Quality Blog

Quality Blog Introduction


EPR’s project management, consulting, and restructuring experience is highly varied resulting in a unique view of the industry. A project managed poorly during construction may have many problems, like safety, schedule, over-runs, etc... However, plant quality is the most significant determinant of the forward value of the asset (plant).

This blog is not presented as deep technical reference but a strategy-level view.  It's assumed the more techincal members of our audience understand the basis for these observations. However, our intention is to bring a discussion level perspective of how construction quality impacts an owner, with enough technical content provided context. If the reader wants to know more about a technical subject (i.e. PWHT of P91) please refer to the reference codes, standards, and specifications for your project (i.e. ASME).

EPR believes all the problems identified could have easily been solved with proactive oversight.  If your project has finished and exhibits some of these concerns, or you are early in construction and desire to avoid these concerning problems, and the more dibilatating latent issues, please call EPR.

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

Anchors Away!


Contractors sometimes take an extraordinary short-term view of their obligations.

At one plant EPR evaluated the owner's engineer had agreed to waive the contract requirement that all embeds were to be hot dip galvanized. The back-story is that the contractor managed to get late on anchor bolt delivery and wanted to skip the delay associated with galvanizing. It is also worth noting that this location was in a polluted location, in a hot humid region, on the sea. This simply means corrosion concerns are very serious.

The photographs were taken before the first unit even reached first fire. Already, the anchor bolts exhibit heavy corrosion and loss of substrate material at the threads.

Within a couple years of COD, it is conservative to expect the anchor bolts to be essentially non-existent. It's not clear how the foundations and structure will resist uplift forces without compromise and risk to the structure.

The "fix" at that time was to add galvanized nuts on top of the previously un-galvanized nuts. Sort of...

Contractor Savings

Non-Critical Path time was saved.  Minimal cost.

Repair Costs

Repair is difficult.  Cost of structural failure could be high if a material uplift condition occurs.

No-No-Shrink Grout


Most structural designers call for an inch or two of no-shrink grout below the baseplates of structural columns. While anchor bolts are installed with nuts to jack and plumb a column, the load is intended to be carried largely by the grout. This means that it needs to be installed on a prepared surface, mixed correctly, and placed with good workmanship to the approximate depth required.

In almost every developing country where EPR has inspected plants, the same recurring problems are visible. Typically, the workman are unaware of the purpose for the grout and methods required to create an acceptable final product.

In the photos, at least three major flaws are shown. First, the foundation surface was not bushed prior to setting the column and instead some half-effort to rough around the joint is attempted. Second, there is insufficient space to apply grout below the baseplate. Third, the grout is poured around the joint, as opposed to being packed under the baseplate. It is clear the workman think grout is simply a "dressing" rather than a purposeful componenet of the structural system.... Read more

Contractor Savings

No Savings.

Repair Costs

Most of the time, the condition is not repairable.  Owner has to accept the defect.

Settle for More!


In nearly every developing country location, plants evaluated by EPR have exhibited very poor performance of soil compaction, especially related to area paving.

At one facility, a more extensive review was conducted because significant settling was evident in dozens of areas. In the first photo, not only is the area paving soil consolidating, so is the soil below the pipe support foundation, which rendered the support ineffectual.  Some of the other pictures show images taken from a borescope beneath a slab where the soil had consolidated in the 12 months after the slab was poured. The findings included exposed rebar, construction debris, form work, voids, unconsolidated concrete, and improper slab thickness/finish. In all, technically nothing about the installation was acceptable.

In the last photo, a small crew can be observed preparing soil for finish grade.  It exhibits pretty well the nature of the problem.  Simply, the crew did not have the tools or knowledge to perform the work correctly. QC was also not likely to be involved to verify soil density.  However, it's a safe bet the QC... Read more

Contractor Savings

Minimal.

Repair Costs

Owner will live with poor conditions and possible operator injury.  Ongoing O&M cost.

Debris at Heights


At a new plant in the Middle East, EPR encountered an alarming amount of debris on steel members, gallery platforms, and other horizontal surfaces up to 150' in elevation from grade.

Power plants move, vibrate, and have operating transients where loads are imparted on the structures and equipment.  Essentially, these items will eventually become falling debris with the obvious safety implications.

To further the concern some of the items are quite significant.  Pieces of angle iron, bolts, nuts, wedges, grinding wheels, and a limitless amount of other items.

In this particular plant, EPR made the contractor clean up one unit.  The debris collected filled a 10-yard dumpster.  There were an additional 15 units in this very large plant.

Most contractors have a clean and close process, but in this instance and in others evaluated by EPR, no real effort was made by the contractors to present a finished product.

Contractor Savings

None.

Repair Costs

Minimal, unless a serious safety incident occurs.

Green Moss


A plant was evaluated that had an extensive desalination operation where seawater was flashed to create drinking water.

On the roof of the process equipment, there were insulated and uninsulated bays.  One of several coatings problems was the difficulty with this arrangement related to coating selection.  The top of the evaporator is essentially flat with bellies in the areas between the structural stiffeners.  Water tends to collect in these locations and will not drain.  In some cases, drain holes didn’t exist so water has been pooling for a couple years. 

In these areas of the tops, the coating selection (urethane) was not suitable for water immersion and breaks down progressively.  On the other hand, leaving the surface in epoxy would solve the water damage problem, but is not a solution because it is susceptible to UV breakdown.  Therefore, the coating system as installed was not compatible with the propensity of the surface to hold and pool water.

