Priming, Booster Pumps and Instruments Flashcards
(33 cards)
What is required to prime a centrifugal pump?
A positive displacement pump
What is the theory of positive displacement?
That water is no compressible and will occupy an area directly proportional to the quantity
What is slip when referring to a pump?
Slip is the term covering the leakage between the internal parts of the pump
What determines slippage?
Slippage is dependent on the condition of the pump and the operating pressure.
What is a good indication that the main pump is primed?
A good solid stream issuing from the priming pump discharge.
A prime is maintained by what?
The rotation of the centrifugal pumps impeller
Pumps shall not be operated dry for a period exceeding how many seconds?
30
When drafting, all lines must be attached and the pump primed PRIOR TO or AFTER placing the pump in gear?
Prior to
What can be done if an air lock occurs in the pump?
Open a discharge gate or prime the pump.
How many types of pressure gauges are there?
Three: vacuum, pressure and compound
Vacuum gauges are measured in what?
Inches of mercury
What does the zero reference point reference on a compound gauge?
Atmospheric pressure
All centrifugal pumps use what kind of gauges on suction side to measure incoming pressure?
Compound gauges
All gauges are of what type?
Bourdon
On a gauge, what is attached to the pinion shaft that holds the assembly together tightly and dampens movement of the pointer?
Hairspring
What type of gauges are oil gauges?
Mechanical or electrical
What does a mechanical gauge consist of?
Consists of a bourdon type with a pointer attached. Psi is interdicted by a small tubing system connected to the engine oil system
What does an electrical gauge consist of?
A sending unit mounted on the engine and connected to a panel mounted receiving unit by means of a wire.
It is possible that a lower oil psi be recorded if engine speed is less than how many rpm?
1000 rpm
What do rapid undulations of pointer usually caused by?
Low oil level
What is an ammeter?
Indicates battery condition
A defective alternator, generator or voltage regulator is indicated when charging rate is….?
Low or discharging
Where should the pointer go on ammeter when engine is stopped?
Back to zero
If engine is stopped but ammeter is showing a discharge, what does this warn of?
That electrical equipment was left on and a short exists.
