CA1087490A

CA1087490A - Variable orifice valve

Info

Publication number: CA1087490A
Application number: CA302,221A
Authority: CA
Inventors: Jesse C. Johnston, Jr.; John E. Nelson
Original assignee: Diamond Power Specialty Corp
Current assignee: Diamond Power Specialty Corp
Priority date: 1977-04-29
Filing date: 1978-04-28
Publication date: 1980-10-14
Also published as: SE7804703L; IT7822777A0; JPS557499U; DE2814275A1; JPS5445829A; FR2389053B1; FR2389053A1; GB1565768A; AU3551678A; AU515315B2; IT1095017B; BR7802652A; SE437714B

Abstract

VARIABLE ORIFICE VALVE

ABSTRACT OF THE DISCLOSURE
A valve body has a chamber containing a tubular guide for a valve stem which extends entirely through the chamber and carries a poppet valve head movable to and from the outer surface of a valve seat mounted in one of the ports of the body. A pressure regulating valve disc is threadably mounted on the guide in the chamber for movement toward and from the inner surface of the seat. A worm shaft journaled transversely in the body meshes with axially elongated gear teeth carried on the periphery of the valve disc. Rotation of the worm rotates the valve disc on the threads of the guide to move the disc toward and from the inner surface of the seat.

Description

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This inven-tion relates to a variable oriEice valve.
A well-known and widely used type of poppet valve employed to control the flow of steam to a soot blower has an internal supplemental pressure regulating valve disc for limiting the effective flow past the poppet valve. The pressure regulating valve disc is threaded on the guide for the poppet valve and is adjustable, to vary the outlet pressure/ by removing a plug in the valve body in order to gain access to the disc. The disc is peripherally notched 50 that when the plug is removed it can be turned by pushing or prying it with a small bar or screwdriver, to vary the maximum pressure setting. The space within the valve body is limited, and time is required to remove the access plug, so that a substantial period of time is required to gain access to the disc and to adjust it. The present invention ~;
has as its ob~ect t~e provision of an improved pressure regulating valve disc construction and improved opera~ing means therefor which provides not only for more convenient adjustment of the pressure setting but also permits quick operation thereof to a fully closed position whereby the ;~
pressure regulating disc can be effectively employed as a safety shutoff.
A related object is to provide such an improved valve comprised primarily of standardized proven components ~hich remain unchanged and wherein only minimum modifications are required which are simple and of low cost but which do not impair the reliability or the performance of the valve. ;-The present invention resides in a valve including a body having a chamber therein and having an inlet port :. . : ~ . - - :

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and an outlet port, both of the ports communicating with the chamber. Valving means is movable -to control ~low through the chamber between the inlet and outlet, and means independent o-E the valving means and ac-tual from outside the body is provided for adjustably limiting the maximum rate o~ such flow. A seat portion surrounds one of the ports and faces the interior of the chamber, and an externally threaded screw portion is provided within the chamber and fixed to the body and projects towards the seat. The screw portion is coaxial with the seat. A valve member is in-dependent of the previously mentioned valving means and is threadably mounted on the screw portion for movement toward and from the seat. According to the invention there is provided an axially elongated gear fast on the periphery of the valve member with a worm being journaled in the bodiy and meshing with the gear. Means extends through and is accessible from outside the body Eor actuating the worm.
The gear is movable axially along the screw portion trans-versely of the worm when rotated by the worm so that the valve member is movable toward and from the seat.
~ dvantages wilI become apparent upon consideration of the present disclosure.

BRIEF DESCRIPTION OF T~IE FIGURES
OF DRAWING

Fig. 1 is a view principally in central vertical section but partly in side elevation of a valve incorporating the-principles of the present inven-tion;
; Fig. 2 is a sectional view taken substantially on the line II-II of Fig. 1 and looking in the direction of the arrows; and

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Fig. 3 is a fragmentary sectional view showing a modi-fied construction.

DETAILED DESCRIPTION OF PREFERRED
FORMS OF THE INVENTION
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Reference character 10 designates generally a valve construction having a body 11 formed to provide a mounting flange 12 surrounding a cylindrical valve inlet chamber 14. Above the inlet chamber 14 the valve body is provided with an outlet cham-ber 18 separated from the inlet chamber 14 by an annular radially inwardly projecting shoulder 20 in which is mounted a valve seat member 22.
The valve seat member 22 comprises an annular Venturi-shaped main portion 24 having a hard face 26 at the bottom formed of a suitable material such as *"Stellite", and having an inte-gral re].atively thin and flexible outspaced cylindrical support-ing portion 28 extending outwardly and downwardly from a mid portion of the body 24 and at its lower extremity secured as by welding, as indicated at 34, to the wall of chamber 14. The cylindrical supporting portion 28 is also spaced radially inward-ly from the wall of chamber 14 except at its secured lower extremity. Clearance is also provided between the inner wall 16 - of the shoulder 20 and the periphery of the portion of the seat member 22 which extends upwardly through and to a position slight-ly above the top of the shoulder. The main portion 24 of the seat member also has a flat outwardly projecting shoulder 30 which closely underlies but is unsecured with respect to the *Trademark w~

