Abstract: A frangible quick disconnect coupling having a coupler and a nipple, also referred to herein as coupling halves which are designed to automatically seal off fluid flow after impact in a modularized race car configuration to prevent fuel spillage. The shut-off mechanisms work under any impact condition, including tension, shear and bending breakaway The couplings are designed for equipment which has been modularized for a quick change environment. A radially floating mechanism allows the couplings to be connected under misaligned conditions for blind mating operation. This mechanism also protects the breakaway structure under severe vibration conditions. All leak paths are completely sealed off throughout the normal connect and disconnect operations to minimize fuel spillage. Streamlined flow passages are designed to minimize pressure loss. Coupling halves are designed for direct mounting to an engine manifold, fuel cell or other structure without hose attachment interfaces.