Can someone tell me how much time we need to defume an aircraft tank before entering it.?

Question

Can someone tell me how much time we need to defume an aircraft tank before entering it.?

Answer 1

All good A&P Engineers know that for info on particular work to be done, they should first check the Aircraft service manuals which they are working on. On the 737 I used to work on, a good de fuming of 18 hours on each tank was enough but it goes without saying, your tank has to be dry before defuming. If there is enough residue, you may need a longer time to get it all out to make it safe for you. Flight line work is hard as you need to get the plane up ASAP so we would drain the tanks, de fume for a few hours, keep the fans running, put on goggles , gas masks and get in. Remember this safety tip, don't take in any torchlights that are not explosive proof. Make sure the lights you use do notlet off too much heat, you dont want to bepart of the BBQ.

Answer 2

It's in the Manual. Right next to the Chapter on removing the access panels for Tank Repair. Glad to help out.

Answer 3

along with the other answer their is a meter that safety/fire dept  uses to measure the fumes that are still in the tank to determined safe levels .  All in all look in the maint manual