[Shop-talk] air compressor

[Randall]

>          Steam locomotives ran at around 200-250 psi during 
> the later part 
> of the steam era (early 1900s-1940s). 

Of course, an important question is how high the pressure actually was when
they exploded.  Races were not uncommon, and the pressure relief valve was
easily modified to allow extra pressure.  It was apparently a common enough
practice that one of Mark Twain's stories used "Hang a monkey wrench on the
valve" as a phrase meaning to turn up the regulator.

-- Randall