1 reply to this topic

[Takechi]

Dear all

 

My plant is during passivate cooling water system. While go from chemical cleaning step to passivation step, we found PH has fallen ( PH around 6.7) Thus, we use sodium hydroxide to increase PH to 7.4 (GE water recommend control range PH 7-8)

 

However, some people compliant us should not use sodium hydroxide to increase PH because sodium hydroxide can lead to FeOH and can lead to corrosion under deposit.

 

They recommend us to use Sodium carbonate.

 

What do you think about sodium hydroxide VS sodium carbonate to increase PH ? If you have doccument about passivation and about advantage of sodium hydroxide and sodium carbonate for increase PH, could you please share to us

 

Remark

1. we use phosphate agent for passivation in no heat load program.

2. My system cooling water volume = 8000 m3/h

3. we use sodium hydroxide to increase PH = 100 liter

 

Thank you for your sharing

 

Salapao

[breizh]

Hi Salapao,

You should be from Thailand !

Consider the resource attached from GE water :

 

https://www.gewater....dbook/index.jsp .

 

Note : Why don't you ask assistance from the vendor of Chemicals for your cooling system ? It should be part of his scope not only to sell the products.

 

Breizh

Edited by breizh, 28 February 2017 - 08:47 PM.