The only fitting that I have that fits my manifold gauge set, has a puncture needle:
So any can that I use it on MUST be emptied entirely, in one go. If only a partial can is used, the rest must be vented/wasted.
However, I also bought a standalone refill can that came with its own hose, connector, and gauge, and a resealable "button" like a can of spray paint or WD-40. And I discovered after I had emptied all of it into the A/C system, that the hose can unscrew from the can. So here's that fitting:
Instead of a needle-pointed screw, this one has a spring-loaded plunger with a flat bottom.
Now, for this unused can that I would normally have used the puncture fitting on, would it also take the non-puncture fitting, go back on the shelf about 1/2 full, and discharge the rest some months later?:
All 3 of the cans shown here are SuperTech branded (Walmart's store brand), but I'm also looking for a way to tell generically. The can in question is sold as just the can, no hose or anything else, and my manifold gauge set only came with the puncture fitting. In other words, if I keep buying these cheap cans, is it worth finding a non-puncture fitting to use with my gauge set?
The can by itself that requires a separate fitting, has a label that says, "PLEASE CONSERVE" and "Always store partially filled cans with recharge hose attached." To me, that wording doesn't necessarily mean that it can use a non-puncture fitting, because a non-leaking puncture one can also satisfy those requirements...except that my puncture fitting does leak just slightly. Not enough to be a concern in use, but enough to make storage impossible.