Blow Down Tube ..HELP

I am installing my Zex and I need to know if I can install the blow down tube on a full bottle?

 

I think so. I think the blow down tube is just a safety feature??

 

no. once you loosen the old valve.....pssssssssssssssssss

 

So what the hell is the blow down tube for?? I screwed mine on when the bottle was full.

 

If you don't have the fitting already on the bottle then no......you'll loose all the spray and probably get hurt in the process.

 

Thanks I will wait till empty