Notecards Flashcards
Any force, which can stop or retard the movement of a body
Resistance
Energy can neither be created nor destroyed, although it may change from one form to another
Law of conservation of energy
An important consideration when dealing with energy is
The state or condition in which it is found
The application of a force to cause movement of an object through a distance
Work
How does a positive displacement pump work?
As the piston is pulled out and increasing volume is formed within the housing, the body and portal food to entered, filling the void. The plunger pushes in the ball at the in wet port closes. The food is pushed out while the ball at the outlet port is opened.
The volume of fluid flowing through tubing in a period of time is
Rate of flow
The generation of heat by working energy traveling through a system to a point of work
System in efficiency
A common food for a hydraulic system consist of
Paraffinic and naphthalenic petroleum oils
Besides acting as a medium for energy transmission the second most important function of a petroleum base fluid is
To act as a lubricant
The process of reducing friction between relatively moving surfaces, which are in contact is
Lubrication
The resistance of a liquid molecules to flow or slide past each other
Viscosity
Say Bo universal second is abbreviated as
SUS or SSU
American Society for testing materials is abbreviated as
ASTM
As high-temperature oxidation at pump outlet occurs resonance materials are formed, but dissolve in the oil when a hot surface is encountered
The resins come out of a solution for a varnish coding, the hot surface this causes moving parts to stick
Other than varnish, resonance materials can also form
Sledge which combines with dirt and floats around in the system plugging small openings
Dirt and a hydraulic fluid can
Plug, sensing orifices, causing moving parts to stick in where excessively
A high-pressure line with a pinhole leak, spraying and oil mist into the air is
A combustible mixture, which can be easily ignited by an open flame
Synthetic fire, resistant materials are man-made liquids, which are
Praised for their resistance to burning while performing close to petroleum oil with respect to lubrication
Atmospheric pressure at sea level standard conditions of 68°F and 36% relative humidity is
14.7 PSIA
To differentiate between two precious scales what does PSIG and PSIA stand for
PSIG denotes gauge pressure and PSIA denotes absolute pressure which is 14.7+ gauge pressure
Cavitation is the formation in collapse of gassiest cavities in a liquid. The two ways they are harmful are.
They interfere with lubrication and destroy metal surfaces
If a pump happens to ingest fluid within trained air, the air bubbles will have somewhat the same effect on a pump as cavitation however because it’s not associated with liquids vapor pressure it is referred to as
Pseudo cavitation
Hydraulic actuators convert
Hydraulic working energy into mechanical, working energy
Hydraulic actuators can be divided into two times
Linear and rotary
Full control valve is a resistance, which
Results in a higher pressure being applied by the pump
If I were operated, check valve will only flow through the outlet to the inlet when
As long as sufficient, pilot pressure is acting on the plunger piston
In cases of Hydro pneumatic, accumulators nitrogen is to be used and never should
Compressed air should never be used over oil
Since church accumulators are a source of hydraulic potential energy, stored energy of an accumulator can be used
To develop system flow when system demand is greater than pump delivery
For proper operation, a positive seal must exist across
A cylinders piston, as well as the rod gland
To protect against excessive shock, a cylinder can be equipped with these to slow down a cylinder, pistons movement before reaching the end of its stroke, and can be applied at either end, or both ends of the cylinder
A cylinder cushion
During retraction, when full pump flow is directed to the rod side of a single cylinder
A piston rod will retract faster than it extended
If more precise metering is required, this type of control valve is used
A pressure compensated flow control valve makes allowances for pressure changes ahead, or after the orifice
If control valve placed at the outlet, port of an actuator control controls, the rate of flow, exiting the actuator this is
This is a meter out circuit and gives positive speed control to actuators
Three-way directional valve can be used to operate
Single, acting actuators, like rams and spring return cylinders
A normally, non-passing pressure control valve, which causes one operation to occur before another is
Referred to as a sequence valve
A normally, non-passing pressure control valve can be used to balance or counteract a weight, such as a Platen of a press
This valve is called a counterbalance valve
A simple relief valve basically consist of a valve body with a spool, which is biased by a heavy spring it actuates by
When pilot pressure at the school and opposite to the spring is high enough, the school moves up opening a path to tank for pump flow
A pressure reducing valve usually is a
Normally passing pressure reducing valve
A pressure reducing valve operates by
Sensing fluid pressure after it has passed through the valve
Two variations of a positive displacement pump are
Fixed displacement and variable displacement
Out of the vein gear, and Pister motors which Are available as variable displacement, motors
Piston motors are available as variable displacement
What does breakaway torque mean?
A demand of load it must satisfy before it will rotate
Besides acting as a food container, a reservoir serves also to
Cool, the fluid, to allow calm contamination to settle out, and to allow in trained air to escape
Out of the L-shaped reservoir, the the overhead reservoir, and the conventional reservoir, which is the most commonly used industrial hydraulic reservoir
The conventional reservoir
Dirt was previously defined as any type of insoluble material in a hydraulic fluid the sources by which enters the system is
Built into a system, generated within a system, and added to a system
If not size correctly, improperly, maintain, this may starve the sump pump
Sump strainer
Positioned in the circuit between the pump and a system component
Pressure filter
