Okay, so I do need to buy a threaded flare cap to lock the air out. So, its okay for co2 to go into the second regulator and be stopped in its track by a flare cap then? Here's an actual pic of my setup incase any others have ideas. Its just weird because I was under the assumption that I would be able to close up the second valve when needed with just the locknut and screw. Thanks for the info P-J.
That pic is not great quality I know. Also, I don't have the tank on in this pic and I thought it was odd that my guage was not reading at zero. It came at zero when I got in mail, but after some co2 went through it never went down to zero. Normal for those to stick a little?