The year was 1981, and MSC had been contracted to gut and refurbish several Edwards Engineering explosion-proof gasoline vapor recovery units. We were a fledgling company founded just five years earlier by our present-day president Harry Hartigan, who can be seen in the upper left and lower right photos. I'm the curly-haired young fellow in the upper right working on a new enclosure and helping Harry guide a new panel into place on the lower right.
In the lower-left photo, one of our technicians is painting the back deck of one of the vapor recovery units. The enclosure above him is awaiting the installation of new explosion-proof bolts. The unit was a cascade refrigeration system utilizing R-502 refrigerant in the high stage and R-503 was used in the low stage to cool methylene chloride down to -100°F in order to condense the gasoline vapors. Both of these refrigerants were banned in 1995.
Working on vapor recovery units sometimes required open-flame brazing or welding while surrounded by tanks filled with millions of gallons of gasoline. The local fire department and the Coast Guard had to be notified prior to any hot work, and a terminal manager equipped with an explosimeter would come out to the site to test the area for combustible gases before our torches could be lit.
A number of the service techs from this era stayed with MSC for decades. Harry and I are both still here, and Mike Roberto retired in 2021. Glenn Daniel, the son of longtime employee Kevin Daniel, followed in his father's career path and recently helped build a custom, tight-tolerance make-up air unit in our shop for one of MSC's largest clients.