Wednesday, December 1, 2010

Various Types of Waters at Power Plants

Raw Water -  Water coming externally from a cross country pipeline into the plant and is stored in the raw water reservoir.

Clarified Water - Raw water after Primary Treatment becomes Clarified Water

DM Water - Part of the Clarified Water is sent to the DM Plant for removal of dissolved salts. This water is used for filling up the boiler is called Boiler DM Water. A part of DM water is also used for cooling the various pumps and equipments in the BTG area and is called DM Cooling Water.

Cooling Water - A part of the Clarified Water is sent to the cooling water forebay for cooling of the condensor. Steam exiting the turbine is condensed into water in the Condensor with the help of Cooling Water

Auxillary Cooling Water -A part of the Cooling Water is used to cool the DM Cooling water via Plate type Heat Excanger. The water used to cool the DM Cooling Water is called Auxillary Cooling Water

Potable Water - is used for drinking and cooking purposes

Service Water is used for generally cleaning, washing, firefighting etc is called Service Water

About Pipes - Part 1

Pipes are generally made of  metal, plastic or concrete.

Metallic pipes are of Cast Iron, Galvanized Iron, Carbon Steel, Mild Steel, Stainless Steel, etc
Plastic Pipes maybe of PVC, HDPE, FRP etc
Concrete Pipes are made of various concrete mixes

Mettalic pipes maybe manufactured by extrusion (also called seamless pipes), centrifugal casting and spinning or welding.

Pipes generally are classified by their Nominal Bore which is their Outer Diameter and by Pipe Schedule which is the thickness of the pipe shell.

Pipes may be joined together by Welding, Flanging or Threading.

If pipe is joined by welding ( either Butt Welding or Socket Welding) then radiographic inspection of the welded joint would be required by the client.

If a mettalic pipe is to laid underground then the pipe must be protected from corrosion by wrapping and coating and also by cathodic protection.