Foster how to select plug and socket guide

Proper coupler selection is important because of the variety of media for which they are used. There are four basic factors that should be considered to assure proper selection:

TYPE

All couplers consist of two basic components - a socket and a plug. The type of coupler varies by the valving arrangements in these two components.

	One Way Shut-Off
	In a "One Way Shut-Off", only the socket has valving to shut off the flow when disconnected; it is, therefore, installed on the pressure side of the line. The plug has no valving and exhausts the downstream line at disconnect.
	Two Way Shut-Off
	The "Two Way Shut-Off" provides valving in both the socket and the plug, thereby shutting off flow at both of the disconnected ends. Originally developed for hydraulic lines, they are suitable for many other media because of the variety of metals and seal compounds offered.
	Straight-Thru
	"Straight-Thru" couplers, as the name implies, do not have valving in either the socket or the plug. Therefore, both ends of the line are exhausted at disconnect.

OPERATION

Operation refers to the action required to connect and disconnect a coupler. Operation is a function of sockets only and does not vary for plugs.

	Manual
	Manual sockets require manual retraction of the sleeve to both connect and disconnect the plug. The "BL Series" (ball lock) is an optional feature available on manual sockets. After connection, the sleeve is rotated locking the coupler against accidental disconnect.
	Automatic
	Automatic sockets accept the plug by simple insertion into the socket and do not require retraction of thee sleeve to connect. The "SL Series" (safety lock) is an optional feature on automatic sockets to prevent accidental disconnect. It is functionally the same as the "BL Series" on manual sockets; the locking mechanism is inside the sleeve.
	Safety Coupler
	Safety sockets are a variation of automatic operation. The socket accepts the plug by insertion. The sleeve is moved straight forward to lock and turn on the air. The sleeve is moved back. rotating first to the left and then to the right. This shuts off the supply line, exhausts the downstream line, and then releases the plug.