Root Cause Analysis

When an incident occurs, you need to understand why in order to ensure it never happens again. Petrotech can perform root cause failure analyses for gas engines and turbines, centrifugal, axial, and screw compressors, as well as hot gas expanders.

Information

Using state-of-the-art techniques and technologies, our experienced personnel can help you determine the factors that led to the incident. Failures can occur even in best run gas turbine, engine or centrifugal compressor. When they happen, there is an inevitable tension between efforts to return a turbine to service as quickly as possible and carrying out a failure investigation. To minimize likelihood of a repeat failure, it is necessary to carry out an appropriate investigation.

Some turbine failures, as in other types of equipment, can be satisfactory investigated by the plant engineering personnel. However, many failures require a more in depth technical investigation. The objective of root cause analysis are make engineering recommendations to avoid repeat failures.

Main stages of root cause analysis:

-       Site investigation:

  1. Interview expert connected with the rotary machine failures.
  2. Witness disassembly of the machine
  3. Conduct initial examination of the components
  4. Secure parts for more detailed examination and quarantine them

-       Data collection and review:

  1. Review short and long-term operational data
  2. Review maintenance records

-       Component evaluation:

  1. Metallurgical examination of damaged and undamaged components
  2. Characterization of failure processes, e.g. thermal fatigue cracking, attack from inside the blade, creep, inappropriate heat treatment, defective or inadequate repairs.

-       Analytical considerations:

  1. Carry out relevant engineering analyses. These could be related to thermodynamic performance, heat transfer and component temperatures, fluid flow, fracture machines and crack growth.

-        Conclusions:

  1. Identify the root cause(s) through a process of systematic investigation and elimination of potential factors
  2. These could be technical and/or human factors.

      Recommendations:

    1. Identify realistic engineering steps which can be taken to break the chain of causation.
    2. Recommend additional monitoring or control steps which should be put in place.

Metallurgical evaluations

  1. In-house metallurgical laboratory
  2. Scanning Electron Microscopy (SEM) with Energy Dispersive Analysis X-Ray (EDAX) analysis
  3. In-house Non-Destructive Testing (NDT) and destructive testing
  4. In-situ metallography
  5. Stress rupture/tensile testing

Rotor dynamic analysis

  1. Lateral and torsional
  2. Bearing and seal re-design

Finite-element structural analysis

  1. Static and modal analyses of impellers, turbine blades, and other components
  2. Simulations of hydrostatic tests and high-temperature heat-treatments of critical components

Field vibration data

  1. Frequency response data from impact testing
  2. Vibration and alignment data from field operation

We support you and try to offer the best solution at the lowest cost and in the most efficient manner possible. Prevention of recurring incidents is of utmost importance for us—and for you.