Design for Leak Testing
Robert Limpenny, IEng, MInstNDT.
4th Vacuum Symposium – Ricoh Arena Coventry
All Aspects of Leak Detection
17th October 2013
4th Vacuum Symposium UK – 16th / 17th October 2013 – Design for Leak Testing – R.J.Limpenny – [email protected] – No 2
INTRODUCTION.
THE FOCUS OF DESIGN IS OFTEN DIRECTED MORE TOWARDS THE
PROCESS, OR EXPERIMENT TO BE PERFORMED WITHIN THE VACUUM,
WITH POSSIBLY LESS CONSIDERATION AT TIMES GIVEN TO THE DESIGN
OF THE VACUUM ENVELOPE, VACUUM GENERATING PLANT OR BY WHAT
MEANS THE VACUUM INTEGRITY MAY BE CHECKED, I.E. LEAK TESTED.
THIS PRESENTATION IS AIMED AT AVOIDING THE NEED FOR HINDSIGHT
IN YOUR VACUUM SYSTEM BUILD, IN FACT I HOPE THAT IT WILL
DEMONSTRATE THAT IT MAKES HINDSIGHT REDUNDANT!
4th Vacuum Symposium UK – 16th / 17th October 2013 – Design for Leak Testing – R.J.Limpenny – [email protected] – No 3
OUTLINE
DESIGN AND MATERIAL FAULTS.
OVERCOMING THE LACK OF LEAK TESTING FEATURES.
DESIGN AHEAD FOR TESTING.
DESIGN FEATURES BUILT IN FOR TEST.
APPLYING DESIGN FOR LEAK TESTING.
4th Vacuum Symposium UK – 16th / 17th October 2013 – Design for Leak Testing – R.J.Limpenny – [email protected] – No 4
CARRIAGES THAT FORM THE JET FAST
TRANSFER SYSTEM DIAGNOSTIC.
DESIGN AND MATERIAL FAULTS
ATMOSPHERE SIDE
VACUUM
BUTTON
TRACK WAY THE CARRIAGES RAN IN
4th Vacuum Symposium UK – 16th / 17th October 2013 – Design for Leak Testing – R.J.Limpenny – [email protected] – No 5
ONE OF THE FOUR IVIS IMAGING UNITS
MOUNTED ABOVE THE TORUS VESSEL.
OVERCOMING THE LACK OF LEAK TESTING FEATURES
IN-VESSEL INSPECTION SYSTEM (IVIS)
4th Vacuum Symposium UK – 16th / 17th October 2013 – Design for Leak Testing – R.J.Limpenny – [email protected] – No 6
OVERCOMING THE LACK OF LEAK TESTING FEATURES
BELLOWS LINE
HELIUM SPRAY
LINES
PUMPING PORT
ADAPTER
HEATER TAPE
BAKE OUT /
THERMAL CYCLING
LEAK TEST
PREPARATION
4th Vacuum Symposium UK – 16th / 17th October 2013 – Design for Leak Testing – R.J.Limpenny – [email protected] – No 7
THE WINNING GASKET PROFILE
CUSTOM DESIGNED KNIFE EDGE
TO SUIT ALIGNMENT WITH UNIT
END OF UNIT FORMING SEAL
SURFACE ON GASKET
OVERCOMING THE LACK OF LEAK TESTING FEATURES
TAPER
LOCATION
4th Vacuum Symposium UK – 16th / 17th October 2013 – Design for Leak Testing – R.J.Limpenny – limpenny @ btinternet.com – No 8
OVERCOMING THE LACK OF LEAK TESTING FEATURES
SPECIAL COPPER GASKET
SPLIT LOCKING COLLET
BACKING RING
PUMPING PORT ADAPTER
“A”
4th Vacuum Symposium UK – 16th / 17th October 2013 – Design for Leak Testing – R.J.Limpenny – [email protected] – No 9
TAPER PROFILE COPPER GASKET POST
THERMAL CYCLING AND LEAK TESTING
TAPER PROFILE GASKET WITH
WITNESS MARK FROM IVIS UNIT
REVERSE OF GASKET SHOWING
THE KNIFE EDGE WITNESS MARK
OVERCOMING THE LACK OF LEAK TESTING FEATURES
4th Vacuum Symposium UK – 16th / 17th October 2013 – Design for Leak Testing – R.J.Limpenny – [email protected] – No 10
