Homework - Hydraulic & Pneumatic Review & Pneumatic Review Flashcards
Pascal’s Law deals with measuring the amount of force that acts on a unit of area. The formula we use to express this is:
F=A x P
Volume is the amount of space a fluid occupies. The formula we use to express this is:
V=A x D
A gain in mechanical advantage is achieved using:
Different size pistons and constant pressure.
Viscosity is:
The internal resistance to flow.
The flash point is the temperature at which a liquid gives off vapor in sufficient quantity to ignite ___________ when a flame is applied.
momentarily
Vegetable based fluid is dyed ______ Seals used are ________________
Blue, Natural Rubber
Mineral based fluid is dyed ______ Seals used are _________________ or _______________
Red, Neoprene or Buna N
Phosphate-ester based fluid is dyed ______________ Seals used are ________________
Purple, Teflon
Skydrol hydraulic fluid:
Is susceptible to water contamination.
Mil-H-5606 fluid has a _____________base.
Mineral
Mil-H-8446 fluid has a ___________-______base. Trademarked as ____________________
Phosphate-Ester, Skydrol
Baffles and fins are sometimes installed in reservoirs to prevent ____________ and _____________ of the hydraulic fluid.
vortexing, surging
The Standpipe is for __________ use.
Normal
The integral reservoir _______ be easily removed.
Cannot
How do we prevent the empty space before the engine driven pump?
Bleed it
Pressurized reservoirs are typically found on:
Transport category aircraft.
The purpose of an aspirator is to:
Pressurize the reservoir.
Two other sources of pressurizing the reservoir are:
Bleed air, hydraulic system pressure.
Hydraulic pumps:
Move fluid through the system and create flow.
A pressure regulator, or unloading valve, must be used with a __________displacement hydraulic pump. Why is it called that? _______________________________________________________
Constant, maintain system operating pressure & unload the pumps.
Hydraulic fluid flowing through a gear-type pump moves ___________ the gears.
Around
What does a pump utilize if the gear seizes to prevent damage to engine gear box? _____________________________________________________________
Relief Valve
A flow control valve that allows flow in one direction but no flow in the opposite direction is a/an _________ valve.
Check
A flow control valve that allows flow in one direction but a restricted flow in the opposite direction is a/an _________ valve.
Restriction
A mechanically operated flow control valve that prevents fluid flowing to one unit before some other unit has actuated completely is called a/an __________ valve.
Sequence
A pressure-operated flow control valve that prevents fluid flowing to one unit until another unit has actuated and hydraulic pressure has built up to a value high enough to shift the valve is called a/an _________ valve.
Priority
A thermal relief valve is adjusted to relieve at a pressure ________ than that for which the main system pressure relief valve is adjusted.
Higher
Another name for a system pressure regulator is a/an/ __________ valve.
Unloading
In order to store an incompressible fluid under pressure in a hydraulic system, a/an _____________ must be used.
Accumulator
The initial pressure of nitrogen used in an accumulator is called the __________. Why would fluid come out the nitrogen port _________________________________________________
Schrader, Ruptured separator/seal
What are three types of accumulators
1.______________
2.______________
3.______________
- Diaphragm 2. Bladder 3. Piston
If preload was at 100 psi and system was pressurized to 600psi; what is the pressure on the air side? _____________
600
If a hydraulic filter clogs, unfiltered fluid flows thru through the system through a __________ valve in the filter. The indicator is called __________
Bypass, Pressure Relieve Valve
An open center selector valve is connected in __________.
Series
A closed center selector valve is connected in _________.
Parallel
Rotary, spool, and poppet valves:
Direct fluid to and from actuators.
Shuttle valves automatically ________ fluid from two sources.
Direct
Check valves allow flow in ______ direction(s) only.
One
Orifice check valve or restrictor valve:
Allows free flow in one direction and restricts in the other
Sequence valves:
Are used to properly sequence events
Priority valves are ____________ actuated.
Hydraulically
Hydraulic fuses:
Provide protection to our hydraulic system in case if electrical overload. Block the line in case of a major leak.
A rotary actuator converts force from a _________ direction into a ___________ motion.
Linear, Rotary
Gaskets are used in applications that _________ relative motion.
do not have
Packing’s are seals that are used in applications that _________ relative motion.
Have
A chevron seal is a ________ seal.
One-way
An O-ring seal is a ___________ seal.
Two-Way
If the pressure in an O-ring seal application exceeds 1500 psi:
The seal may extrude out of the groove.
What color dot or stripe is on the packing for the following fluids? MIL-H-5606 O-Rings _____________ Skydrol (8446) O-Rings ____________ Fuel O-Rings ___________
Blue, Green, Red
Actuators convert fluid pressure to ________.
Work
High heat generated in the lines from pressure and high flow rates can be prevented with the use of ___________________________________
Heat Exchanger
Why are quick disconnects used?
Minimize fluid loss. Prevent contamination
A low-pressure pneumatic pump is typically used for:
Instrument air
Engine bleed air used for _______________ pressure pneumatics typically fall in the range of ?
Medium , 100 to 150 psi
High pressure pneumatics typically fall in the range of
1000 to 3000 psi
The most important consideration in a full pneumatic system is removal of ___________.
Compressed Air
Pneumatic systems utilize:
Check valves
The most likely place one would expect to see a full pneumatic system is:
In a contemporary general aviation aircraft.
Oil from the discharge of a wet-type air pump is collected by a/an ________________ and returned to the engine.
Collector
The vanes of a dry-type air pump are made of ___________________.
Carbon
The air pressure in a full pneumatic system is maintained in the correct range by the action of the ________________ valve.
Control
Water is removed from the compressed air in a full pneumatic system by the ____________________________.
Vapor Separator
Pneumatic systems utilize:
Relief valves
(1)Relief valves are used in pneumatic systems as damage-preventing units. (2)Check valves are used in both hydraulic and pneumatic systems.
Both statements are true
The air that is expended and no longer needed when an actuating unit is operated in a pneumatic system is.
Exhausted or dumped, usually overboard.
Relief valves are used in pneumatic systems.
As a damage prevention units.
Name two advantages of a pneumatic power system when compared with a hydraulic one.
Free and No return line
- What type of linear actuator is this? ———————
_____________________________________________
Single acting linear
- What type of linear actuator is this? ———————
_____________________________________________
Double-acting unbalanced
- What type of linear actuator is this? ———————
_____________________________________________
Double-Acting Balanced
