Floating Ball Valve vs Trunnion Ball Valve
A floating ball is pushed toward the downstream seat by line pressure, while a trunnion-mounted ball is mechanically supported and transfers pressure load through the seat system. That difference changes torque, seat loading and the way larger or higher-pressure valves are selected.
Floating construction is commonly used where compact size and simpler construction suit the bore and pressure range. Trunnion construction becomes more attractive as size, pressure, actuator requirements or isolation philosophy make controlled seat loading important.
For an RFQ, do not choose between floating and trunnion from size alone; include differential pressure, service fluid, seat material, bore, fire-safe requirement, operation and the required shutoff or DBB/DIB philosophy.