Roto Seal Coupling Roto Seal Coupling - Use of a Roto Seal coupling is such a way that any fluid whether it is grease oil, thermal oil, coolants, hydraulic fluid or mobile oil, can flow from one agent to another agent easily. Roto Seal Coupling is a type of rotating joint which is used for allowing rotation of parts that are united with each other. https://www.concordevalves.com/Roto-Seal-Coupling.html