Large-scale development Projects

CRADLE TO GRAVE SERVICES

 

1.
1.

FLANGE & GASKET DESIGN, INTEGRATION WITH LARGER STRUCTURE

2.
2.

FORCE TESTING

3.
3.

MOCK UP TESTING

(LAB CONDITIONS, CLEAN ROOM, UHV)

4.
4.

MANUFACTURING

FLANGES, CHAMBERS & TUBES, METAL GASKETS

5.
5.

ON-SITE ASSEMBLY, INSPECTION

6.
6.

SPARES & LONG-TERM INVENTORY

1. PRELIMINARY DESIGN

2. DEVELOP FORCE TESTING HARDWARE

Force-test flanges and gaskets for each junction.

3. MOCK VESSELS / TUBES

Build and assemble mock components with RGAs, vacuum pumps, turbos, other connections and junctions that represent full scale. Assemble in Bostec lab for testing and validation.

4. USABILITY TESTING

Study ease of installation, spacing conflicts, thermal cycling, bake to 240º C, seismic, repeated thermal cycles, shock tests, clown mallet.

5. PARTIAL PRESSURE TESTING

Measurement of partial pressures to calibrated UHV standards. Multiple points across vessels and tubes. ‣ Surface area & finish ‣ Gaskets & Flanges ‣ Junctions & Welds ‣ RGAs, Baratrons ‣ Vacuum Pumps, Turbos, etc

6. MANUFACTURE PRODUCTION LEVEL FLANGES & GASKETS

7. ASSEMBLE COMPONENTS AT PRODUCTION SITE

Repeat Partial pressure Testing of Mock Tube

Measurement of partial pressures to calibrated UHV standards. Multiple points across vessels and tubes. ‣ Surface area & finish ‣ Gaskets & Flanges ‣ Junctions & Welds ‣ RGAs, Baratrons ‣ Vacuum Pumps, Turbos, etc

Accelerators

Fermilab’s Tevatron was a landmark particle accelerator; until the startup in 2008 of the Large Hadron Collider (LHC) near Geneva, Switzerland. It was the most powerful particle accelerator in the world, accelerating antiprotons to energies of 500 GeV, and producing proton-proton collisions with energies of up to 1.6 TeV, the first accelerator to reach one “tera-electron-volt” energy.

Bostec engineers worked with FermiLab to solve persistent leakage problems with their aluminum seals that were the principle seal in the 3.9 mile particle accelerator. Failures were principally attributed to seals that had insufficient crush zones to conform to existing flanges, wrong material substrates, and poor tolerances. The existing design also had no mechanism to protect the critical knife edge during replacement; the knife was often unknowingly damaged by technicians who were rushing to complete the work quickly to avoid radiation exposure. The initial design was flawed and plagued FermiLab technicians for many years. Long repair and replacement times resulted in radiation overexposure for many technicians.

Bostec took a holistic approach to the project and redesigned all aluminum seals throughout the ring to one common configuration. Protective shoulders were included with each gasket to shield critical surfaces from damage and aid technicians in installation. Care was taken to ensure the new gaskets were backward compatible with existing flanges.

Before and after results have been significant. Repair times are now reduced considerably, in the range of 50%. Technicians are now more confident seals will not be damaged during installation and consequently are comfortable moving much faster. Gasket failures with the old design were in the neighborhood of 50%; thus 1 out of 2 failed. Using Bostec’s new designs, yields have so far been 100%, no failures have yet been recorded.

BOSTEC’S ROLE: FACILITY-WIDE REDESIGN

In 2017, Bostec was named the sole supplier of metallic gaskets to CERN.

CERN operates the worlds largest proton accelerator which covers 26 km of tunnels under the city of Geneva. CERN had been experiencing significant leakage problems with its copper and aluminum seals. Over 10% of their junctions were failing, causing the main beam line to be shut down and costing millions of Euros in lost revenue due to delayed projects.

Bostec undertook a facility wide redesign of all metallic gasket seals in 2016. Time was short and Bostec’s work was conducted on an emergency basis. An American engineering team was assembled and dispatched to CERN. The team lived in Divonne, France, nearby to CERN, to work out new designs and fix the problems. There was considerable travel back and forth to the US to coordinate with manufacturing. Prototypes were built in America and rushed back to CERN for installation and UHV testing. In all, 39 gasket profiles were re-designed ranging in size from 100mm to over 3000mm. All the new designs proved to be successful and Bostec commenced manufacturing of production gaskets to replace the leaking seals. The complete redesign effort took over 1 year and the costs were in time, travel and overhead were high but small in comparison to the lost revenue CERN was experiencing. Full replacement of all gaskets at CERN took over 2 years and consumed over 30,000 metallic seals ranging from 2” to over 40” in diameter.

Assembly yields now are near 100%. In addition, Bostec tackled high failure rates with CERN’s energized seals. That obsolete design required high tensile strength metallic bolts that became nuclear activated over time.

Fusion

The majority of components in a Tokamak system operate at some level of UHV. Most junctions are metal sealed due to radiation. Elastomers are forbidden. The challenge with Fusion systems is the large size and off-round shapes of the flange assemblies. The flanges themselves are heavy and difficult to handle. And the metal seals are equally as large and often difficult to seal. Once in production, radioactivity added to the problems.