Question 1: After I close the bottle, should I purge the nitrous out of the lines then, or is that a waste.
Question 2: If I don't purge, will the line hold the pressures and should I just purge when I reopen the bottle?.

 

I think its better to purge to relief the pressure at the solenoid, lines and fitting. Depending on the periods between each use the pressure will be lost gradually.

 

as long as you haven't taken the bottle off, I don't think it would matter just a waste, but ricers love to purge all the time, as well as hard core drags, nx even makes a light that comes on and makes it really easy to see your purge at night.. Most always purge before a real race the rest of the time you might just put in a little more ambient air than no2, no hurt there...

 

ditto.

 

Me too! When you shut the bottle valve, let the pressure out of the system with the purge. Its going to leak out anyway, evnetually. The pressure pushes the plunger in the solenoid down into the elastomeric seat. Keeping the pressure on the seat when it isn't in use can cause the seat to deform, and even tear, at least with the NOS solenoids.

 

Another vote to purge the system after you close the bottle. I always purge on unsuspecting people.