pH Value of BFW

Lots of ways. Corrosion is the most common. Maintain your PH at recommended levels. A search brings up many pages of related reading.

http://www.gewater.com/handbook/boiler_water_systems/ch_11_preboiler.jsp

Not very much, if it is maintained correctly.

You can go to this link http://www.cleanboiler.org/Eff_Improve/Operations/pH_Treatment.asp.

The PH is kept around 11 to make sure that the different chemical treatments operate correctly: Oxygen scavenging, preventing corrosion of the steel pipes etc, sludge formation at the bottom ....

Dear Mr.LAALuckie,

I think you are referring the pH 11 is for the DRUM Water. The Feed Water entering the Boiler will be in the range of 8.2 to 8.5 AS MINIMUM and 9.0 - 9.2 as Max.

The Higher pH of 11 in the Drum is on account of Addition of Chemicals which is pumped by LP DOSER and HP DOSER.

DHAYANANDHAN.S

Dear Friend,

Boiler FEED WATER pH is ONE OF THE MOST IMPORTANT FACTOR. If pH is LOWER THAN 7.0, the WATER CONDITION ENTERS IN TO ACIDIC ZONE.

ACIDIC CONDITIONS combined with HIGH TEMPERATURE especially in the presence of OXYGEN, the CORROSSION will take place at a very fast rate and eat away the Tube material and result in Tube Birsting, some times ending up in catostrophic disaster. That is why DE-AERATOR is compulsorily to kept in good working condition.

For example in certain specified conditions - a solution of 6.0 pH at a Temperature of 30 Deg.C and if the Temp. of the solution is increased to 40 Deg.C the CORROSSION will INCREASE BY 8 TIMES i.e 800% than the Corrossion at 30 Deg.C level.

Biler Feed Water Temp. is always maintained HIGH - depending upon the pressure etc. and CORROSSION will be kept under control.

Hence always the pH of FEED WATER is maintained in ALKALINE ZONE say from 8.5 to 9.2

DHAYANANDHAN.S

chemical injection is done for tanks.Then what deareator does.

Dear Mr.ahmad301,

The Deaerator, REMOVES the DISSOLVED OXYGEN in the Feed Water, simultaneously it heats the FEED WATER.

Deaerators are available which will give Oxygen Content in the Feed Water up to 0.007 ppm level.

DHAYANANDHAN.S

• First of all you must know that pH is a temperature dependent parameter.For pure water it is 7.00 at 25degree C,it is 7.47 at 0 degree C & it is 6.14 at 100 degree C.
• A change of 1 pH value represents a change of 10 times.A pH of 3 is 10 times more acidic than a pH of 4.
• At lower pH than recommended,chances of corrosion increased,at higher pH chances of scaling increased.
• As per ASME pH must be maintained above 9.5
  

And you said that you wouldn't do homework!