If you're feeling flush you could always go 22mm copper, stuff/fudge/mate plastic outlet pipe from the macerator to 22mm copper (22mm to 28mm coupler, plastic pipe stuffed up the 28mm end with plus some builders friend?) use a couple of 28mm to 22mm reducers and a 28mm swept bend for the right angles, no problem getting a shut off valve, swept Tee in the line with a compression stop end for rodding with a flexible wire, maybe insulate on the external run, all soldered except for the shut off valve.
Lawrence.
Lawrence.
