3 replies to this topic

[hanugro]

Hi all, I have a project in building an LPG cylinder retester plant. I have no experience in working with LPG before.

I need to evacuate LPG leftover in small (3kg) LPG cylinder before opening the valve for retesting and repainting the cylinder. The leftover would mostly be in gasses state due to low pressure left. Few might be still in liquid state. The common method in my country would be to flow the remainder pressure to water and left it expose to open air.

I am thinking of evacuating and transfering all the left over LPG to a bigger tank and probably use it for the oven burner saving cost and environment. I would process thousand of small cylinder LPG tank daily so the left over could be quite significant. Is it possible to do that?

If it is, then what is the suitable evacuating vacuum pump that I can use for this project. Many thanks for your help.


Best regards.

[Qalander (Chem)]

Dear hanugro Hello/ Good Morning,

You have tried your best to describe the issue, I have few queries in order to help you.

1) There is a possibility if you have many places(points) to have the cylinder emptied then by gravity the contents should and must come out

2) Subject to the (receiving) container is kept always at lower pressure(near ambient) and emptied out to have ample space

3)The usual possibility for LPG cylinders is to contain heavier hydrocarbon gases contents or slight left-over entrained aqueous contents caustic and /or sulfide;all this must easily drain-out safely without much of a hassle under gravity alone.

4) I consider, that to be safer as water in contact with LPG could pose 'hydrates' issue.

5) However after emptying,proper water flushing the requisite hydro test may be safe/ alright.

Hope this proves helpful.

[hanugro]

Thanks for your attention.

The point I want to know is whether it is possible to collect the remaining LPG and transfer it to bigger tank (50kg) then using it to fuel my oven burner? If it is possible, then what is the brand and model of vacuum pump that I should use?

BR.

[Qalander (Chem)]

I expect many other knowledgable colleagues will enlighten you further indeed!

As regards the use of emptied out LPG is enquired this is possible but a thorugh and detailed analysis;even considering NFPA 86 and other binding standards will have to followed.
On googling 'NFPA 86' more than 500000 hits just one is attached as sample info/guidance.

Hope this proves useful for way forward.