1. Vacuum System Design for the Target Monolith System
Peter Ladd Vacuum Systems Engineer
and ESS Vacuum Team
European Spallation Source ERIC
2019/04/29

2. Topics Addressed
Operational Capabilities of the Monolith Vacuum Systems
Monolith Vacuum Systems Interface Documents
Operational and Design Pressure for the Monolith Vacuum Systems
Primary Monolith Vacuum Systems and Functions
Vacuum Piping Outline
Vacuum Pump Performance
Impact of Pump Inlet Conductance
Pump down for Various Pump Combinations
Removal of Water Vapour
P&ID Vacuum Pumping Systems
Layout of Vacuum Systems
Major Mechanical Equipment List
Major Instrumentation List

3. Operational Capabilities of the Monolith Vacuum Systems
The monolith vacuum systems are designed to maintain the vacuum environment in the monolith vessel required for operations.
These systems are designed to permit continuous operation following a single equipment failure within these system but excludes failures of non-functional components i.e. piping, wiring etc.
The operational reliability of interfacing equipment is outside the scope of the vacuum system and is not addressed.
Access to the monolith vacuum systems during operations is prohibited including all areas within the “Triangular Room” (Pump Room) and the “Connection Ring Gallery”. Operational access to all systems is provided through the vacuum control system, located in the “Utility Room”.
Redundant systems (and components) are provided where considered necessary to allow continued operations following a single equipment failure with full or limited capability.

4. Monolith Vacuum Systems Interface Documents
The current interface documents will need t o be reviewed and updated to reflect the finding and determinations made at the Monolith Vacuum Systems CDR.
The CDR design of the Monolith Vacuum Systems is significantly different to that proposed at the PDR and these changes will need to be reflected in the Interface Documents, although no significant impact on other systems is anticipated.

5. Operational and Design Pressure for the Monolith Vacuum Systems
“Requirements and Guidelines” specified in the “ESS Monolith Vessel Vacuum Rules, ESS ” are based on the assumption that the nominal operating pressure of the monolith vessel will be limited to 1 bar differential and the maximum upset pressure will be limited 1.5 bar absolute differential pressure in accordance with the Swedish ordinance for non-pressure vessel components.
Operating Pressure
Standard off-the-shelve vacuum equipment is designed for use at <1 bar differential pressure and will not meet the Swedish ordinance AFS 2005:2 at higher differential pressures.
If a higher monolith pressure were selected, standard off-the-shelf vacuum equipment would not be available and equipment would need to be qualified as “pressure equipment” i.e. designed and qualified to meet a pressure >1 bar differential.
Vacuum System Design and Operating Pressures:
The system design and equipment identified for use in this CDR will comply with the “ESS Monolith Vessel Vacuum Rules, ESS ” i.e. design operating pressure < 1 bar differential and the maximum upset pressure will be limited 1.5 bar absolute differential pressure .

6. Primary Monolith Vacuum Systems and Functions
The Monolith Vacuum Systems will perform the following primary functions:
Roughing system, used to evacuated the monolith volume and provide cross over to high vacuum operation,
High vacuum operation, has 3 primary functions:
Provide sufficiently low vacuum (<10E-3 mbar) for operation of cryo-condensing coils for pumping water vapour,
Provide sufficiently low vacuum (<10E-3 mbar) for leak testing both during installation, start up and operational maintenance periods as needed.
Evacuation and maintaining the monolith vessel at high vacuum vacuum during operations,

7. Vacuum Piping Outline

8. Vacuum Pump Performance

9. Impact of Pump Inlet Conductance

10. Pump down for Various Pump Combinations - 1
Design parameters
Monolith Design Parameters:
Free volume: m3
Surface area: 2,362 m2
Nominal Temperature: 80°C
Vacuum Design Parameters:
Outgassing rate: 1*10-8 mbar*L/s/cm2
Constant leak rate into vessel: mbar*L/s
Notes on Vacuum Design Parameters:
The outgassing rated used is the anticipated rate at the 10 hour point i.e. vessel has been under vacuum for 10 hours before pump down undertaken.
The pump down calculations use a fixed outgassing rate.
Leak Testing with the proposed vacuum system:
Detection time constant, 45 seconds to 95%, leak detector backing TMP's, monolith pressure < 1E-3 mbar
Clean up time,10 minutes, based on 6 decade reduction in helium partial pressure, monolith pressure < 1E-3 mbar

