Monitoring

Laser Strain Gauge

A reusable strain gauge for creep strain measurement during outages and safe life assessment of critical components.

This patented technology is useful for monitoring vulnerable components e.g. suspect welds and weld repaired components.

Benefits:

  • Reusable
  • Also used for laboratory specimen testing.
  • Early warning of the onset of end-of-life creep failure processes.
  • Enables timely run, repair, or replace decision-making.

Electrical Potential Drop

Continuous online monitoring of high temperature pipes and welds for creep damage and end of life warning.

A new contacting EM method that responds to changes in the electrical resistance (ACPD) or impedance (DCPD) in full-size metallic components. Conductivity changes due to advancing creep cavitation damage, even before crack growth, will result in a change in the EPD. This allows monitoring of critical components like weld repairs, to warn about imminent cracking and failure.

Benefits:

  • Continuous online monitoring.
  • Can detect subtle changes in microstructure e.g. grain size variation, creep cavitation, and even material loss through corrosion.
  • Refined and tested version of the PD monitoring techniques widely used in crack growth monitoring. Shares principles with PD monitoring techniques widely used in mechanical property testing of metallic specimens.

Experimental studies on full-sized P91 pressure vessels showed that EPD [1]:

  • Provides 2-3 weeks warning of impending failure.
  • Allows plant operation to be halted and components to be inspected/repaired/replaced before catastrophic failure.

Inspection

Electrical discharge spark erosion

Semi-invasive on-site sampling for condition and life assessment of in-service components.

Uses a consumable electrode to cut out ‘boat samples’ of varying sizes and thicknesses via electric spark erosion. Purified water is used to remove debris and provide cooling. Straps or magnets can be used to mount the EDSE on components.

Benefits:

  • Sampling thin pieces from surface portions of thick components prevents damage to plant equipment.
  • Reduced damage comparison to mechanical cutting tools.
  • Samples can be machined into three mechanical test-pieces (e.g., creep, fatigue, tensile.)
  • Cutting electrode geometry ensures that the remaining cavity has rounded edges with 4 mm radius i.e. no stress concentration.

Scanning force microscope

Portable atomic force microscope for high resolution imaging and microstructural analysis of metallic and non-metallic components on-site.

Effective tool for P91 and P92 component inspection where conventional techniques do not always show early-stage creep damage.

Benefits:

  • Surface preparation equivalent to replication i.e. 1 μm polish and etch.
  • Attaches to on-site components using straps and/or magnets.
  • Spatial resolution comparable to scanning electron microscopy (SEM).
  • 3D scanning provides topographical data e.g. surface roughness and cavity depth volume.
  • The portable model of SFM can be used on-site, linked to a laptop, and instantaneously transmit images by internet.

Smart Sleeve for Portable Hardness Testing

Portable hardness testing system for improving on-site data collection.

An electronic levelling system which can be attached to conventional portable hardness testers to ensure the perpendicularity of the indentor.

Benefits:

  • Compatible with MIC10 and other portable hardness indentors.
  • Reduced scatter from ± 20 VPN without Smart Sleeve to ± 2 VPN with Smart Sleeve.

Repair

Obikou

Reinforcement for creep damaged or vulnerable pipes.

Thin (~ 0.1 mm thickness) stainless steel bandages provide enhanced creep strength in high temperature pipes.

Benefits:

  • Simple stress analysis to determine the number of layers.
  • Easy installation – straight pipes and pipe bends, seam welds and base metal.
  • No limit to pipe size.