I was called to a reported smell of gas…… in a commercial kitchen ……. worst place to look for one…… after about 30 minutes I had drawn a blank…. and could smell nothing…… tightness test gave no drop…….. sooooo…….. what next? leaking service main perhaps?…… Then suddenly I got a whiff of gas……… not much but some…. and there was no gas pipe in that area…… ! what to do?……. Then i realised it wasnt natural gas I could smell….. it was LPG…….. a quick root around produced this…… leaking at the valve!