“Duty” of pumps. This indicates the measurement of the work performed by pumps. “Duty trials” are careful tests of the work done by the larger pumping-engines.
Elbow. This fitting is used for uniting two pipes together at right angles. The illustration shows a malleable-iron gas-pipe elbow.
Elbow.
Equilibrium Valve. A valve balanced by an equal pressure on both ends.
Expansion Joint. A telescopic slip joint having a packed stuffing box, permitting the parts it connects to expand and contract under variations of temperature.
Expansion Joint.
Face. The broadest flat surface of a piece of work, or the one having the greatest area.