Bad idea screwing straight onto isolating valve unless it is a flat faced one. If not flat faced get some tap tail adapters to fit in the bolofix valves.
At risk of being called a bodger, I have done this several times at home by the simple expedient of flatting the end of the iso by rubbing it over abrasive paper on a flat block to keep it square.
At risk of being called a bodger, I have done this several times at home by the simple expedient of flatting the end of the iso by rubbing it over abrasive paper on a flat block to keep it square.