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shoulder 20. The upper extremity of the main portion 24 of the seat member de~ines a flat valve seat portion 78. The valve is designed for e~ficient handling o~ steam and/or other hot fluids.
In view of the fact that in such service temperature differences of substantial value will unavoidably exist around the periphery of the valve body in the area of the valve seat, it will be appreciated that some distortion of the valve body is unavoid able. In event of such distortion of the valve body, the seat member main portion 24 and seat portions 26, 78 carried thereby will remain substantially undistorted, by virtue o~ the flexi-bility of supporting portion 28 and the lateral clearances be-tween the seat member and body, and the relative movability of the abutting portions 20 and 30.
The seat-engaging peripheral portion 27 of the poppet valve head 36 is also relatively flexible. The poppet valve head 36 is mounted as by means of the clamping nut 40 on the lower extremity of the vertically reciprocatable stem 38 for movement toward and away from the seat face 26 when actuated by the trigger ~ leve~ 62. The stem 38 extends upwardly through a packing gland : 20 generally designated 48 to a position above the valve body 11 where it is engageable with and actuatable by an arm 67 o~ the lever 62~ The valve is biased upwardly to closed position by a compression spring 54 which is trapped between a bottom retainer formed by a flange 56 on a hat-shaped cap screw 52 which covers :
the packing gland, and an upper sheet metal spring retainer 58 which is keyed to the upper end of the stem 38. Retainer 58 ~as .
flanges 66 which extend upwardly on either side of arm 67 and ... .

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are attached thereto by means of a cotter pin 68 so that in event of failure of the spring 54 the valve will be positively pulled upwardly and closed by the trigger lever 62 when it is rocked clockwise, as viewed in Fig. 1. A peripherally slotted portion 39 of the stem 38, is interengaged with the retainer 58 and the aperture in retainer 58 is large enough, and the slotted portion 39 is long enough axially, to permit the retainer 58 and flanges ~6 to rock slightly for free movement of the parts.
The stem 38 is slidably supported in a cylindrical guide 44 wh.ich is externally threaded and secured in a conform-ably threaded aperture 49 in the top wall 19 of the body 11.
The guide projects both upwardly from the wall 19 to support the packing gland and downwardly into the chamber 18 to a position close to the upper extremity of the seat member 22.
A pressure limiting valve disc generally designated 70 is threadabl~ fitted on the exterior of the guide ~4 so that by rotation on the threads of the latter the disc is movable to and from engagement with the upper seat portion 78 of seat member 24.
The periphery of the disc is provided with integral axially elon-gated ~ear teeth 72 which mesh with a worm 74 carried b~ a shaft 76 journaled in the walls of the body 11. Shaft 76 has a squared or otherwise nonconcentric projecting terminal portion 77 acces sible from the exterior and adapted to receive a wrench or crank which permits rotation of the disc to move it along the threads on the guide, to and from seat portion 78. The worm wheel teeth 72 on the disc are straight and/or itted loosely enough with respect to the teeth of the worm to permit the disc to move WS~

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axially without binding on the worm. The shaft portion 76 of the worm pro~ects through a packing gland generally designated 80, the compression nut 82 of which is provided with a sufficient range of movement, in proportion to the amount of packing material 83 contained in the gland, so that the gland can be tightened suf-ficiently by means of the nut 82, to effectively clamp the shaft against rotation and thereby positively hold the disc in its adjusted position.
Inasmuch as the inlet 15 of the valve may be connected to a source of fluid such as steam at a pressure higher than would be safe to deliver to the served apparatus, a stop may ~e provi-ded to prevent full opening of the pressure regulating valve disc member 70. As shown in Figs. 1 and 2, a stop nut 85 fitted on the valve guide and tightened against the bottom of the wall 19 limits the upward movement of the valve disc 70 and thereby limits the pressure deliverable to the outlet 21.
In the modi~ied construction shown in Fig. 3, in which parts similar to those already described are designated by like reference numbers primed, the stop 85 is omitted, and upward movement of the valve disc 70' is limited by a flange portion 88 integral with and which extends radially inwardly at the lower end of the body of the disc 70' far enough to underhang the bottom end of the guide 44' and limit the upward movement of the disc.
This Detailed Description of Preferred Forms of the invention, and the accompanying drawings, have been furnished in compliance with the statutory requirement to set forth the best mode contemplated by the inventor of carrying out the inven~ion.

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The prior portions consisting of the "Abstract of the Disclosure"
and the "Background of the Invention" are furnished without prejudice.

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Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE PROPERTY
OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. In a valve including a body having a chamber therein and having an inlet port and an outlet port, both of said ports communicating with the chamber, valving means movable to control flow through the chamber between said inlet and outlet, and means independent of said valving means and actuatable from outside the body for adjustably limiting the maximum rate of such flow, comprising a seat portion surrounding one of said ports and facing the interior of the chamber, an externally threaded screw portion within the chamber fixed to the body and projecting toward said seat, said screw portion being coaxial with said seat, a valve member independent of said previously:
mentioned valving means and threadably mounted on said screw portion for movement toward and from said seat, characterized by an axially elongated gear fast on the periphery of said valve member, a worm journaled in the body and meshing with said gear, and means extending through and accessible from outside the body for actuating the worm, the gear being movable axially along said screw portion transversely of the worm when rotated by the worm, whereby the valve member is movable toward and from said seat.

2. A valve as defined in Claim 1 wherein said screw portion is axially apertured to define a valve guide, a seat member carrying said seat portion and having a second seat sur-face located outside and facing away from said chamber, said first-mentioned valving means comprising a poppet valve element engageable with said second seat surface outside said chamber and having a stem portion extending through said guide and chamber, further characterized in that said valve member com-prises an annular disc having integral gear teeth on its per-iphery meshing with and actuatable by said worm and having a flat end surface engageable with said first-mentioned seat portion.

3. A valve as defined in Claim 2 further character-ized by an integral stop portion carried by the disc and engage-able with an end of the screw portion to limit movement of the disc away from said seat portion.