[wnrf piper]

Depending on line size, pipe run. Jacking bolts & plates may be requied to spread the flanges. Theseaa re usually lugs which have been welded to the flanges. So if you take Antons bolt numbering then the Lugs would be welded on at bolt No.1 & 5. One lug one be drilled and tapped to take a suitably sized bolt. A spanner is then used to tighten the bolt up against the lug on the opposite flange. There can be several variations of these, but the principal is the same.