i believe oftec only "recommend" the use of flared fittings.
Is somewhat different from oftec's T32 document which states.
Only metric flared fittings are recommended
for the jointing of soft copper oil lines. They
can give a mechanically superior joint to the
commonly used alternatives and, more
importantly, they also greatly reduce the risk
of air entrainment into suction line.
So oftec don't "only recommend" flared fittings, they "recommend only" flared fittings.
The building regs are formed to incompass BS specs and 5410 part 1 sect 8.3.1 states
.Fire valves shall be fitted so as to cut off the oil supply remotely from the heating appliance in the event of an accidental fire occurring in or around the appliance. etc
For externally located heating appliances, the oil supply should be cut off at least 1m away from the appliance
Not my "opinion", its what's contained in the bs spec. it goes on to give other details which I have outlined in earlier posts, but I'm not going to type the whole of the spec.
Just do as much or as little as you want and get the building control officer to sign your form, as they can sign whatever they want. If you have an oftec guy do it, they should conform to the oftec requirements to allow them to self certify, if they don't want to they should have the principle to de-register and do it their way and not pretend they they are doing it the "approved" way.
That's it, I shan't reply to any more on this topic.