Parker’s 8200 Series couplings feature a unique valve design that enables connection even when the coupler, nipple, or both are under pressure. The internal valves remain closed during connection and only open once pressure on the female body is relieved and then reapplied. This pressure sequence can be performed using either open-center or closed-center hydraulic systems with a control valve, making the 8200 Series ideal for demanding applications that require reliable, pressure-tolerant connections.