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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
Difference between electrical and mechanical energy?
Light travels exclusively through space or along optical fibres by the mechanism of electromagnetic propagation. Electrical energy can also do that, in which case it is called microwave radiation or radio waves, but it can also be carried on wires.
How do you calculate hp from amps?
1 HP is 746 watts in principle. The power is in watts, and the power is the volts times the amps. For an AC motor the power is the volts times the amps times the power factor times a factor that depends on the power-conversion efficiency of the motor.
Why a gap is left between two pieces of rails in the railway line?
These days that's no longer always the case. It used to be because as the rail warmed up in the sun it got longer, so gaps was left for the rail to have something to expand into. w/o the gapsor with too small gaps it happened that the rail broke loose from the sleepers and caused the train to derail. To day many railroads are using concrete sleepers, which are strong enough to keep the rails in place w/o any gaps.
A hose is a hollow tube designed to carry fluids from one location to another. Hoses are also sometimes called pipes (the word pipe usually refers to a rigid tube, whereas a hose is usually a flexible one), or more generally tubing. The shape of a hose is usually cylindrical (having a circular cross section).
What is Pneumatic double acting cylinder?
- single acting: actively driven by hydraulic fluid pressure in only one direction, passively returned in the other direction by another force (e.g. springs, gravity)
- double acting: actively driven hydraulic fluid pressure in both directions
What are the properties of hydraulics and pneumatics?
One similarity is that they both use fluids. Both gasses and liquids are fluids. the two are also compressible.
Pneumatic vs hydraulics which is cheaper?
As systems, neither one is better than the other. There is no "Better", only "More suitable for a specific purpose." Car tyres are Pneumatic... they're full of air. Air is compressible, which is why it's used. If you filled your car tyres with Hydraulic fluid (which is incompressible) you would not only increase the weight of the tyres dramatically (and hence increase the relative tread-wear), but also make them hard, decreasing their ability to absorb shock. This would defeat many objects in the design of car tyres! The rams on a digger or crane, however, are Hydraulic. They need to be filled with something that is not compressible in order to fulfill their function. If you were to fill the rams on a digger with air the arm would bounce up & down like a yo-yo! Also, at the pressures required by these systems, air would quickly leak from the seals, no matter how tight they were. Hydraulic fluid, being far more viscous than air, however, does not leak under the same conditions. As a rule, Pneumatic systems are employed where a certain amount of "play" or "give" is required, or where the loss of fluid would be undesirable (Air power-tools for example) Hydraulic systems are used when extremely great pressure is needed in order to move something. Hydraulic systems are also easier to control & regulate due to their ability to retain pressure indefinitely. There are many uses for both Hydraulic and Pneumatic systems but because both types have specific roles, there is no saying that one system is better than the other.
What are the fluids used in pneumatic and hydraulic systems?
Pneumatic systems use air or an inert gas. Hydraulic systems use water or oil.
What are the three basic parts of a pneumatic system?
All pneumatic systems start with an aircompressor. This compressor is usually rigged with a electronic pressure switch, which shuts the compressor off once the system has reached pressure. The compressor uses an accumulator to store additional compressed air in reserve in case the amount of air required by the system exceeds the compressor's output. Both of these components are connected to an air regulator, which reduces the combined compressor and accumulator output pressure to the desired psi (usually pressure gauges are placed before and after the regulator). This resulting air feed is then connected to a series of mechanical or electric solenoids (air valves). Two lines run out of each solenoid, each connects to an opposite side of the pneumatic piston (s) that the solenoid controls. When triggered, the solenoids direct the air into the front or back of the piston depending on the desired direction of the piston. Return air from the opposite side of the piston is usually vented. This results in the pneumatic pistons emitting a hissing sound whenever they are moved.
CFM is a way of saying ft3/min, or cubi feet per minute. It is a measure of the volume of air a fan can move in a minute. Generally speaking, the higher the CFM, the more powerful a fan it is. Or, if you happen to be in the aircraft industry, CFM refers to the company CFM International, a 50-50 joint venture between General Electric of the United States and Snecma in France.
What is the working principle of a monoblock pump?
