. Bidwell, Middletown, Ohio, assigner to Magnode Products, Inc., Trenton, Ohio Filed `l'une 30, 1971, Ser. No. 158,431 Int. Cl. C23f 13/00 U.S. Cl. 204--197 9 Claims ABSTRACT OF THE DISCLOSURE An anode fitting for protecting metallic surfaces such as water heaters, water tanks, and the like which are in contact with an electrolyte, from corrosion, the fitting including a connector member adapted to ybe secured to the metallic surface in electrical contact therewith and having a fluid passageway therethrough, the connector member including a hollow nipple portion having a depending tubular portion. The tubular portion includes an annular ange portion therein which is positioned so as to form a socket at the distal end of the tubular portion, the socket being adapted to receive an electrode formed of a metal which is higher in the electromotive series than Ithe meta-l forming the metallic surface. The electrode includes a core wire secured in electrical contact to the annular flange portion and a coating of insulating material lines the fluid passageway, and covers the outside of the tubular portion and substantially fills the space between the electrode and the socket.

This invention relates to an anode fitting, and more particularly to an improved anode fitting for use in the cathodic protection of metallic surfaces.

BACKGROUND AND OBJECTS Metal receptacles of the type usually adapted to store water for varying periods of time are frequently made from iron. One major problem with these receptacles is the corrosive action of the water on the iron which is particularly acute in the case of such receptacles as hot water heaters where connections to a building are made through copper piping. Thus at the connection of the copper piping to the iron vessel, an electrochemical action may take place in the presence of water. In the case of pure water, the electrolytic action would be negligible, however, ordinary tap water contains many ions added for treatment purposes or naturally occurring in the Water, and thusly the water becomes a fairly good electrolyte. Thus corrosion at the juncture of the iron receptacle with the copper piping is substantial in the absence of some protection against this type of corrosion.

Many prior art devices have been proposed to eliminate this type of corrosion, however, such prior art devices have frequently suffered from a number of disadvantages.

The primary of these disadvantages have been the cost of prior art anodes and their complexity of construction.

One prior art device is shown in the U.S. patent to Craver, 2,740,757. This device utilizes an electrical resistor to reduce the current flow which is initiated by the galvanic action, thus reducing the electrolytic corrosion.

Another prior art device is shown in the U.S. Pat. 999,108 to Hickey. This device uses a zinc anode in a steel or brass fitting which is in electrical contact with a receptacle.

In this type of fitting, the zinc ould be corroded due to the galvanic action and the corrosion would occur at the contact with the steel fitting.

U.S. Pat. 2,568,594 to Robinson, uses insulation between the electrode and the receptacle, and additionally uses an electrical resistor to reduce current flow.

ICC

Accordingly, a primary object of this invention is to overcome the disadvantages of prior art anode fittings.

Another object of this invention is to provide an anode tting of simple yet effective construction.

Yet another object of this invention is to provide an anode fitting having a long service life and being free from the necessity of premature replacement.

Yet another object of this invention is to provide an anode fitting for metallic receptacles and having a sacritical electrode which is electrically insulated from the fitting and is in indirect electrical contact with the fitting through a core wire.

A further object of this invention is` to provide an anode fitting of rugged construction to prevent damage to the nttmg during installation.

These and other objects and advantages of this invention will become apparent when considered in light of the following description and claims when taken t0- gether with the accompanying drawings in which:

FIG. l is a central vertical cross sectional view through a water tank showing the anode fitting of this invention mounted therein;

FIG. 2 is a longitudinal sectional view of the anode fitting of this invention;

FIG. 3 is a sectional View taken along lines 3-3 of FIG. 2 and viewed in the direction of the arrows;

FIG. 4 is a sectional view along lines 4-4 of FIG. 3 and viewed in the direction of the arrows;

FIG. 5 is a sectional View similar to that of FIG. 3 showing an alternate embodiment of this invention;

FIG. 6 is a sectional view similar to FIG. 3 and showing another alternate embodiment to this invention; and

lFIG. 7 is a sectional view similar to FIG. 3 and showing still a further alternate embodiment of this invention.

With reference now to FIG. 1, a metal receptacle 10 which may be the Water tank of a hot Water heater or other type of receptacle is shown. Mounted Within the top wall 12 of receptacle 10 is the fitting 14 of this invention. Fitting 14 includes a threaded nipple 16 which is secured within receptacle 10 by means of a nut 18. A suitable pipe provides the necessary service connection to the water supply or to fixtures.

