3rd 6th Month Final Flashcards
Not wearing required protective equipment
Unsafe acts
Four main types of hazards
Electrical, chemical, mechanical, and environmental
An example of Contacted-by accident
A splash from a chemical
If you discover a spill, do not attempt to clean it up unless
You have been specifically trained to do the job
What should you do first if you think you are in a dangerous situation that takes action right away
Ask your supervisor to eliminate the danger
What should you do if you see a way to make your job safer
Tell your supervisor about it
The hazard communication standard has five main objectives
Reduce workplace injuries and illnesses, require chemical manufacturers and distributors to identify chemical hazards, communicate chemical hazards to all employees, and to replace state right-to-know programs with a uniform federal standard, and
OSHA requires all employees to be
Trained to recognize and handle safely all chemicals at work
What section of the MSDS identifies the personal protective equipment required for your physical safety and also includes personal hygiene methods and ventilation recommendations
Control Measures
OSHAs main concern is
Employee safety
EPAs main concern is
Environmental protection
One responsibility of your employer regarding personal protective equipment is
Conduct a survey to identify the PPE to be worn in the workplace
Why do glove manufacturers publish the results of their testing in a chart
So the right gloves can be selected more easily
How much clearance should a hard hat provide
1” clearance between your head and the top of the shell
What offers better protection than safety glasses
Safety Goggles
Two kinds of atmosphere-supplying respirators
Supplied-air respirator and self-contained breathing apparatus
What are chemicals that cause explosions, fires, or violent chemical reactions
Physical Hazards
Chemicals that can cause illness or injury when inhaled, swallowed, or touched
Health Hazards
Health Hazard categories
Irritants Corrosives Sensitizers Target-organ chemicals* Reproductive hazards Carcinogens
From the stomach, chemicals go into the ________ where they are absorbed into the bloodstream and travel throughout the body
Intestines
What helps control chemical hazards
PPE (personal protective equipment )
What should you do for inhalation first aid
Assist the victim to an area of fresh air, outdoors of necessary. Get medical help
Wrench safety tip
Fully engage the wrench’s jaws with the nut
Gloves, ties, and loose clothing or hair is not appropriate around
Revolving tools like grinders, drills, and saws
What does the grounding (third) wire protect you from
Shock and burns
What should you do before you disconnect a pneumatic hose or tool
Turn off air supply and release the pressure
Gasoline engines should only be refueled after
Engine has cooled
80% of the workers who are injured while handling materials hurt the
Lower part of their backs
Important rule for lifting
Keep your back straight
Who is allowed to operate forklifts or special-purpose trucks
Only trained and authorized operators
Accidents can be prevented on conveyors if
Workers are careful to turn off power and lock it out while work is being done
When is it safe to stand under a suspended load
Never
Guards that do not move when the machine is in operation are
Fixed guards
If the guard is 32” or more from the danger point, the opening can be as large as
6”
What type of guard had no physical barrier between the operator and the danger zone
Presence-sensing guard
What must you do to bring a machine to a zero energy state
Push the start button to make sure the power is off. Then push the stop button to prevent accidental start-up once power is turned on again
When should tags be bypassed or ignored
Never
The loss in potential, per unit charge, is called? And is measured in?
Voltage drop or potential difference between two places.
Volts
How is Ohm’s law written
V = IR
A hot wire is either
_________ or __________
Black or Red
What will happen if u touch someone who is in contact with the electrical source
You will become part of the circuit too
What is the most common way of preventing the accumulation of static electricity.
