Of Splices and Prices

Dear Ms. Frog,

The other rejuvenation vendor refers to a “blow & go” injection method.  What is blow & go?  Does blow & go make sense for me?

California Dreamin’

Dear Dreamer-

Nobel prize winner, John Steinbeck, set his novella Of Mice and Men in California.  Few would know that my Great-great-…-great Grandmother, Salinas Bull Frog, a friend of Steinbeck talked him out of his working title, which was “Of Frogs and Men.”  As appealing as that title is, Salinas pointed out three problems to John.  First and foremost, a frog would not be pleased to ride around in Lenny’s pocket.  Second, the words Mice and Men are mutually alliterative and would sell more books.  And lastly she pointed out the play upon the famous line of the poem by Robert Burns that most would recognize, to wit,  “The best laid schemes o' mice an' men.”  Again, clever marketing cachet.

You have to be wondering where this frog is going with this lesson in American literature!  Bear with me for now; it will come into focus soon.  In the story, Lennie, a giant of a man, but with limited mental abilities, loves to pet soft things and cares for a mouse in his pocket.  He accidentally gets into really big trouble and the mob rushes to judgment and would undoubtedly kill Lennie, an outcome that would not be tolerated in 21^st Century California.  The story brings tears to my big eyes, but like Lennie, first impressions are often wrong and a more careful analysis and a cooler head are required to reach the right conclusion.  “Of Splices and Prices” requires the same careful analysis, and if they are paying attention in Stockholm, perhaps this post will land the first ever Nobel Prize in Literature to an amphibian.

First, the phrase, “blow and go” was coined by injection operating personnel about a dozen years ago shortly after a pricing paradigm called “Productivity Pricing” was introduced.  Productivity pricing was benevolently conceived by my Novinium colleague, Glen Bertini, to address productivity issues with the more traditional unit pricing.  When a rejuvenation supplier provides straight unit pricing to a circuit owner, the circuit owner has no incentive to provide timely switching orders.  At first glance the circuit owner might prefer the unit approach.  A more enlightened consideration recognizes that the rejuvenation supplier, over the long run, must simply raise prices to cover the inefficiency this situation creates.  Hence, productivity pricing introduces a time-based charge so that both the circuit owner and rejuvenation supplier are incented to work efficiently.  That’s the good news – productivity pricing leads to lower rejuvenation cost per foot.  The bad news, and unintended consequence of productivity pricing, is that minimization of the rejuvenation cost is not the optimum strategy for a circuit owner.  Those operating guys were the first to recognize this fact when they coined the “blow and go” phrase.  They recognized that the rejuvenation vendor’s profit was maximized by injecting all the cables that are easy to inject and abandoning those that present any challenge.

In order to enjoy this result it is necessary to suspend consideration of the cables that must be replaced -- the "go" part of blow and go.  As illustrated nearby, rehabilitaiton encompasses both rejuvenation and replacement.  It is not prudent to consider the two separately.

From where I am sitting in the rejuvenation supply side of the equation, it is tempting indeed to embrace blow and go.  But at Novinium we have a different perspective.  Sure we want to make a profit like the next guy, but we believe that we are best served by aligning our interests with those of our cherished circuit owner customers.  So no, Dreamer, you do not want to embrace “blow and go” and you do not want to embrace productivity pricing.  I will share with you a better pricing paradigm in a moment, but first, let’s see why “blow and go” is usually not the lowest capital solution to your underground reliability issues.

Here is where the “Splices” portion “Of Splices and Prices” comes into play.  On average about half of legacy splices support flow with the unsustained pressure rejuvenation (UPR) paradigm.  Blow and go ignores those cables with problematic splices and those cables must be replaced for a reliable circuit.  You like rejuvenation in part, because it is so much more capital efficient than replacement.  With blow and go in a typical URD project, about a third of the cables must be replaced.  With an aggressive splice replacement approach, Novinium routinely injects over 90% of the cable segments it addresses.  Digging and repairing splices cost money, but it costs a lot less than replacing the cables for the 20-25% of the cable population where the tactic is judiciously applied.  The figure nearby illustrates the concept.  As the aggressiveness with which splices are addressed is increased, the capital cost of rejuvenation (including the capital cost of addressing associated splices) goes up, but the total capital cost of rehabilitation goes down.  Remember, replacement costs much more!

There is a better way.  We call it Enhanced Productivity Pricing (EPP) and it builds upon the operational lessons of the last two decades to provide a highly reliable, fully rehabilitated circuit at the minimum capital cost.  This result is achieved by carefully aligning the interests of the circuit owner with those of the rehabilitation supplier.