With reference to FIG. 2, the nipple or connector portion 16 of the fitting 14 is seen to include a depending tubular portion 22. Tubular portion 22 has a disc-shaped flange 24 integrally formed therewith with an aperture 26 substantially centrally positioned therein. Nipple 16 is seen to be hollow having a stepped and lined fluid passageway 28 with an annular recess at the end thereof. It communicates with an outlet passageway 30. The step occurs as shown at 49. The lower part of tubular portion 22 together with a disc-shaped flange portion 24 forms a socket 32. The socket is adapted to receive a stepped down portion 34 of an electrode 36. When the fitting is being manufactured, initially the reduced socket engaging section 34 is spaced from tubular portion 22. After the electrode 36 is positioned within the socket 32, a continuous, homogeneous coating 38 of an insulating material is applied to the fitting 14 by casting, dipping or other .suitable processes. The insulating coating 38 covers the inside of nipple 16 throughout the length of the fluid passageway 28 and at the end thereof filling annular recess 29 to provide a reinforcing and end sealing seo'- tion 39, and as seen in FIG. 3. It coats the walls of outlet and extends downwardly around the tubular portion 22 and fills the space between the portion 34 of electrode 36 and socket 32.

Prior to the application of the insulating coating, the core wire 40 of the electrode 36- is inserted through aperture 26, and Welded, soldered or otherwise suitably bonded to disc-shaped flange portion 24 so as to provide electrical connection between the core wire 40 and the ange portion 24. After the insulation coating 38 is applied, core wire 40 becomes the only electrical connection between electrode 36 and the nipple 16. The effect of this arrangement is that the electrode 36 will be corroded at its distal end rather than at the connection with the nipple 16. This prevents the corrosion of the electrode at its attached end, materially lengthening the life of the fitting.

As best seen in FIGS. 3 and 4, the stepped down portion 34 of electrode 36 is provided with a pair of diametrically opposed recesses 42. In this manner, when the insulation material 38 is potted around the fitting 14, it fills recesses 42. By utilizing an insulating coating of a synthetic resinous nature such as polyethylene, polypropylene, polytetrauoroethylene, and the various nylon resins, which harden upon curing, a pair of projections or lugs 44 are formed and serve to secure the electrode 36 to the nipple 16.

In the preferred embodiment, the electrode 36 is made of magnesium with a steel core wire. However, other suitable metals may be utilized for the electrode such as aluminum, or zinc. Of primary importance, however, is the fact that the material of which the electrode is made must be higher on the electromotive series than the material utilized in the receptacle 10, or other material which is desired to protect. In this manner, the metal of the electrode is corroded instead of the metal of the receptacle.

Referring now to FIG. 5, an alternate embodiment of this invention is shown. A fitting generally designated 56 is seen to include a nipple 58 which is externally threaded as at 60 and internally threaded as shown at 62.

An extension member 64 includes an upstanding threaded portion 65 which is threadedly engaged into threads 62 on nipple 58. The extension member 64 includes a fluid passageway 66, and nipple 58 includes a fiuid passageway 68. As in the embodiment of FIGS. 2 and 3,

fluid passageway

66 and 68 are lined with an insulating material 70.

With reference to FIG. 6, another embodiment of this invention is shown wherein a nipple 72 is provided with a longitudinal fluid passageway 74 and transverse passageways 76. A depending socket portion 78 of nipple 72 is internally threaded as at 80. An extension member 82 which is threaded as at l84 engages threads 80 of socket portion 78.

Passageways

74 and 76 as well as extension member y82 are coated with an insulation coating shown at 86.

Referring now to FIG. 7, still another embodiment of this invention is shown which includes a nipple 88 which is internally threaded at its upper end as best seen at 90. An internal extension member 92 having external threads 94 threadedly engage threads 90 of nipple 88. Extension member 92 is provided with a longitudinal fiuid passageway 96 and a transverse fluid passageway 98. As in the previous embodiments,

fiuid passageways

96 and 98, as well as the lower portion of extension member 92 are coated with an insulating coating 100.

The embodiments shown in FIGS. -7 are particularly important where certain specifications may call for a nipple being of brass or copper, while the cost of brass or copper prohibits its use for the entire fitting. In this manner, the extension members containing the electrode socket may be made of steel, and no effectiveness of the sacrifical electrode will be lost. Yet the overall cost is less expensive than if the entire metallic portion of the fitting were made of brass or copper.

