I'm a beginner in pipe stress as in using CII likewise. I need to confirm that to include the thrust load induced by PSV during relief, the load calculated as per B31.3 should be added to the input spreadsheet and refer to the tee. With the PSV modeled like an angle valve, say the branch line is going to atmosphere or could be to a silencer, and the base of PSV is connected to a tee on pipe, is the thrust load be referred to the tee in the pipe or the node (kind of a tee too) where PSV branched to vent? Thanks to this forum.