Here is how EPP works.  Each of the important, but independent tasks required to test and treat a cable are given individual unit prices.  For a typical looped URD cable for example, these tasks include …

1.     closing the normal open at the beginning of the day

2.     switching a cable out of service and grounding it, when performed by Novinium

3.     testing the cable for splices and corrosion

4.     pinpointing splices and corrosion when required

5.     excavating/restoring a pit when required

6.     removing old splices and installing new splices when required

7.     preparing ends for injection

8.     injection

9.     finishing the injection (removing equipment, clean-up, etc)

10.   switching a cable back into service

11.   opening the normal open at the end of the day

Each of these tasks are billed only as they are executed.  There are no separate charges for time in any of the injection units, 3-9.  For the switching units 1, 2, 10, and 11, Novinium agrees with the circuit owner on an appropriate time standard for each.  We then track the actual time to execute these steps.  For example if step 2 should take 15 minutes, but is delayed by the circuit owner’s dispatch operator and the step requires 30 minutes, the excess time is billed as non-injection activity at an agreed upon hourly rate.  Other tasks, ancillary to the injection, also crop up in a typical rehabilitation job.  For example, suppose a bushing fails when an elbow is removed.  The injection team must cease their injection activity and replace the failed bushing.  Again, this time is billed to the nearest tenth of an hour as non-injection activity. 

Enhanced productivity pricing or EPP is the best way to structure a rehabilitation program.  EPP aligns the strategic interests of the circuit owner with the rehabilitation supplier.  We still get customers that want to use the blow and go paradigm and we are happy to comply, but at least we tell them there is a better way.  Unfortunately the productivity pricing paradigm has been utilized for over a decade, so some are reluctant to change.  Which reminds me again of something the author “Of Mice and Men,” John Steinbeck once said, “It is the nature of man as he grows older … to protest against change, particularly change for the better.”

Looking out for you and embracing the future,

Thermo

Better with Presure

Dear Frog of Knowledge,

How can we be sure that the higher pressure does not damage the polymer insulation or impact the contact between the semiconducting conductor shield and the conductor?  Also, does the expansion affect the interface adhesion between the insulation and the insulation shield, especially for older cables with thermoplastic EIS?

Regards,

SFZ

Dear SFZ-

First of all, Novinium is the only company in the world that can use all of the available injection paradigms.  The state-of-the-art in rejuvenation technology is sustained pressure rejuvenation or SPR.  The folks at Novinium invented that technology.  The old method is called unsustained pressure rejuvenation or UPR and Novinium founders invented that approach too.  To learn more about the differences between SPR and UPR check out my blog entry, “How to inject cables” at …

http://www.novinium.com/frogblog/post/2010/06/18/How-To-Inject-Cables.aspx

To get a direct and comprehensive answer to your question read the paper, “Silicone Injection:  Better with Pressure” at …

 http://www.novinium.com/pdf/papers/Better_With_Pressure.pdf

I have reproduced the summary of that paper below …

“Rejuvenation injection pressures up to 1000 psig have been in use for over two decades.

Thousands of cables have been treated with moderate pressures in the 100 psig to 400 psig range. Every time moderate pressure injection has been examined against a lower pressure control, the higher pressure injection has outperformed the lower pressure control.

Cables are designed to accommodate the radial stresses that occur throughout their service. A cable warms with increasing load and cools when the load decreases. The 5.8-times and 6.8-times differences between the linear expansion with temperature of conductors and their insulating polymers create transient gaps between the conductor and the conductor shield.  These transient gaps are a normal part of daily operation and deflections of 1% of the cable radius are common. The very similar deflection experienced when a cable is injected a single time creates no forces that are materially different and induces no geometrical deflections that are greater than a single temperature escalation from ambient to a cable’s maximum operating temperature. In contrast to the daily temperature cycles endured by a cable, sustained pressure rejuvenation involves a single cycle. Because sustained pressure rejuvenation utilizes an injection adaptor with shrinkback restraint, the only possible manifestation of the single pressure cycle or future daily temperature cycles is entirely eliminated. Experiments confirm that there are no significant changes in the geometry of a cable treated with the SPR process. Field observations such as that memorialized in Figure 8 (of the paper) confirm the laboratory measurements.

Not only does moderate pressure injection provide higher performance (even with older technology fluids), but it also lowers the cost of injection and makes possible the use of advanced rejuvenation materials. Few circuit owners would consider buying a cable today, which did not have anti-oxidant or tree-retardant properties. The newest generation of rejuvenation fluids has about two to three times the viscosity of the first generation fluid, because these fluids include advanced functionalities that provide 2 to 4 times more post-injection life than the lower viscosity 22-year old technology.

Sustained pressure rejuvenation (SPR), thermally enhanced rejuvenation (TER), and Unsustained Pressure Rejuvenation (UPR) are tools that circuit owners should have available for their rehabilitation programs. No one tool works best in every circumstance.”

Rejecting the one-size-fits-all mentality,

Thermonuclear

40-year Life

Dear All Knowing Frog,

What tests have you performed to verify the 40 years of additional life, thus being able to extend a 40 year warranty?

