Quality Blog

Project Blog Introduction


EPR’s project management, restructuring, and consulting experience is highly varied, often very technical, but always deeply immersive.  These formative experiences, on top of our traditional project management expertise, has resulted in a unique industry perspective.  

Poorly managed construction may exhibit problems such as safety, schedule, and escalated cost.  However, plant quality is the most significant determinant of the forward asset (plant) value.

This blog is not intended to be a deep technical reference but rather a discussion-level view.  However, our intention is to bring a real-world perspective of how construction quality impacts an owner, with enough technical content to provide context.  It is assumed the more technical reader will understand the basis for these observations.

Additionally, some posts deal with ‘case studies’ of projects EPR evaluated where poorly conceived execution strategy prior to mobilization created enormous realized construction risk and soured the asset with enduring bad quality.  EPR believes a poor execution strategy places an owner’s team at a severe disadvantage often preventing plant delivery commensurate with the contractor agreement.

All the problems identified in this Blog could have easily been avoided with skilled proactive oversight with minimal or no incremental cost.  If your project is near COD or early in construction and exhibiting some of these (or other) concerns, EPR can help.

To discuss your project needs, please contact EPR...

Flex-abuse


Where labor and supervision are less skilled, electrical installation quality can be very poor.  However, keep in mind that all EPC contracts have codes, standards, and often owner specifications that provide overlapping requirements that mandate this be done properly and that it is verified by contractor QC personnel.  But, to no avail.

One aspect seen on almost every developing country project, is the abuse of liquid-tight metal flex.  Please note the photos are from NEW plants, and alarmingly in some cases not even to COD.

Flex is designed to be used in locations where there is differential movement between a piece of equipment and conduit feeding a circuit to the equipment.  Flex is not intended to be a shortcut device where an electrician does not have the skill to make proper conduit bends. 

Far too often, flex is used where it should not be. To put an approximate number on it, easily 50% of flex use should not exist.

In other cases, the proper fittings are not provided on each end, grounding continuity is not assured, excessive flex length is used, leaky installation is... Read more

Contractor Savings

Costs somewhat more to perform correctly.

Repair Costs

The life-cycle ramifications for owners can be significant due to water damage of electrical and I&C devices leading to intermittent system ghost trips and failures.

Trust Us, it’s P91


At one of the world’s most spectacular power-desalination facilities, the systemic weld defect discovery resulted in a soul-crushing realization that some contractor’s self-interest has no moral boundary.  If they think they can get away with something, they will certainly try, regardless of the impact to a client/owner and even themselves.  Even more troubling, there really is little financial gain with some of these actions.

What started as an investigation into welding defects not properly identified in QC documentation, evolved quite dramatically when a P91 (9% Cr) hot reheat steam piping failed radially at a fabricated wye (fitting) near a steam turbine.  Luckily, the failure was not catastrophic, being about 12” long, and allowed a prompt orderly unit shut down with no injury.

The fitting was cut out, and boat samples of the crack area were sent to a contractor lab and owner lab for metallurgic analysis.  In the meantime, the head scratching started.  It was clear early that the weld records had issues, this was visible internally.  However, while waiting for metallurgy results, a... Read more

Contractor Savings

Savings from less rework and use of less skilled welders.  Maybe $1mm.  Cost to reweld all the large-bore in a huge power plant…??

Repair Costs

Repair cost to the EPC contractor was immense, but the cost to the Owner was far greater due to the extended outages which persisted many years while O&M was trying to run the facility.  This was well over a $100mm problem to the Owner the 1st year alone.

Weld Record Anomalies


Our default perspective is positive, and we prefer to be able to accept a story or data (documentation) as reasonably true even if we don’t believe all of it.  We became gob smacked as a seemingly curious paperwork question morphed into extreme seriousness, the deeper we dug.

As an introduction, a review was performed of a very large facility shortly after COD.  One aspect of the review was welding code compliance (ASME).  This review was performed for all Section 1, BEP, and NBEP field welds for all the units/blocks.  This started as a documentation review.

