Pumps Flashcards
What is used to determine the density of a liquid?
Hydrometer
The term specific gravity is used to describe which characteristic of liquid?
Density relative to water
Convert 200psia to psig
185.3 psig
The amount of liquid that is tranferred per min of a rotary pump is defined by?
GPM
What controls the direction of flow in a reciprocating pump?
Valves
Names two types of positive displacement pumps?
Reciprocating and rotary
What must a pump overcome in order to be able to movd the liquid?
Pump head
What pump has one internally cut gear and one externally cut hear separated by a crescent?
Internal gear pumps
Which pump uses stationary curved passages within the casing?
Diffuser
What ard flexible tube pumps used for?
Measured flow
What type of flow does an axial flow pump create
Straight line flow does not change in direction
What is atmosperic pressure?
It is 14.7 psi at sea level
What is the major advantage to centerline mounted pumps?
Thermal growth has little effect on them
The head produced by a pump varies directly with?
The square of the impeller diameter
Capacity varies directly with?
The diameter of the impeller diameter
Brake horsepower varies directly with?
The cube of the impeller diameter
What do you use to minimize clearances between impeller and casing? What does this reduce?
Wear rings and the reduces suction recirculation
When should wear rings be replaced?
They should be replaced when theyre 3 times the initial clearance
What shape are the rotors in an external vane pump?
Oval
What must you do before disassembling a lobe pump?
Check for mate marks on the timing gears
What lind of pump can be activated by the air?
Diaphramp
What device is moved to vary output in an axial piston pump
Swash plate is moved
What is the difference between a pumps actual displacement vs its theoretical?
Slip and friction are the differences
How is thd capacity of a postitive displacement pump regulated?
By varying the speed
What is volumetric efficiency?
The ratio of actual fluid pumped to theoretical value
On plunger pumps what is used to control direction of flow?
Check valve
What would you use to check temperature of pumps or other rotating equipment?
Pyrometer
What causes aeration?
Air being drawn into the suction line (low pressure on the suction side)
What protects the shaft of a pump near the gland?
Shaft sleeve
When a pump operates at a higher temperature then the motor, where should the motor be placed to compensate for this during alignment?
Motor should be shimmed higher than the pump
Which pump can pump a liquid without contaminating the liquid
Diaphram
Pump centerline to the level of the discharge tank is called?
Discharge head
Pump centerline to the level of supply is known as.
Static suction head
What device is moved to vary the output of a rotary vane pump?
The cam rings
How can you tell if a vane pump is balanced or not?
Balance has the rotor centered in an elliptical housing and offset rotor is unbalanced
What would you use to test a pumps efficiency
Metering and pressure gauges
What type of seal is a mechanical seal?
Axial seal
Typical packing is considered what type of seal?
Internal seal
What does the sizing 1.5 x 3 x 6 for a pump mean?
Size of discharge, size of suction, soze of impeller
What is the difference between a piston pump and a plunger pump
A plunger pump has its plunger sliding inside the packing and a piston pump has its packing sliding with its piston
What type of lubricator must be used to carry the lubricant long distances?
Oil mist systems
How is leakage reduced behind the impeller eye?
Static and dynamic
Alignment
What should you do before laser alignment?
Rough alignment
Laser beams from the laser are harmful too?
Your eyes
When a motor runs at high speeds the alignment accuracy becomes?
The accuracy becomes more important
What is the minimum number of reference points for laser alignment?
3 points
What is the main referance point fof laser alignments?
12 o’clock position
With cross dialing bar sag is added to ______ dial and subtracted from _____ dial
Added to A dial and subtracted from B
What are the 4 major pieces of a laser alignment kit?
Transmitter, detector, and the brackets control unit
