Test baseplate - A specially designed structure to support the pump during a
performance test in a test well.
Test curve - A graphical representation of the results of a performance test,
under controlled laboratory conditions, showing the capacity, head, efficiency,
horsepower, and NPSHR of a tested pump.
T.I.R. - see Total Indicator Runout.
Torsional critical speed - a resonant frequency associated with the torsional or
angular deflection of a rotor; not to be confused with lateral critical speed which is
associated with the lateral deflection of a rotor.
Torque - the measured ability to produce rotation or tuning motion (such as the
torque of a motor), or the ability to resist such rotation (such as the torque of a
Total Indicator Runout (T.I.R.) - the runout (or being out of dimension) of a surface
as measured manually on a dial indicator. A measurement on a pump part or
component will indicate its out-of-squareness equal to the reading, or its
eccentricity equal to half the reading, on the dial indicator.
Trip speed - a preset speed at which an emergency over-speed control device
shuts down a pump. This is to prevent a variable speed pump from developing
excessive capacity or pressure, or to prevent the driver from being overloaded.
Two plane balancing - the correction, or reduction, of residual unbalance to
comply with specified or acceptable unbalance limit by removing (preferred
method) or adding weight in two correction planes. See single plane balancing.
Two-stage pump - a pump designed with two impellers that are mounted in
series. One impeller discharges the liquid into the next impeller and the pump
develops two-stage pressure. The two impellers are usually mounted on the shaft
back-to-back, or face-to-face for axial thrust balance.
F: glossary T1