Female Series “A-HD” is the evolution of Stucchi technology and quality applied to flat face couplings. Available in dimension 10 (3/8’) and 12.5 (1/2’), this series is the Stucchi solution to the problem of the connection in presence of internal residual pressure on the female side. It will connect with residual pressure without releasing any fluid into the environment. The mating circuit will need to be without residual pressure (male open to drain). The modular structure allows the flexibility to offer several types of threads or special ports in order to satisfy diverse applications while maintaining a compact dimension.