Pumps Flashcards
Non positive pump names
Dynamic,centrifugal,kinetic or continuous flow
Non positive delivery
High liquid, low pressure
Define specific gravity
Specific gravity is the ratio of density of a substance to that of water
What is water sg
Cold water has an SG of 1
What happens to specific gravity of a substance as temperature increases?
If the temperature goes up, the SG goes down
Capacity of a pump
Capacity is the pumps volume output in gallons per minute. Or 1/min
Displacement
Displacement is the pumps volume output per revolution/stroke
Under perfect conditions, how much water can a pump lift at sea level
34 feet or 10.37 m.
As a raise in altitude above, sea level, the atmospheric pressure goes?
Down
At sea level what is the atmospheric pressure of weight on an area of one square inch
14.7 psia
What is cavitation?
If the temp goes up on a liquid or a pressure is reduced, small pockets of gas begin to form example is vapor, they move them to higher pressure areas such as the loot discharge, and the bubbles implode and collapse, making it sound like there are rocks in the pump turning back into a liquid breaking down components
How can you check if the pump is cavitating?
Throttle the discharge, see if it gets quieter if it does, your pump was cavitating.
What is suction head?
This is where the level of supply liquid is above the pump in the centre line.
Static suction head
Vertical distance from the centre line of the suction I have the pump to the surface of supply
Discharge head
This is the vertical distance from the centre line of the suction eye to the surface of the liquid in the tank
Total static head
Vertical distance from the liquid level to the liquid discharge level
Suction lift
Supply tank is below the pump inlet
Static suction lift
Vertical distance from the centreline of the suction eye of the pump to the surface of supply 
NPSHA should be 10% greater than NSPHR
Yes
If a pipe diameter is halved in a flow system, the velocity of the fluid in the system should have to be ?
Four times the original flow amount to maintain the same output flow due to the friction losses
As he raise an altitude, they will be more or less atmospheric pressure exerted on the fluid in the tank to help push the fluid into the pumps in light
Less
How to calculate psi
Feet Times .433
How to calculate feet
Psi divided by .433.
Capacity varies directly with the diameter
Head varies with the square of the diameter
Brake horsepower varies with the cube of the diameter
When are dynamic pumps used
The flow produced by a pump varies
Directly with the impeller diameter
Pumps convert mechanical energy into
Hydraulic energy
The component that converts mechanical energy into kinetic energy is
Impeller
Vacuum pressure
Vacuum pressure expresses pressure below atmospheric pressure. It is frequently measured in inches of mercury.
Mercury
Hg
Centrifugal, axial, reciprocating or mixed flow. Which one is not dynamic
Reciprocating
Head pressure is
Is the height in feet of a column of water that is one foot square at the base.
Aeration
Where a partial vacuum is created at the pump inlet, suction,flange leaks can draw air into pump. It reduces the amount of liquid that can pass through the pump.
Turbulent flow
Turbulent flow occurs when the particles of liquid no longer move parallel with the axis of the pipe.
Turbulent flow is caused by
Bends, abrupt changes in cross sections, fittings in the pipe, velocity that is too high
What happens if velocity decreases
Pressure increases
Total energy in a closed system is the total head and is made of two components
Head pressure= from the pressure acting upon the liquid.
Velocity head = from the speed of the liquid
Total static head = long
Static discharge head and static suction lift are combined to equal total static head
Static discharge head is on the top
Static suction lift is on the bottom braking at the impeller eye
The measure of intensity of effort described as force per unit of area
Pressure
This term is used when the level of supply liquid is above the centreline of the pump
Suction head
The condition where the supply reservoir is located below the pump
Suction lift
Another name for regenerative turbine pumps
PERIPHERAL
This type of flow occurs when the particles of the liquid no longer move parallel to the pipe axis
Turbulent
The pressure at which a liquid flashes into a vapour
Boiling point
Pressure that is below atmospheric
Vacuum
Another name for an axial flow pump
Propeller
What type of flow are open impellers for?
Radial flow
