High Temperature Service

Equipment for service at high temperatures faces long-term damage associated with thermal degradation and the formation of creep cavities.

However, most material design data is short-termed, and for this reason, equipment design life is usually conservative.

Equipment that operates at base load often exhibit actual life longer than the design life. Material condition and equipment remaining life assessments are therefore becoming attractive tools to prevent premature retirement of these components while still ensuring their reliability.


Typical Problem Areas

  • Material condition and life assessment of main steam pipes and superheater tubes (creep).
  • Material condition and life assessment of boiler and heat recovery headers (creep & creep-fatigue).
  • Material condition and life assessment of non-rotating steam and land-based gas turbine components (creep & creep-fatigue)
  • Hydrogen attack of reactor pressure-vessel for hydrogenation service
  • Sigma phase embrittlement in boiler superheater tubes

Our Expertise

SVT are experienced in material and fracture mechanic issues relevant to high temperature applications, including coal-fired power generation, incinerators, heat recovery units, and gas turbines.

 

Our materials engineers conduct life assessment to widely acceptable standards (e.g. British Energy R5 procedure, ASME Code N47, BS 6539, BS 6525, and available EPRI reports) and material condition assessment by non-destructive replication techniques, for early detection of thermal degradation and creep damage.

Our experience in replication and micro-structural assessment in general encompasses various class of material from low alloy Cr-Mo steel to nickel base superalloys.


In parallel with SVT's materials and fracture mechanics expertise, our strong capability in computational stress analysis (FEA), is also instrumental in providing reliable life assessment for components with component geometry where thermal transients induce creep-fatigue damages.

 

High temperature hydrogen attack

SVT has the capability to evaluate the effect of hydrogen on structural integrity of steel components, including high temperature hydrogen attack and hydrogen-temper embrittlement interactions in steel.

Whilst service is usually set below the upper limit temperature, damage might occur due to hot-spots which then lead to unexpected failures. Material conditions assessment on suspected locations is therefore crucial to ensure that failure is not imminent.