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Pneumatics
Being the driving force behind most factory, manufacturing, mining machinery, heavy vehicles and equipment, pneumatics are a vital part of our industry today. The field of pneumatics is vast and knowledge is constantly requested in the workings and troubleshooting thereof.
464 Questions
How does a pneumatic cylinder act with water in the air?
Air cylinder or air rams consists of a tube with a sealed base, a piston attached to a rod and a gland to seal the tube and rod where the rod exits the barrel. This assembly is called the cylinder or ram.
The ram is ported in the top and bottom to allow pressurized air to enter and exit the cylinder. This moves the piston which is attached to the rod and created the movement.
Cylinders are usually stationary at one end and the rod is attached to a moving part. This is called a double-acting cylinder because pressurized air can be let into both sides of the cylinder to create movement.
A single-acting cylinder relies on gravity to extend or retract it as it is only ported on either the top or bottom side of the cylinder.
What is the input output fault finding technique?
Its fairly self explanatory, put the input IN then check the output at the OUTPUT.
What are static load and dynamic load?
A static load is the effect of gravity on an object or structure.
A dynamic load is the forces that move or change when acting on a structure.
Example of a dynamic load:
Force of wind or the weight of a truck
Example of a static load:
Weight of a bridge
How do you maintain a pneumatic system?
use two syringes attached with tubing, make sure one is totally pulled out and the other is all the way in. apply force to the syringe that is out and the other one should go out. if you can make a hydraulic system, because liquid cannot compress, and air can, meaning the hydraulic system will work faster than a pneumatic system.
How is hydraulic system better than pneumatic system with a brief disicussion?
Difficult question to answer without context. Key thing to understand is a pneumatic system uses a compressor, whereas a hydraulic system uses a pump.
Hydraulic fluid is essentially incompressible, whereas compressed air will fill any volume.
Ask yourself: What is my pneumatic/hydraulic system supposed to do?
How fast should it react and what horsepower is available to drive my compressor/pump? What force do I need at my actuator/motor or whatever the system is expected to power?
Generally, I think pneumatic systems can react more quickly but power density is lower, so if the load is very high a hydraulic system might be better.
A typical shop pneumatic system might only operate at 50psi, whereas a hydraulic system can operate at 3000psi.
Finally, it's also worth thinking about system safety: if a pneumatic component fails, there will be an explosive decompression, but if a hydraulic component fails, it will leak but will not explode because hydraulic fluid does not store energy, it only transmits it.
They are powered by compressed air, supplied via an air-hose under high pressure from an electric or petrol engined compressor.
Examples of pneumatic systems?
Simplest example I can think of is possibly an automatic door, where the pneumatics are pushed along, operating the valve which opens the door. Where a pilot makes it return to its original position.
Pneumatic pressure is the pressure exerted by a pressurized gas.Compressed air is commonly used for this purpose.Vehicle tires are inflated with compressed air or nitrogen.Placing a pressure gauge on the valve will read a number on the dial, say 28 or 32.Which means the pneumatic pressure exerted by the gas inside the tire is 28/32 psi.
How do you decide when to use pneumatic or hydraulic power?
when high power transmission is involved then hydraulics is the best option this because there are hydraulic fluid available to suit the various pressure levels. liquids have almost zero compressibility.
in pneumatic system air is the working fluid, too high pressure could compress the air to such an extent to liquify it causing the tubes to crystallize and burst it. air is highly compressible and hence power loss should also be accounted for the compressed air so only low power systems possible here eg: pneumatic door openers .
Is a crane a pneumatic or hydrolic system and why?
Older type cranes used pneumatics for the operation of the crane's control systems. The actual movement of the crane's working components are usually operated by hydraulic cylinders or winch systems. The winch systems used to be powered by mechanical friction mechanisms but are typically powered by hydraulic motors today. Typically, pneumatics are never used to power the crane's load bearing functions
Why we don't use high pressure in pneumatics?
one reason air is much harder to control the heat and air has a lot of water in it and a hydraulic system dose not need water in the hydraulic oil. There is no way at the high pressure that a hydraulic system has to work at,it would not be possible to control the heat.
How are pneumatics better than hydraulics?
Poster below is correct. Air systems typically have a tank that is the analog of a hydraulic reservoir.[ebolton]
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Actually there is need for air reservoir in industrial pneumatics systems.
Hydraulics can handle more powerful aplications than pneumatics for the same overall dimensions, or can be more compact for the same power.
What are the Advantages and disadvantages of electro-pneumatics?
