Ok so the man from Chubb had a look at the bottles and said something along the lines of how old they are and that he'd scrap them because the handles were 'broken' (I cut them down to fit)... not much help really.

Alan I tried calling the company you mentioned but nobody answered the phone.

So what would be my options now. The bottles I have show a design pressure of 55 Bar and a Test pressure of 200 Bar, if I get them hydro tested to 200 bar along with a certificate will they be accepable for use? Alternatively can I design my own bottles for 55-70 Bar and hydro test them to 200 Bar? The burst disk is set at 190 bar if I'm not mistaken so this should rupture before the tested pressure is exceeded. Would there be any problems doing this? Obviously they wouldn't be BS stamped but I can get them made in accordance with ASME which I hope would be sufficient.

Sorry for the weird questions but I really need some 100mm diameter bottles. Sadly a pair of 105mm or 117mm bottles wont fit. A single bottle is an option if I really have to, but using two is my preference.