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Quotes for Success by Warren Buffet






• On Earning: "Never depend on single income. Make investment to create a second source"
• On Spending: "If you buy things you do not need, soon you will have to sell things you need"
• On Savings: "Do not save what is left after spending, but spend what is left after saving"
• On Taking Risk: "Never test the depth of river with both the feet"
• On Investment: "Do not put all eggs in one basket"
• On Expectations: "Honest is very expensive gift. Do not expect it from cheap people"

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Analog Addressable Fire Alarm System

Main Panel Block Diagram

The fire alarm system continuously monitors the detectors.Detectors are divided into zones. (Using Software configuration file in the base board).Detectors are connected to the system through loops. (physically)The Loops are connected to the loop boards. Each Board can have 3 loops. Each loop can have 254 detectors. (Depending on the address size)Each Loop has an address and each device has an address given using DIP switches. (These are stored in the Software config file)Devices send digital data packets containing the Addresses and the Data.The digital data packets are sent digitally using analog signals through the twisted pair cables. (Analog Addressable Signals)

ID address on DIP switches

All addressable loop units must be given an address between
1-254 to be operational. The loop units located on the same
physical loop must all have unique addresses. The address is
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The DIP switch values follow th…

Boiler Scale Formation

Boiler Corrosion

Galvanic Corrosion
Can occur due to Oxygen attack or contact of two dissimilar metals in an electrolyte (eg: Copper + Steel).

Oxygen Attack (Pitting Corrosion)
At the Anode:

Metal goes into solution               Fe ⟶ Fe2+ + 2 e-OXIDATION

At the Cathode:

Oxygen is reduced           ½ O2 + H2O + 2 e- ⟶ 2 OH- REDUCTION

The variables pH, temperature and the concentration of oxygen affect the rate of corrosion.
To avoid this alkaline conditions are maintained in the boiler.
Oxygen reacts with iron to give ferric oxide (rust) Fe2O3 which will not protect the metal from further attack and metal is continuously dissolved.

4Fe + 3O2 → 2 Fe2O3 Hematite (ferric oxide)

Oxygen corrosion is usually observed as localized pitting on a metal surface. (Pitting Corrosion)



This form of corrosion can be reduced by:

1.by reducing the level of oxygen as far as possible using mechanical means which include deaeration and/or judicious heating, coupled with good feed-system design (Cascade Tank)

by ensuring that t…