No I just need a rotation of about 40 degrees. I did think about the sleeve over the joint but I guess the seal will have the same problem of wearing out because of the temperature as well as movement.
I am making a dust cleaning system for induction furnaces in my steel mill and for that I have to design a mechanism with which about 7m length of 16inch diameter pipe can rotate about an elbow attached to one end but wihtout any leakages. ANY HELP would be appreciated.