11. Pump down for Various Pump Combinations - 2

12. Removal of Water Vapour, 1
Impact of Pressure and Temperature on phase state on water removal
Water Phase Diagram
Curtesy:
At expected operating
temperature, sublimation
rate is: ~ 40 mbar L/cm2 s
Pumping speed of the mechanical
pumps at 6.05 mbar (ice point) is
22 mbar L/s
and the cryo-condensing coil
at 10-3 mbar is 7 mbar L/s

13. Removal of Water Vapour, 2
Prospective on In-Leakage

14. Removal of Water Vapour, 3
Mechanical Pumping

15. Removal of Water Vapour, 4
Cryo-condensing Coil , Coil sizing

16. P&ID Vacuum Pumping Systems

17. P&ID Roughing System

18. P&ID High Vacuum System

19. P&ID Cryo-condensing Pumping System (Water Pumping)

20. P& ID PBW and PBW Vessel

21. Layout of Vacuum Systems, 6-1
Line sizing
The line diameters for the various systems has been optimized over the operational pressure range using conductance equations incorporating laminar, transitional and molecular flow regimes for the lines lengths of the various systems.

22. Layout of Vacuum Systems, 1
Vacuum System Connection Points, connection ring and PBW vessel
All systems are connected to the monolith connection ring or proton beam vessel (PBV). Port allocations is as follow:
Port Reference
Port Size
Function
X03
DN200CF
Rough line
Monolith vacuum gauging
Calibrated leak
X06
DN350CF
Cryo-pod installation
X55
DN40CF
X58
High vacuum pump (TMP) connection
X88
Connection Ring Port Allocations
Port Reference
Port Size
Function
X48
DN100CF
Connection for evacuation and pressurization of the BPW inflatable seals
X52
DN40CF
PBV evacuation and venting connection
PBW Vessel Port Allocations

23. Layout of Vacuum Systems, 2
Connection Ring Layout, port allocation for the vacuum systems is 1027

24. Layout of Vacuum Systems, 3-1
Vacuum Equipment installed in Connection Ring (CR) Gallery
Roughing system installation:
Roughing line with instrumentation and leak calibration connections
Roughing line routed from CR, port X03, to shield wall penetration
Monolith vacuum gauging
Calibrated leak for MSLD calibration
Rough line is also used for venting the monolith
Cryo-pod installation (2):
Cryo-pod mounted to CR via high vacuum isolation gate valve, ports X06 and X88
Each Cryo-pod incorporates the following equipment:
Cryo-chiller cooling lines, supply and return, routed from cryo-pod to shield wall penetration
Evacuation valve, with cryo-pod evacuation line, routed from cryo-pod to shield wall penetration
Vent valve, open to CR gallery
Water drain line valve and drain line , routed from cryo-pod to shield wall penetration

25. Layout of Vacuum Systems, 3-2
Vacuum Equipment installed in Connection Ring (CR) Gallery
High vacuum system installation
High vacuum system mounted to CR at port X 58 via a connection tee to provide 2 connection ports for 2 independent high vacuum systems,
Each high vacuum system installation incorporates the following equipment:
High vacuum gate valve mounted to the tee,
Turbomolecular pump (TMP) nominally rated at 1200 l/s, Pfeiffer Hipace 1200 or equivalent,
Vent valve mounted to the backing line of the TMP,
Backing line routed from the TMP to the shield wall penetration
Cooling water, supply and return
Vacuum Instrumentation Port
Vacuum instrumentation mounted to CR at port X 88
Vacuum gauging for monitoring monolith vessel pressure,
Residual gas analyzer RGA for monitoring of monolith vacuum environment

26. Layout of Vacuum Systems, 3-3
Vacuum Equipment installed in Connection Ring (CR) Gallery
PBW vessel vacuum system installation
PBW Vessel evacuation system, connected to Proton Beam Vessel (PBV) at X42
Evacuation line routed from X42 to the shield wall penetration
PBW pillow seal evacuation and inflation system
PBW pillow seal evacuation and inflation system, connected to to Proton Beam Vessel (PBV) at X48
4 lines routed from closing flange of PBV servicing front and rear grooves and pillows,
individual Turbo pumping stations (groove pumping) and pressurization line (pillow inflation) serving each set of lines.
Turbo pumping stations nominally rated at 67 l/s, Pfeiffer HiCube 80 Eco or equivalent,

27. Layout of Vacuum Systems, 4
Shield wall penetration
Space allocate for vacuum system penetration of the shield wall is limited to a hole of 250mm diameter. The following table shows the allocation of space in the penetration:

