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US 4,736,092 AGranted
Braze heater assembly and method
AssigneeWestinghouse Electric Corp.
InventorsWilliam E. Pirl, John M. Driggers, Donald R. Stoner
Life of this patent
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AssigneeWestinghouse Electric Corp.
InventorsWilliam E. Pirl, John M. Driggers, Donald R. Stoner
Estimating the term…
An improved heater assembly and method for applying a brazing heat across a selected longitudinal section of a tube is disclosed herein. The heater assembly generally comprises a heater mandrel having an electrical resistance heating element coiled thereabout, and a support mandrel for supporting and centering this heating element. The heater mandrel further includes a means for directing a flow of inert gas in the space between the coiled heating element and the inner walls of the tube being brazed in order to purge this space of ambient atmospheric oxygen and prevent the heater mandrel from oxidizing. The support mandrel includes a centering means in the form of two roller assemblies, each of which has three spring-loaded rollers equidistantly spaced 120.degree. around its diameter. In the method of the invention, the heater mandrel is inserted into the tube and slid across the longitudinal section to be brazed. The heater then applies a brazing heat while a purging flow of inert gas is directed in the annular space between the coiled heating element and the inner walls of the tube. After the brazing operation has been completed, the flow of purge gas may be increased to cool down the heater assembly. The heater assembly is particularly useful for brazing reinforcing sleeves across sections of corrosion-damaged heat exchange tubes in nuclear steam generators.
A heater assembly for applying heat across a selected longitudinal section of the interior of a conduit, comprising a heater mandrel which is slidably insertable within said conduit, and which includes means for directing a flow of inert gas in the space between said heater mandrel and the inside of said conduit in order to purge this space of ambient atmospheric oxygen.
A heater assembly for applying heat across a selected longitudinal section of the interior of a conduit, comprising a heater mandrel which is slidably insertable within a conduit, and a support mandrel having a centering means for centering the heater mandrel along the longitudinal axis of the conduit, wherein said heater mandrel includes means for directing a flow of inert gas in the space between the inside of the conduit and the heater mandrel in order to purge this space of ambient atmospheric oxygen.
A heater assembly for applying heat across a selected longitudinal section of the interior of a conduit, comprising an elongated heater mandrel which is slidably insertable within said conduit, and which includes a means for directing the flow of inert gas in the space between the heater mandrel and the inside of said conduit in order to purge this space from ambient atmospheric oxygen and thereby prevent the heater mandrel from oxidizing.
A heater assembly for applying heat across a selected longitudinal section of the interior of a conduit, comprising an elongated heater mandrel having an electrical resistance element mounted around its outside surface and a generally cylindrical support mandrel having a centering means formed from a plurality of roller assemblies for uniformly spacing the electrical resistance element within the interior of the conduit.
A heater assembly for applying a brazing heat across a selected longitudinal section of the interior of a tube, comprising:
A heater assembly for applying a brazing heat across a selected longitudinal section of the interior of a tube, comprising:
A heater assembly for applying heat across a selected longitudinal section of the interior of a conduit, comprising a heater mandrel which is slidably insertable within said conduit, and which includes means for directing a flow of inert gas in the space between said heater mandrel and the inside of said conduit in order to purge this space of ambient atmospheric oxygen, and a support mandrel, and a clamping means for detachably securing said heater mandrel to said support mandrel.
A heater assembly for applying heat across a selected longitudinal section of the interior of a conduit, comprising a heater mandrel which is slidably insertable within a conduit, a support mandrel having a centering means for centering the heater mandrel along the longitudinal axis of the conduit, and a clamping means for detachably securing said heater mandrel to said support mandrel.
A heater assembly for applying heat across a selected longitudinal section of the interior of a conduit, comprising
A heater assembly for applying heat across a selected longitudinal section of the interior of a conduit, comprising a source of pressurized inert gas, and a heater mandrel which is slidably insertable within said conduit, and which includes means for directing a flow of inert gas in the space between said heater mandrel and the inside of the conduit in order to purge this space of ambient atmospheric oxygen, wherein said gas flow directing means is fluidly connected to said source of pressurized inert gas.
A heater assembly for applying heat across a selected longitudinal section of the interior of a conduit, comprising a longitudinal heater mandrel which is slidably insertable within said conduit, and which includes a bore that is transversely disposed with respect to the longitudinal axis of the mandrel for directing a flow of inert gas in the space between said heater mandrel and the inside of the conduit in order to purge this space of ambient atmospheric oxygen.
Dependencies are inferred from the claim text.