Articles

Tetra In Action #7 - March, 2017

May 2017: Effective Operation of HRSGs

May 24 & 25, 2017 at The Chateaux Deer Valley in Park City, Utah USA 

This course is primarily intended for O&M staff at all levels of experience working in combined cycle power plants, but should also be of interest to engineers and managers involved in new project development. The course gives attendees a comprehensive yet in-depth survey of a broad range of topics relating to the design, operation and maintenance of the HRSG and associated steam cycle systems. This year we've added additional material on emissions controls by SCR and CO catalysts as well as additional insights on chemical and fireside cleaning, low load operation and desuperheater design.

Tetra Engineering has offered this course for many years and it is updated annually. The instructor/seminar leader is David Moelling, P.E., Tetra Engineering's Chief Engineer. 

For more information see hereTo register please contact Natalie Vasa at our offices in the United States: Cette adresse e-mail est protégée contre les robots spammeurs. Vous devez activer le JavaScript pour la visualiser. or +1 (860) 651-4622 ext. 102.


HRSG Inspection Planning Guide Snapshots

Effective maintenance scheduling and planning is critical to completing required work during outages and preventing minor problems from expanding to major problems and possibly leading to forced outages. Approaches to maintenance scheduling and planning vary from site to site.  Today, the general emphasis is on preventive maintenance activities that are timed to prevent forced outages due to component degradation.  A combination of planned part replacements and careful inspection of parts not routinely replaced is the basis for an effective maintenance program.

Some HRSG components are relatively difficult to repair or modify and require coordination between several organizations (plant staff, OEM, contractors, insurance inspectors, etc.).  Because the schedule for HRSG maintenance is dictated by GT maintenance schedules, there are typically limited opportunities to perform comprehensive inspections of component conditions.  

Marc Graham during an inspection in the United States 2010.

If you are interested in the full version of the HRSG Inspection Planning Guide (2nd edition) contact Ms. Christine Vallon at Cette adresse e-mail est protégée contre les robots spammeurs. Vous devez activer le JavaScript pour la visualiser..  


Fastest Ever Crossing of South America!

Tetra Engineering congratulates our very own Andreas Fabricius and his cycling partner Axel Carion for achieving the fastest ever time crossing South America by bike! Their 10,685km journey to cross the entire continent North to South lasted just under 50 days, 8 days faster than the previous World Record.

Their efforts battling through deserts, over mountains, and hailstorms alike (see photos below) were to raise money for Pompiers Sans Frontières (Firefighters Without Borders - see website) who provide crucial resources to underfunded firefighters in South America. Read more about their story here.

Tetra once again congratulates Andreas and Axel for their outstanding performance, and look forward to any future endeavours the duo may have.

 

Tetra In Action #6 - February, 2017

Assuring HRSG and Boiler Pressure Part Quality

June, 2017 - Managing Boiler & Steam Cycle Pressure Part Integrity

This training course is primarily intended for experienced O&M staff working in thermal power and process plants, but could also be of interest to corporate engineering and management staff. The objective is to give attendees a comprehensive view of the strategy, actions and considerations involved in effectively managing and thereby assuring the integrity of piping, tubing and vessels that form the pressure boundary to steam or water process fluid. A range of topics relating to the design, inspection and repair of relevant components are treated using a combination of theory and numerous practical examples. The examples are all based on actual project cases encountered by Tetra Engineering staff at plants around the world.  The full course syllabus can be found here.

To register and secure your spot today contact Christine Vallon or call our European office at +33 (0)4 92 96 92 54.

For our full range of courses see our 2017 schedule at http://tetra-eng.com/training


Covered Piping System Maintenance Programme

Since 2007 the ASME B31.1 Power Piping Code has included Chapter VII, establishing mandatory requirements for Operation and Maintenance. The key elements of this program are discussed here, and require that Operators outline a detailed maintenance plan for their Covered Piping Systems (CPSs).  The Code also requires that operators perform regular Condition Assessments of their CPS ensuring that relevant degradation mechanisms are being covered.

Tetra provides the following services to Owners and Operators of Combined Cycle and Thermal Power Plants to help meet the ASME requirements and thereby assure the long-term integrity of their piping systems:

  • Technical Support For Implementing a B31.1 Compliant CPS Maintenance Programme
  • Grade 91 and CSEF Integrity Assessment
  • Piping Degradation Risk Assessments
  • Piping Inspection and Condition Assessments

Tetra has developed PipeVue 2.0, a unique and powerful software tool to manage the data from design, inspections and repairs of piping in an integral manner, by linking all this information to a 3-D model of plant piping and making it accessible through a simple click of the mouse


Tetra Engineering in the Guinness World Records!

Tetra Engineering's own Andreas Fabricius and cycling partner Axel Carion are currently past the half-way mark of their World Record attempt to cross the South American continent North to South by bicycle.  Scott Napier's current record stands at 58 days.  See this photo below of Andreas crossing the Argentinian border at 4400m elevation (14400ft) days ago.  You can follow their journey (here) and track their progress.  Their journey is raising money for Pompiers Sans Frontières (Firefighters Without Borders - see website), providing crucial resources to underfunded firefighters in South America. 

Tetra Engineering is sponsoring their effort and wishes them good luck! 

 

Tetra Article in Power Magazine

A recent article published in Power Magazine explains the continuing importance of Condition Assessments of HRSGs in optimising Operational and Capital Expenditure. See this link for more details. 

