Sait final review Flashcards
Bent Shaft produces the highest vibration at?
1X rpm
Misalignment can be distinguished from an imbalance vibration because?
Axial readings will be high compared to radial
Which condition will produce a frequency less than 1x frequency?
Oil whirl
High axial readings showing a 180 degree change of phase between bearings is an indication of?
Bent shaft
Velocity is used as a measurement of vibration frequency in the range of?
600 to 60,000 cpm
Phase readings are expressed in?
Degrees
For vibration measurements which device converts mechanical vibrations into electrical signal?
Velocity transducer
Rigid rotor is one that which operates?
Considerably below its first critical speed
The frequency of vibration caused by an imbalance would be?
1x the rpm
Displacement is measured as?
Mills peak to peak
Velocity is measured as?
Inches per second, peak
Acceleration is a rate of change of?
Velocity
The vibration characteristic referring to a type of resonance which occurs in a rotating machine component revolves at a speed close to its natural frequency is known as?
Critical speed
A gradual deviation from a desired governor speed would be known as?
Speed drift
Direct acting mechanical type governors utilize?
Centrifugal forces and mechanical linkage to operate SAV (Steam admission valve)
The governor characteristic that requires a specific speed decrease before the governor tries to give an increase in throttle is called?
Speed droop
The purpose of the mechanical flyball governor is to?
Maintain the selected speed
The governor that will keep a large diesel running at a constant speed regardless of varying load is called?
Isochronous
When a steam turbine is reaching top speed the flyweights on the governor will?
Be moving away from center increasing the force acting on the speeder spring
The dilution zone on a gas turbine combustion chamber is where?
secondary air is mixed with the burnt gases.
When a gas turbine exhausts to a heat recovery steam generator it’s called?
Cogeneration
Which type of gas combustors must be equipped with their own igniters?
Can type
What will cause the most pitting wear on the blades of a gas turbine?
Unburned liquid fuels
Turbine sections of a gas turbine has fewer stages than the steam turbine because?
The pressure drop is smaller.