Pneumatics Flashcards
What components does a typical pneumatic system have?
Compressor, receivers, filters, pressure regulators, lubricator so, muffler, dryer, actuator, control valve, and conductors
Where should the air intake be located?
In the coolest place possible
What is the air receivers purpose?
To compensate for fluctuations in demand, and to dampen pulsations?
What is the regulatory division that enforces code, and does inspections regarding receivers?
Alberta boilers branch
What things must every receiver have?
Gauge, drain, pressure relief valve
What must the pressure relief valve be set at?
Must be set no higher than the lowest maximum pressure rating of any part in the system
How should safety relief valves be mounted, and why?
Vertically, usually on top, to prevent dirt and sludge from blocking them.
What are the three types of commonly used pipe systems?
The grid (dead end) system Decentralized system (unit system) Loop system
What is the preferred or recommended piping system?
The loop system
Describe the grid, or dead end system of piping
It is the simplest, only requires one compressor, usually starts with a larger diameter supply line that gradually decreases. One drawback, is that systems at the end of the line could face air starvation when upstream demand is heavy
Describe the decentralized (unit) system
it is composed of two or more compressors each with their own grid. The grids may or may not be interconnected. Its advantage of this is each compressor is close to its point of use which means there is less pressure drop and more uniform supply and pressure
Describe the loop system of piping
Two or more compressors feed into the same loop allowing compressed air to flow in either direction.
What materials are typically used for piping?
Plastic, brass, copper, aluminum, because they are all non corrosive. Black pipe is still commonly used due to its cost, but it is prone to rusting and scaling
What is a FRL unit ?
Filter, regulator, lubricator. They are installed in this order, and are often symbolized as a single valve in a drawing called a simplified air service unit
What are filters typically protecting from?
Contaminants from construction/assembly, oil and wear particles, pipe scale and rust.
How do you tell if an inline filter becomes plugged?
With gauges on either side you can see a pressure drop across the filter
Describe regulators
Different components require different pressures, and usually the supply from the compressor is too high. It is piloted downstream, with a gauge so proper pressure can be set.
What does the exhaust air contain?
It usually contains oil in the form of mists and vapours
Where is an oil lubricator located?
They are located close to the device that requires it. They are not transported all through the lines
What are some guidelines when dealing with oil in a pneumatic system
Prevent compressor oil from entering the airstream, put lubricator so close to the component they will lubricate
When does moisture fall out of compressed air?
When the dew point is reached
What do the symbols graphically portray?
Function, method of actuation, number of connection or ports, number of different switched positions, representation of flow path
Describe a lubricator symbol
Diamond shape with a small line coming from the top point
Describe a compressor symbol
Circle with a triangle pointing outward, and triangle is not coloured in
