1. Copyright © TWI Ltd 2007 World Centre for Materials Joining Technology A temperature controlled mechanical test facility to ensure safe materials performance in hydrogen at 1000 bar R.I. Hammond R.J. Pargeter (ruth.hammond@twi.co.uk)

2. Copyright © TWI Ltd 2007 World Centre for Materials Joining Technology Safe storage Liquid / solid / gasLiquid / solid / gas Need materials which are resistant to gaseous hydrogen for allNeed materials which are resistant to gaseous hydrogen for all Hydrogen embrittlement.Hydrogen embrittlement.

3. Copyright © TWI Ltd 2007 World Centre for Materials Joining Technology Hydrogen embrittlement Below 100°C with no straining generally no problemBelow 100°C with no straining generally no problem But strain in the presence of hydrogen leads to Hydrogen Environment Embrittlement (HEE)But strain in the presence of hydrogen leads to Hydrogen Environment Embrittlement (HEE) HEE affects low cycle fatigue, tensile, toughness.HEE affects low cycle fatigue, tensile, toughness.

4. Copyright © TWI Ltd 2007 World Centre for Materials Joining Technology Testing in high pressure hydrogen Most data available are statically loadedMost data available are statically loaded HEE only observed if strain in hydrogenHEE only observed if strain in hydrogen HEE affected byHEE affected by –Strain rate –Temperature –Pressure.

5. Copyright © TWI Ltd 2007 World Centre for Materials Joining Technology Design and build of new facility 1000 bar1000 bar 99.9999% hydrogen99.9999% hydrogen -150°C to +85°C-150°C to +85°C MeasureMeasure –LCF –Tensile –Toughness Current vesselCurrent vessel –500 bar –99.9999% hydrogen –Ambient to +85°C

6. Copyright © TWI Ltd 2007 World Centre for Materials Joining Technology Four strands to project Equipment designEquipment design Physical protectionPhysical protection System designSystem design Operating procedures.Operating procedures.

7. Copyright © TWI Ltd 2007 World Centre for Materials Joining Technology Equipment design Pressure vesselPressure vessel –National codes –Materials.

8. Copyright © TWI Ltd 2007 World Centre for Materials Joining Technology Physical protection Plexiglas roofPlexiglas roof Reinforced wallsReinforced walls Test cell: spark freeTest cell: spark free Blast doorsBlast doors Hydrogen sensorsHydrogen sensors

9. Copyright © TWI Ltd 2007 World Centre for Materials Joining Technology System design (1) PLCPLC –Purge and pressurisation cycles –Safety: never a flammable mixture –Purity: 0.000 001% contaminants

10. Copyright © TWI Ltd 2007 World Centre for Materials Joining Technology System design (2) InterlocksInterlocks –Prevent pressurisation –Trigger automatic shut-down Test cell door closedTest cell door closed Pressure vessel closedPressure vessel closed Hydrogen detectorsHydrogen detectors Fire detectorsFire detectors Emergency stop buttonsEmergency stop buttons

11. Copyright © TWI Ltd 2007 World Centre for Materials Joining Technology System design (3) Hydrogen detectorsHydrogen detectors –Low: 400 ppm (alert operators) –High: 1000 ppm (triggers shut-down) Automatic shut-downAutomatic shut-down –High hydrogen –Fire alarm –Emergency stop button –Power cut (UPS keep safety systems running)

12. Copyright © TWI Ltd 2007 World Centre for Materials Joining Technology System design (4) Shut downShut down –Stop booster –Close valves on bottles Shut down and ventShut down and vent –Vents –Purge vessel Solenoid valves

13. Copyright © TWI Ltd 2007 World Centre for Materials Joining Technology System design (5) AutodiallersAutodiallers Safety aspects regarding hydraulicsSafety aspects regarding hydraulics Pneumatics: compressed air run in thin plastic tubes around lab, designed to melt if there is a fire. Low air pressure will trigger shut-down.Pneumatics: compressed air run in thin plastic tubes around lab, designed to melt if there is a fire. Low air pressure will trigger shut-down.

14. Copyright © TWI Ltd 2007 World Centre for Materials Joining Technology Operating procedures Checklist for routine operationChecklist for routine operation Unusual operation needs special risk assessmentsUnusual operation needs special risk assessments Skilled operatorsSkilled operators –Compressed gases –Flammable/explosive –Servo-hydraulic equipment.

15. Copyright © TWI Ltd 2007 World Centre for Materials Joining TechnologyConclusions For a safe hydrogen economyFor a safe hydrogen economy –Need safe, economical materials and fabrication methods –TWI already has facility to carry out mechanical tests at 500 bar but are extending this to 1000 bar over a temperature range of -150°C to +85°C