EP0237321A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Stuffing box packing and method for manufacturing the same
Assignee: SEALING EQUIPMENT PRODUCTS CO Inc
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Filing: 1987-03-10
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Granted: —
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Expires: 2007-03-10
Abstract
Abstract A helical spacer (12) is slid onto a cylindrical mandrel (38) and a flexible corrugated ribbon (T) of plastically deformable packing material, especially expanded graphite, is helically wound onto the mandrel (38) between turns of the spacer (12). This assembly is placed in a tubular die (14) and tubular punches (28) are run into the die (14), and moved axially towards one another telescopically of the mandrel (38). The punches (28), engaging opposite turns at ends of spacer (12) axially compress and radially expand the helix, raising its density. The helical packing stock (GSP) is disassembled from the spacer (12) and mandrel (38) by rotation, and supplied to the trade. In use, some of the stock is telescoped onto a valve stem, or a mandrel of the same diameter as the valve stem, and cut to length, eg. using a pen knife. In this way, one stock of packing material can serve valve stems of a range of sizes.
Inventors
- 👤 Garry W. Dodson
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-23 09:39
CPC Classifications
F; F16; F16J; F16J15/00; F16J15/16; F16J15/18; F16J15/20; Y; Y10; Y10S; Y10S425/00; Y10S425/007; Y10S425/047
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
147 words
A packing, for the stem of a valve which projects axially into a stuffing box and provided with a packing gland which is securable in place to retain packing in the stuffing box to a selected depth, in an annular space about the valve stem, said packing comprising: a longitudinally elongate spiral of packing material, this spiral being of substantially uniform transverse cross-sectional shape and constituted by more than one helical turn; said spiral comprising a plurality of axially pre-compressed, radially adjoining layers of a plastically deformable packing material, compression-crumpled into a united structure; said spiral being sufficiently radially flexible as to permit a length of said spiral, constituted by more than one helical turn thereof, to be conformingly telescopically selectively received on any valve stem having a diameter which falls within a predetermined range of diameters including ones both larger and smaller than a medial diameter.
Claim 2
Dependent Claim
147 words
A packing, for the stem of a valve which projects axially into a stuffing box and provided with a packing gland which is securable in place to retain packing in the stuffing box to a selected depth, in an annular space about the valve stem, said packing comprising: a longitudinally elongate spiral of packing material, this spiral being of substantially uniform transverse cross-sectional shape and constituted by more than one helical turn; said spiral comprising a plurality of axially pre-compressed, radially adjoining layers of a plastically deformable packing material, compression-crumpled into a united structure; said spiral being sufficiently radially flexible as to permit a length of said spiral, constituted by more than one helical turn thereof, to be conformingly telescopically selectively received on any valve stem having a diameter which falls within a predetermined range of diameters including ones both larger and smaller than a medial diameter.
Claim 3
Dependent Claim
14 words
A packing as claimed in Claim 1, wherein said plastically deformable material comprises graphite.
Claim 4
Dependent Claim
15 words
A packing as claimed in Claim 2 wherein said spiral consists substantially entirely of graphite.
Claim 5
Dependent Claim
38 words
A packing as claimed in any one of the preceding claims, said spiral is constituted by a plurality of helical turns of said packing material and said spiral is adapted to be field-cut to length using a pen-knife.
Claim 6
Dependent Claim
40 words
A packing as claimed in any one of the preceding claims, wherein said plurality of layers of radially adjoining layers of graphite, compression molded into a united structure, is constituted of a plurality of layers of flexible foamed graphite tape.
Claim 7
Dependent Claim
25 words
A packing as claimed in any one of the preceding claims, wherein said tape is transversally corrugated with respect to the length of such tape.
Claim 8
Dependent Claim
31 words
A packing as claimed in Claim 6, wherein said radially adjoining layers of graphite, compression-crumpled into a united structure have multiple zig-zag interlocking folds extending along the lengths of such layers.
Claim 9
Dependent Claim
38 words
A packing as claimed in any one of the preceding claims, wherein said layers of said united structure are so compressed that they are about one-half the uncompressed width of said layers of said flexible foamed graphite tape.
Claim 10
Dependent Claim
25 words
A valve having a stuffing box provided with a valve stem packing constituted by a packing as claimed in any one of the preceding claims.
Claim 11
Independent Claim
139 words
A method for providing a multi-layer spiral of a plastically deformable material, comprising: providing a mandrel having a generally cylindrical outer peripheral surface; disposing a spacer of multiple-turn helical form on said mandrel so that the spacer thereof is juxtaposed with the outer peripheral surface of the mandrel; axially spreading said spacer so as to provide an inter-turn space extending helically about said spacer; laying a plurality of lengths of plastically deformable material, one upon another, in layers in radial superposition, into said inter-turn space, so that said lengths extend along said space throughout more than one helical turn; while radially confining said space and said spacer with an outer body, applying compressive force to said spacer at opposite ends thereof so as to compression-crumple said layers into a united structure; and removing said unit structure from said spacer.
Claim 12
Independent Claim
139 words
A method for providing a multi-layer spiral of a plastically deformable material, comprising: providing a mandrel having a generally cylindrical outer peripheral surface; disposing a spacer of multiple-turn helical form on said mandrel so that the spacer thereof is juxtaposed with the outer peripheral surface of the mandrel; axially spreading said spacer so as to provide an inter-turn space extending helically about said spacer; laying a plurality of lengths of plastically deformable material, one upon another, in layers in radial superposition, into said inter-turn space, so that said lengths extend along said space throughout more than one helical turn; while radially confining said space and said spacer with an outer body, applying compressive force to said spacer at opposite ends thereof so as to compression-crumple said layers into a united structure; and removing said unit structure from said spacer.
Claim 13
Dependent Claim
21 words
A method as claimed in Claim 9 for preparing a packing as claimed in any one of Claims 1 to 8.
References Cited (Backward Citations)
No citation records indexed.
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