Means to prevent external plug valve leakage

Claim 2

A plug valve comprising, a valve body having inlet and outlet ports therein, a valve chamber in said valve body between said inlet and outlet ports and intersecting said ports and open at its opposite ends through said valve body, a tapered valve plug rotatably mounted in said chamber and having a transverse bore therethrough alignable with said inlet and outlet ports, said tapered valve plug having an end face at one end thereof and extending at said one end into one of said chamber open ends, the valve plug being larger in diameter at the other end thereof and extending at said other end into the other of said chamber open ends, a reduced diameter valve stem on said other end of said valve plug and extending axially therefrom through said other open end of said chamber to exteriorly of the valve body and defining with said valve plug an annular shoulder, external stem sealing means at said other open end of said chamber in sealing relationship with said valve stem, a valve bonnet secured to said valve body over said other open end of said chamber and in surrounding relationship to said stem, an annular pressure ring in overlying relationship to the stem sealing means, a plurality of equally spaced adjusting screws extended through said bonnet and into engagement with said pressure ring for pressing the stem sealing means into sealing engagement with said stem and to initially adjust the position of said valve plug in said chamber, sealing means at said one end of said valve plug and said one open end of said chamber to seal said one end of said valve plug relative to said valve body, a cap secured to said valve body Over said one open end, and an adjusting screw means threadedly extended through said cap and into cooperative association with said end face to urge said valve plug toward said stem sealing means to effect a leak tight seal at the other end of the valve plug.

Claim 3

A valve as defined by claim 1, wherein said adjusting screw means includes a rotatable micrometric screw having an outer end exposed for manipulation exteriorly of the valve body.

Claim 4

A valve as called for in claim 1, in which a flexible sealing diaphragm is interposed between the end face of the valve plug and the said adjusting screw means for applying an axial force to said end face of the plug.

Claim 5

A valve as called for in claim 3, wherein an enlarged bearing member is interposed between said diaphragm and the said adjusting screw means for applying an axial force to the end face of the plug.

Claim 6

The valve as defined by claim 1, wherein the rotatable screw has micrometric threads thereon for making fine adjustments of said plug.

Claim 7

A plug type valve comprising in combination: a rotary plug which comprises, a circumferential end portion, a circumferential intermediate portion, an end face, and an actuating stem having a free end extending from said intermediate portion; a through port in the plug between the stem and said end face; an annular shoulder on said circumferential intermediate portion of the plug and surrounding said stem, said shoulder having an annular surface exposed in the general direction of the free end of the actuating stem; a valve body having an inlet port and an outlet port, and a lined intermediate transverse bore rotatably supporting said circumferential portions of the plug; a bonnet surrounding the actuating stem and having an annular clamping face overlying an annular margin of said bore; diaphragm means having an aperture in which the stem is rotatable, said aperture having an inner marginal portion overlying and contacting the exposed surface of said plug shoulder; said diaphragm means having an outer peripheral margin; means securing the bonnet upon the valve body with the outer peripheral margin of said diaphragm means clamped and sealed between said annular margin of the body bore and said clamping face of the bonnet; a pressure ring surrounding the stem, said ring having one face in contact with the diaphragm means, and an opposite face exposed to the bonnet; a plurality of equally spaced adjustable means extended through said bonnet and into engagement with said pressure ring for advancing the pressure ring against the diaphragm means and to force said diaphragm means against the aforesaid annular surface of the plug shoulder; and adjustable means cooperatively associated with the end of the plug opposite said stem for bodily shifting the plug axially in the direction of the bonnet, for modifying the force imposed by said plug shoulder surface and said pressure ring upon the inner marginal portion of the diaphragm means.

Claim 8

A plug type valve comprising in combination: a rotary plug which comprises, a circumferential end portion, a circumferential intermediate portion, an end face, and an actuating stem having a free end extending from said intermediate portion; a through port in the plug between the stem and said end face; an annular shoulder on said circumferential intermediate portion of the plug and surrounding said stem, said shoulder having an annular surface exposed in the general direction of the free end of the actuating stem; a valve body having an inlet port and an outlet port, and a lined intermediate transverse bore rotatably supporting said circumferential portions of the plug; a bonnet surrounding the actuating stem and having an annular clamping face overlying an annular margin of said bore; diaphragm means having an aperture in which the stem is rotatable, said aperture having an inner marginal portion overlying and contacting the exposed surface of said plug shoulder; said diaphragm means having an outer peripheral margin; means securing the bonnet upon the valve body with the outer peripheral margin of said diaphragm means clamped and sealed between said annular margin of the body bore and said clamping face of the bonnet; a pressure ring surrounding the stem, said ring having one face in contact with the diaphragm means, and an opposite face exposed to the bonnet; a plurality of equally spaced adjustable means extended through said bonnet and into engagement with said pressure ring for advancing the pressure ring against the diaphragm means and to force said diaphragm means against the aforesaid annular surface of the plug shoulder; and adjustable means cooperatively associated with the end of the plug opposite said stem for bodily shifting the plug axially in the direction of the bonnet, for modifying the force imposed by said plug shoulder surface and said pressure ring upon the inner marginal portion of the diaphragm means.

Claim 9

The valve as defined by claim 6, wherein said adjustable means last mentioned includes a rotatable screw having an outer end exposed for manipulation exteriorly of the valve body, and means at the inner end of said screw for applying force to said end face of the plug.

Claim 10

The valve as defined by claim 7, wherein the combination includes a cap secured to the valve body in covering relation to said end face of the plug; and a flexible sealing diaphragm having a central portion disposed intermediate said means at the inner end of said screw and said plug end face; said last mentioned flexible sealing diaphragm having an outer marginal portion secured and sealed between the valve body and said cap.

Claim 11

The valve as defined by claim 7, wherein the combination includes a cap secured to the valve body in covering relation to said end face of the plug; and a flexible sealing diaphragm having a central portion disposed intermediate said means at the inner end of said screw and said plug end face; said last mentioned flexible sealing diaphragm hAving an outer marginal portion secured and sealed between the valve body and said cap.

Claim 12

The valve as defined by claim 6, wherein the combination includes a deformable delta ring having sealing contact against the stem, and positioned for wedging between the pressure ring and said diaphragm means first mentioned.

Claim 13

The valve as defined by claim 10, wherein the stem where contacted by said delta ring, and the plug in the regions of said shoulder, said end face and said circumferential portions, carry a coating of fluorocarbon material of the class of Teflon.

Claim 14

The valve as defined by claim 6, wherein the stem, and the plug in the regions of said shoulder, said end face, and said circumferential portions, carry a coating of fluorocarbon material.

Claim 15

The valve as defined by claim 6, wherein the aforesaid plurality of adjustable means for advancing the pressure ring, comprises a set of three adjustable screws carried by the bonnet, said screws being substantially equidistant from the plug stem, and substantially equidistant from one another.

Claim 16

The valve as defined by claim 6, wherein the aforesaid plurality of adjustable means for advancing the pressure ring, includes means to tilt said pressure ring relative to the mean plane of the bonnet; and the stem and the plug in the regions of said shoulder, said end face, and said circumferential portions, carry a coating of fluorocarbon material.

Claim 17

The valve as defined by claim 14, wherein the combination includes a deformable delta ring having sealing contact against the stem, and positioned for wedging between the pressure ring and said diaphragm means first mentioned.

Claim 18

The valve as defined by claim 6, wherein is included in the combination a dust guard surrounding the actuating stem exteriorly of the bonnet.