Tetra in Action #5 - October, 2016

Assuring HRSG and Boiler Pressure Part Quality

Remember -Certification Does Not Always Equal Quality!

HRSGs and power boilers are built by assembling large numbers of components, mostly by welding.  Design choices in optimizing heat transfer against overall cost lead to configurations that aim to minimize the number of welds per square meter of heat transfer surface.  In addition, fabrication of the modules is frequently subcontracted by the OEM for manufacture in regions where manpower is cheaper.  The OEM becomes in effect an integrator of components built by others.  How can Product Quality for pressure parts be assured in that context?

Under the ASME Power Boiler Construction Code, the approach is to initially to certify a manufacturer by approving a suitable QC program, including the qualification of welding procedures and welders themselves.  Going forward, Quality would then be assured by the manufacturer’s adherence to their approved program and by the presence of the ASME Authorized Inspector on site. 

The Authorized Inspector has a number of compulsory checks that must be made in person but, in practice, a large portion of the welding continues without any further follow-up, except where the Code requires NDE.  If the approved QC program becomes a box-ticking exercise – for example when schedule constraints take priority – weld quality can decline resulting in unrepaired defects.  The problem for the Purchaser is to determine whether the manufacturer’s QC program can be trusted to guarantee a quality product.

Tetra’s experience is that product delivered by a number of OEM’s has on frequent occasions displayed unacceptable weld quality, despite the OEM and/or subcontracting fabricator having a valid quality certification in place.  The cause is systemic management focus on schedule and cost, with quality given a lower priority.  Many rejectable weld defects are not visible from the outside and only infrequently will the module fail the field hydro tests (although this has occurred).  The main concern is that a large population of weld defects present in a set of tube modules will affect pressure part longevity, particularly if the plant is in cyclic operation.
To assist clients in their pressure part procurement process, Tetra Engineering performs:

  • Project Vendor and Product Sourcing Quality Assessments
  • Expert and Enhanced Factory Fabrication Surveillance (see following example)
  • Warranty Risk Evaluation

A Recent Case History

Weld Inclusion

During a recent Tetra project thousands of still images of tube to header welds were taken using a borescope in several HRSGs at a plant site just after commissioning.  The images were thereafter reviewed independently by at least two engineers.  The tube to header welds were found to be characterised by a general lack of good workmanship with numerous defects or flaws apparent.  The initial inspection of one set of upper SH headers yielded 20 tubes that had weld defects serious enough to require repair.  It should be noted that repair can be difficult because of poor access.  Similar results were found in SH modules from the other units.

 

  Results on Header
Category Count %
Accept 100 53%
Substandard 68 36%
Fail/Repair 20 11%
Total 188 100%
Results: Borescope Inspection Campaign of 188 tubes 

For more information about this service send us an email (Cette adresse e-mail est protégée contre les robots spammeurs. Vous devez activer le JavaScript pour la visualiser. ).


A Successful First Boiler & Steam Cycle Knowledge Workshop in Dubai!

Tetra Engineering held its first steam Boiler & Steam Cycle Knowledge Workshop at the Media One Hotel in Dubai.  Five of the seven workshop topics were presented by a team of four instructors from our company, the other two were presented by external collaborating partners: Mr. Jamie Pollock of Mettek Ltd. and Messrs. Tord Forslund & Leif Andersson from CCI Valves. Attendees could sign up for topics “à la carte”, these ranged from how to meet B.31 requirements for piping inspections to particular problem issues such as waterside deposition or creep. See here for more information.

HRSG Workshop


HRSG Inspection Planning Guide Snapshots

One of the first applications of the borescope was for inspecting steam turbine rotor discontinuities in the 1920s.  Today a wide variety of commercial borescopes and videoprobes can be used for access within HRSG components.  These include both flexible and rigid borescopes and a variety of videoprobes and end effectors.   Mirror or prism attachments can be used to get right angle views of tubes or pipe connections.   Access can be via hand-holes or other penetrations.
Flexible video inspection probes employ high-resolution camera at the probe tip to capture detailed color inspection footage.   Interchangeable lenses bring subjects both near and far into sharp focus.  Variable-intensity fiber optic illumination floods hidden targets with cool, white light.  Knobs on the handset control the tip’s up/down and left/right articulation.

 Borescope

Figure: Typical Flexible Fiberscope (Courtesy, InterTest, Inc.)

If you are interested in the full version of the HRSG Inspection Planning Guide (2nd edition) contact Cette adresse e-mail est protégée contre les robots spammeurs. Vous devez activer le JavaScript pour la visualiser.

HRSG Tube Failure Guide, 3rd Ed.

Pre-Publication Discount Available on HRSG Tube Failure Guide, 3rd Ed. 

The latest updated edition of Tetra Engineering's HRSG Tube Failure Diagnostic Guide will be published August 15, 2016.

Thousands of combined cycle professionals are familiar with Tetra's HRSG Tube Failure Diagnostic Guide; first published during the 'bubble' in construction in the early 2000s.

The latest edition includes additional material on waterside deposits, creep fatigue cracking, fireside corrosion and others.  Many new photos and illustrations now make it easier to use.

Each copy of the Guide is offered at $195 USD after August 15.  The special pre-publication price is $165 USD.  Inquire for volume discounts.  Shipping is in addition to the per copy charge.

For more information please contact Natalie Vasa at Cette adresse e-mail est protégée contre les robots spammeurs. Vous devez activer le JavaScript pour la visualiser. or by phone at +1 860 651-4622