Plastic holding materials for highly basic products 2

[SusanH]

My company is looking to get a new holding tank to contain both highly caustic bulk (pH > 13) as well as chlorinated products. So now the SS is out of the question, I'm wondering what sort of plastics are appropriate? I assumed that PVC would be appropriate, but have been told that it can break down at high pH and/or high temperature. Any materials or coating tips would be greatly appreciated.

 

[unclesyd]

As you didn't state any temperature the first candidates would be polyethylene or polypropylene.
Watch out of the standard FRP materials due to the High Ph, which will attack the glass. The FRP's can be used if special consideration are taken.

Come back with approximate sizes and temperatures.

 

[SusanH]

The volume of the tank would be between 3000 and 5000 gallons, probably closer to 5000. The highest temperature of material being tansfered to the tank would be about 140F. As well the room is not well insulated and the air temperature could drop below freezing in the winter (not sure if that's a consideration).
Thanks for your help.

 

[EdStainless]

There are two metals commonly used in Cl bearing caustic serivice. One is Ni200 (comercially pure Ni) and the other is E-Brite (XM-27, 26-1) a ferritic stainless. Since E-Brite is difficult to weld I wouldn't suggest making a tank from it. Ni200 could be used as a liner in a tank. Use steel for the structure.
E-Brite usually is used in heat exchangers in caustic plants.

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Corrosion never sleeps, but it can be slowed down.