Methods for sealing liquid-cooled stator bar end connections for a generator
First Claim
1. A method of sealing a stator bar end and a fitting receiving the end to effect a seal substantially impermeable to liquid, the fitting having a chamber for receiving a liquid through an opening in the fitting and in communication with hollow strands forming at least a portion of said stator bar end for flow of the liquid through the hollow strands, comprising the steps of:
- inserting a viewer and epoxy applicator through the opening in said fitting for viewing a joint portion between the fitting and the stator bar end and applying epoxy thereto, respectively;
viewing said joint portion;
applying the epoxy to said joint portion using said applicator while maintaining the joint portion in view through the viewer; and
curing the epoxy to form a seal substantially impermeable to liquid at the portion of the joint to which the epoxy is applied.
1 Assignment
0 Petitions
Accused Products
Abstract
The method includes sealing the stator bar end connections from within the stator bar end fitting. Particularly, a low viscosity epoxy is initially applied from within the chamber of the end fitting by use of a boroscope and a syringe-type applicator, the low viscosity epoxy being applied to all joints between the adjacent strands of the stator bar and between the fitting and the outermost strands of the stator bar. A high viscosity epoxy is then applied over the low viscosity epoxy using the boroscope and applicator to provide a thick barrier seal between the liquid coolant in the chamber and the brazing material. The epoxy is then cured. The process ensures that the brazing material is isolated from the liquid coolant by the barrier seal whereby potential leaks are prevented and partially developed leaks or leaks extant are arrested because sealant material is disposed at the liquid coolant/braze interface.
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Citations
19 Claims
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1. A method of sealing a stator bar end and a fitting receiving the end to effect a seal substantially impermeable to liquid, the fitting having a chamber for receiving a liquid through an opening in the fitting and in communication with hollow strands forming at least a portion of said stator bar end for flow of the liquid through the hollow strands, comprising the steps of:
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inserting a viewer and epoxy applicator through the opening in said fitting for viewing a joint portion between the fitting and the stator bar end and applying epoxy thereto, respectively; viewing said joint portion; applying the epoxy to said joint portion using said applicator while maintaining the joint portion in view through the viewer; and curing the epoxy to form a seal substantially impermeable to liquid at the portion of the joint to which the epoxy is applied. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A method of sealing joint portions between strands of a stator bar end and having a fitting receiving the end, the fitting having a chamber for receiving a liquid through an opening and in communication with hollow strands forming at least part of the strands of said stator bar end enabling flow of the liquid through the hollow strands, comprising the steps of:
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inserting a viewer through the opening in said fitting for viewing joint portions between adjacent strands; inserting an epoxy applicator through the fitting opening; viewing the joint portions between the strands; applying the epoxy to said joint portions between the strands while maintaining the joint portions between the strands in view through the viewer; and curing the epoxy to form a seal substantially impermeable to liquid at the portion of the joints to which the epoxy is applied. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18, 19)
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Specification