Regards,

California Extrapolatin’

Dear Extrapolatin’-

I have a similar question for the global warming crowd.  Why when weather is so difficult to predict 10 days out do some have such confidence in computer models that presume to predict the weather decades into the future.  Those guys should focus on next weekend, because I want to know if it is going to rain on my planned swamp picnic.  Predicting the future performance of cables is much easier than predicting long-term weather trends, and much less controversial too.  First the common threads – both predictions utilize finite volume modeling, a very computationally intensive task.  Second, many initial conditions can be established with decent engineering precision.

Now the five biggest differences:  (1) Nobody has a complete model of the weather, and you can’t measure what you don’t understand.  A patented model (See U.S. Patent 7,643,977) of cable rejuvenation is available and has been vetted against publically available data.  (Editor’s note:  I know this is what the global warming prognosticators said too, but they did not get a patent on their model.  There is a legal requirement to disclose the best mode … in other words, you can’t fudge the data with the USPTO.)  (2) The ultimate value of any weather parameter at very large times is unknown (indeterminate) and therefore can only be known by model extrapolation or by waiting for a very long time.  Neither is a satisfying prospect.  The condition at very large time for rejuvenation is unambiguous – the concentration of the treatment fluids will be zero and the impact on reliability will be zero.  (3) Weather is perturbed in unpredictable ways by cosmic radiation, sunspot activity, changes in the earth’s magnetic fields, and others.  The only significant perturbation to the rejuvenation model is the fluctuating operating temperature of the cable.  Historical weather patterns, historical load patterns, and load growth can generally be estimated with engineering accuracy. (4) The size of a finite volume used by the weather guys is a cube on the order of 8³ km³ and the Δt (time) is measured in fractional hours.  In contrast, the volume of a single finite volume in our work is 10¹⁸ times smaller and the Δt is often as small as six seconds!  Smaller time slices, much much smaller finite volumes yields more accurate results. (5) The weather is a three-dimensional problem; a cable collapses to a two-dimensional problem.

There are two papers published in 2005 and available in the Novinium Library, which describe the challenges of extrapolating cable life.  They are available at:

Accelerated Aging of Rejuvenated Cables-Part I (click here to view)

Accelerated Aging of Rejuvenated Cables-Part II (click here to view)

As mentioned previously U.S. Patent 7,643,977 published in January 2010 lays out the details of how the method introduced in the second paper is implemented.  We call the ‘977 model “MFlux,” which is short for “Mass Flux.”  A friend of mine, Dr. Dan Scott, a Stanford trained Operation Research mathematician, continues to advance the implementation of MFlux at Novinium.  The model has demonstrated that it can predict actual performance within about a plus-or-minus 10% error band.  The key paradigm shift required to understand how such extrapolations can be made requires you to abandon traditional accelerated life studies, which are loaded with inherent compromises between the effects of different accelerating variables.  For example, the permeation of fluid along the radius of a cable is profoundly impacted by the temperature.  In a traditional experiment it is difficult to balance the accelerating effects of temperature and voltage.  If one variable is accelerated by 10X and another variable is accelerated 100X, the results are not likely to be easily extrapolated.  MFlux solves that problem.  Finally a direct answer to the first part of your question, “What tests have you performed?”  We have done hundreds, perhaps thousands of tests of six primary types:

1.    We measure the permeation properties of individual components.

2.    We measure the permeation properties of component pairs.

3.    We measure the reaction kinetics of our reactive species.

4.    We measure the permeation and reaction results in one-sixth scale model cables and full size cables.

5.    We measure the dielectric impact of fluid components on cable polymers.

6.    We measure the dielectric properties of fluids on full size cables.

Most of this work is carried out at the Michigan laboratory of Dr. David Busby.  The work on full size cables is done only to validate the results of the MFlux model.  Once the permeation properties and reaction kinetics are determined for a fluid formulation we can perform virtual experiments without any compromises to accelerating factors.  We use the e-field environment, geometry, and temperature/loading environment of the actual cable in question.  No acceleration is required – time is virtual.  The time it takes to perform such a simulation is limited only by the speed of the computer and the efficiency of Dr. Scott’s MFlux algorthim.

Now for the second part of your question, “What tests have you performed to verify the 40 years of additional life, thus being able to extend a 40 year warranty?”  In every actual and virtual experiment that we have ever run, Ultrinium fluid technology outperforms the technology that has been in use for over 20 years by at least a factor of 2 and usually more like a factor of 3.  Now the old technology is good, after all it was invented by Novinium founders.  In fact it typically provides about 20 years of additional life in non-demanding applications.  Being twice or three times better than good provides us the confidence to offer a 40-year warranty.   

Extrapolating appropriately,

Thermonuclear