Millwright TEST #3 QUESTIONS AND
CORRECT ANSWERS 2025
Barrier Fluid: - Correct Answer--A fluid 5ntroduced under pressure into the
chamber between dual seals. It prevents The entry of process fluid at a
lower pressure and provides both cooling and lubrication to the sealing
faces.
Buffer fluid: - Correct Answer--A fluid introduced at atmospheric pressure into
the chamber between dual seals. it provides both cooling and lubrication to
the sealing faces.
Cavitation: - Correct Answer--The formation and eventual collapse of bubbles
in a fluid. Generally, its caused by the pumped liquid flashing to a vapor as it
enters the low-pressure area at the impeller inlet.
Concentric: - Correct Answer--Describes two or more circles or arcs that
share a common center.
Crazing: - Correct Answer--The development of a network of tiny cracks in a
surface.
End Play: - Correct Answer--Relative to pumps and similar equipment, the
amount of linear
(end to end) movement exhibited by a shaft.
Flashing: - Correct Answer--The near instantaneous change of state from a
liquid to a vapor. Typically due to a pressure condition too low at the current
temperature to maintain the liquid state.
lapped: - Correct Answer--Smoothed or polished.
Optical Flat: - Correct Answer--A precisely lapped and polished piece of
glass, typically flat within a few millions of an inch, Its used with a light
source to analyze the flatness of other surfaces.
Pipe strain: - Correct Answer--Undesirable stress placed on pump structures
due to the poor alignment and/or insufficient support of connected piping.
Generally pumps should not be used as a point of support for connected
piping.
, Shaft deflection: - Correct Answer--Undesirable play in a shaft that allows
movement perpendicular to its length (Side to Side).
Shaft Runout: - Correct Answer--Undesirable deviation in the surface of a
shaft from its centerline as it rotates.
TRADITIONAL shaft seals consist of? - Correct Answer--Rope or braided
packing wrapped around the shaft and packed into a stuffing box. The series
of packing rings is then tightly compressed to prevent or limit leakage.
When using packing a certain amount of ________ is expected. - Correct
Answer--Leakage
Tightening the gland that compresses the packing *(1): ________ ___ _______.
The packing is replaced when the *(2):
__________________________________________________. - Correct Answer--(1)
compensates for wear
(2) Leakage rate becomes excessive and adjustments are no longer possible
Packing also places an additional *(1): ______ on the *(2) _______, due to
friction, which also wears on the shaft at the point on contact. - Correct
Answer--(1) Load
(2) Driver
The *(1): _______ _____ was developed to replace less effective shaft-sealing
methods like packing. Pumps originally built with packing can often be
retrofitted to use a mechanical seal. Mechanical seals offer a dramatic
reduction in leakage and, when properly installed and maintained , they do
not cause *(2): ______ __ ___ _____. However mechanical seals are much more
complex and far more expensive than packing. - Correct Answer--(1)
Mechanical Seal
(2) Wear on the shaft
A mechanical seals ability to prevent leaks is largely dependent on? - Correct
Answer--Precisely machined and aligned surfaces, as well as proper
installation.
CORRECT ANSWERS 2025
Barrier Fluid: - Correct Answer--A fluid 5ntroduced under pressure into the
chamber between dual seals. It prevents The entry of process fluid at a
lower pressure and provides both cooling and lubrication to the sealing
faces.
Buffer fluid: - Correct Answer--A fluid introduced at atmospheric pressure into
the chamber between dual seals. it provides both cooling and lubrication to
the sealing faces.
Cavitation: - Correct Answer--The formation and eventual collapse of bubbles
in a fluid. Generally, its caused by the pumped liquid flashing to a vapor as it
enters the low-pressure area at the impeller inlet.
Concentric: - Correct Answer--Describes two or more circles or arcs that
share a common center.
Crazing: - Correct Answer--The development of a network of tiny cracks in a
surface.
End Play: - Correct Answer--Relative to pumps and similar equipment, the
amount of linear
(end to end) movement exhibited by a shaft.
Flashing: - Correct Answer--The near instantaneous change of state from a
liquid to a vapor. Typically due to a pressure condition too low at the current
temperature to maintain the liquid state.
lapped: - Correct Answer--Smoothed or polished.
Optical Flat: - Correct Answer--A precisely lapped and polished piece of
glass, typically flat within a few millions of an inch, Its used with a light
source to analyze the flatness of other surfaces.
Pipe strain: - Correct Answer--Undesirable stress placed on pump structures
due to the poor alignment and/or insufficient support of connected piping.
Generally pumps should not be used as a point of support for connected
piping.
, Shaft deflection: - Correct Answer--Undesirable play in a shaft that allows
movement perpendicular to its length (Side to Side).
Shaft Runout: - Correct Answer--Undesirable deviation in the surface of a
shaft from its centerline as it rotates.
TRADITIONAL shaft seals consist of? - Correct Answer--Rope or braided
packing wrapped around the shaft and packed into a stuffing box. The series
of packing rings is then tightly compressed to prevent or limit leakage.
When using packing a certain amount of ________ is expected. - Correct
Answer--Leakage
Tightening the gland that compresses the packing *(1): ________ ___ _______.
The packing is replaced when the *(2):
__________________________________________________. - Correct Answer--(1)
compensates for wear
(2) Leakage rate becomes excessive and adjustments are no longer possible
Packing also places an additional *(1): ______ on the *(2) _______, due to
friction, which also wears on the shaft at the point on contact. - Correct
Answer--(1) Load
(2) Driver
The *(1): _______ _____ was developed to replace less effective shaft-sealing
methods like packing. Pumps originally built with packing can often be
retrofitted to use a mechanical seal. Mechanical seals offer a dramatic
reduction in leakage and, when properly installed and maintained , they do
not cause *(2): ______ __ ___ _____. However mechanical seals are much more
complex and far more expensive than packing. - Correct Answer--(1)
Mechanical Seal
(2) Wear on the shaft
A mechanical seals ability to prevent leaks is largely dependent on? - Correct
Answer--Precisely machined and aligned surfaces, as well as proper
installation.
