Valve and choke stem packing assemblies

Patent metadata

Field	Value
Publication number	US-10415719-B2
Application number	US-201414502892-A
Country	US
Kind code	B2
Filing date	Sep 30, 2014
Priority date	Sep 30, 2013
Publication date	Sep 17, 2019
Grant date	Sep 17, 2019

Abstract

A stem packing assembly including a first annular member defining a central axis, a second annular member defining a central axis coaxial with the central axis of the first annular member, and an annular energizing member defining a central axis coaxial with the central axis of the first annular member. In an embodiment, the stem packing assembly can have a leakage rate according to ISO 15848-1 of less than 1×10 −4 mgs −1 m −1 for at least 500 cycles at 160° C., and less than 1×10 −4 mgs −1 m −1 for at least 500 cycles at −46° C. In another embodiment, the first annular member can include a PAEK, the second annular member can include a PTFE, and the annular energizing member at least partially includes a PTFE.

First claim

What is claimed is:

1. A stem packing assembly comprising:
a plurality of first annular members, having a first surface and a second surface, each defining a central axis;
a plurality of second annular members, having a first surface and a second surface, each defining a central axis coaxial with the central axis of the first annular members, wherein consecutively arranged first annular members are spaced apart from one another by at least one of the second annular members and wherein at least one of the first and second surfaces of the first member defines an internal angle to offset two or more segments by a relative angle α to permit the first surface of the second member to splay the first member in the radial direction upon application of a axial loading condition; and
an annular energizing member defining a central axis coaxial with the central axis of the first annular member, wherein the annular energizing member includes a first component and a second component, wherein the first component comprises a contiguous planar surface and the second component comprises a contiguous planar surface, wherein the contiguous planar surfaces of the first component and the second component contact each other, wherein the contiguous planar surfaces of the first component and second component are each perpendicular to the central axis, wherein the second component comprises a jacket having a cavity, and an energized element at least partially disposed within the cavity, wherein the second component is a single piece,
wherein all of the first annular members comprise PTFE, wherein all of the second annular members comprise PAEK, and wherein the stem packing assembly has a leakage rate according to ISO 15848-1 of:
less than 1×10 −4 mgs −1 m −1 for at least 500 cycles at 160° C.; and
less than 1×10 −4 mgs −1 m −1 for at least 500 cycles at −46° C., and wherein the assembly further comprises a fourth member comprising a contiguous planar surface, wherein at least one of the first annular members comprises a contiguous planar surface, wherein the contiguous planar surfaces of the fourth annular member and the first annular member contact each other, and wherein the contiguous planar surfaces of the fourth annular member and the first annular member are each perpendicular to the central axis.

2. The stem packing assembly according to claim 1 , wherein the jacket further comprises a first extension and a second extension.

3. The stem packing assembly according to claim 2 , wherein the first extension has a length that is greater than the second extension.

4. The stem packing assembly according to claim 1 , wherein the energized member has an asymmetrical cross-sectional profile.

5. The stem packing assembly according to claim 1 , wherein the energized element comprises a toroidal shaped spring having a generally circular cross section.

6. The stem packing assembly according to claim 1 , wherein each of the plurality of first annular members has a lower surface, and wherein the lower surface of at least one annular member of the plurality of first annular members has an internal angle, α, of at least 5° and no greater than 60°.

7. The stem packing assembly according to claim 1 , wherein the second component is in axial alignment with the first component, and wherein the first component contacts the second annular member, and wherein the first and second components are adapted to independently float relative to one another.

8. A stem packing assembly comprising:
a first sealing element including:
a first annular member, having a first surface and a second surface, defining a central axis; and
a second annular member, having a first surface and a second surface, defining a central axis axial with the central axis of the first annular member, the second annular member abutting the first annular member, wherein at least one of the first and second surfaces of the first member defines an internal angle to offset two or more segments by a relative angle α to permit the first surface of the second member to splay the first member in the radial direction upon application of a axial loading condition;

a second sealing element including:
a third annular member defining a central axis coaxial with the central axis of the second annular member, the third annular member abutting the second annular member;
a fourth annular member defining a central axis coaxial with the central axis of the third annular member, the fourth annular member abutting the third annular member, wherein the third annular member is bonded to the fourth annular member; and
an annular energizing member defining a central axis coaxial with the central axis of the first annular member, wherein the annular energizing member includes a first component and a second component, wherein the first component comprises a contiguous planar surface and second component comprises a contiguous planar surface, wherein the contiguous planar surfaces of the first component and the second component contact each other, wherein the contiguous planar surfaces of the first component and second component are each perpendicular to the central axis, wherein the second component comprises a jacket having a cavity, and an energized element at least partially disposed within the cavity, wherein the jacket comprises a first extension having a scraper extending in a radial direction, and a retaining axial extension extending from the distal end of the first extension, and an energizing element, wherein the second component is a single piece;

wherein:
the stem packing assembly has a leakage rate according to ISO 15848-1 of less than 1×10 −4 mgs −1 m −1 for at least 500 cycles at 160° C., and less than 1×10 −4 mgs −1 m −1 for at least 500 cycles at −46° C.,
the first and third annular members comprise PTFE,
the second and fourth annular members comprise PAEK, and
the annular energizing member at least partially comprises PTFE, and wherein the assembly further comprises a fourth member comprising a contiguous planar surface, wherein at least one of the first annular members comprises a contiguous planar surface, wherein the contiguous planar surfaces of the fourth annular member and the first annular member contact each other, and wherein the contiguous planar surfaces of the fourth annular member and the first annular member are each perpendicular to the central axis.

9. The stem packing assembly according to claim 8 , wherein the first annular member is engaged with the second member.

10. The stem packing assembly according to claim 8 , wherein the energized member has an asymmetrical cross-sectional profile.

11. The stem packing assembly according to claim 8 , wherein the first extension has a length that is greater than the second extension.

12. The stem packing assembly according to claim 8 , further comprising a third annular member, wherein the energized element is disposed between the third annular member and the jacket.

13. A stem packing assembly comprising:
an annular energizing member defining a central axis, wherein the annular energizing member includes a first component and a second component, wherein the first component comprises a contiguous planar surface and the second component comprises a contiguous planar surface, wherein the contiguous planar surfaces of the first component and the second component contact each other, wherein the contiguous planar surfaces of the first component and second component are each perpendicular to the central axis, wherein the second component comprises a jacket having a cavity and an energized element at least partially disposed within the cavity, wherein the jacket comprises a

Assignees

• Saint Gobain Performance Plastics Corp

Inventors

• Leboeuf Mathilde
• Kustermans Jan
• Singh Rojendra
• Valdenaire Christophe
• Rousseau Filip
• Dubois Herman M

Classifications

• F16K3/02

  with flat sealing faces; Packings therefor · CPC title

• F16J15/3236

  with at least one lip for each surface, e.g. U-cup packings · CPC title

• F16J15/18

  with stuffing-boxes for elastic or plastic packings · CPC title

• F16K41/04 Primary

  with at least one ring of rubber or like material between spindle and housing · CPC title