A quick disconnect, as it is used in manufacturing, provides a means of quickly disconnecting a line without the loss of hydraulic fluid or entrance of air into a system. The quick disconnect system is important for a number of reasons, not the least of which is that being able to disconnect quickly can save time, money, and in some cases, lives.
The quick disconnect consists of a coupling assembly with two halves, which are held together by a union nut. Each half contains a valve held open when the coupling is connected. When the coupling is open, it allows fluid to flow through in either direction. When it is disconnected, a spring in each half closes the valve, preventing the loss of fluid and the entrance of air. This happens quickly, shutting the system down almost immediately – hence, the name quick disconnect.
Quick disconnect couplings are designated as connecting devices designed to permit easy and immediate connection and separation of air or fluid for pneumatic or hydraulic lines without the need for tools. When a person has to stop and grab a tool in order to disconnect, it takes time and manpower. When installed in a fluid system, quick disconnect couplings save time by eliminating the need for system bleeding, recharging, or purging of air due to a lag time in the disconnection process.