Anti-free flow valve, enabling fluid flow as a function of pressure and selectively opened to enable free flow

A valve that limits free fluid flow until selectively opened, comprising:

• (a) a valve body of elastomeric material having a first port and a second port;
• (b) a generally planar elastomeric membrane having opposed surfaces, said elastomeric membrane being disposed within the valve body, intermediate the first and second ports, secured and supported around its periphery by the valve body;
• (c) a slit disposed within said elastomeric membrane, extending between its opposed surfaces, fluid flow between the first and the second ports being enabled when the slit opens in response to a fluid pressure across the elastomeric membrane exceeding a cracking pressure;
• (d) tabs that extend externally of the valve body, on opposite sides thereof, said tabs distorting the valve body when squeezed by an operator, so that the distorted valve body deforms the elastomeric membrane to force the slit to spread apart, forming a substantially unrestricted path of fluid communication through the valve, so that fluid freely flows between the first and second ports;
• and
• (e) the tabs for selectively deforming including means for selectively latching the elastomeric membrane in a deformed state in which the slit has been forced to spread apart, allowing fluid to continuously flow freely through the valve.