Got a new pressure barrel which is fitted with a S30 cap for the small CO2 bulbs. Alas, it seems to have a leak somewhere- very little gas seems to stay atop my cider. I've greased every joint and seal, but it seems to be coming from the safety valve on the side. I previously had an ancient boots barrel whose gas fitting finally gave up and this was its replacement. So I'm a bit disappointed that it's leaking already. So what am I doing wrong? Is there anything else I should be doing/checking? In the long term I might go to a separate bottle system so I can resurrect the old barrel too.