3 replies to this topic

[Sridhar P]

DM tanks are normally given rubber lining. But i have also seen epoxy coating is used instead of rubber lining. Can you please share your experience on the above two linings and your recommendation of which is better over the other technically/commercially and in maintanece aspects.

[Satyajit]

Hi Sridhar,

DM tank are normally atmospheric and operated at room temperature. So the corrosion rate is not so severe.The tanks are normally stainless steel and only epoxy resin is applied inside. The rubber lining is used for more corrosive environment and with mild steel.Nowadays,it is a good practice to put N2 blanketing to avoid O2 ingress and avoid further corrosion.

The SS tank with epoxy resin I commissioned in 1996, is still working fine.

Best regards,

Satyajit

[Sridhar P]

Dear Satyajit,

Generally we use carbon steel tanks with rubber lining or epoxy coated instead of SS tank because of the cost. Rubber lined tanks works well without any problem but i dont have any feedback or recommendations or merits of epoxy coating over rubber lining.

Also I feel Statinless tanks doesnot require epoxy coating to hold DM water.

Also If am right,N2 blanketing is to avoid C02 ingress and not for the O2 ingress.

[Satyajit]

Hi Sridhar,
You are right.
But I would prefer to go for SS Demin Tank .

On Blaketing issue. It has two benefits.
1. To avoid CO2 contamination as you rightly pointed out. Increase of CO2 in Demin water would increase its conductivity and so also
the losses as blow down from boiler.
2. To avoid O2 ingress into demin water in CS tanks
( consider the case of damaged rubber lining or damaged epoxy lining or low level or both)
and to avoid corrosion related issue.
Regards,
Satyajit