1. 2K Cold Box Mechanical Design
Nate Laverdure
LCLS-II 2K Cold Box FDR
March 28, 2018

2. Status of design outputs
Outline
Status of design outputs
Complete subsystem design
Complete technical specifications for build-to-print fabrication, shipping, installation, and integration
Outline plan for configuration change

3. Documentation list Title Status
79222-S003 Technical Specification for Initial Construction of LCLS-II 2K Cold Box
Released
79420-S004 Technical Specification for SLAC LCLS-II Cryogenic Multi-Layer Superinsulation (MLI) Requirements and Installation
79222-D6001 LCLS-II 2K Cold Box Drawing Index
LCLS-II 2K Cold Box with Cold Compressor (SCB) Flow Diagram (P&ID)
Released Rev J
LCLS-II 2K Cold Box Complete Assembly and all mechanical and electrical sub-assemblies
Released Rev A
79222-A0003 LCLS-II 2K Cold Box Valve Panel Anchorage & Structural Analysis
79222-A0002 LCLS-II 2K Cold Box Vacuum Skid Anchorage & Structural Analysis

4. Design documentation
79222-S003 Technical Specification for Initial Construction of LCLS-II 2K Cold Box

5. Design documentation
79222-D6001 LCLS-II 2K Cold Box Drawing Index

6. Mechanical drawing package structure
Complete Assembly
Instrumentation Installation
Utility Installation
Anchor Installation
Gauge panel and two electrical enclosures
Valve panel and several utility piping spools
Insulating Vacuum System
Shipped Assembly
Structured to minimize mechanical reassembly work on SLAC site

7. Mechanical drawing package structure
Complete Assembly
Includes all installation, outfitting of all external piping and external instrumentation
Instrumentation Installation
Utility Installation
Anchor Installation
Gauge panel and two electrical enclosures
Valve panel and several utility piping spools
Insulating Vacuum System
Shipped Assembly

8. Mechanical drawing package structure
Complete Assembly
Instrumentation Installation
Utility Installation
Anchor Installation
GC scope
Offloading
Anchoring in place
Gauge panel and two electrical enclosures
Valve panel and several utility piping spools
Insulating Vacuum System
Shipped Assembly

9. Mechanical drawing package structure
Complete Assembly
Complete 2K Cold Box vessel including vacuum shell, internal piping, internal instrumentation
In shipping configuration for transport to SLAC
Instrumentation Installation
Utility Installation
Anchor Installation
Gauge panel and two electrical enclosures
Valve panel and several utility piping spools
Insulating Vacuum System
Shipped Assembly

10. Review of mechanical details
General arrangement, location of interfaces
Configurations and bayonet installation/removal
Mechanical design details
Thermal reliefs
Cold compressor installation
Bellows/straightener assembly
Heater assembly
Central support column

11. Interface locations – main cryogenic process interfaces
He-505
CC6 suction
He-504
CC5 discharge
He-506
CC6 bypass
He-501
2k suction from linac
He-507
30K to 4KCB
He-508
4K fom LHe dewar

12. Interface locations – warm utility interfaces
He-515
Relief valve discharge collector
He-511
3 atm He supply
GV-512
Guard vacuum
IA-513
Instrument air
CW-517 & 518
Cooling water supply & return
He-510
Cleanup return to recovery system

13. Interface locations – warm utility interfaces

14. Design considerations for future configuration change
Changes to two piping spools
U-tube configuration change

15. Future configuration change – affected piping spools
CC1
INLET FROM TRANSFER LINE
CC2

16. Future configuration change – affected piping spools
Abandoned in place
Removed spool
Cut locations
Replacement spool
Cut locations

17. Future configuration change – proposed sequence
Process conditions
Linac warm, 1 atm
Backfill insulating vacuum and make entry
Peel back insulation, cut piping, remove spools
All cuts are in vertical orientation for cleanliness
Spools can be removed through manway
No instrumentation on removed spools
CC1 suction and discharge piping abandoned in place, can be secured to vacuum shell