OVERCOMING THE LACK OF LEAK TESTING FEATURES
HOW THE SPLIT CLAMP MIGHT LOCATE
ON THE TAPER OF THE IVIS UNIT
TWO HALVES OF SPLIT CLAMP WHICH
BOLTS UP AROUND IVIS UNIT
PUMPING PORT ADAPTER WOULD BE CLAMPED TO THE
FACE OF THE UNIT VIA BOLTING THROUGH THESE HOLES
4th Vacuum Symposium UK – 16th / 17th October 2013 – Design for Leak Testing – R.J.Limpenny – [email protected] – No 11
DESIGN AHEAD FOR TESTING
INNER LINE
OUTER LINE
WELD / TEST
/ WELD, ETC
APPROACH
OUTER WELDS TESTED IN ONE GO
4th Vacuum Symposium UK – 16th / 17th October 2013 – Design for Leak Testing – R.J.Limpenny – [email protected] – No 12
DESIGN AHEAD FOR TESTING
COMPLEX MACHINED PUMPING PORT ADAPTER
REQUIRED TO LOCATE ON A TAPER SECTION
SIMPLE PUMPING PORT ADAPTER BASED ON A STANDARD
VACUUM FITTING AND LARGER RUBBER BUNG
INNER LINE
ADAPTER
OUTER LINE ADAPTER
4th Vacuum Symposium UK – 16th / 17th October 2013 – Design for Leak Testing – R.J.Limpenny – [email protected] – No 13
PRE-POSITIONED CUSTOM KNIFE EDGE
TO ALLOW EASY TESTING OF ITEM
CUSTOM GASKET
DESIGN FEATURES BUILT IN FOR TEST
SPLIT CLAMP
IDEAL FEATURE
TO CLAMP TO
WELDS UNDER TEST
4th Vacuum Symposium UK – 16th / 17th October 2013 – Design for Leak Testing – R.J.Limpenny – [email protected] – No 14
DESIGN FEATURES BUILT IN FOR TEST
TWO HALVES OF SPLIT CLAMP
FIT AROUND ITEM AND BOLT UP
CLAMP FORMS BOLTING
RING SO ITEM CAN BE
BOLTED DOWN TO SEAL
CUSTOM SIZE
COPPER GASKET
4th Vacuum Symposium UK – 16th / 17th October 2013 – Design for Leak Testing – R.J.Limpenny – [email protected] – No 15
4K SHIELD
4K ARM ATTACHED VIA
INDIUM SEAL TO 4K SHIELD
77K SHIELD
4K SHIELD PUMPING
PORT ADAPTER
4K SIDE ARM PUMPING
PORT ADAPTER
APPLYING DESIGN FOR LEAK TESTING
4K SHIELD INDIUM SEAL
4K SHIELD INSIDE
77K SHIELD
4K = -269°C
77K = -196°C
4th Vacuum Symposium UK – 16th / 17th October 2013 – Design for Leak Testing – R.J.Limpenny – [email protected] – No 16
ACKNOWLEDGEMENTS.
University of Leicester (UoL) & UoL Space Research Centre (SRC), Leicester, UK.
Courtesy EFDA JET and Culham Centre for Fusion, Oxfordshire, UK.
Babcock International Group, Whetstone, Leicestershire, UK.
Oxford Instruments plc (O.I.), Nanoscience, Tubney Woods, Oxfordshire, UK.
ConFlat (CF) – registered trademark of Varian Inc.
Edward & Sammy Limpenny, presentation technical support.
Thanks to – SRC / UoL – Terence Ashton, Virgil Taillandier, Dr Gauthier Torricelli,
Dr Jon Lapington, Colin Brooks, Baden Favill, Steve Leach, Kevin Turner, Chris
Bicknell, and Kamlesh Chandarna – JET – Chris Warrick – Babcock – Mick Aylwin
– O.I. – Mike Venman.
4th Vacuum Symposium UK – 16th / 17th October 2013 – Design for Leak Testing – R.J.Limpenny – [email protected] – No 17
THANK YOU FOR YOUR ATTENTION
Robert Limpenny., IEng., MInstNDT.
Email – [email protected]
Tel – 00-44-(0)116-2891123