28. Layout of Vacuum Systems, 5-1
Vacuum Equipment installed in Triangular Room (Pump Room)
Roughing system installation:
160mm roughing line routed from shield wall penetration to roughing pumps, supported by pipe hangers. Two vertical drops, reducing to DN100, for roughing pump connection,
Vertical drop incorporates DN100 formed bellows and isolation gate valve, DN100 series 14 or equivalent.
Two (2) NeoDry 300E vacuum pumps, with DN100 inlet connection, positioned in series, directly below roughing line, incorporating gas ballast and exhaust ports,
Exhaust port DN25 routed to off gas system and drain
Cryo-pod installation:
63mm evacuation line routed from shield wall penetration to evacuation pumps, supported by pipe hangers. Two vertical drops, reducing to DN40, for evacuation pump connection,
Vertical drop incorporates DN40 formed bellows and isolation gate valve, DN40 series 14 or equivalent.
Two (2) NeoDry 7E vacuum pumps, with DN40 inlet connection, positioned in series, directly below evacuation line, incorporating gas ballast and exhaust ports,

29. Layout of Vacuum Systems, 5-2
Vacuum Equipment installed in Triangular Room (Pump Room)
Cryo-pod installation, cont’d:
Cryo-chiller cooling lines, supply (2) and return (2), routed from shield wall penetration to cryo-chillers,
Cryo-chillers (2), location in pump room TBD,
Cryo-pod evacuation line, routed from shield wall penetration to off gas system,
Water drain line, routed from shield wall penetration to water pump exhausting to drain,
High vacuum system installation
100mm backing line routed from shield wall penetration to roughing pumps, supported by pipe hangers. Two vertical drops, reducing to DN40, for backing pump connection,
Vertical drop incorporates DN40 formed bellows and isolation gate valve, DN40 series 14 or equivalent,
Two (2) NeoDry 60E vacuum pumps, with DN40 inlet connection, positioned in series, directly below backing line, incorporating gas ballast and exhaust ports,
Exhaust port DN25 routed to off gas system and drain
Vertical drops also incorporates DN40 control valve, VAT series 615 or equivalent for MSLD connection.
Exhaust port for MSLD, DN25 routed to off gas system

30. Layout of Vacuum Systems, 5-3
Vacuum Equipment installed in Triangular Room (Pump Room)
PBW Vessel vacuum system installation
63mm pumping line routed from shield wall penetration to mechanical pumps, supported by pipe hangers. Two vertical drops, for pump connection,
Vertical drop incorporates DN40 formed bellows and isolation gate valve, DN40 series 14 or equivalent.
Two (2) NeoDry 7E vacuum pumps, with DN40 inlet connection, positioned in series, directly below pumping line, incorporating gas ballast and exhaust ports,
Exhaust port DN25 routed to off gas system and drain
PBW pillow seal inflation system installation
2 Air pressurization lines (pillow inflation) complete with pressure regulators and filters

31. Major Mechanical Equipment List 6-1
Roughing System installation:
1 VAT, DN100 series 48 roughing valve,
2 Kashiyama Neodry 300E pumps,
2 VAT, DN100 series 14 isolation gate valve,
1 VAT, DN25 Series 264 or equivalent vent valve
Cryo-pod installation:
2 VAT, DN350 series 48 isolation gate valve,
2 cryo-pods with cryo-condensing coils, custom designed for ESS installation,
2 evacuation valves, VAT, DN63 Series 264 or equivalent,
2 vent valves, VAT, DN16 Series 264 or equivalent,
2 Telemark 1800 cryo-chiller or equivalent,
2 sets, supply and return, vacuum jacketed cooling lines
1 self priming diaphragm water pump

32. Major Mechanical Equipment List 6-2
High vacuum system installation
2 High vacuum gate valves, VAT, DN350 series 48 or equivalent
2 Turbomolecular pumps (TMP), Pfeiffer Hipace 1200 or equivalent,
2 Vent valves mounted to the backing line of the TMP, VAT, DN16 series 264 or equivalent
2, Backing valve VAT, DN40 series 264 or equivalent,
2 Kashiyama Neodry 7E pumps,
2 VAT, DN40 series 14 isolation gate valves,
PBW vessel vacuum system installation
2 VAT, DN63 series 48 roughing valve,
2 VAT, DN100 series 14 isolation gate valve,
PBW pillow seal evacuation and inflation system
Turbo pumping stations nominally rated at 67 l/s, Pfeiffer HiCube 80 Eco or equivalent,

33. Major Instrumentation List
Pirani Gauge, as required
Cold Cathode Gauge, as required
Calibrated leak, 1
Residual gas analyzer, 1
Mass spectrometer leak detector (MSLD), 1

34. Thank you for your attention!
New Frontiers to be conquered and advancements to be made in neutron sciences with the long pulse and power offered by the European Spallation Source
Thank you for your attention!
AVS 63rd International Symposium 8th November 2016