Manhole (or handhole) type curved (oval, elliptical) cover into a PV or pipeline?
Or a flat (rectangular) plate with an outlet pipe or fitting on the non-circular plate on the side fitting or enclosure on a PV or pressurized pipeline?
...Or a flat (rectangular) plate with an outlet pipe or fitting on the non-circular plate on the side fitting or enclosure on a PV or pressurized pipeline?