My new gas hob installation instructions say "The end of the inlet connection point has a 1/2" thread that allows for fixed connection ..." This looks like a
1/2" BSP although I have not checked. It then says "If you need to make a cylindrical connection, replace the factory fitted L-tube with the one in the accessory bag". From the diagrams it looks like all the seals are made with white fibrous washers (supplied). The alternative L-tube appears to have a coarser more angled thread. Any idea what thread this is, and what it is used with ? Cheers, Simon.