US 4,790,065 AGranted

Method for servicing a steam generator

AssigneeWestinghouse Electric Corp.

InventorsFrank W. Cooper, Jr., Raymond P. Castner

Life of this patent

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Abstract

A servicing machine for a steam generator is accurately set up in the generator channel head with a pivoted arm mounted for rotation in a plane parallel to the tubesheet. The angular position of the arm, the longitudinal position of a carriage mounted on the arm and the vertical position of a platform on the carriage are remotely controlled to maneuver a probe used in mapping the precise location of the thousands of holes in the tubesheet. Various operations are then performed at each precise hole location by tools carried by the arm mounted carriage to prepare for installation of new tubing. The operation of a pair of remotely controlled pivoted arms, one on each side of the channel head divider plate, is coordinated to automatically position the ends of U-shaped tubes in corresponding holes in the tubesheet on opposite sides of the divider plate and to secure the same in place.

Claims10

Dependent claims

A method of servicing a steam generator having a planar tubesheet provided with an array of holes therethrough and bisected by a divider plate perpendicular thereto including the steps of:

mounting first and second tool arms for rotation about one end thereof in planes parallel to a first face of the tubesheet, one on each side of the divider plate;
controlling the angular positions of said first and second tool arms in the planes parallel to the tubesheet and the positions of carriages movable longitudinally along the first and second tool arms to sequentially align tools carried by the carriages with a plurality of preselected pairs of corresponding holes in the tubesheet, said corresponding holes in each pair being on opposite sides of the divider plate;
operating tools carried by said carriages to spot-face said corresponding holes on opposite side of said divider plate to a common plane;
positioning one end of a U-shaped tube into each of said corresponding holes from the second face of the tubesheet until they project through said first face thereof;
operating a tool carried by said first carriage to push a first end of said U-shaped tube into the tubesheet until it is substantially flush with said spot-face and securing it in place;
and
operating a tool carried by said second carriage to push the second end of said U-shaped tube into the tubesheet until it is substantially flush with said spot-face and securing it in place.

4 more elements

Apparatus for servicing a steam generator having a planar tubesheet provided with an array of holes therethrough and bisected by a divider plate perpendicular thereto, said apparatus comprising:

first and second tool arms mounted for rotation about one end in planes parallel to a first face of the tubesheet, one on each side of the divider plate;
first and second carriages movable longitudinally along said first and second tool arms respectively;
first and second extendable tool holders carried by said first and second carriages respectively;
and
means for controlling the angular position of said first and second tool arms in the planes parallel to the tubesheet and the positions of said first and second carriages along the respective tool arms to align said tool holders with a preselected pair of corresponding holes in the tubesheet, one on each side of the divider plate, and for controlling the operation of tools carried by the respective tool holders to, said means for controlling angular positions including means for operating drilling apparatus mounted on said tool holders to spot-face said corresponding holes on each side of said divider plate to a common plate, and means to extend said first tool holder to push against a first end of a U-shaped tube which is inserted through one of said corresponding holes in said tubesheet from the second face and extends beyond the first face, until it is flush with said spot-face;
to operate a tool carried by the first tool holder to secure said first end in place in the tubesheet, to then extend the second tool holder to push the end of said U-shaped tube which is inserted through said other corresponding hole in the tubesheet and extends beyond the first face until it is also flush with the spot-face and to operate a tool carried by the second tool holder to secure said second tube end in place in the tubesheet.

3 more elements

Dependencies are inferred from the claim text.

Facts

Application: 06/311,712Filed 15 Oct 1981 · division
Priority: 18 Oct 1978
Granted: 13 Dec 1988
Term ends: Not estimatedThe source records don’t support an estimate.

Classification10 codes

F22B 37/005
Maintenance, repairing or inspecting equipment positioned in or via the headers: positioning apparatus specially adapted therefor
G12B 5/00
Adjusting position or attitude
Y10T 29/49352
Heat exchanger or boiler making: repairing, converting, servicing or salvaging
Y10T 29/49718
Method of mechanical manufacture: repairing

Family

Serial952,431Parent of this division · filed 18 Oct 1978
Serial164,859Parent of this division · filed 1 Jul 1980
US 4,347,652 AParent of this division
US 4,262,402 AParent of this division
US 4,790,065 AThis patent

From the US filing history. Foreign family members aren’t listed.