This was not an academic concern, as there are indications the coatings had already failed.  One photo shows the adhesion x-cut... Read more

Contractor Savings

None.

Repair Costs

Unknown, but significant.

Adverse Shrinkage


In a Middle East plant inspected, recurring problems with the process drain system was discovered.  It originated from a design flaw where the desalination units had to be blown down more robustly than anticipated to achieve proper conductivity in the steam cycle.  To compound the process control difficulty, the drain material selected by the EPC contractor was PVC, which simply cannot stand elevated temperatures.

PVC is interesting because unlike may materials it's strength simply disappears once the working fluid gets to about 140F.  It also shrinks axially when it undergoes heating and cooling cycles.  For condensate drains to be routed to sumps which feed an underground network of PVC piping material is certainly a high-risk proposition.

After a bit of excavation and diagnosis, it was confirmed that the process water overflow of the sumps was from collapsed drain lines, piping that pulled away from the sumps, and other similar failures.

The only permanent remedy is to replace the PVC with a material that can withstand condensate temperatures of 212F.

This is an engineering... Read more

Contractor Savings

There was minor savings, amont unknown.

Repair Costs

Once repair costs under Warranty considered, this was costly for the Contractor.

Mechanical Damage


In many developing country locations, a recurring problem is the mechanical damage to otherwise properly applied coatings due to handling abuse.

For most plants, structural steel is shop (off site) fabricated, loaded on trucks or ships, and delivered to the construction site for erection.  This is an important process because it can become quite expensive and time consuming to field repair coatings.  This can be even more true in locations with high humidity because a proper repair must be effected within the coating manufacturers indicated limitations.  This is sometimes hard to achieve.

An owner should likewise be concerned because a repaired coating system is never as durable as the original coating.  The first photo shows a typical "handling" problem.  The subsequent photos show poor repairs and unrepaired damage.  Both are so common, it seems normal.

One plant in Asia had structural steel and piping that was so abused with mechaincal damage that the plant looked 15 years old even before COD.

Contractor Savings

Nothing.  It costs nothing to handle coated pipe/steel carefully.

Repair Costs

If all teh repairs were affected, it would have cost severeral tens of millions of $.

Inspection Futility


Often field quality suffers from a lack of oversight; quality control, supervision, or owner involvement.  Sometimes a contractor and owner set out to assure their interests are protected, but it fails anyway.

Using a large international source inspection firm tends to be where problems arise.  Those firms use local inspectors to keep costs down by limiting travel.  However, local inspectors are often the same people that visit particular shops and due to familiarity, a relationship develops which compromises the effectiveness of the shop inspection.  Instances exist in remote areas where inspectors are relatives of shop owners.  The main take-away, is that inspections by ineffective, conflicted, or technically limited personnel with no personal connection to your project is wrought with peril.

The opinion of the author is that if an inspection is worth performing by an owner, send your own people, or an inspector well known and hired directly.  It will be more cost than outsourcing with a large international inspection firm, but it will be worth it.

At one facility, the contractor... Read more

Contractor Savings

None.

Repair Costs

$150k +/- and wasted time.

Pumping Rocks


At a plant in the Middle East, the EPC contractor failed to appreciate the difficulty and consequences of not properly cleaning the LP Steam distribution system and Condensate system during commissioning.

The plant was a very large combined-cycle plant with back-pressure steam turbines that fed a 72" header.  That LP header in-turn fed a billion dollars in desalination equipment.  This steam network was huge.  Also given it's size, it would have been difficult in certain locations to get a sufficient steam velocity to remove scale and debris.  It is doubtful, given the evidence of fouling in the system, that anyone tried very hard to achieve a degree of cleanliness.

One snapshot of the damage in the system is the return condensate pump impeller indications.  These impellers are supposed to have a straight (square) leading edge.  Keeping in mind, these pumps were only a year old, this is not normal wear.  Also, condensate is supposed to be very clean with no debris...

A borescope was used to inspect the impellers in situ during a strainer cleaning.  Debris in the strainers is evident... Read more

Contractor Savings

Maybe some schedule time.

Repair Costs

Impellar replacement.  Probably $250k +/- depending on number of times.  54 units.

Getting Touchy


Coatings are typically shop applied and touched up in the field.  On a large power station, there is considerable touch-up and it must be done correctly.

Briefly, as mentioned elsewhere in this Blog, coatings are not "paint", they are an engineered product that requires skilled personnel to apply properly.  In this case there are three coats in the system.  A zinc primer, epoxy mid-coat, followed by a urethane top coat.  Details... No coating will stick to steel substrate that is dirty, too smooth, or otherwise not prepared to the coating manufacturers requirements.  An epoxy mid-coat sticks well to a zinc primer, but does not stick to a urethane top coat.  If epoxy is left without a urethane top coat, it deteriorates from UV.  Urethane in most case needs to be applied over epoxy.

So, if a repair needs to be made, the existing paint needs to be taken off down to the primer, or mid-coat, depending on the damage.  However, epoxy (mid-coat) cannot be "slapped on" as to overlap onto existing urethane.  It will not stick.  Also, coatings cannot be applied over corrosion or dirt; seems obvious... Read more

Contractor Savings

No savings.

Repair Costs

Varies by plant, but to re-perform is significant.  If unrepaired, O&M is constantly painting, or lets plant rust.

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