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57 Cards in this Set
- Front
- Back
What is the definition of a compressed air system? |
Pneumatic systems that operate above atmospheric pressure and are used as a source of energy to drive numerous types of equipment |
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What are the typical components of a pneumatic system? |
Compressors, receiver tanks, filters, pressure regulators, lubricators, mufflers, dryers, actuators, control valves (pressure switches), conductors, drains, and safety relief valves. |
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Where do you want your inlet installed for your compressor system? |
In a cool shaded place. Cool air is ideal for compression. |
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How much air supply must the receiver tank hold? |
Enough to prevent a pressure drop of more than 5psi what all service outlets are being used. |
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What should the delta P be on a compressed air system? |
15psi. |
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What is the most common type of compressor? |
Belt-driven type. |
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Receivers are usually equip with what to control operation of the compressor in response to pressure drops due to usage? |
A pressure switch. |
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On smaller systems without aftercoolers, what do they use to cool the air and allow moister to settle out? |
The receiver. |
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What is best practice for installing piping for a compressor? |
Fewest bends possible and large enough to minimize pressure drop. |
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What is an air receiver and what codes are enforced for it? |
An air receiver is a pressure vessel and applicable codes are enforced under the alberta boiler and pressure vessels act. |
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What must a air receiver (pressure vessel) have? |
A gauge, drain, SRV, and connections to the piping system. Large systems must have a manhole. |
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What does the pressure switch control? |
The compressor cycle cut-in and cut-out pressures. |
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What should the PRV be set to on the receiver? |
10 psi above the cut out pressure setting. |
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If shut off valves are required, where does the PRV go? |
Must be mounted on the compressor side of the shut off valve. |
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Where do you install an automatic moisture trap? |
On the lowest part of the receiver. |
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Where should the water be discharged from the moisture trap? |
To a floor drain. |
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What must you never do to suction piping? |
Reduce it to less than the compressor intake. |
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Where is an oil separator installed and what is it used for? |
Between the compressor and receiver and are used to prevent lubricants from the compressor from reaching the receiver. |
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What is the role of the aftercooler? |
To bring the temperature of the compressed air down to ambient temperature. |
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Aftercoolers the same size as the suction piping should be installed where? |
Between the compressor and receiver, grading towards the receiver. |
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If the length of the aftercooler exceeds 3 meters, what must you do to the suction pipe? |
Increase it 1 pipe size. |
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What are the two models or aftercoolers? |
Water-cooled and air-cooled |
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What is the role of the intercooler? |
Their purpose is to cool the compressor air by 10F between the cylinder stages. |
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Where is the intercooler mounted? |
Between the cylinders. (Finned pipe) |
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What percentage does the intercooler reduce the average power requirements of a compressor? |
15%. |
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What is the role of compressor unloaded valves? |
To limit pressures according to fluctuations in demand. A form of control to prevent over pressure and possible explosions. |
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What type and material should air dryers be? |
Absorptive type and should be made of silica gel, activated alumina or an equivalent. |
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Where are dryers installed? |
Downstream of the receiver tank. |
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What can be advisable to install at the immediate upstream of then hose connections? |
Dust filter. |
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When are oil lubricators sometimes required? |
For automatic lubrication of pneumatic tools. |
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What is the most common type of compressor for small and medium installations? |
Piston-type (reciprocating) compressors. |
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What are the ranges on a reciprocating compressor? |
40cfm to 10,000cfm and 20psi to 30,000psi. |
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What is a variation of reciprocating compressors? |
Diaphragm compressor. |
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How does a diaphragm compressor work? |
Has a diaphragm mounted above the cylinder, which prevents contaminants such as compressor lubricants from entering the airstream. |
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Where are diaphragm compressors used? |
In clean rooms such as hospitals, food processing plants, and medical/pharmaceutical industries. Applications where clean are is essential. |
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What are mechanically actuated diaphragm compressors manufactured for? |
Low flow rates, moderate pressures and vacuum service. |
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If higher pressures are needed, what type of diaphragm compressor is used? |
Hydraulic. |
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What are the 2 type of rotary vane compressors? |
Single vane Multiple vane |
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What are the two type of flow (dynamic) compressors? |
Screw (axial) compressors or turbo (centrifugal) compressors. |
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What speeds to flow (dynamic) compressors operate at? |
In excess of 5000 RPM |
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What is the most popular style of compressor for industrial applications? |
Screw (axial) compressors. |
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What is the max pressure drop during peak demand on an air distribution system? |
5psi. |
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What is required on a horizontal distribution piping system? |
That all pipe is graded in the direction of flow. |
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What pipe can be used in a small distribution system? |
It may consist of copper (type K or L) that is soldered or brazed. |
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What pipe can be used in a larger air distribution systems. |
Sched 40 black iron joined with threaded joints for up to 2” and welded joints over 2”. |
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Where should individual service outlets be taken off from? |
The top of the supply main and should be equip with a drip leg below each air hose connector. |
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To obtain 1 cubic foot of compressed air at 100psig the compressor needs to move: |
7 cubic feet of air into the suction inlet. |
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Air has the ability to hold how much extra/less moisture for each 20 degree Celsius change in temp? |
Rise- twice as much Drop- half as much |
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What is an FRL? |
A filter,regulator,lubricator is used to get rid of contaminants, adjust pressure, and add or remove oil. |
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Does a FRL have a direction of flow. |
Yes. You MUST install correctly. |
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At 2000m above sea level, air is approximately how heavy? |
80% of the volume at sea level. |
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At 2000m, how much more air must be delivered to the compressor suction? |
30% more. |
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What you should you do to the main line to cover potential expansion? |
Increase the length with a “little bit extra” |
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What materials are commonly used in compressed air systems, because they are non-corrosive? |
Plastic, brass, copper, and aluminum. |
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Black pipe is still commonly used because it is low cost, but what is the drawback? |
Causes rusting and scaling, leading to major system trouble. |
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What is the logical pipe choice for small to medium size systems? |
Plastic. |
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What is the advantage of plastic coil piping? |
Can drastically reduce the pressure loses that normally result from using standard pipe fittings and sharp changes of direction. |