While this invention has been described, it will be understood that it is capable of further modification, and this application is intended to cover any variations, uses and/ or adaptations of the invention following in general, the principle of the invention and including such depar- 4 tures from the present disclosure as come within known or customary practice in the art to which the invention pertains, and as may be applied to the essential features hereinbefore set forth, as fall within the scope of the invention or the limits of the appended claims.

What I claim is:

1. An anode fitting assembly for protecting a metallic surface in contact with an electrolyte from corrosion including:

(a) a connector fitting adapted to be secured to said metallic surface in electrical contact therewith and having a fluid passageway therethrough,

(b) said connector fitting including a hollow nipple part and a depending tubular part which has outlet openings through the walls thereof immediately below the nipple part,

(c) said tubular part including a socket section at the lower end of the tubular part disposed immediately below the outlet openings and which has a discshaped fiange forming a top wall which closes the top thereof,

(d) an elongated electrode having a reduced socket engaging section at the top thereof which is positioned in the socket section and spaced from the socket walls,

(e) the electrode being formed of a metal which is higher in the electromotive series than the metal forming said metallic surface,

(f) the electrode including a central core wire having a top end thereof extending out of the top of the socket engaging section and secured in electrical contact to the disc-shaped ange,

(g) the length of the reduced section of the anode being slightly longer than the length of the socket section,

(h) a single, relatively thick, continuous and homogeneous synthetic resin insulation coating which lines the fiuid passageway, encapsulates the tubular part, and fills the space between the reduced section of the electrode and the socket and extends over a portion of the top of the anode adjacent its reduced section,

(i) the insulation coating extends into a recess at the top end of the passageway to form reinforcing and end sealing section.

2. An anode fitting as in claim 1 and wherein:

(a) said electrode is formed from a metal selected from the group consisting of magnesium, aluminum and zinc.

3. An anode fitting as in claim 1 and wherein:

(a) said tubular part has a diameter less than the diameter of said nipple member thereby forming a shoulder between said tubular portion and said nipple member,

(b) said insulation coating covering said tubular portion having a thickness substantially equal to the thickness of said shoulder.

4. The anode fitting assembly as set forth in claim 1,

wherein:

(a) the passage in the nipple part of the connector fitting has a stepped section of enlarged diameter adjacent the top thereof.

`5. The anode fitting assembly as set forth in claim 1, wherein:

(a) the disc-shaped lflange has a substantially centrally positioned aperture,

(b) the core wire end is welded to the disc-shaped flange adjacent the aperture.

6. An anode fitting assembly as set forth in claim 1,

wherein:

(a) the depending tubular part threadedly engages the nipple part,

(b) the parts are made of different metals.

7. An anode fitting as in claim 6 and wherein:

(a) said fiuid passageway includes a first uid passage extending longitudinally through said nipple member and a second iluid passage extending transversely through said tubular portion,

(b) said rst and second fluid passages being in fluid communication with each other.

8. An anode fitting assembly for protecting a metallic surface in contact with an electrolyte from corrosion including:

(a) a connector litting adapted to be secured to said metallic surface in electrical contact therewith and having a Iiiuicl passageway therethrough,

(c) said tubular part including a socket section at the lower end of the tubular part disposed immediately below the outlet openings and which has a discshaped flange forming a top wall which closes the top thereof,

(e) the electrode being formed of a metal which is higher in the electromoti-ve series than the metal forming said metallic surface,

(f) the electrode including a central core wire having a top end thereof extending out of the top of the socket engaging section and secured in electrical contact to the disc-shaped ange, and

(h) a single, relatively thick, continuous and homogeneous synthetic resin insulation coating which lines the iiuid passageway, encapsulates the tubular part, and fills the space between the reduced section of the electrode and the socket and extends over a portion of the top of the anode adjacent its reduced section,

(i) the passage in the nipple part of the connector tting has a stepped section of enlarged diameter adjacent the top thereof.

9. The anode tting assembly as set forth in claim 8,

wherein:

(a) the uppermost periphery of the nipple part at the top of the passageway has an annular recess,

(b) the insulation coating which lines the passageway extends into the recess to form an annular reinforcing and end sealing section at the end of the nipple part.

References Cited UNITED STATES PATENTS 3,206,530 9/ 1965 Bolter 264-261 3,542,663 11/1970 Alewitz 204-197 2,740,757 4/ 1956 Craver 204-197 2,486,936 11/ 1949 Fergus 204-197 2,486,871 11/ 1949 Osterheld 204-197 3,037,920 6/ 1962 Vixler 204-197 TA-HSUNG TUNG, Primary Examiner U.S. Cl. XR. 204-286, 297 R