TRT active gas leak repairing F. Perez, C. Degeorge, S. Katunin, I. Zhukov, V. Myalkovskiy, S. Konovalov, A. Romaniouk, H. Danielsson, A. Catinaccio, K. Zhukov

outline TRT End-caps active gas leaks Side C and Side A leaks map Leak location in peek pipes View of cracks in different locations Tube repairing on side C Tube repairing on side A Results

TRT End-caps active gas leaks Side C: Side A:

Side C leaks map A1, 17 l/h A2, 5 l/h B5, 0.3 l/h B3, 2 l/h A6, huge A4, huge A3, 0.3 l/h

Side A leaks map A6, 4.5 l/h B1, 75 l/h B5, 9 l/h A5, 0.3 l/h A4, 0.8 l/h

Leak location in peek pipes Work started at side C. To find out where the leak is we cut output peek tube and install the endoscope inside the tube. Tube have dimensions 6*5 mm. We used endoscope OLYMPUS IPLEX lx IV8435 with 4mm scope, 3.5 meters long. When scope was inserted we found that there’re cracks in places of stress are into Swagelok SS connections (detector outlet, PPF1 connector) and bracket zone. Places of stress Wheel type A

View of cracks in different locations Tube insert, SS Peek pipe Side C, A4, crack along the pipe at PPF1 Swagelok connector

View of cracks in different locations Peek pipe Side C, A4, crack in bracket zone

View of cracks in different locations Peek pipe Side C, A2, crack in detector output Swagelok connector Tube insert, SS

Tube repair on side C The input peek pipe A4 was cut but nothing was found which pointed that only combination of stress and ozone from TRT lead to peek cracking. It was decided to repair all output peek pipes: 1.Because of unreachable state of PPF1 connector it was decided to do by-pass from SS 8mm pipe (6 mm polyurethane blue pipe used) 2.Insert 4mm SS pipe into peek pipe to the Swagelok connector at detector side to fully exclude peek pipe on this level 3.Connect 4mm steel pipe to polyurethane pipe with glued connection

Repair at PPF1 level Some tubes were damaged on PPF1 level and not accessible for repair. It was decided to make by-pass with 6mm blue polyurethane tube connected to SS 8mm tube at calorimeter flange (see pic).

Repair at the detector level It was decided to by-pass peek tube from the Swagelok connector at detector side to the PPF1 level. 4mm SS pipe was installed into peek pipe. To provide gas tightness special expandable device was developed. It’s a SS piece with polyurethane (UR3435 elastomer) joint at the end (see pic). Insertion + expansion Final setup

Repair at the detector level Final device: Polyurethane jointDevice fully assembledInsertion (test) After expansion (test)Insertion into detectorExpansion rod in the tube

Tubes connection on side C After removing the M2.5 rod, the 4mm stainless still pipe was glued into the polyurethane blue pipe for all 14 outputs at side C. It was used two component epoxy adhesive 3M Scotch-Weld DP490

Tube repair on side A Situation at side A is a bit different: 1.There is no Swagelok connections at detector side. Glued connection are used for peek pipes. 2.For tubes A1, A2, A3, B8 different peek tube are used (6*4mm instead of 6*5mm). For these four tube special device was developed. 3.Tube A2 was unreachable for 8 mm SS tube cutting.

Glued connections on side A Exterior view of wheels B connection Interior view of wheels B connection Exterior view of wheels A connection

Repair at the detector level side A Expander piston For 6*5mm peek tube it was decided to use the same mechanism already used for side C but with some adjusting of the expander piston from 3.9 to 4.2. This device was installed into peek tube in glued connection zone.

Repair at the detector level side A The 6*4mm pipes didn’t show any cracks but it was decided to by-pass the bracket zone to prevent any damages in future. It was impossible to use device mentioned before because it doesn’t fit into 4 mm pipe. It was used glued mechanism showen below.

Final device for 6*4 mm peek tubes Two special thin carbon fiber rings were glued to 3.2mm SS pipe to guide the tube during insertion. Scotch DP490 was applied on the stainless steel tube. Then a third carbon ring and long carbon tube were inserted to be used as piston. tightness After insertion of the full mechanism into peek pipe to final position, the long carbon tube was pushed to compress the adhesive and seal between SS tube and peek tube. Then carbon tube removed and ULTEM socket was glued to connect SS tube to polyurethane tube.

Special case: A2 on side A As it’s impossible to cut SS 8mm tube of A2 wheel on calorimeter flange it was decided to prepare special connection before PPF1 zone to remove stress from PPF1 side.

Results All pipes were carefully investigated inside/outside. Few large and small leaks were repaired but some situated in inaccessible areas. Inaccessible crack A6, side CMisalignment of the tube in connector, A1, Side C For the cases when leaks were not fully repaired the installed tooling allows to shift regulation point close to the detector what makes possible to control the leak rate.

Results for TRT End-caps, summary table

Special thanks to Francisco Cyril Serguei Francisco Perez Gomez, Cyril Degeorge and Serguei Katunin

Thank you very much!