Boiler glossary

Boiler glossary Q


QUADRANT -- A slotted segmental guide through which an adjusting lever works. It is provided with means for locating the lever in any desired angular position. See link-motion.
QUADRUPLE EXPANSION ENGINE -- A steam engine in which the steam expands successively in four cylinders of increasing size, all working on the same crankshaft.
QUALITY CONTROL -- A form of inspection involving sampling of parts in a mathematical manner to determine whether or not the entire production run is acceptable, a specified number of defective parts being permissible.
QUALITY OF STEAM -- Term used to express the moisture content present in saturated steam. Quality of steam affects the energy content of the steam.
QUARTER -- The upper part of a vessel's sides near the stern.
QUICK-BREAK SWITCH -- A switch having a spring or other device to produce a quick break, independently of the operator.
QUICK-REVOLUTION ENGINES -- A term formerly applied to high-speed steam-engines direct-coupled to generators.