Grounding
Unplanned connections to ground are called
Ground faults or unintentional grounding
Fuses and circuit breakers are designed to act as
__________ for electrical circuits
Safety Valves
An example of a typical hazardous electrical location is
Petrochemical Plants
If something is designed to release only low levels of electrical energy it is referred to as
Intrinsically safe
It is important to keep electrical enclosure doors secured and locked. And _______________ when equipment is energized
Door screws be tightened
The fire triangle does not take in to account what fourth element
Chain Reaction
The combination of the the four fire elements make up the
Fire pyramid
What class are fires of flammable or combustible liquids, gases, grease, and similar materials
Class B
What is the symbol for class B flammables
Red Square
What puts out a fire by reducing the temperature of the fuel
Water
What should you do with a fire extinguisher after use
Turn in for refilling
What should you use to lift instead of your back
Legs and arms
Alpha, beta, and gamma rays are examples of
Ionizing radiation
Workers can be exposed to __________ when performing brake or clutch repairs
Asbestos particles
Who has issued many rules and regulations governing the control of chemicals and waste
EPA (Environmental Protection Agency)
Any platform or work surface above ______ feet requires fixed railing
Four
How far out a ladder should be placed from the wall is called the
4 to 1 rule. Ladder should be 1/4 the working length from the wall
What occurs when the body cannot cool itself sufficiently
Heatstroke
What is one of the most important safety concerns for workers in confined space
Atmosphere
_______ is a very sensitive organ and is particularly vulnerable to the intense light, radiation, heat, and sparks from welding
The eye
Pneumatic equipment may be different, but they all convert __________ in to work
Compressed air
An example of a positive-displacement compressor
Reciprocating piston
A piston moving back towed the crank created enough pressure to permit air at __________ to open the valve and push air into the expanding space
Atmospheric pressure
_________ power is needed to compress the air because cooling between stages reduces the volume of air that is compressed in the second stage
Less
the two primary functions of compressor lubricating oil are to reduce friction and to
Improve the transfer of heat in the compressor
Relieving the internal pressure so a compressor is easier to start is called
Unloading
Single stage vane compressors are capable of developing up to ______ psi discharge pressure
50psi
Screw compressors operate at speeds between ________ and ________ rpm
3,000 and 12,000 rpm
An example of a low-pressure high-volume compressor is a
Impeller compressor
Two disadvantages of centrifugal compressors are
They require more horsepower per CFM than other compressors and they operate at very high speeds
The most efficient method of controlling centrifugal compressor output is
Speed variation
Unless really dry air is required, most plants simply _______ the _______ with an after cooler and remove condensed vapor
Cool the air
_________ ___________ is economical for large compressors or any that operate more than 10 hours a day
Water Cooling
What is caused by the physical attraction that an unsaturated desiccant and moisture have for each other
Adsorption
When the air receiver is the correct size for the volume of air in the system it allows the receiver to balance off available compressor capacity against
Much larger peak air-flow demands that occur
How does a non-centrifugal inertial separator work
Instead of following a circular path, the airflow is made to change direction sharply several times as it passes through the filter
Very fine oil particles in compressed air are called
Aerosols
If a filter stops 100% of a given particle size, the size is referred to as its
Absolute rating
Wetted filters have a higher initial cost than dry filters because they can be
Cleaned many times
With this type of lubrication, more positive lubrication is available at greater distances from the lubricator and is especially effective with complicated piping systems and intermittent equipment operation
Fine lubricators
What occurs when air-flow velocity is increased or air is forced to flow through a smaller line
Turbulence
_________ pressure is affected more by friction with the walls of the piping than is airflow at ___________
pressure
Lower
Higher
All horizontal Compressor discharge and distribution lines should slope approximately __________
The slope should be __________ in the direction of the airflow
1” for every 10’ of pipe
Downward
NPT has a spiral clearance along the crest of the thread, and it seals against air leaks with flank-to-flank (side to side) contact, with the aid of
Pipe compound (pipe dope)
When disconnecting air lines, a blast of escaping air can blow _______ or ________ into your eyes or face
Dirt or chips
A valve with four primary connections and either four or five external ports
Four-way valve
A special four-way valve with five external conditions, all connected to primary system connections
Five-way valve
An excellent valve for very high-pressure service or as a throttling or flow-reducing device
Needle valve
The most widely used valve that is easy to operate, even with high pressures, because the internal forces balance each other
Spool valve
Valves that are used to simplify pneumatic circuits
Four-way valves
Many four-way valves have two _________ ports, but are still classified as four-way valves
