Prextex male elbow angst

greatgimpo

I'm fitting a pretty awkward bath tap valve with diverter into a small wall, using male prestex elbows for the h&c supplies in, and the shower hose out. I need the Prestex elbows to be screwed into the valve tight (with PTFE), but ideally to 'stop' tight to the shoulder at the right angle. Naturally they won't be 'stopping' at the right angle, so my question is, should I just make sure the PTFE is sufficiently tight to hold it at the desired angle, or pack the shoulder out with fibre washers to make up the gap?