Replace Bulk Solvent Storage Tank Manway with Liquid In? 1

[motty75]

Hi,

We have several solvent bulk storage tanks which need to have their manways replaced. I had assumed that it would be necessary to drain down the vessels but have heard rumours that some people have done this with liquid in the vessels. Do you have any experience of completing activities like these? I'm most interesting in what basis of safety people have employed if this has been done.

The solvents will be above their flash points but no welding or hotwork will be required (bolting only).

Thanks for any help,

Neil

 

[dcasto]

This is a risk management question you and the proper people in your company can answer. I've performed similar tanks with and without emptying. Emptying means removal and inerting the tank to under 10% LEL. When the tanks still had liquids, we still permitted the task and ran the job just like a hot work with all the LEL meters, fire watch, and people performing the task with a higher level of PPE. We used all brass tools and monitored people for heat stress because of the added clothing.

 

[ash9144]

As dcasto mentions there are major safety concerns associated with opening a vessel with solvent in it. I would make sure that was the absolute last possible option before proposing it. There would also be environmental issues to consider as well based on your facilities permit. If possible pulling a small vacuum on the tank could be beneficial.

 

[0707]

dcasto

has put the correct answer

luis