I have recently purchased an old Boots Pressure Barrel with the aforementioned screw, spring and O-ring safety valve.
Mine has the original black plastic sparklet injector in the lid with the screw-up bulb holder and the press button the other side to introduce the CO2.
Unfortunately the valve is corroded inside and leaks like a sieve. The whole bulb is discharged in about 1 minute.
I tried to take the injector head apart to polish it but could not get into it at all. I couldn't even get it out of the plastic housing.
I have now removed it from its 16mm hole and junked it so I am left with a peferctly servicable lid but no injector; just a 16mm hole.
Question - what do I need to put in its place?
Can I get a similar sparklet injector as the original or is a bottle system (S30??) better?
Thanks for any advice