Presentation on theme: "Gluing penetrators with (data) fibers and copper (power) cables at Nikhef. Version: 22052013_V2 Date: June 19 2013 A.Korporaal – Nikhef Amsterdam."— Presentation transcript:
Gluing penetrators with (data) fibers and copper (power) cables at Nikhef. Version: 22052013_V2 Date: June 19 2013 A.Korporaal – Nikhef Amsterdam
Mounting penetrator B02 (AA5080) in HERA-pressure vessel.
Penetrator B02 (X2) (AA5080) failed at approx. 50 bar ! Identical were applied in Motril-tests. Hole filled with oil caused by leakage along fibers and one copper feed trough.
Analyzing failed penetrator B02 (X2) (AA5080) (Applied in Motril tests- April 2013) Epoxy observed along copper cable along 25mm between shrink sleeve and cable (capillary effect) 12mm Epoxy observed here
Failure of B02-penetrator (AA5080) = (X2) at approx. 50 bar ! Post Mortem analysis: 1.Fibers not broken (laser beam (1310nm) checked) 2.Leakage along fiber feed trough (Ø0,7) (no displacement of 2 fibers observed.) 3.Leakage along 1 (Cu-) power- feed through (Ø1,3) observed. 4... Possible causes: a.Vertical gluing applied. ( viscosity and gravity helps epoxy flow along a larger distance. ) b.Epoxy between isolation and shrink-sleeves was observed (Capillary effect !?) c.Glue (EPOTEK 353ND) cured for 120 min. at 80°C => O.K ! After curing (12 hrs.) => ? d.Underwater test with air along the shrinkage around the wire isolation shows air bubbles on opposite site. e.Before analyzing we pulled out the cables. The EPOTEK glue was brown colored (full cured) inside the feed-through, but also a poor filling ! Till 25 mm below we observed bad cured epoxy (yellow colored) between wire isolation ! => Need attention ! => Isolation of wires FREE space (min. 2mm) to epoxy ?! f.Shrinkage was applied BEFORE epoxy curing ! => Capillary effect, no epoxy observasion possible.
DOM Penetrator gluing procedure. Applicable for PPM-DU and forthcoming (Pressure tested at 600 bar (60MPa) ) Use horizontal gluing only !! (used for MPMT-DOM ( 31 x 3” pmt’s) in Antares, succesful tested at 400 bar. Prevent capillary effects by means of isolation offset (min. 2mm !!) Apply all shrink sleeves AFTER epoxy curing ! Use ethanol for degreasing/cleaning each wire and fiber with wipes. 2 fibers (B.B.-XS) and both copper AW 6712 and AW 6715 were applied in PPM-DU DOM. Hardened EPOTEK 353ND Before curing: Transparent/yellow After curing: Amber/Brown Isolation offset w.r.t. G10-stud min. 2mm for all wires ! Fill all holes careful with EPOTEK 353ND (use cocktail picker) until a filleted shape is visible outside the G10-stud both BEOC- and DOM-side ! Note: Apply epoxy from this side only ! Curing time: 60-120 min. at 80°C + 12 hrs. at 80°C DOM side BEOC side Picture 01
Horizontal gluing (two wires / 2 fiber(s) ) Note: Technical drawings are leading => consult them ! HORIZONTAL Gluing procedure (ambient temp.: >20°C !) Material needed: Epotek 353ND – 4 gram packs. Disposable round aluminum mixing tray. Wooden cocktail pickers. 1. Prepare necessary copper wires Alpha Wires 6715 L= 600mm: * Strip insulation over 100mm (both cables) 2. Clean all stripped copper- and feed through (par ex.: STUD 3A- AA6247) using wipe tissues with ethanol during 60 sec. 3. Pull the copper wires trough the G10-stud and mount this on the aluminum heater. Switch on the heater. 5. Thoroughly mix the Epotek 353ND pack and put the glue in a disposable round aluminum mixing tray. Take note of the time ! The potlife is max. 4 hours. Don’t use it after 4 hours !! 4. Put on stripped part of each copper wire EPOTEK 353ND separately with a cocktail picker Only at the BEOC side and watch for the glue to appear on the other side, this might take some time (1- 2min). On average 3-4 drops of glue are needed. Cure at 80°C during 1 hrs. Be careful not to spill glue on anything else than on the surface of the G10 stud and be careful not to put glue in the hole for the fiber. Put some thermal isolation on the heater and copper wires. To make sure the wire does not cool down the glued area too much. Below 60°C the glue does not cure properly ! See NEXT page…….. Observe if epoxy EPOTEK 353ND until a filleted shape is visible outside the G10-stud. Picture 02 DOM sideBEOC side
