My son has just brought a flat with a recently refurbished kitchen and I noticed that the gas hob has been connected using one of those short lengths of bendy (corrugated ) copper pipes between the hob connection and a gas isolation valve. The installation looks quite neat and professional, with good support to the pipe work and the 300mm long flexible section fits into compression fittings at either end, one at the gas valve and one at the hob. I have only previously seen this type of bendy copper pipe on water connections. Is it OK to use it on a gas installation like this?