Mike Roach
Liskeard
Clive Smith
David Critchlow
I believe it could be Air Supply Isolating Cock but I’m not a Hitachi expert (not an expert at anything really!) – see http://www.firstgreatwestern.info/acronyms.html
Cheers Regards, Dave Critchlow
Many thanks David- you are an expert David at finding out! Congratulations and thanks once again. That link provided by David/FGW is well worth checking on.