Why are pneumatic cylinder bodies built with lower structural strength material?
Pneumatic Cylinders operate at much lower pressure
What would be the reason for actual performance to deviate from estimated values?
- Air Compressibility
- Air Leakage from the cylinder
- Temperature changes causing pressure changes for the fixed chamber volume
How would increasing the number of vanes in a pneumatic motor impact the following parameters?
Torque
Rotational Speed
Air Leakage
Friction between vanes and housing
Torque - Increases
Rotational Speed - Decreases
Air Leakage - Decreases
Friction between vanes and housing - Increases
What is the minimum number of vanes in a pneumatic motor?
3
What is the main difference between an anvil and a rod in a pneumatic cylinder?
The anvil is a metal part that is not connected to but is in contact with the piston at specific points of time. The anvil will only move forward if the piston hits it.
List 3 conditions for selection of air intake locations in a pneumatic system
- Avoid areas with dusty air
- Shield intake from rain water
- Shield intake from sunlight
Classify the 3 intake-line filters in pneumatic systems
- Dry
- Oil Bath
- Oil Wetted
Define dew point
The temperature at which water becomes water droplets
What happens when water drops below dew point?
The water will become water vapour and condense itself into a solid
How does air temperature change along the working lines?
The temperature in the working lines decreases
What are two issues resulting in the working lines caused by temperature drops?
- Pressure Drop
- Water Condensation
How is centralized different from decentralized distribution systems?
- Centralized system has one compressor station that feeds multiple work stations
- Decentralized system has multiple compressors feeding 1 or 2 work stations
List the 6 factors that contribute to pressure drop in pneumatic lines
- Absolute roughness
- Hydraulic Diameter
- Pipe Length
- Fluid Density
- Fluid Viscosity
- Average Flow Velocity
List the factors required to size a receiver
- Compressor volume flow rate
- Min and Max compressor settings
- Compressor idle time
- Atmospheric Pressure
What is compressor idle time?
The time it takes for the receiver to go from max pressure to min pressure
List the 4 groups of distrubution systems in pneumatic systems
- Fixed piping: Centered grid system
- Fixed piping: De-centralized grid system
- Fixed piping: Loop System
-Flexible hosed portable compressors
What is the main advantage of loop distrubution system?
It runs parallel to the reciever which reduces flow speed but reduces pressure drop which then reduces power consumption then reducing operating costs
How would pressure drop change with increasing air viscosity?
Increasing air viscosity will cause a larger pressure drop
What are two techniques used in two-stage filters?
A two stage filter uses centrifuged and straight filtering to work
Which two forces are required for an automatic draincock to open?
Air pressure and the weight of impurities filtered out
What does FRL stand for?
Filter, Pressure Regulator and Lubricator
