Patent ID: 8656946

Claim:
A valve including: a valve body through which a valve bore passes from a first valve opening to a second valve opening; a first closure member moveable within the valve bore to close the valve; a second closure member moveable within the valve bore to concurrently close the valve when the valve is also closed by the first closure member; a rigid intermediate member within the valve bore between the first closure member and the second closure member and moveable by action of movement of the second closure member to urge movement of the first closure member to render the first valve opening in fluid communication with the second valve opening, wherein a length of the intermediate member matches a separation of opposing nearmost surfaces of the first and second closure members when both the first and second closure members are in a respective position within the valve bore which closes the valve; and a first biasing member disposed within the valve bore, the first biasing member having a first end in contact with the first closure member and a second end in contact with the second closure member; wherein the first biasing member is configured to bias the first closure member away from the second closure member.