Exhaust
The pressure at which the valve initially opens, determined by the adjustment of the spring
Cracking pressure
Diaphragm relief valves open much faster than poppet valves because
The compressed air works on a larger pressure-sensitive area than in a poppet valve
A valve that it’s only job is to protect the system and its components from damage in the event that the pressure control should fail
Pressure-relief valve
How does a pressure regulator work
As air passes through the regulator outlet, a small amount is bled off into the underside of the diaphragm, forcing the diaphragm upward against the spring pressure. When the secondary pressure equals the spring pressure, the sealing element is pulled upward, closing off the valve opening. As the secondary air is used, the line pressure drops, allowing the diaphragm to move down, which permits more air to flow through the valve
A valve that restricts the amount of exhaust air that can pass from the cylinder through the valve and governs the speed at which the cylinder can retract
Exhaust-flow control metering valve
Pivoted cylinder mountings are classed as being
Trunnion or clevis
Checking a control valve to determine if it is capable of handling the air of a cylinder is commonly referred to as
Calculating the capacity coefficient
Piston motors have a stalling torque almost __________ the starting torque. It takes less torque to keep a motor turning than to start it. And even more torque to stall it
Double
The horsepower output of pneumatic motors is the product of
Shaft speed and torque
On a typical horsepower curve, the maximum power output is obtained at ________ speed and _________ torque output
Medium
Medium
The thrust of the piston against the _________ ________ attached to the offset shaft causes the cam plate to rotate
Wobble Plate (or cam)
The force of a hydraulic fluid is spread over a __________ area, so it creates a ________ pressure
Smaller
Greater
What takes in a volume of air from the atmosphere and compress it to a smaller volume to increase its pressure
Compressor
What are centrifugal and axial-flow rotary compressors classified as
Dynamic or nonpositive-displacement
What generally determines the size of a filter
Intake requirements
Why is corrosion resistant piping used
Because water tends to promote rust and scale in pipes and fittings
After lubricating oil is added, the air should travel no more than
30 feet
What are used for showing the physical relationship and interconnections between components
Pictorial symbols or views
What symbols clearly emphasize the function and method of operation of components
Schematic Symbols
Pilot and signal lines are drawn as a
Series of long dashes
Understanding a circuit can be best accomplished by studying
Small segments at a time
What happens when it is almost impossible to draw it as a composite schematic symbol, or even as a cutaway view
Manufacturer then devises a graphic symbol
According to ASME codes, receivers must be equipped with
Pressure gauges and safety valves
Slightly oversized pipe sizes are especially desirable when
The pipes are long and the system must meet the demands of a considerable number of tools or other types of pneumatic equipment
Pipe supports should be placed close enough together to prevent
Any appreciable sag
If a tubing flare is not a good one, what should be done
Cut it off and do it over
As a general rule, how long can pneumatic hoses be
Should not be any longer than necessary
What is the purpose of a planned maintenance program
To ensure that all equipment is checked on a regular basis
What can excessive line pressure result in
Accelerated wear
Air control valves for industrial control circuits are, for the most part, designed and built for use with pressures up to
150 psi
When is it best to do a daily maintenance report or checklist
Beginning of shift
Where can you usually obtain records of control-valve and cylinder operating cycles
Production records
Troubleshooting checks themselves are determined by
Type and number of components and by the operation that the machine performs
In many plants, the sequence of troubleshooting starts at the ________ ________ and proceeds through the system to the actuator
Air supply
The system description and operation section provides a concise description of
Signal, logic, and actuation functions
What happens when piston seals become worn and leak
Air continually leaks through the exhaust ports
If the valve action is sluggish, check the ________ _________ for insufficient lubrication or swollen seals
Moving parts
Heat generated during compression is controlled in what two ways
Cooling and limiting the pressure of the compressed air
If the surrounding air is dusty or oily, more frequent cleaning, possibly with a ___________ or __________, is required
Detergent or steam
The shorter life of discharge valves is a result of heat and accumulation of ____________
__________
Carbon deposits
One way to check if the trouble is in the starting unloader system, is to let out all of the air in the ___________
____________ and start the compressor again
Compressor reservoir
3 maintenance items that are the same for all rotary compressors
Lubrication, bearings, and seals
A control malfunction can be isolated by analyzing the performance, or lack of performance, of the
Components in the pneumatic circuit
In some circuits a loss of power may put the circuit _________ ___ ___________ or stop it entirely
Out of sequence
Solenoids are activated by a magnetic field set up by the flow of __________ _____________ in the coil.
