These chaps seem to do what's needed. Either galvanised flexible steel exhaust hose (like the flexible conduit, but less leaky), or possibly their stainless steel over-braided marine fuel hose would fit the bill.
No connection with them, but I do need to look into some more robust flexible coolant hose for the milling machine, lathe and surface grinder!
Edited By Mark Rand on 10/09/2019 00:27:56