It consist of
1.a cylinder with a piston
2.piston rod,connecting rod
3.crank and crank shaft
4.delivery pipe
5.suction pipe
6.delivery valve
7.suction pipe with a foot and filter
During suction stroke the piston moves to the left, causing the inlet valve to open.
Water is admitted into the cylinder through the inlet valve.
During the discharge stroke the piston moves to the right closes the suction valve and opens the out let valve.
Through the outlet valve the volume of liquid moved out of the cylinder.
How does pneumatic bicycle pump work?
You'll have to start with determining which kind of valve you've got. For the US there are basically two options:
- Schraeder valve, the same as on a car
- Presta valve, which is narrower.
Then find a pump with the appropriate nozzle. For Schraeder, just remove the cap and go at it. Particulary if you're filling from a compressor, don't exceed the max allowable pressure stated on the tire sidewall.
For Presta, remove the cap, undo the locknut, give the valve a push to break the seal. Then apply the nozzle and inflate the tube.
For Europeans there's the added option of the Dunlop valve, which can be inflated with the same type nozzle as the Presta, but there's no locknut that needs to be opened.
What is the Cost of pneumatic control valve product?
Pneumatic process control valves are used in process industries to control the flow of fluid by using pneumatic actuators.
It requires 4.5 to 6 Kg/sq. cm of pressure to operate the valve.
Control room sends electrical signals of 4-20 ma to field where I/P converter converts these electrical signals into pneumatic signals.
Actuators use these signals to operate the valve.
Actuators moves the stem up and down depending upon input signals and control the valve opening.
4ma- 0% opening
8ma- 25% opening
12ma- 50% opening
16ma- 75% opening
20ma- 100% opening
Difference between pneumatic and hydraulic machine?
Pneumatic system is operated by compressed air while hydraulic system is operated with pressurised hydraulic oil
or any type viscous oil.
Hydraulic systems can usually produce higher control forces and work under extreme
operating conditions. This is the system that is primarily used on aircraft to move
control surfaces and engine controls.
You can often classify pneumatic systems because they have a pump (gas pump) and
hydraulic systems have a piston.
That is the difference. Also, pneumatic systems are louder because it is a gas under pressure.
1. By definition, hydraulics is used in controlling or harnessing power
with the use of pressurized fluids whereas pneumatics studies how pressurized
gases influences mechanical motion or movement.
2. Hydraulics uses an incompressible fluid medium like oil whereas pneumatics
uses a compressible gas like air.
3. Hydraulic applications demand greater pressures during operations that reach
thousands of pounds per square inch whereas pneumatic applications only
require 100 psi pressures more or less.
4. Most hydraulic applications generally use bigger components that pneumatic applications.
5. Hydraulic systems are generally more difficult to operate compared to pneumatic applications
there are two types of pneumatic comparators. 1 is a back pressure type and the other is the flow velocity type. in back pressure type- comparators use air pressure to sense changes in dimension.
What are the disadvantages of Electro pneumatic?
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.
If the beams are made of the same thickness and cross-sectional dimensions the box beam is twice as strong, vertically and the same strength horizontally. However, if a diagonal force is applied, the box beam could collapse where the I-beam is less likely to do so.
What are the benefits of pneumatic control system?
nComponents have long working life resulting in longer system reliability nEnvironmentally friendly
nSafety issues are minimized e.g.. Fire hazards; unaffected by overloads (actuators stall or slip)
pneumatic actuators in a system do not produce heat (except for friction)
How does a 4 way pneumatic valve work?
Moduflex dual valve combines two, 4-way valves into one valve body, it features two independently operated valves in the Size 1 valve body. :)
What are two uses for the pneumatic system?
hydralics are used in car brakes,space ships,air planes,heavy equipment,lifts.
Pneumatics is the when you use compressed air to move a pistion, a pistion could be virtually many things. ---- It is just like a hydraulic system but instead of a fluid you use air as the working fluid.
Disadvantages of pneumatic system?
Pneumatic and hydraulic controls are extensively used in production plants for natural gas. Safety is the reason.
However in earlier times (my only experience) they were subject to zero-point drift.
This may have changed with the application of binary logic to these control systems. Other disadvantages are limited speed, and the lack of industrial support for this branch of logic computation.
In order to keep the site free from electricity, the prime mover motors were steam powered from locally generated steam.
