Hi Mick,
I agree with you, I would normally offset the bypass to ensure that the removal of the CV is not fouled by the bypass pipework – after all, one of the reasons for having a bypass is to allow maintenance on the CV.
Now – why this isn’t addressed in literature, is something I can’t answer, but I would expect that a seasoned piper with be looking at access and maintenance as part of his/her design, in much the same way as we would allow for pulling tube bundles from an exchanger, or agitator removal from a vessel.
This is one of many reasons, that a piping project requires that senior level experienced pipers are employed, rather than just cad operators.
Not everything that we do is covered by a code, standard, work instruction, manual etc … somethings require the experience of a senior level piper.
Anton
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