Page 314 - Root Cause Failure Analysis

302 Root Cause Failure Analysis

shaft encoder A device that senses the true running speed of
the shaft and sends a signal back to the speed-
control mechanism; also referred to as a
resolver.

shroud A protective covering, usually of metal plate or
sheet.
single-channel data Acquired in series or one channel at a time.

sinusoidal function The real or complex function sin(u) or any
function with analogous continuous periodic
behavior.
slip For a pump, it is the rate at which liquid leaks
from the discharge side to the suction side. For a
conveyor, it is the amount of material that
bypasses the system.

solenoid An electrically energized coil of insulated wire
that produces a magnetic field within the coil.
specific gravity The ratio of a material’s density to the density of
some standard material (i.e., water at 60°F or air
at standard temperature and pressure); also
known as relative density.
stagnant Motionless.

static head Pressure of a fluid due to the head of fluid above
some reference point.
static pressure The pressure exerted in a nonoperating system.

steam trap A device that separates and removes condensate
automatically from steam lines.
suction lift The head, in feet, that a pump must provide on
the inlet side to raise the liquid from the supply
well to the level of the pump; also known as the
suction head.
synchronize Make to occur at the same time.
three-phase alternating current Alternating current delivered through three
wires, with each wire serving as the return for
the other two and with the three current
components differing in phase successively by
one-third cycle, or 120 electrical degrees.
throttle A choking device to regulate flow of a fluid.