1. Field of the Invention
The present invention is directed to a method for providing a threaded fitting in a water tank header, to a header produced by the foregoing method, and to a water tank including the header.
2. Related Art
The construction of water heaters typically involves the connection, by welding, of a pair of headers to a cylindrical wall, to form a tank. For the delivery of water into the tank, and the withdrawal of water therefrom, threaded pressure vessel connections are typically provided as part of the headers. The headers are typically each defined by a stamped body and, for each threaded fitting, a flanged threaded fitting which is welded to the body.
Forming one aspect of the invention is a method for producing a header from a steel blank, the header having a boss and being of the type that is welded in use to a cylindrical wall to produce a tank subassembly, the boss being interiorly threaded to define a threaded pressure vessel connection, the method comprising the steps of: extruding the boss in the steel blank; and tapping the thread.
According to another aspect of the invention, the extrusion of the boss can be carried out with an extrusion punch and extrusion die.
According to another aspect of the invention, the extrusion can involve passage of the extrusion punch through a preformed hole in the blank into the extrusion die.
According to another aspect of the invention, the extrusion punch can be about a 0.960″ extrusion punch, the preformed hole can be about a 5/16″ hole and the steel blank can be about 0.135″ thickness HRPO draw quality steel.
According to another aspect of the invention, the extrusion punch can be a 0.960″ extrusion punch, the preformed hole can be a 5/16″ hole and the steel blank can be a 0.135″ thickness HRPO draw quality steel.
According to another aspect of the invention, the extrusion punch can travel at about 480 inches per minute as the boss is formed.
According to another aspect of the invention, the extrusion punch can have a TD coating.
According to another aspect of the invention, the extrusion punch can be lubricated with Syndraw 99 lubricant.
A header produced according to the inventive method forms another aspect of the invention.
Forming yet another aspect of the invention is an improved water heater. The water heater is of the type comprising: a cylindrical wall and a pair of headers welded to the wall to form a tank; and a heating element coupled to the tank and adapted to heat the contents thereof. The improvement comprises: a header member, produced according to the inventive method, defining at least one of the pair of headers.
Other advantages, features and characteristics of the present invention will become more apparent upon consideration of the following detailed description of an exemplary embodiment of the invention and the appended claims with reference to the accompanying drawings, the latter being briefly described hereinbelow.
A method for producing a header according to an exemplary embodiment of the invention is described hereinafter in detail.
However, as an initial manner, reference is made to
The method allows, inter alia, for threaded fittings to be provided on a water tank top header without the need for welding. This avoids, for example, weld splatter, as well as the need for an inventory of separate fittings, with commensurate impacts upon costs.
In the method, a blank of 0.135″ HRP draw quality steel is stamped in a conventional manner to form a dish (not shown) generally in the form of the prior art main body top header, but differing in that 5/16″ holes are provided in the landings that, in the prior art, would have had threaded fitting flanges secured thereto.
Thereafter, a 0.960″ extrusion punch, provided with a TD coating, is passed through each hole into a mating die to produce a boss.
To avoid tearing, the punch is lubricated with Syndraw 99 lubricant and passed through the hole at about 480 inch/minute or less.
Thereafter, a ¾ NPT tap (not shown) is used to cut interior threads in each boss.
Whereas a single embodiment is herein described, it will be evident that modifications can be made. Accordingly, the invention should be understood as limited only by the accompanying claims, purposively construed.
This application claims priority to U.S. Provisional Application No. 61/734,115, filed Dec. 6, 2012, which is herein incorporated by reference.
Number | Date | Country | |
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61734115 | Dec 2012 | US |