Due diligence again!

Paul Hetherington | TLT President's Report January 2021

In instances where failures might occur, due diligence can save your job.

You have the responsibility to make decisions and take actions that are reasonable and defendable.

In the September 2020 TLT, I talked about my strong fundamental belief in the proper process of due diligence and how that belief (or maybe a little fear at times) guided my approach to making everyday lubrication recommendations and decisions.

My previous article talked about the problem and subsequent corrective actions in resolving the inappropriate use of an EP grease in a backstop on an inclined conveyor. Well, here is another story (experience) where a decision I made might have actually led to a failure, but my overall due diligence might have helped to save my job.

Many years ago, I made a decision that might have led to the failure of two 50-MW steam turbine generators (STGs). To simplify a long story, we had a bit of a foaming issue in all four of our STG units. Oil analysis of all four units showed failing results on the standard ASTM D892 foam sequence tests. Since the oil volume in the reservoirs was quite large (10,000-plus liters each), I obviously didn’t want to just recommend changing the oil without first investigating other options.

After extensive investigation, I sourced the exact antifoam additive used by the oil supplier in the original oil. As many of you know, common antifoam additives are not dissolved into the oil but are actually very finely dispersed in the oil and in a very minute amount. To make it more difficult, the typical antifoam additive that was being used was a highly viscous product at room temperature. Therefore, I had to develop a rather extensive procedure utilizing a series of new clean paint cans and a paint shaker (which we actually had on site) and some oil from one of the actual reservoirs.

After multiple processes, I finally had an appropriate cocktail mixture that I felt could be added to the reservoirs to top treat and restore the antifoaming characteristics. Very slowly I added the additive mixture through the top hatch of the tanks on all four units and actually videotaped the process—I wish I still had that video. Literally within minutes, the foaming went away, and I went home that evening feeling quite proud of myself.

A little side note—usually when telling this story during training seminars I jokingly comment that in situations like this to always be the one behind the camera and not the one on the video. And, yes, of course, I was the videographer and coerced a colleague to do the deed of pouring in the antifoam cocktail.

Sometime in the next 24 hours or so, one of the units came crashing down, and about 24-48 hours after that another one also failed. Both failures were related to the thrust bearing on the main shaft driven oil pump. A full root cause analysis was initiated (and, no, I didn’t lead it) to determine the cause of the failures.

The RCA was unable to determine the specific cause of the failure other than the coincidence of timing with adding the antifoam additive. In either event, the units were returned to service with the same oil, and no further incidents occurred on any of the four units. In addition, though, the investigation identified that I had taken every reasonable step (due diligence) throughout the entire process to ensure a successful outcome.

I have used this story many times when teaching lubrication seminars specifically when discussing the concerns with compatibility and mixing different products. But I also use it as an example in trying to promote my belief in taking every reasonable step possible when making a decision. You can’t always guarantee that every action is going to be successful, but you do have the responsibility to make decisions and take actions that are reasonable and defendable along the way.

Paul Hetherington is manager technical services for Petro-Canada Lubricants in Peachland, British Columbia, Canada. You can reach him at paul.hetherington@hollyfrontier.com.