Mechanical Equipment Part 1

 Mechanical Equipment:

Mechanical equipment is used to start, stop, heat, cool, liquefy, vaporize, transfer, store, mix, or separate the commodity flowing through the piping system.

Types of Equipments:

1) Horizontal Vessels:

• It is a cylindrical-shaped storage tank whose long axis is parallel to the horizon.
• It is also called as Accumulators.
• It is used primarily as a receiving and collecting container for liquids and therefore, has no internal moving parts.
• Support saddles are welded on the underside of the vessel to prevent it from rolling off its concrete foundations.
• Nozzles on the top of the vessel allows liquids to enter and fill the vessel. A nozzle on the bottom allows the liquids to be drawn out.
• Smaller nozzles can be used for venting & instrumentation.
• A large diameter manway (typically 18”) is provided for inspection and maintenance.
• Drawing Symbol:

Vertical Vessels:

• The vertical vessel is a cylindrical vessel whose long axis is perpendicular to the horizon.
• Also called as Fractionation Columns.
• They have internal plates called trays that aid in the separation and collection of the various molecular compounds of a feed stock.
• The process of breaking down a feed stock into its molecular compounds is fractional distillation.
• Fractional distillation is carried out in these columns.
• After further refinement and processing, these compound will become by-products such as diesel, gasoline, kerosene etc.
• Some vertical vessels can exceed 200 ft in height.
• Drawing Symbol

3) Ladders, Cages, & Platforms:

• Ladders allow workers to access the higher elevations of equipment for routine inspection and maintenance.
• Ladders are made of steel bar and plate, and are welded or bolted to the exterior of a vessel. 
• Cages are designed to enclose a ladder and prevent a worker from falling away should he lose his grip on the rungs.
• Platforms are like small elevated walkways around the outside of a vessel or between equipment and structures.
• With 3' tall handrails, workers can safely operate, inspect & repair.
• Platforms are spaced so ladders will not have a vertical run of more than 30'-0'', but are not spaced closer than 8'-0'' to provide adequate headroom clearance.

4) Pumps:

• Pumps are mechanical devices used to move fluids under pressure from one location to another.
• Pumps accelerate the speed at which a commodity travels within a pipe, thereby increasing its rate of flow. 
• Pumps used in piping facilities will be one of the following classifications: 

1. Centrifugal
2. Reciprocating
3. Rotary

4.1. Centrifugal Pumps:

• The centrifugal force created by the high speed impellers  of a centrifugal pump creates a smooth non pulsating rate of flow.
• With a fast spinning impeller creating a low pressure center point, any commodity entering the pump will naturally seek the center of the impeller only to be spun out at a high rate of speed.
• The efficient operation makes it the standard of most piping facilities.

4.2. Reciprocating Pump:

• The reciprocating pump uses internal parts, similar to a piston or plunger, that alternately move back and forth to create pressure.
• With each stroke of the piston, pressure  is increased forcing the commodity out of the pump. 
• The reciprocating pump is installed in piping systems where extremely high pressures are required

4.3. Rotary Pump:

• The rotary pump is similar to the reciprocating pump in that it is a positive displacement type. 
• Rotary pumps use mechanical devices such as pistons, gears, or screws to discharge a commodity at a smooth, continuous rate of flow. 
• It performs without creating the extreme pressure surges often associated with the reciprocating pump.

5) Pump Drivers:

All pumps require a starting device to function. These devices are known as drivers. The driver is connected to the pump via a rotating shaft. The shaft turns the impellers, gears, screws, or pistons to initiate the pumping action. The pump drivers used are Electric Motor, Diesel Engines, Steam Turbines

• An electric motor is the most commonly used.
• As alternative to electricity and as a backup to the electric motor, a Steam Turbine is often employed. It can also be used during power outages or when motor is being repaired.
• Steam turbines are also used in areas where explosive gases are present.
• A diesel engine is used during times of emergency. When piping system are shut down, diesel engines provide power to operate firewater systems & other essential services.

6) Compressors:

• The compressor is similar to the pump, but it is designed to move air, gases, or vapors rather than liquids. 
• The compressor is used to increase the rate at which a gaseous commodity flows from one location to another. 
• Gases, unlike liquids, are elastic and must be compressed in order to control their flow characteristics. 
• Like pumps, compressors are manufactured in centrifugal, reciprocating, and rotary configurations.

Click here to continue to Mechanicals Equipment Part 2