Ok. So when you're not welding, but the gas is on, pressure builds up in the pipes and is released when you start again. I've often thought, as a lot of my welding is very stop-start, that I could be wasting a lot of gas this way. I've also just upgraded to a set of 15m interconnecting cables and now everytime I let go the trigger there is a long hiss as the pipes fill up again. Now I'm sure I must be wasting gas! So the first question is: do these so-called 'gas economisers' work? I have to confess it's the kind of thing I'm normally highly suspicious of (kind of like those magnetic collars everyone says are great. Call me stubborn but I'm afraid I'm still not convinced!)! Secondly, I thought I might give Feromaxx a go next time round. Will one work with the higher pressure of these bottles? Danke.