Getting the Power to Control

Written by Thomas Yoon

One ofrepparttar advantages of using machines to control processes for you is that you can harness tremendous amounts of power and energy which humans do not possess.

By a flick of a switch, huge sliding flood gates can move to allow large quantities of water to flow out of a dam. With just a slight twist on a handle, supertankers weighing hundreds of thousands of tons are able to turn because ofrepparttar 133424 corresponding rotation of huge rudders.

Similarly, processes operating valves can be remotely operated to control flow, temperatures, pressures and so on.

All these final control elements - flood gates, rudder, valves - must be operated by actuators. The function ofrepparttar 133425 actuator is to move to control elements inrepparttar 133426 processes.

In order to moverepparttar 133427 actuator, there must be a medium for transmittingrepparttar 133428 required power or action. Allrepparttar 133429 actuators are mechanical in nature. The common means of transmittingrepparttar 133430 power are: pneumatic (air), hydraulic (fluid), and electrical (motors).

The actuators must be designed to work for that medium. There are several advantages and disadvantages for choosing a particular medium. For example, pneumatic actuators are particularly useful whenrepparttar 133431 atmosphere contains flammable gases. By using pneumatic actuators, there is very little chance that a spark can be generated to cause a fire. However using air for actuating may be more expensive to install and to maintain.

Mechanical Seals for Zero Leakage

Written by Thomas Yoon

A centrifugal water pump contains a few basic components as follows:

1) The housing for containingrepparttar water. 2) The impeller attached to a rotating shaft that movesrepparttar 133423 water. 3) The coupling that transmitsrepparttar 133424 rotating action of a motor (or other prime movers) torepparttar 133425 pump shaft. 4) The seal betweenrepparttar 133426 housing andrepparttar 133427 rotating shaft. 5) The bearings for ensuring thatrepparttar 133428 shaft turns smoothly. 6) The inlet andrepparttar 133429 outlet ports for channelingrepparttar 133430 water flow throughrepparttar 133431 pump.

In order for a pump to work,repparttar 133432 pump impeller must generate pressures insiderepparttar 133433 pump housing. The seal betweenrepparttar 133434 housing andrepparttar 133435 rotating shaft plays a critical role in makingrepparttar 133436 pump work.

One ofrepparttar 133437 most common ways of sealing a rotating pump shaft is by using mechanical seals.

The 3 components of a mechanical seal are: 1) The rotating component that moves together withrepparttar 133438 rotating shaft. 2) The stationary component that is fixed torepparttar 133439 pump housing. 3) The spring that pressesrepparttar 133440 rotating component ontorepparttar 133441 stationary component axially.

Rotating Component

This is a ring, usually consisting of 2 types of materials - a soft carbon piece with a highly polished axial surface, and a rubber material or o-ring that is able to griprepparttar 133442 shaft for sealing against water leak throughrepparttar 133443 shaft surface.

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