1. Manufacturing Engineering Hydraulic and Pneumatic Systems
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2. History of Hydraulic and Pneumatic Systems
Throughout the history of mankind manual labor has been used to build, develop and advance our societies to a higher standard of living. With the dawn of the industrial revolution, engineers and inventors looked for new and more efficient ways to manage labor. They found their answer in technology.
NOTES:
Show examples and discuss the efficiency of the waterwheel and windmill
Systems - two early uses of hydraulic and pneumatic power.
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3. History of Hydraulic and Pneumatic Systems
The technological advancements of the 21st century have allowed us to understand advance concepts in the design and use of hydraulic and pneumatic systems .
NOTES:
Show and discuss examples of modern hydraulic and pneumatic equipment.
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4. Copyright © Texas Education Agency, 2012. All rights reserved.
Hydraulic Systems
Hydraulic systems operate on the principle of Pascal's Law. This principle states that when pressure is placed on a confined fluid, the pressure (force) is transmitted in all directions equally.
Piston -B
Piston -A
NOTES:
Hydraulic Presses, (2012)
Pascal’s law is based on the principle that liquid can not be compressed.
When pressure is applied, equal force (pressure) is transmitted throughout the
entire system. A small force can then control a large force. This force can be
used to accomplish work in linear, rotational, etc., direction. Heavy tasks like lifting,
pressing, pulling, cutting, drilling can be accomplished with minimal human effort.
Safety Factors:
OSHA Safety Hazard Information Bulletin on Hydraulic Systems Preventive
Maintenance, (1992)
Safeguarding Equipment and Protecting Workers from Amputations,
(2001)
Discuss the safety aspects of working with fluid under pressure. Some hydraulic
systems are pressurized up to 5000 pounds per square inch, or more. High pressure
leaks are dangerous!!!! High pressure fluid from small openings in the lines can
pierce skin and cause serious injuries. It is important to use correct lines and
properly tighten all connections during maintenance. Also relieve all system pressure
before disconnecting lines.
Fluid under Pressure; Equal force throughout system
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5. Hydraulic Systems Hydraulic Cylinder Hydraulic Motor Reservoir
NOTES:
A typical hydraulic system is shown above. Discuss the list of components below.
Additional components are on the list for added discussion.
Actuators: converts the hydraulic pressure (energy) to mechanical energy to
operate the load.
--cylinder - converts hydraulic energy to linear energy to operate piston rods
--hydraulic motor - converts hydraulic energy to rotational energy to rotate a
shaft
Pump: provides a pressurized fluid supply to the hydraulic system to operate the
Actuators; pressure may be pounds per square inch (psi), or more
Gauges: provide an analog or digital indication of system pressure
Pressure relief valves: placed in specific locations in a hydraulic system to
relieve excess pressure to prevent system overload which would result in leaks,
damaged components, etc.
Control valve: used to direct fluid to the proper component, like an actuator,
gauge, output line, etc.
Filter: a critical component used to trap particles (usually metal or dirt) that could
clog and damage system components
Reservoir: serves as a storage container for hydraulic fluid
Hydraulic fluid: liquid used to circulate through a hydraulic system to transfer
energy between components and to the load; the fluid provides cooling and
transfers particles (contaminants) to the filter
Tubes / Hoses: stainless steel or rubber connecting lines that connect system
components and are used for fluid transfer
Fittings / connections: threaded or clamped connections that are used to connect
the tubes and hoses to system components; must be of proper size and
orientation to prevent leaks
Hydraulic Lines
Filter
Control Valve
Pump
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Return Line

6. Copyright © Texas Education Agency, 2012. All rights reserved.
Pneumatic Systems
Pneumatic systems convert the energy from compressed gas (usually air) into mechanical energy.
Mechanical energy is used to perform work through cylinders or rotary actuators (drilling devices).
NOTES:
Hydraulic Presses, (2012)
Discuss the similarities and advantages of both hydraulic and pneumatic systems.
Pneumatic systems have many similarities with hydraulic systems.
Both systems use a pressurized, liquid medium (hydraulic fluid and air are liquids),
lines, control valves, cylinders and actuators.
Pneumatic systems have distinct advantages over hydraulic systems:
Lower pressure (usually less than 300 psi), no chance of fluid spills or product
contamination.
Pressurized air can be stored for later use if power is not available from the
compressor.
Hydraulic systems have distinct advantages over pneumatic systems:
Hydraulic systems are very stable under load and can carry very high load
capacities.
Safety Factors :
Construction Safety and Health: Hand and Power Tools,
(1996)
Discuss the safety aspects of working with pressurized. Some pneumatic
systems are pressurized up to 5000 pounds per square inch, or more. High
pressure leaks are dangerous!!!! High pressure air from small openings in the
lines can pierce skin and cause serious injuries. It is important to use correct
lines and properly tighten all connections during maintenance. Also relieve all
system pressure before disconnecting lines.
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7. Copyright © Texas Education Agency, 2012. All rights reserved.
Air hose connection
Pneumatic System
Pneumatic Cylinder
Compressor
Storage Tank
Relief Valve
NOTES:
A typical pneumatic system is shown above. Discuss the list of components below.
(remind students that there are close similarities between the components in both
hydraulic and pneumatic systems)
Pneumatic system terms:
Actuators: converts the pneumatic pressure (energy) to mechanical energy to
operate the load.
--cylinder: converts pneumatic energy to linear energy to operate piston rods
--pneumatic motor: converts pneumatic energy to rotational energy to rotate
a shaft  
Gauges: provide an analog or digital indication of system pressure.
Control valve: used to direct air pressure to the proper component, like an
actuator, storage tank, output line, etc.
Pressure relief valves: placed in specific locations in a pneumatic system to
relieve excess pressure to prevent system overload which would result in leaks,
damaged components, etc.
Compressor: a key component in a pneumatic system and is used to pressurize
air and transport it through the system.
Gauge
Control Valve
Control Valve
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