Life of rubber in a ferric chloride vessel 1

[Davidorias]

I have a vessel made of carbon steel, with rubber inside. It's 20 years old. The proportion of chloride is 40%. Could it be considered that it has finished the life of service?.

Thanks

 

[cub3bead]

Have you considered getting a rubber lining inspector out to the site to evaluate the condition of the lining? The inspector might be able to estiamte how much useful life remains in your vessel.

 

[Davidorias]

I suppose you are referring to a coupon of rubber. But it's a destructive test, and we must put the vessel out of service without knowing how is the rubber.

 

[cub3bead]

I was not suggesting destructive evaluation of your equipment. But you will have to allow the inspector access to your tank to determine the condition of the linig.

 

[sbush]

The typical life of rubber linings in this type of service is 15 - 20 years. Over time, the lining can become too hard or too soft and develope cracks or holes leading directly to the metal substrate.

If the vessel can be removed from service, drained, emptied, cleaned of loose debris, and dried out; then a spark test could be performed to determine the integrity of the lining. A testing laboratory such as Law Engineering offers this service, and there may be other rubber lining specialists in your particular area. You must also have a hardness test performed using a durometer. Instead of removing a coupon, perhaps you could supply the lab with a removable manway cover or blind flange that has the same lining as the vessel and stays in contact with the ferric chloride solution. Again, Law Engineering, or a similar analytical lab or rubber lining specialists could perform the testing service.

I can't think of any suggestions, if the vessel cannot be removed from service, other than to simply replace it based on the age of the vessel alone and just how important the integrity of the vessel is to the application.

If you decide to replace the lining or purchase new vessels, I encourage you to look a using a thermoplastic polyvinyl chloride lining known as Koroseal, manufactured by Polymeric Protective Linings of Livonia, Michigan. It's about the same cost as rubber, but works better for much longer time.

S. Bush

http://www.water-eg.com

 

[Davidorias]

Thank you very much for your help.

Regards