Note: Technical drawings are leading => consult them ! HORIZONTAL Gluing procedure (ambient temp.: >20°C !) 5. Prepare (1-12) B.B.-XS Fiber(s) L= 1000mm: Place fiber on flat table desk and strip insulation along approx. 10- 12mm at 500mm from edge very careful by chemical stripping. Use paint stripper (Alabastine Super Afbijt) or special coating stripper. Soak the fiber for 2 minutes in the coating stripper. Gently clean the fiber using a wipe tissue with ethanol. Do this by wiping one time (max. 2 times) over the fiber. Repeat this a second time with a new wipe tissue with ethanol. It prevents that any residue is left on the fiber. 6. After a amber/brown discoloration is observed at the glued area of the G10-stud, the fiber can be feed trough the G10-stud. Make sure the stripped part of the fiber is in the G10-stud. 7. Same gluing procedure as the copper wires. If a stripped fiber area is outside the stud very gently put some glue on to the bare fiber. This protects the fiber. 8. After 1 hour and if the glue is discolored the stud with the wires and fiber is ready for the next step. 9. Put heat shrink sleeves on the copper and fibers. (Low temperature heat shrink sleeve) Use a temperature hot air heater set to 130°C to shrink the sleeves. See NEXT page…….. Horizontal gluing (two wires/1-12 fiber(s) ) CONTINUED Observe if epoxy EPOTEK 353ND until a filleted shape is visible outside the G10-stud. Picture 02 DOM sideBEOC side
Note: Technical drawings are leading => consult them ! HORIZONTAL Gluing procedure (ambient temp.: >20°C !) 10. Clean the titanium part with a tissue with ethanol. Insert the G10-stud with the wires and fibers into the titanium feed-trough. Mount this onto the heater. Switch the heater on. (80°C) Pull the stud via a copper wire completely to the bottom of the titanium feed-trough. Make sure it stays there ! Add about 3 drops of Epotek glue in the hole from the BEOC side. Watch what happens when the glue is applied. There is enough glue if there is a small fillet visible at the edge between the G10- stud and the titanium wall. 11. Thermally isolate the heater with the feed trough. 12. After at least 12 hours of curing at 80°C the feed-trough should be ready for the silicone rubber compound. 13. Mix the silicone rubber compound (Polyservice PS 8530 A/B) in 1:1 ration in a disposable round aluminum mixing tray. 14. Use a syringe with a dull needle to apply the glue. If the feed through is still warm the silicone will harden within minutes. This enables to fill the holes with silicone compound with a single batch of silicone. Fill the holes both on BEOC and VEOC side as well till penetrator edges. This have to be done in vertical penetrator orientation ! The penetrator is ready! See NEXT page…….. Horizontal gluing (two wires/1-12 fiber(s) ) CONTINUED Observe if epoxy EPOTEK 353ND until a filleted shape is visible outside the G10-stud. Picture 02 DOM sideBEOC side
Penetrator PPM-DU (Antares) gluing assembly. Penetrator assembly without electrical/optical feed-though. View from DOM to PS 8530-silicone compound cured compound (dark green colored) hardness 30 shore A
Recommendations: 1.Apply horizontal gluing. 2.Clearance (minimal 2 mm) between isolation/ shrink-sleeves to prevent capillary effects. 3.Follow applying and curing instructions of epoxy (EPOTEK 353ND) very carefully ! 4.Apply heat shielding around gluing tool is to secure ambient temperature around product better during epoxy curing. 5.Apply all shrink-sleeves AFTER epoxy curing to prevent possible capillary effects !!
(Preliminary) Laser test on (serial) fibers (May 16 2013) at 1 bar (dBm) at 600 bar (dBm) 1310 nm-6,92-7,19 1550 nm-6,78-7,10 DOM-penetrator 2x copper (AW6715)+ 2 B.B-XS fibres (AA6299) = (X3) at 600 bar ! (Pressure load: 100 bar/6,5 minutes) May 16 2013 Nikhef- H147b