Just thought I'd post this because I don't think it's come up yet.
After closing your bottle, it's a very good idea to relieve the pressure from the nitrous system. If you don't have a purge kit, this means making a nitrous run with the bottle closed. Simply get on the nitrous enough to relieve the pressure from the system, indicated by the pressure valve you should have on the bottle.
I do this every time I use my nitrous, and it will prolong nitrous solenoid and line life, as well as preventing nitrous pooling in your intake.
On a side note, I'm getting a remote bottle opener in the next few days
After closing your bottle, it's a very good idea to relieve the pressure from the nitrous system. If you don't have a purge kit, this means making a nitrous run with the bottle closed. Simply get on the nitrous enough to relieve the pressure from the system, indicated by the pressure valve you should have on the bottle.
I do this every time I use my nitrous, and it will prolong nitrous solenoid and line life, as well as preventing nitrous pooling in your intake.
On a side note, I'm getting a remote bottle opener in the next few days