The new downstairs toilet needs to be connected to a pan off-centre, so I need a dog-legged flush pipe. Are there any connectors suitable for joining 38mm od flush pipes (to normal 40mm waste for example) ? Can they be solvent welded ? If not, are the concertina types smooth or concertina on the inside. If concertina, I'll make the cistern a bit higher to compensate for lost pressure. Thanks, Simon.