Initial findings were curious.  Of the 25,000 large-bore field welds, only one (1) documented repair (R1) was indicated.  Otherwise, the records showed no defects in any visual or radiographic inspections.  Please keep in mind, the labor in this location was less than average and the work conditions extreme.   In a western context, a good site welding program reject rate is perhaps 1-2%.  In this situation, 4% would have been an overachievement, but 0%.  This did not smell right.  But all the paper appeared fine, except…

In one... Read more

Contractor Savings

Savings from less rework and use of less skilled welders.  Maybe $1mm.

Repair Costs

Repair cost to the EPC contractor was immense, but the cost to the Owner was far greater due to the extended outages which persisted many years while O&M was trying to run the facility.  This was well over a $100mm problem.

RTV to Fit


EPR has been in many greenfield plants just prior, or just after COD.  Basically, new plants.

Without hesitation, liquid-tight flexible metal conduit (flex) is abused and mis-installed possibly more than any other heavy industrial components, especially in developing regions.

Often labor is not given proper instruction and almost never the proper tools to install this system correctly.  This results in fittings that are, at best, hand tight.  Consequently, there are grounding concerns even in the best cases where flex appears to be installed correctly, assuming an internally grounded flex is used and the correct fittings.  In most cases leaks occur and instead of tightening the fittings, a big smear of RTV is used as a seal.  This usually does not work and creates a mess of the install.

In some plants, we have run studies in limited areas intending to be ‘representative’ and found >95% of flex fittings are loose. 

For Owners concerned about the longer-term implications of moisture in electrical and instrument equipment, this is not a positive finding.

Contractor Savings

None.  Probably costs more to perform incorrectly.

Repair Costs

The cost of repair would seem manageable, but this defect is so pervasive in most plants that cost can be material.  However, the O&M cost for an Owner can be even higher due to device mortality.

Spaghetti Vaults


To get a quick understanding of an EPC Contractors performance, look at a few cable vaults.  Contractors that have reasonably competent labor and supervision can typically plan cable pull work and install the requisite raceway and supports in advance of their work.  This is more than a nice-to-have, since it is a code requirement, and with good reason because it is intended to greatly reduce cable damage.

In a vault there are a great many details that need attending, like cable voltage separation, grounding issues, cable bend radiuses, combed/groomed/tied cables, water management, and a variety of meaningful details.

The pictures are from a couple large, NEW, greenfield plants in developing countries that were recently completed.  It is possible for an Owner to monitor and insist the pictured results are avoided, but it does take engagement and follow-through.

If you see this condition start to develop on your project, it is a strong forward indicator of broad electrical quality and safety concerns.  Often this condition can lead to grounding, relay, intermittent instrument faults... Read more

Contractor Savings

None.

Repair Costs

Condition is very difficult to repair, and expensive after-the-fact because usually cable must be replaced with the coincident outages.

Generator Circuit Breaker (Explosion)


The more interesting findings during our assessments are related to poor commissioning practices. These items tend to be more complex than construction defects and typically more serious from a safety, equipment protection, and reliability perspective of the asset.

One case involved an "explosion" of a generator circuit breaker.  The event took place about one year after COD, destroyed the GCB and damaged an F-class turbine generator (both stator and rotor).

The Event: During a unit start the operator was at the elevated GCB panel.  The generator field breaker was closed, so the generator exciter was energized.  The operator inadvertently pushed the earthing switch button which activated.  The earthing switches are NOT designed to be activated when the generator/exciter is energized.  The switch exploded (vaporized) with the GCB housing being damaged and opened like a tin can.  The operator was shielded from bolts and other shrapnel, but luckily did not fall from the platform.

Background: The GCB vendor provided a set of dry contacts on each earthing... Read more

Contractor Savings

Possibly only a time savings, but doubtful.

Repair Costs

Unit was out of service for 6 months.  New breaker, rewound stator and rotor, recommissioning of unit...  All-in costs between contractor, owner, an insurance company was about $8mm.

