Resources

Consult our range of free resources.

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Technical Guides

Tetra has published a series of guides which are available for ordering.

HRSG Inspection Planning Guide (2nd Edition)

Inspection is part of routine maintenance for any Heat Recovery Steam Generator (HRSG). Visual inspections are performed at regular intervals in accordance with the requirements of regulatory bodies and insurers.Inspection is part of routine maintenance for any Heat Recovery Steam Generator (HRSG). Visual inspections are performed at regular intervals in accordance with the requirements of regulatory bodies and insurers.

HRSG Tube Failure Diagnostic Guide (3rd Edition)

Heat Recovery Steam Generator (HRSG) tubes provide the media for extraction of useful energy from the waste heat in gas turbine exhaust at combined cycle power plants (GT-CCs) or from heat generated by process streams at petrochemical facilities.

Technical White Papers

A selection of technical papers available for reference.

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Visual HRSG Inspections

Visual HRSG Inspections

The predominant technique for inspecting HRSGs is visual. Visual inspection is performed at nearly every...

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Tube Metallurgical Analysis

Tube Metallurgical Analysis

What is normally included in a metallurgical analysis? Visual examination may be obvious, but there is a ...

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Pipevue 2.0

Pipevue 2.0

PipeVue 2.0  PipeVue 2.0 has been specifically developed by Tetra Engineering to store and organize the large ...

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Surface Replica Testing

Surface Replica Testing

Preparation of surface replicas is considered a type of visual test. It has proven to be a valuable tool...

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Sulphuric Acid Dewpoint Corrosion

Sulphuric Acid Dewpoint Corrosion

The key factor in determining rate of cold-end deposits in HRSGs firing natural gas is the sulphuric acid dew ...

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HRSG Inspection Frequency

HRSG Inspection Frequency

Effective maintenance scheduling and planning is critical to completing required work during outages and preve...

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To discuss how we might assist you to improve your plant's performance or to maintain its value over time

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Papers, Presentations and Articles

Selected papers, presentations and articles from major industry conferences and events.

Title
Author
Counterfeit, Fraudulent and Suspect Items (CFSI) – Steel and HRSGs
Counterfeit, Fraudulent and Suspect Items (CFSI) – Steel and HRSGsCounterfeit, Fraudulent and Suspect Items (CFSI) – Steel and HRSGs
Taylor M.
IMechE HRSG User Group 2022
Adapting Existing Thermal Desalination Plants to Produce Hydrogen
Adapting Existing Thermal Desalination Plants to Produce HydrogenAdapting Existing Thermal Desalination Plants to Produce Hydrogen
Malloy J.
2022 World Utilities Congress
Root Cause Failure Investigation of MSCV Drain Failures
Root Cause Failure Investigation of MSCV Drain FailuresRoot Cause Failure Investigation of MSCV Drain Failures
P. Jackson, A. Wholey, E. Tsai and D. Burns
ASME 2022 Pressure Vessels & Piping Conference
Predicting and Preventing Risk of Vibration Induced Failures in Boilers and Heat Recovery Steam Generators (HRSG)
Predicting and Preventing Risk of Vibration Induced Failures in Boilers and Heat Recovery Steam Generators (HRSG)Predicting and Preventing Risk of Vibration Induced Failures in Boilers and Heat Recovery Steam Generators (HRSG)
Fabricius A., Malloy J., Taylor M., Moelling D.
Proceedings of the ASME 2022 Power Conference
Flow Accelerated Corrosion Failures in Nominally Low-Risk HRSG Tube Locations
Flow Accelerated Corrosion Failures in Nominally Low-Risk HRSG Tube LocationsFlow Accelerated Corrosion Failures in Nominally Low-Risk HRSG Tube Locations
Malloy J., Fabricius A., Taylor M., Rusaas J., Vestdam K.
Proceedings of the ASME 2022 Power Conference

Previous Projects

With over 30 years of experience in power and industrial steam generation services, Tetra Engineering has along history of projects.

CFD Analysis of GRP Piping Caustic Dosing, 2018
Middle East.

CFD Analysis of GRP Piping Caustic Dosing, 2018

Caustic soda is injected into the product water in order to raise the pH as required by the specification. Inspection of GRP piping has often shown large amounts of deposition inside these pipes. Deposition is mostly observed downstream of the injection point of sodium hydroxide and can therefore be attributed to unsuitable chemical injection. Typical injection setups utilise four simple (no nozzle) injection ports at 90° from one another causing ineffective mixing of the flows, leading to the observed precipitation. Tetra performed a CFD analysis of the caustic injection process to investigate the degree of mixing of the two flows and simulate the effects of modifying the volumetric flow rate.

MSV Stellite Cracking Failure Analysis, 2018
Middle East.

MSV Stellite Cracking Failure Analysis, 2018

Caustic soda is injected into the product water in order to raise the pH as required by the specification. Inspection of GRP piping has often shown large amounts of deposition inside these pipes. Deposition is mostly observed downstream of the injection point of sodium hydroxide and can therefore be attributed to unsuitable chemical injection. Typical injection setups utilise four simple (no nozzle) injection ports aStaff at a CCGT plant engaged Tetra to investigate the root cause of the cracking and damage appearing on the Main Steam Valve (MSV) stellite seat ring(s). The metallurgical analysis identified iron dilution from the F91 valve seat into the hard-facing alloy as the root cause of the debonding.  The extent of the iron dilution is a sign of excessive heat input, most likely caused during the welding process. This points towards the welding during fabrication as the actual root cause of the failure. The driving force for failure / debonding of the Stellite hardfacing could also include residual stresses from welding and/or transient heat transfer stresses and/or thermal shock during operation.t 90° from one another causing ineffective mixing of the flows, leading to the observed precipitation. Tetra performed a CFD analysis of the caustic injection process to investigate the degree of mixing of the two flows and simulate the effects of modifying the volumetric flow rate.

Root Cause Analysis of HP Drum Nozzle Cracking, 2018
Europe

Root Cause Analysis of HP Drum Nozzle Cracking, 2018

During the 2018 shutdown at a CCGT in Europe several of the HRSG HP drum riser nozzle and downcomer nozzle welds were checked and all were found to be cracked on the inside of the drum, at the weld toe or between weld beads, with the cracks following the fusion line back to the nozzle. The drum feedwater inlet and steam outlet nozzles (above drum waterline) were both undamaged. The drums were removed and all welds were repaired in the workshops. Tetra performed Finite Element Analysis (FEA) and operational data analysis and could conclude that the operational stresses were high enough given the current cycling regime to cause the cracking observed. The quality and design of the original welds is also likely to have contributed to the cracking.

Diverter Damper Design & Operation Review, 2018
Middle East

Diverter Damper Design & Operation Review, 2018

Tetra was engaged by a client to investigate the recently observed cracking on the diverter damper actuator. The design documentation and failure mode was reviewed. From this initial review it could be concluded that the shaft cracking is most likely a result of the operating procedure, where  the damper is kept in an open position for an extended period of time. The exposure to hot flue gas in combination with the load acting on the toggle arms is the most likely source of the cracking

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To discuss how we might assist you to improve your plant's performance or to maintain its value over time

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