Couplings provide quick connect/disconnect capability with self-sealing action for use on Ground Support Equipment (GSE) and other aerospace applications. Simple one hand operation to connect and disconnect with positive visual and touch indicate full engagement. FULLY interchangeable with many existing 3000 psi and 1000 psi GSE couplings meeting specifications MIL-H-5440 Type 1 and 2, MIL-C-25427 Type 1 and 2, and MIL-C-5502. Superior sealing during transition and in the uncoupled state as a result of incorporating elastomeric and thermoplastic valve seals, thus not relying on metal-to-metal sealing.