working pressure

working pressure (countable and uncountable, plural working pressures)

1. The pressure that something that operates under and contains pressure normally works at; the specified maximum working pressure is set below the test pressure.
   • 1943 March and April, “L.N.E.R. New Mixed-Traffic 4-6-0 Locomotive”, in Railway Magazine, page 104:

     It is a general-purpose type, with weight and clearances sufficiently restricted to enable it to have a considerably wider radius of action than the "V2" 2-6-2s and "K3" 2-6-0s, but at the same time, with the help of a working pressure of 225 lb. per sq. in., of considerable power.