US2002965A - Throttle valve - Google Patents

Description

May 28, 1935.

F. J. SMITH 2,002,965v

THROTTLE VALVE Filed Feb. 15, 1935 ATTORNEY Patented May '28, 1935 -v PATENT oFElcE THBOTTLE VALVE Frank J. smith, Kansas city, Mo., assigner so Standard Oil Company, Chicago, Ill., a cor poration of Indiana Application February 13, 1933, Serial No. 656,451

8Claims.

This invention relates to improvements in throttle valves and more particularly to throttle valves of the sliding gate type.

Heretofore the use of throttle valves of-the gate type in iluid flow lines wherein fluids containing relatively hard matter in suspension are passed through the valve at high velocities has v resulted in the erosion of the valve body shell at the low preure side of the gate. This erosion of the valve body is largely due to the diversion of portions of the iluid stream against the inner side walls of the valve body as the fluid passes under the gate and against the vertical shoulders provided as a guide for the gate and against which the gate bears when closed.

An object of nry invention is to provide `a throttle valve wherein erosion of the body shell, as described, is reduced to a Another object is to provide a throttle valve of the gate type wherein turbulence of the uid stream on the low pressure side of the gate is materially reduced.

A further object is to provide a throttle valve of the gate type wherein erosion of the opposed surfaces of the gate and gate seat through the so-called wire drawing effect of the high velocity stream is minimized.

A still further object is to provide a gate type throttle valve wherein the valve opening is rectangular in cross section, thereby permitting an opening of the shortest possible width as well as reducing the boundary of the valve opening linearly.

Other objects and advantages of my invention will become apparent after reading the follow ing description and claims and after consideration of the drawing, irr which:

Fig. l is a vertical sectional view of a gate type throttle valve constructed in accordance with my invention;

Fig. 2 is a sectional view along the line 2 2 of Fig. l;

Fig. 3 is a vertical sectional view of another form of the valve, parts thereof being` broken away;

Fig. 4 is a sectional view.along the line I-I of Fig. 3;

Fig. 5 is a view similar to Fig. 3 of another form of the valve;

Fig. 6 is a sectional view along the line B-B of Fig. 5;

Fig. 'I is a fragmentary sectional view of a further form of the valve; and

Fig. 8 is a sectional view along the lines 8-8 of Figures 2 and 6.

In general, the throttle valve selected for illustration comprises a body shell A, rectangular in cross section at its mid-portion, a bonnet B,

-a rising stem gate C, a yoke D supported upon the'bonnet and a hand wheel E for elevating the valve gate C.

With reference to Figs. l, 2 and 8, the valve body or shell A is provided with flanges 2 at its outer ends for connecting standard pipe sections thereto. The cross section of the body A at its outer ends is circular as indicated at 3 gradually merging with the rectangular cross section at the mid-point of the body. The bottom wall and two side walls of the body A are formed with inwardly projecting convex cylindrical surfaces 4 and 5, the surface l on the lower or bottom wall comprising aseat for the gate C. Vertical grooves 6 extending longitudinally of the surfaces 5 provide a slide-way and guide for the gate C. 'I'he lower wall or edge 'l of the gate C is cylindrical and generated upon substantially the same radius as the cylindrical seat I of the valve, thereby providing a iluid opening when the valve gate is elevated having the'characteristics of a venturi.

A valve stem I I may be formed integrally with the gate C and provided with external screw threads I2 at its outer end engageable with a threaded bushing I 3 secured to the hand wheel E. The bushing I3 may be xed against axial movement upon the yoke D but free to rotate relative thereto. A packing member Il may -be employed for establishing a duid-tight seal between the bonnet B and valve stem Il.

It is intended that a throttle valve constructed as described shall be used in series with a shutoff valve since no provision is made for establishing a duid-tight seal between the gate and the gate engaging portions of the valve body. As may be seen the contacting portions 'l of the valve gate C and its seat l lie on a straight line in a plane parallel with the axis of the valve body and therefore the throttling characteristics of the valve are maintained substantially uniform from the slightest elevation of the gate from its seat l to its full elevated and open position, an advantage which is not to be found in the ordinary type of gate valve wherein both the lower edge of the gate and its seat are curved upon like radii in a plane transverse to the axis of the valve body.

In use, uid passing from the high pressure to the low pressure side of the valve through the gate opening by virtue of the uniformly curved convex cylindrical walls thereof is parcinity ofthe low pressure side of the gate, a condition which is not true in gate valves of the ordinary type wherein it is customary to employ shoulders on the inner walls of the body shell to guide the valve gate and to form a seal between the gate and the body shell. These shoulders are found in gate valves of ordinary construction and by virtue of their disposition in a plane perpendicular to the direction of ow cause the uid passing through the gate opening to be diverted and to impinge upon the inner side walls of the body shell in the immediate vicinity of the gate, particularly upon the upper body wall. If the fluid passing through the valve contains solid matter in suspension such as coke, where the valve is employed in a tar drag line, the particles of coke by virtue of the velocity of the uid stream and of the diverted portion thereof will cause rapid and serious erosion of the metal walls of the valve shell. In my improved valve there is no tendency to so divert the fluid stream but instead the venturi-like walls of the revtangular gate opening by virtue of their convex and cylindrical contour tend to avoid turbulence and to encourage axial flow of the uid through the low pressure side of the valve body into the pipe sections connected thereto.

