Cheers ‘Woodbloke’; I wanted to try to keep the pipework to 150 for the main runs, as my JET cyclone will accept it: but although most posts on-line appear to agree, most are from the USA, and as we know cheaper and easier to come by there!
I’m now contemplating using underground ‘sewer’ pipe at 110mm for which 45 take off’s are available.
I’ll then cobble together parts from my old system to route to each piece of kit.
I’m going to partition the workshop and put the extractor and my compressor in the partition to cut down the noise in the shop. Sooo much planning what with that and the electric supplies 
