A. Close the water valve and the regulating valves to the other feeds.
Open drain cock and draw out a small quantity of water so as to bring
the oil in top part of lubricator below the top end of oil pipe leading
to feed arm, then open wide the regulating valve to feed that is stopped
up and the pressure from the equalizing tube will force the obstruction
out of the feed nozzle and up into the body of the lubricator. Next,
close this regulating valve until the feed glass fills with water, then
open water valve and start feeds.