J. H. Chrzanowski NSTX TF Flag Joint Design Review 1

NSTX TF Flag Joint Design ReviewFabrication and Assembly

April 10, 2003

By: James H. Chrzanowski

J. H. Chrzanowski NSTX TF Flag Joint Design Review 2

Contents of Presentation

• Identify the components of the Hub Assembly• Discuss improvements to TF bundle• Discuss new TF flag assembly• Discuss differences between the upper and lower

hub assemblies• Discuss fabrication issues• Discuss the assembly details and sequence

J. H. Chrzanowski NSTX TF Flag Joint Design Review 3

TF Flag Assembly Identification

Upper TF Hub Assy. Lower TF Hub Assy.

Upper Inner TF Flags

TF Flag Support Box

Upper Outer TF Flags

Lower Outer TF Flags

Lower Inner TF Flags

Upper Hub

structure

Lower Hub

structureTorque restraint collar

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New TF Bundle/ Hub Assembly

• The new TF bundle will be fabricated in-house• This decision is based upon quality and schedule issues• PPPL has also retained possession of the original molds

used in the TF bundle fabrication• There were several Quality concerns associated with the

original TF bundle construction by the outside vendor.• These quality concerns resulted in:

– coolant leaks– Additional rework of electrical faces in-house

• In-house fabrication will result in closer supervision and better quality control

J. H. Chrzanowski NSTX TF Flag Joint Design Review 5

New TF Bundle Fabrication

• Once leaks were found on the TF bundle, new conductor was procured in FY-01 for possible future replacement of the TF bundle (CDA10700 OFHC silver bearing copper)

• An epoxy cure oven is presently being designed and fabricated for this purpose (ready by end of May)

J. H. Chrzanowski NSTX TF Flag Joint Design Review 6

TF Bundle Epoxy Cure Oven

•Oven will be used for curing the B-stage T/T and groundwall insulation on the TF bundle

•Will be used for soldering the coolant tubes into the conductors

•Sized to accommodate the OH solenoid molds for possible future upgrades

•Modular design oven for easy disassembly & storage

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Quality Problems with Original TF Bundle

Numerous coolant tube leaks developed once operations began

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Improvements to TF Bundle

• Design Improvements:

• Coolant Tubes– Improve integrity of coolant tube design

– Routing- Upper tubes to come straight out the top

– Type of tubing- straight length seamless Cu

•  Joint Improvements– Replace joint Inserts- Tap-lok Inserts

– Improve shimming- Flag box

– New fastener design

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Upper Hub Assembly

• The new upper hub assembly has (2) different flag designs

– Inner Flag- Bolted joint

– Outer Flag- E-beam welded flag

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E-Beam Welding of Upper Outer FlagsWeld flags to upper outer conductors following initial machining, but prior to final machining and bundle assembly

•Bolt on electrical end flags following epoxy fill of flag boxes

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Kapton insulation along entire length of flag

Dry glass insulation along length of interface fills space between flag and box

TF Flag Structural Boxes

Epoxy fill holes

Stainless steel boxes

Gaskets for sealing boxBlind tapped holes

0.010 in. allowance for fitup of flag to conductor

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Typical TF Flag Joint-(Upper inner; lower inner & outer)

Tap-lok inserts

Stainless steel washer plate, belleville washers and nuts

A-286 fasteners

Shear Pin & Block (stainless steel)

Flag box (stainless steel)

* Fasteners will be discussed in detail by Mike Kalish

Flag resistance lead

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Upper TF Hub Assembly-1

• Preposition lower hub plate [1]

• Insulate flags (Kapton & glass) [2]

• Position flag boxes over flags [3]

• Attach front contact face [4]– Note: front contact faces may be

attached either prior to or after epoxy fill of boxes)

13

4

2

Lower hub plate

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Upper TF Hub Assembly-2

• Complete assembly of Flag boxes [1]

• Install center hub structure into position [2]

• Fasten upper and lower plates to the flag boxes [3]

1

2

3

Center hub structure

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Upper TF Hub Assembly-3

• Install shear blocks and pins [1]

• Install leads for flag resistance measurements

• Install studs and pre-assembled boxed inner flags into position [2]

• Jack flags to contact shear blocks

• Install upper hub plate

• Secure the mid and upper plates to the flag boxes [3]

1

2

2

Upper hub plate

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Upper TF Hub Assembly-4

• Jack flags to contact shear blocks

• Vacuum fill the individual flag boxes with Hysol epoxy [1]

• Install the torque restraint support ring to the TF bundle via epoxy/ glass lay up [2]

1

2

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Installation of Torque Restraint Support Ring

• Install torque restraint collarBuildup of dry glass and Hysol epoxy (wet lay-up) over ground wall

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Pre-Assemble the Lower Hub Assembly

•Pre-assemble lower hub structure prior to TF installation

• Epoxy fill the flag boxes

•Do not install lower torque restraint collar

•Disassemble lower hub structure

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Installation of TF Bundle

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Final Assembly of Lower Hub Assembly

• Complete assembly of the lower hub structure including torque restraint collar

• Install pedestal and complete bus and umbrella component assembly