18. Future configuration change – proposed sequence
Insert new spool, weld
Spool can be inserted through manway
No instrumentation located on new spool
QC checks
ASME B31.3 pneumatic leak check
Sensitive helium leak check
Insulate
Clean up
Blowdown, pump, & backfill process piping
Pump down insulating vacuum

19. Cold box configurations – u-tubes
Size
Both
SCB-MCB-CCR
5-3/16”
LHD-SCB-VAP-03
3-1/8”
High flow - CC-1 through CC-5
SCB-CC6-BYPASS
Low flow - CC-2 through CC-6
SCB-CC5-CC6

20. Cold box configuration control
Bayonet installation/removal procedure

21. Bayonet installation/removal procedure

22. Thermal relief assembly
All 2K Cold Box cryogenic reliefs are:
Thermal reliefs
ASME reliefs
Protected against air contamination via guard vacuum enclosure
Exhausted to header which is protected against moisture entry and vented outdoors

23. Thermal relief assembly

24. Thermal relief assembly
Relief inspection/replacement process:
Warm up 2K Cold Box and bring to 1 atm
Backfill relief exhaust header with 3 atm He purge
Break fittings around relief shroud and remove
Disconnect relief flange and install blank while under purge
Inspect/test relief on bench or replace
Disconnect blank and install relief while under purge
Re-install relief shroud
Pump relief exhaust header to guard vacuum and backfill with 3 atm He purge

25. Mechanical details – cold compressor installation

26. Mechanical details – cold compressor installation

27. Mechanical details – bellows/straightener assembly
Used in CC-1 and CC-2 inlet piping spools

28. Mechanical details – bellows/straightener assembly
Cleanup of stagnant annular volume
Recommendation: Large virtual leak exists between flex ID and process piping. Need to address this.
Response: 12x 1/8” holes to facilitate pump and backfill of annular space

29. Mechanical details – heater assembly
Scaled from SNS and earlier heater designs

30. Mechanical details – control valves

31. Mechanical details – internal piping support
Only 1 permanent support required for the design
Located on the heater assembly (small heat in-leak has no adverse effects)

32. Mechanical details – insulation

33. Mechanical details – manway
Based on 30” design used at JLab 4K Cold Box

34. Mechanical details – central support column
Maintains flatness of top plate during assembly
Threaded rods and nuts for leveling during installation
Shims inserted between flanges to carry large compression load
And during operation
Encased in passive copper conductor
Insulated with MLI
Thermal deflection limited to a few thousandths

35. Mechanical details – vacuum pumping system

36. ES&H design considerations – ODH
2K Cold Box located in the cold box building, a class 1 ODH area
Mitigations:
Warning Signs
Installed Oxygen Monitor
Ventilation
Training for personnel

37. ES&H design considerations – noise
DOE standard: no personnel exposure to noise above 85 dBA without hearing protection
Noise generated by all cold compressors is expected to be lower than 85 dB when measured from 1 m distance from equipment
No hearing protection needed inside the cold box room

38. ES&H design considerations – fall protection
Cold Box top plate height: 12.5 feet
Safe access to components located on the top plate is provided by a work platform

39. ES&H design considerations – egress & work access
180-degree access around bayonets for system configuration changes
Access on at least 1 side of control valves, relief valves, cold compressors, and feedthroughs for maintenance
~24” aisle width or more for egress from work areas

40. ES&H design considerations – confined space
Design minimizes the requirement to work within the 2K CBX insulating vacuum enclosure
Cold compressor motor cartridges installed via bolted flange connections on the top plate
Flange provided on top plate for ventilation

41. Maturity of design is commensurate with FDR
Summary
Maturity of design is commensurate with FDR
All design outputs are complete and approved
Mechanical and electrical drawing set
Technical specification and included references
Proceeding with approved procurement of 2K Cold Box vessel