Internal post flow control
A flow control including an annular flexible member and an internal post disposed downstream of the flexible member is described. The annular flexible member has a deflectable inner edge that defines a passage channel and the annular flexible member and internal post define a control gap therebetween wherein the deflectable inner edge of the annular flexible member deflects axially under increasing fluid pressure to reduce the control gap and consequently control fluid flow.
1. A flow control comprising:
an annular flexible member having a deflectable inner edge defining a passage channel wherein the deflectable inner edge of the annular flexible member comprises a radially inwardly extending rim; an internal post, at least a portion of said internal post being disposed downstream of the annular flexible member, the internal post extending longitudinally from a solid upstream end portion to a downstream base portion wherein the internal post cross-sectional area increases from the upstream end portion to the downstream base portion,
the annular flexible member and internal post defining a control gap therebetween wherein the deflectable inner edge of the annular flexible member deflects axially under increasing fluid pressure thereby reducing the control gap.
2. The flow control of claim 1 further comprising a housing having a longitudinally extending passage way therethrough with a central longitudinal axis wherein said annular flexible member and said internal post are disposed in said passageway.
3. The flow control of claim 2 wherein the annular flexible member is rotationally symmetrical around the central longitudinal axis.
4. The flow control of claim 1 wherein the annular flexible member has an outer peripheral portion and the outer peripheral portion is of greater thickness than said inner edge.
5. The flow control of claim 1 wherein the annular flexible member is formed from an elastomeric material.
6. The flow control of claim 5 wherein the elastomeric material is selected from the group consisting of nitrile rubbers, hydrogenated nitrile rubbers, ethylene-propylene-diene polymers (EPDM) and combinations thereof.
7. The flow control of claim 5 wherein the elastomeric material is an elastomer having a hardness range from about 3 to 100.
8. The flow control of claim 1 wherein said flow control provides substantially constant flow over a pressure range of from about 5 to 100 psi.
9. The flow control of claim 1 wherein the passage channel defined by the inner edge of the annular flexible member has a substantially circular cross-section.
10. The flow control of claim 9 wherein the passage channel has a substantially annular cross-section as defined by the internal post and the inner edge of the annular flexible member.
11. The flow control of claim 1 wherein the upstream end portion of the internal post is disposed downstream of a plane transversely bisecting the annular flexible member.
12. The flow control of claim 1 wherein the annular flexible member is substantially symmetrical with respect to a plane transversely bisecting the annular flexible member.
13. The flow control of claim 2 wherein the housing comprises an annular groove and an outer peripheral portion of the annular flexible member is positioned within said annular groove.
14. A flow control assembly comprising:
a housing having a longitudinally extending passageway therethrough with a central longitudinal axis; and
a flow control disposed in the passageway of said housing wherein the flow control comprises:
an annular flexible member having a deflectable inner edge wherein the deflectable inner edge includes a radially inwardly extending rim and a solid internal post disposed downstream of the annular flexible member, said flow control including a flow passage of alterable cross-section, said flow passage having a first cross-section as defined by the deflectable inner edge of the annular flexible member and a second cross-section as defined by the deflectable inner edge of the annular flexible member and an outer periphery of the internal post,
said first cross-section being substantially circular and said second cross-section being substantially annular wherein the deflectable inner edge of the annular flow member deflects axially under increasing fluid pressure thereby altering said second cross-section to control flow of a fluid through said flow control assembly.
15. The flow control assembly of claim 14 wherein the annular flexible member has an outer peripheral portion and the outer peripheral portion is of greater thickness than the inner edge.
16. The flow control assembly of claim 15 wherein the housing comprises an annular groove and the outer peripheral portion of the annular flexible member is positioned within said annular groove.
17. The flow control assembly of claim 14 wherein said annular flexible member is formed from an elastomeric material.
18. A flow control comprising:
a housing having a longitudinally extending passage way therethrough with a central longitudinal axis;
an annular flexible member having a deflectable inner edge defining a passage channel;
an internal post, at least a portion of said internal post being disposed downstream of the annular flexible member, wherein said annular flexible member and said internal post are disposed in said passageway and the annular flexible member is rotationally symmetrical around the central longitudinal axis;
the internal post extending longitudinally from a solid upstream end portion to a downstream base portion wherein the internal post cross-sectional area increases from the upstream end portion to the downstream base portion,
the annular flexible member and internal post defining a control gap therebetween wherein the deflectable inner edge of the annular flexible member deflects axially under increasing fluid pressure thereby reducing the control gap.
19. The flow control of claim 18 wherein the deflectable inner edge includes a radially inwardly extending rim.
20. A flow control assembly comprising:
a housing having a longitudinally extending passageway therethrough with a central longitudinal axis; and
a flow control disposed in the passageway of said housing wherein the flow control comprises:
an annular flexible member having a deflectable inner edge wherein the annular flexible member is rotationally symmetrical around the central longitudinal axis and a solid internal post disposed downstream of the annular flexible member, said flow control including a flow passage of alterable cross-section, said flow passage having a first cross-section as defined by the deflectable inner edge of the annular flexible member and a second cross-section as defined by the deflectable inner edge of the annular flexible member and an outer periphery of the internal post,
said first cross-section being substantially circular and said second cross-section being substantially annular wherein the deflectable inner edge of the annular flow member deflects axially under increasing fluid pressure thereby altering said second cross-section to control flow of a fluid through said flow control assembly.