I'm currently taking apart a William boiler (the Martin Evans design) to replace what I suspect is a sheared off bolt in the ring of bolts around the regulator, and to potentially improve the seal on the seat. I'm attempting to remove the regulator tube intact but its very firmly in place. I've taken out the vertical steam collector pipe within the dome, removed all the bolts and am trying to ease the tube out but it seems very well stuck in place, presumably by all the brown jointing compound that seems to abound in this particular engine. Does anyone have any tips please? Anything I may have forgotten to disconnect? I don't want to force anything. I have applied gentle heat and penetrating oil to no effect.

In the absence of any replies, I post this for the benefit of anyone else who comes across this problem: after I cut the edge of the flange off I was able to get access to the sheared off bolt to remove it. Once this had been spun out the regulator unscrewed out freely. The regulator is screwed into the steam pipe.