Fluid flow control valve and flow control devices and methods employing same

A method of controlling fluid flow employing a flow control valve comprising a resilient valve body including a fluid flow lumen therein, said fluid flow lumen having an interior surface and an inlet portion, and the flow control valve further including a rigid valve member located within the fluid flow lumen, the rigid valve member being generally spherically shaped with a maximum diameter sized cross-sectionally larger than the fluid flow lumen to contact the interior surface of the fluid flow lumen and block the fluid flow therethrough when the resilient valve body is in a relaxed condition, said resilient valve body further including an annular shoulder positioned between the rigid valve member and the inlet portion of the fluid flow lumen, the method including:

• applying sufficient upstream pressure in the fluid flow lumen to flex the resilient valve body to a position in which the interior surface of the fluid flow lumen is spaced from the rigid valve member to allow the fluid flow through the fluid flow lumen;
• reducing the upstream pressure to provide a primary seal annular contact between the rigid valve member and the interior surface of the fluid flow lumen on both sides of the maximum diameter of the rigid valve member;
• and
• contacting an exterior surface of the resilient valve body, where the exterior surface is external to the fluid flow lumen, with a downstream fluid under pressure, to assist in providing the primary seal annular contact between the interior surface of the fluid flow lumen and the rigid valve member and a supplemental seal between the annular shoulder of the resilient valve body and the rigid valve member, where the supplemental seal is separate and distinct from the primary seal and is formed primarily by the pressure from the downstream fluid of the resilient valve body and a resiliency of the resilient valve body.