Metal hose is generally in many roller continuous coiling machine.
Corrugated compensator is generally the sheet by methods similar to the above rolled into a tube, for thick, only non continuous curved plate forming; then welded longitudinal seam; then useful roller in external and internal rolled into thin wall corrugated, can be pressed into the fluid from the internal or external, plastic molding, can be explosive forming, can also be electric deposition.
The general subject of industrial valves is casting molding.