The Lawrence Welk Show


EPR performed a verification of final completion on a large coal plant in a developing country.  

A critical system in any power facility is its instrument air (IAS), because a loss of instrument air means a loss of control in many instances.  Further, IAS is expensive because air compressors take a material amount of parasitic load in addition to the drying needed to wring out any moisture.

In this facility thousands, or perhaps more, IAS leaks were observed.  This is due in part to unqualified installers and also the lack of tools necessary to tighten the joints.  Tubing systems are fantastic because they are high pressure, install quickly, and durable if installed correctly.  However, contractors often underappreciate that a tubing system is a technical installation that requires the workers to be trained.  In this plant it was apparent that any joint which did not leak, was purely an accident, because the recommended OEM installation practices were simply not followed.

This will cost the Owner hundreds of thousands per year in additional compressor power consumption and increased... Read more

Contractor Savings

No Savings.  Probably cost more with unqualified personnel.

Repair Costs

Really not possible to repair all leaks.  Owner Cost will be several $100k/year for plant life.

HRSG Hot Spots


As much as this appears to be a coatings issue, it is an HRSG (heat recovery steam generator) erection problem.  More specifically, a range of problems which result in hot gases coming in contact with the casing.

In the 12 units inspected at one site, all of them had visible indications of external coating damage from excessive temperatures.

Those same units were internally inspected, and the list of erection defects was extensive.  Well beyond the issues that related to hot spots.

Some of the issues were missing insulation, liner damage, missing liner panels, buckled flashing, and other assembly problems.

When EPR gets involved at a site where there is visible external damage to HRSG coatings, we usually consider it an indicator of much more extensive internal problems mostly unrelated to this issue.  So far, this has been accurate.

Once the HRSG problems are resolved, the hot spots can be remediated with new coatings applied using an appropriate repair procedure.

Contractor Savings

None.

Repair Costs

Cost is mostly due to poor thermal operation of the HRSG’s.

5kV Cable Mischief


The photos of the damaged 5,000-volt cables are from three plants that recently entered operation (at time of inspection).  For every photo shown, there were dozens of similar defects.

In some instances, the cuts and holes appear to be deep enough to damage the copper shield tape.  Damage to the outer jacket will allow moisture into cable jacket and cause premature failure.

The cables were seemingly not installed in a workmanlike manner and appear to have been damaged during cable pulling.  This casts suspicion of the installation methods, field construction supervision, and quality control inspection processes.  As a reminder, pulling cable in a raceway with sharp edges or in a manner that damages the cable is a code violation.

This type of defect does not need much explanation, but in addition to being prohibited by electrical codes, the EPC contract also had specific language related to damaged cables and accepted project methods for resolving such issues.  In the absence of an Owner approved exception, there were none, the cables needed to be replaced.

In addition, the... Read more

Contractor Savings

None.

Repair Costs

Cost of proper repair is cost of replacement.  This is very high.  Cost to Owner depends on how many failures related to fires, outages, or injury occur.

Uncured Coatings


One of the more interesting construction defects observed at a plant in Asia is a nearly universal application of coatings that did not cure.

As background, modern "paint" used in a power plant is a complex engineered product often applied in two or three layers. This is because each layer has a purpose. For example, inorganic zinc is often used as a primer, but not suitable as a top coat. Similarly, epoxy is used as a second coat, but not a topcoat because it is poor at enduring UV unlike a urethane. 

Each of the layers must be properly mixed, and usually is catalyzed with a hardener. The proportion of hardener to base product is very important. Too little, the coating never cures and perpetually stays soft. It's a failed coating. Another important factor is to keep water (rain and condensation) from the coating components.  Water affects curing also.

At the plant in question, easily 70% of the coated plant (large coal plant) had coatings that were not cured.  To test this defect, ASTM has a MEK (Methyl Ethyl Ketone) wipe test which roughly involves a clean cloth, a little MEK, and... Read more

Contractor Savings

None.

Repair Costs

Colossal.  Left unrepaired...

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