I’ve been using an Ultraflate Plus c02 pump for a couple of years now, but when changing the cartridge yesterday all the gas escaped as i tightened the canister holder.

so i tried again, same thing, and again…

I’m not doing anything different, they are the 12g non threaded (genuine,Genuine Innovations!) cartridges.

I’m wondering whether there should be a rubber seal where the cartridge is pierced????

Help please!

Ta