In Figs. 3 and 4 I have illustrated another form of the valve wherein convex and cylindrical surfaces IS similar to the valve seat 4 are formed on both inner side walls of\the valve body shell A to provide a convex guideway for the valve gate C. In this embodiment of the valve the gate C is formed with concave cylindrical grooves I1 in its opposite side walls within which the guides I6 extend, thereby to locate the yalve gate against lateral movement. The advantage of this form of the valve over that illustrated -in Figs. 1 and 2 is that the grooves B are omitted and the possibility of turbulence in -the uid stream which might occur under higher differential pressures is thereby eliminated. In other respects the valve functions in a similar manner to that described in connection with Fig. l.

In Fig. 5 I have illustrated another form of the valve wherein the convex and cylindrical surfaces on the inner side walls of the body shell are entirely eliminated. The valve gate C is held against lateral movement along the axis of the body A by grooves I8 formed in the side walls of the valve body beyond the conflnes of its normal rectangular cross section as best illustrated in Fig. 6. The advantage attributed to this form of valve over those heretofore described resides largely in the simplicity of construction, particularly in the formation of the body casting and of the finishing thereof. In operation the valve functions in the same manner as that described in connection with the foregoing figures.

In Fig. 'l I have shown a further form of the valve in which guide means for the valve gate C are located exteriorly and above the uid conducting portion of the body A in that region of the body casting between the bonnet B and the major portion of the body casting. In this form of the valve the inner side wall of the body shell is entirely free of either grooves or protruding cylindrical surfaces except for the valve seat 4 which cooperates with the lower surface 'I of the valve gate to form a venturi-like gate opening during the ow of uid through the valve as described. The horizontal cross-sectional contour of that portion of the valve shell A upon which the bonnet B is mounted closely follows the cross-sectional contour of the valve gate C so that the valve is held against movement other than along an axis transverse to the axis of the body shell. The lateral edges of the valve gate may contact with the flat inner side walls of the rectangular mid-section of the body A. It will be noted that this valve may be used only as a throttle valve and not as a shut olf valve.

It should be understood that the described embodiments of the invention herein set forth are presented for the purpose of illustration only and that various changes may be made therein without departing from the spirit and scope of the invention.

I claim:

1. A throttle valve comprising, a body shell having a rectangular cross section, and a valve gate adapted for movement transversely of the axis of said shell, said shell being formed with a convex and cylindrical seat for said gate protruding within said rectangular cross-sectional portion of said shell, the contacting and lower end of said gate being convex and cylindrical and lying parallel with said seat throughout the entire range of movement of said gate.

2. A throttle valve comprising, a body shell, and a valve gate adapted for movement transversely ofthe axis of the shell, said shell being formed with an integral convex and cylindrical seat for said gate, said gate and said seat cooperating to form a laterally elongated venturi opening when the gate is elevated.

3. A throttle valve, of the gate type, including a sliding valve gate and a seat for said gate, said gate and seat each being formed with opposed convex and cylindrical portions.

4. A throttle valve comprising, a tubular uid conducting body shell having at least its mid-portion rectangular in cross section, convex and cylindrical guide members formed onthe opposed and inner sidewalls of said shell mid-portion, and a valve gate operatively engaged with said guide members and adapted to be moved transversely to the axis of said shell.

5. A throttle valve, of the sliding gate type, comprising, a body shell having convex cylindrical guide portions on its opposed and inner side walls, a valve gate slidably mounted transversely of the axis of said. body shell and formed with concave cylindrical side wall portions adapted to receive said convex and cylindrical guide portions of said shell, said body shell and said gate being further formed with opposed integral convex and cylindrical contacting surfaces providing a venturi-like valve gate opening.

6. A throttle valve comprising, a body shell having at least the mld-portion thereof rectangular in cross section, convex and cylindrical guide members formed on the opposed and inner aide walls of said shell mid-portion, and a valve gate operatively engaged with said guide members and adapted to be moved transversely to the axis of said shell, said shell being formed with a convex cylindrical valve gate seat, said gate being formed with a convex and cylindrical seat contacting portion.

7. A throttle valve of the gate type comprising, a body shell, said body shell being rectangular in cross section in at least its mid-portion, a valve gate adapted for movement transversely of the mid-portion of said body shell, a valve gate seat formed on the inner wall of said body shell adapted to be engaged by said valve gate to provide contact between the valve gate and the seat along a line above and parallel to the adjacent bottom surface wall of said body sneu.

8. A throttle valve comprising, a fluid conducting tubular body, said body shell being rectangular in cross-section, at its mid-section, and circular in cross-section at its opposite end portions, said rectangular portion being of greater cross-sectional area than said end portions, a Valve gate y mounted for movement transversely across said rectangular mid-section, and a valve seat formed

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