ADVANTAGES OF PNEUMATICS.
1. Simplicity of Design And Control
The control machines are easy to design. i.e they can be manufactured using standard cylinders & other components. Controlling mechanism simply contains two ON-OFF states, so its easy to implement and understand.
Also these components have versatile usage, they can be used in many situations. Pneumatics are easy to install and have useful mechanical movements. For an instance Straight-line movements can be obtained without further adjustments, such as levers, cams...etc
2.Reliability
pneumatic control mechanism is well known for its long lasting operation life time. In fact they need very little maintenance but operates continuously with high reliability.
Air /gas used as the working fluid is less likely to damage the equipments since gas are good in absorption of shock, and excessive forces, but hydraulics react directly transferring the stress to mechanical parts.
3.Safe to use
Pneumatic controls have high safety profile due to many reasons. Air used in these are fire proof, and less vulnerable to explosions and electric hazards. These are adoptable in extreme weather conditions, and we can rely on their continuous operation. This is because compressed air can stay in good condition in high temperature fluctuations, unlike hydraulic s ystems that tend freeze or boil in these situations.
Even a leak occur there is less chance of getting fire. Also there is no toxicity in air used, so we can expect no harm to living beans. Since pneumatics are sound in safety, very less precautions need to be taken.
4.Storage
Compressed Gas can be stored easily, and once compressed, above a certain threshold level they can be operate with out further need of compressing. This feature allows the use of machines when electrical power is lost.
5. Clean
Since working fluid is purified air, there is no messy waste produce at the end of the day. A little leak will not make the surrounding shady. Also, since ir is used no risk of toxic hazards t o machines or humans. Industries like pharmaceutical, food..etc tend prefer pneumatics for their cleanness.
6. Easily transported
Air is easily obtainable from atmosphere and can be used with little purification. Air can be pumped to long distances in pipelines, so can control pneumatic equipments for long distances. This makes central controlling possible. These also requires no return line, so easy to manage and cost effective.
7. Light in weight
Air is very light compared with other fluids, which are very heavy. They don't need high power to transfer.
8.Cost Effective
This is a very economical controlling mechanism. The Pneumatics require low maintenance cost, since wear of equipments are very less. These operates at low pressure , so equipments can be produced for low cost using cheap materials. In contrast hydraulic controlling systems require high pressure, so need tough materials, which comes in high prices.
9 high speed working medium
Compressed air controllers are able to achieve high work speeds, the flow rate may go up to 20 m/s, while hydraulics is restricted around 5m/s.
10.safe operation in Overloads
The shock absorbent properties of air make overloading safe. Under excessive forces air can compress easily avoiding damage to equipments.
11 Variable pressure
Pneumatic systems can work in various pressures, this also alow the speed control.
DISADVANTAGES OF PNEUMATICS.
1. Air is largely compressible, which may be good for some reasons, but the major draw back is the inefficiency in accurate positioning and speed controlling. These often need to be tuned to work correct and sound. Since Compressible,not possible to achieve uniform and constant piston speeds.
2.Unable to work with heavy loads (commonly used working pressure of 7 bar, the require output force is economical only up to about 20 KN to 30 KN ) Unlike hydraulics or electrical system these cant be used for heavily loaded operation.
3. Air used needs to be purified, air containing moisture may lead to corrosion of the equipments.
What advantage does galvanised pipe have over black mild steel?
Great material for oil lines /natural gas /steam / hydronics / condensate /chilled water piping /air
What is the history of pneumatic systems?
Joseph Bramah patented the hydraulic press in 1795.[1] While working at Bramah's shop, Henry Maudslay suggested a cup leather packing.[2] Because it produced superior results, the hydraulic press eventually displaced the steam hammer from metal forging.[3]
To supply small scale power that was impractical for individual steam engines, central station hydraulic systems were developed. Hydraulic power was used to operate cranes and other machinery in British ports and elsewhere in Europe. The largest hydraulic system was in London. Hydraulic power was used extensively in Bessemer steel production. Hydraulic power was also used for elevators, to operate canal locks and rotating sections of bridges.[1][3] Some of these systems remained in use well into the twentieth century.
Harry Franklin Vickers was called the "Father of Industrial Hydraulics" by ASME.
What Specifics dangers when working with pneumatic system?
The main danger is the pent up power of compressed air. If the tie rods on an air cylinder fail the end would fly off at some terrific speed whereas with an hydraulic cylinder as soon as the end came off the pressure would be gone even though it was much higher to start with.
