Low Friction Live-Loaded Packing
AssigneeFisher Controls International LLC
InventorsMichel Lovell, Ted Grabau
Life of this patent
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Abstract
A valve packing assembly for a control valve includes a seal assembly, a loading assembly, and a packing retainer. The seal assembly has a seal component to provide a fluid seal around a valve stem and an anti-extrusion component to substantially prevent extrusion of the seal component about the valve stem. The loading assembly is configured to advantageously provide a predetermined packing stress to the seal assembly that is in the same direction as a process stress applied to the seal assembly by a process fluid, thereby substantially reducing packing friction and packing wear in the control valve assembly.
Claims45
A valve packing assembly for a control valve assembly, the valve packing assembly comprising:
- a seal assembly to provide a fluid seal around a valve stem;
- and
- a loading assembly having a loading means adapted to provide a loading force to exert a packing stress upon the seal assembly such that the loading force provides a predetermined packing stress supplemental to a process packing stress resulting from a process pressure within the control valve assembly.
A cartridge packing assembly to seal a valve stem in a control valve assembly, the cartridge packing assembly comprising:
- a seal assembly having a seal component to provide a fluid seal around the valve stem and at least a first anti-extrusion component to substantially prevent extrusion of the seal member about the valve stem;
- a loading assembly having a loading means to provide a predetermined packing stress upon the seal assembly and at least one spacer to couple the loading means to the seal assembly;
- and
- a packing retainer adapted to be disposed in an outboard packing box of the control valve assembly, the packing retainer defining a packing bore receiving the seal assembly and he loading assembly wherein the packing retainer includes a predetermined length between a retainer shoulder and a loading means seating surface to control a loading assembly force that defines the predetermined packing stress in the control valve assembly.
A valve packing assembly for a control valve assembly, the valve packing assembly comprising:
- a seal assembly having a seal component to provide a fluid seal around a valve stem and an anti-extrusion component to substantially prevent extrusion of the seal component about the valve stem;
- a loading assembly having a loading means to provide a loading force to exert a packing stress upon the seal assembly;
- and
- a packing retainer having a packing bore receiving the loading assembly upon a seating surface and being configured to couple the seal assembly and loading assembly to the control valve assembly, the packing retainer further configured to include a predetermined length between at least a retainer shoulder and the seating surface to control a loading force that defines a predetermined packing stress to substantially reduce packing friction and packing wear in the control valve assembly.
Dependencies are inferred from the claim text.