Electrical current
Air demands from other machines connected to the common air supply may periodically __________ _____ ________ ________ ____ ____ _________
Where the circuit is troublesome
Reduce the air pressure to a point
Valve shifting without a signal is caused by one of two factors
Vibration or momentary loss of pressure
Heavy oils are not recommended because they can gum up or form _________ on the moving parts of the valve and in its bore
Varnish
If the controls stick, check to see if the seals are
Swollen or soft
What kind of cylinders are used in most industrial applications
Tie-rid cylinders
Most industrial pneumatic cylinders are supplied with a bushing or gland in the front head. This gland acts as a support, or ___________, for the piston rod as it travels back and forth during its work cycle
Bearing
Most pneumatic cylinder seals have a maximum heat resistance of 180F to ________F. Applications that involve higher temperatures or other harmful conditions require special seals
200*F
Improperly torquing tie-rods causes
Internal misalignment
The only function of the cushion sleeve is to protect
The cylinder from damage
Without clean, filtered air, air motors will have a
Limited service life
When installing couplings, lubricate the nipple and inside the hose with a _________ _________ if the fitting is difficult. Never use oil or grease on a coupling
Soapy solution
When you repair air motors or tools, remember that they are
Precision built
Inspect the ________ or __________ ___________ of a pneumatic grinder
Arbor or motor shaft
Because of their _________ ____________ ___________, radial-piston air motors require less maintenance than other air motors
Slower operating speeds
In air-oil tanks, because the hydraulic oil is pressurized by compressed air, the pressure achieved in the system is substantially lower than that of a conventional hydraulic system. To overcome this lower pressure, relatively large _________ ___________ are required for anything except low output force.
Work cylinders
The main components in a booster are its
Air piston and hydraulic ram
The __________ ____________
Valve is used to adjust the oil levels between the makeup tank and return tank
Manual shutoff
The possibility of air leakage in an air-oil cylinder is eliminated by placing a ________ _________ or _________ between the two sets of rod seals in the center of the unit
Bleeder space or passage
The two independent actions of a air-hydraulic system are used for economy and ________
Speed
In an automatic interlocked air-oil system, the two actuating valves reduce the response time required for the valve shift, which increases
The speed of operation
Pipe up to 12” diameter usually is designated by its
Nominal inside diameter
Pipe is generally coated on the outside with galvanizing, paint, insulation, or some other substance to prevent
Corrosion, condensation, and heat loss
The thread used on pipe is the
Tapered “V” shape AS or NPT
For low pressures and cold services, _________ gaskets are generally used
Rubber
To differentiate between pipes carrying different substances, pipe systems are often
Color coded
All pipe systems should be installed in accordance with the
American Standard Code of Pressure Piping
Piping should be supported to provide the necessary rigidity to
prevent Metal fatigue, prevent sagging, and to provide drainage
__________ strainers are commonly used where frequent cleaning is necessary
Duplex
__________ ___________ strainers are used to automatically strain raw water to remove silt and debris
Self-cleaning
Warm-up or __________ ____________ lines reduce wear and make large valves easier to open
Pressure equalizing
A ____________ line is used to control the concentration of impurities in a pressure vessel
Blowdown
The most versatile of the many kinds of plastic pipes is __________. It is inert in continuous service to all acids, caustics, chlorides, solvents, and bleaching agents
Teflon
An unexpected event that results in injury to an employee, illness, or damage to property
Accident
Force per area unit
Pressure
The input component of a system
Pump
The output component of a system
Actuator
The power source of a system
Prime mover
How to abbreviate Mercury
Hg
What is caused by a resistance to flow
Pressure
The pressure at the pump is the _________ of the pressure required to open individual valves
Sum
