What is the main purpose of using a coupling.?

Answer 1

Let us go by specification.
1.C.S. coupling,3000#,socket weld ends.
Here,coupling is to be used for two pipe ends by welding.
2.C.S. coupling,3000#,threaded ends.(internal)
Here,coupling is to be used for two pipe ends by thread joints either using ptfe tape or thread sealant.
3.C.S. reducing coupling,3000#,socket weld ends/threaded.
Here,coupling is to be used for two different size pipe ends by welding/jointing threaded ends.
4.Flexible couplings-tyre type,love-joy type,spacer type,geared coupling.
Here,coupling is to be used for power transmission from motor to rotating equipment like pump,compressor,agitator,centrifuge etc.hear, the radial and axial alignment should be within 50 micron(0.05mm) for higher RPM.
5.Fluid coupling:It is used for connecting motor to the equipment listed above and ropeway,blowers etc,where high starting torque is required.
-A coupling is a device used to connect two shafts together at their ends for the purpose of transmitting power. Unlike a clutch, couplings do not allow disconnection of shafts during operation.

Rigid couplings
are used when precise shaft alignment is required; shaft misalignment will affect the coupling's performance as well as its life.
Flexible couplings
are designed to transmit torque while permitting some radial and axial and angular misalignment. Flexible couplings can accommodate angular misalignment up to a few degrees and some parallel misalignment.
Coupling is also an aviation term for aircraft dynamic interactions where movements in one aircraft axis are coupled to another axis, for example: inertia coupling and roll-coupling.

You must visit:
http://en.wikipedia.org/wiki/Coupling
http://www.unionmillwright.com/shaft.html

Answer 2

If you are talking about a coupling between an engine or motor and a pump or compressor its main purpose is to transmit the torque from the driver shaft and to prevent (if it is a flexible coupling) out of balance forces and vibration being transmitted from one shaft to the other.

Answer 3

coupling can
connect two shafts
connect two pipes
connect motor to pump
etc
as indicated above a coupling connects so that rotation/fluid/power can be transmitted

Answer 4

Hi,
i want to add something to first answer. coupling is a piece which joins two other pieces of pipe (carrying anything, not only water), rod or any solid thing. as its name it couples two things.

Answer 5

1. To join two pipes which are not long enough to transfer water.

2. To use in vantage points to make it easy to check water flow if any problems should arise.

Answer 6

To connect two rotating shafts that are not in perfect alignment.