Valves
A double check valve ( 10 ) with two separate elements ( 20, 25 ) individually movable to close the valve and collectively movable to open the valve. The separate elements are independently closing the valve, and collectively controllable to open the valve, to allow pressure release or to allow injection of fluid (e.g. lubricant). In an example, the double check valve includes two separate check valves with a stinger element ( 30 ) between them which is operable to internally sting the one check valve when (e.g. by action of) the other check valve is stung by a user (e.g. using a stinger means) thereby to open both check valves individually and the double check valve as a whole.
1. 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.
2. The valve according to claim 1 in which the rigid intermediate member is dimensioned to be in contact with both the first closure member and the second closure member only after the second closure member is displaced from a position within the valve bore which closes the valve.
3. The valve according to claim 1 wherein the rigid intermediate member has an axially transverse width less than the width of the valve bore.
4. The valve according to claim 1 in which the rigid intermediate member is a metal rod.
5. The valve according to claim 1 in which the valve bore defines a first valve seat and the first closure member is moveable within the valve bore to engage the first valve seat and dimensioned to close the valve when so seated.
6. The valve according to claim 5 in which the rigid intermediate member is moveable by action of a movement of the second closure member towards the first valve seat to urge movement of the first closure member away from the first valve seat.
7. The valve according to claim 5 in which the valve bore defines a second valve seat and the second closure member is between the first and second valve seats and is moveable within the valve bore to engage the second valve seat and dimensioned to close the valve when so seated.
8. The valve according to claim 1 in which the valve is a check valve.
9. The valve according to claim 1 in which the valve is selected from the group consisting of a gate valve, a plug valve, a globe valve, and a ball valve.
10. The valve of claim 1 , further comprising a second biasing member disposed within the valve bore, the second biasing member being configured to bias the first closure member toward the second closure member.
11. The valve of claim 10 , wherein the second biasing member has a compression strength that is greater than a compression strength of the first biasing member.
12. A lubrication fitting including:
a valve including,
a valve body through which a valve bore passes from a first valve opening to a second valve opening, and in which the valve bore is a lubricant conduit,
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 distance between 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, a second end, and an axial length measured from the first end to the second end;
wherein the axial length of the first biasing member is equal to the separation distance between the first closure member and the second closure member.
13. The valve member of claim 12 , further comprising a second biasing member disposed within the valve bore, the second biasing member being configured to bias the first closure member toward the second closure member.
14. The valve member of claim 13 , wherein the second biasing member has a compression strength that is greater than a compression strength of the first biasing member.
15. A method for controlling fluid communication with a pressurized region, the method comprising:
engaging a first closure member with a first valve seat disposed within a valve bore of a valve body;
engaging a second closure member with a second valve seat disposed within the valve bore;
biasing the first closure member away from the second closure member with a first biasing member, wherein the first biasing member has a first end in contact with the first closure member and a second end in contact with the second closure member; and
moving the second closure member from the second valve seat;
moving the first closure member from the first valve seat simultaneous with moving the second closure member from the second valve with a rigid intermediate member extending between the second closure member and the first closure member.
16. The method of claim 15 , further comprising:
biasing the first closure member toward the first valve seat with a first biasing force;
biasing the first closure member away from the second closure member with a second biasing force that is less than the first biasing force.
17. The method of claim 15 , further comprising:
relieving pressure from the pressurized region while disengaging the second closure member from the second valve seat and disengaging the first closure member from the first valve seat.
18. The method of claim 17 , further comprising:
supplying a lubricant to the pressurized region through the valve bore.