Feb. 17, 1931. v w. E. KINGV 1,793,094
I DRILLING VALVE Filed may 17. 1928 'wam 5.1@ BY 3| F- I MMATTORNEYS.
of oil or Patented Feb. 17, 1931 UNITED STATES WAgLTER E. KING, OF HOUSTON, TEXAS, ASSIGNOR TO JAMES S. ABERCROMBIE, 0F
HOUSTON, TEXAS DRILLING VALVE Application filed Hay 17,
Myinvention relates to an improved tyEe of valve to be used at the upper end of t e casing employed in well drilling.
In the drilling of wells particularly where heavy gas pressures are encountered, it is common to employ a valve in the casing at a point above the surface of the ground and below the upper end of the casing. This is a valve which may in emergency be closed to prevent the blowing out of the gas from the well, or which may be closed as soon as the well begins to flow so as to prevent the loss gas before the well has been properly equipped to handle the production.
Most of these types of valves are subject to rapid wear when the valve is being closed. An ordinary type of gate Ivalve is usually employed and the forward end of said valve is worn b the passing fluid so that when it is seated 1t is incapable of making a Huidtight seal with the casing. v
It is an object of my invention to provide a valve with a broad seating surface and packing thereon adapted to act under the pressure of Huid in the well to resist the passage of said fluid.
Itis an object to provide a cylindrical valve head or piston wit the packlng so arranged thereon as to eiectively seal the passage through the casing but which will not'be materially worn before the valve can be seated. Referring to the drawing herewith, Fig. 1 is a central vertical section through a valve showing my invention employed thereon, the
vlve being in open position.
Fig. 2 is a similar vertical section showing the valve in closed position.
ig. 3 is a perspective view of the valve head showing the arrangement of the packin thereon.
ig. 4 is a similar view showinila sllghtly different arrangement ofthe pac 'ng Like numerals of reference are employed to designate like parts in all the views.
In the construction of my valve, I have a valve body luwhich is adapted to be set vertically when in use and has a lower threaded seat 2 for engagement with the casing, and an upper threaded socket 3 for engagement with the extension of the casing or wlth a casing 1928.' Serial No. 278,541.
head, as may be desired. vThere is a central passage 4 through this valve body through which the drill stem may work in drilling and which accommodates the flow of liquid in the drilling of the well, and when the well is flowing. At one side of the passage 4 and centrally thereof, I form a circular valve seat 5, said seat being recessed slightly in the side wall of the passage.
Opposite the seat 5 is a cylindrical bonnet 6, the interior of which forms a' cylinder in which the valve 7 may slide. The outer end of the bonnet 6 has a threaded socketS to receive the housing 9 for the valve stem.
'Ifhepiston 7 within the cylinder is of cylindrical shape to fit the cylinder and is preferably hollow in construction, having a chamber 10. At'the outer end of the piston the wall thereof is formed with a threaded opening 11 to receive the threaded end 12 of the valve stem 13 and, as will be seen from the drawing, said stem may be screwed inwardly within the chamber 10 when the valve is opened.
The valve stem 13 extends outwardly through the housing 9. The inner end of the housing is closed by a threaded plug 14 and the outer end of the same has the walls extended inwardly about thc valve stem 13, forming a chamber 15 centrally of the housing. Within this housing the valve stem 13 has a radial flange 16 -to resist longitudinal movement of the valve stem. On each side of the flange 16 within the chamber 15, I prefer to place anti-friction bearing races 17 so as to allow for the free rotation of the valve stem. At the outer end of the housing, the space about the valve stem is closed by a stuiing box, indicated generally at 18.
The valve piston is provided with packing, especially arranged to prevent the assage of fluid through the valve body 1. Elleferrin to Fig. 3, it will be noted that the forwar end of the piston is recessed to receive a ring 20 of compressible packing material. This ring is spaced slightly from the outer circumference of the piston so that the outer side of the packing ring 20 will lit against the ends 21 of the packing strips 22.
The packing strips 22 are set within a groove in the side of the piston longitudinally thereof and extending from the forward end rearwardly to a line spaced slightly from the outer end of the piston. There are two strips of packing 22 extending along the side of the piston and at the outer end of the piston they are curved laterally away from each other circumferentially about the piston, a. groove being formed in the body of the Valve to receive said strips. As each strip is extended half way about the piston, they meet at each side and extend forwardly from the meeting point to the forward edge of the piston. This arrangement will be clear from the drawing.
The packing strip 22 is formed with a groove or slot 24 therein, formed alongthe outer side of each strip, and extended inwardly to form a lip on the packing projecting in the direction of the fluid pressure. Thus, in Fig. 3 the lip of the groove 24 is arranged along the lower side of the horizontal portion and around the inner side of the circumferential portion so that the pressure of fluid engaged within said groove 24 of the packing will tend to expand it outwardly against the walls of the cylinder and preserve a close fit, preventing the passage of the Huid.
In Fig. 4, the arrangement of the packing is similar to that disclosed in Fig. 3, except that the packing strips 22 commence at the forward end with packing strips 25 extending diametrically across the end of the piston where it fits within its seat.
In the operation of my valve, it is contemplated that the piston valve member 7 will be held against rotation in the cylinder 6, and this may be accomplished by a pin or screw indicated in dotted lines at 26 fitting within a groove 27 in the side wall of the piston above the horizontal center thereof. Thus, when the valve is to be closed, a handle or crank will be placed upon the outer squared end 28 of the valve stem and the rotation of the stem in the right direction will force the valve forwardly across the passage 4, bringing the forward end of the valve within the seat 5. In the embodiment shown in Fig. 3, the packing ring 20 will be compressed within the seat to form the seal therewith, and around the outer margin of the ring, the side strips 22 will close the seat. The horizontally arranged packing 22 will fit along the 'side wall of the cylinder indicated at 29 in Fig. 1, and a seal against the passage of fluid will be thus obtained. Any fluid tending to escape into the chamber of the cylinder 6 will be prevented from so doing by the packing strips 22, as will be seen from Fig. 2. The modified form of arrangement of the packing shown in Fig. 4 will accomplish the same purpose as in the Fig. 3 embodiment, and in this embodiment the packing is all spaced from the lower edge which is most exposed to wear.
It is to be noted that the particular wear upon the piston will'take place just as the valve is being forced into its seat. -Gas and oil mixed with sand are forced upwardly through the valve body at a high rate of speed, the sand acting as a sand blast to wear away the sides of the passage as it is narrowed by the closing valve. In a cylindrical piston, such as is described in this specification, the wear about the seat 5 and the end of the valve as the valve is closed will be greatest at the edges of the valve and seat, and it will be noted that the arrangement of the packing and the valve as herein shown is such 'that the wear upon the packing surface is reduced to a minimum, and the employment of this valve in well drilling, a tight seal may be obtained with this valve in cases where it would be practically impossible with the old typeof gate valve.
The opening around thelower forward end of the closing piston is constantly narrowing as will be seen from noting the Shape of the cylindrical portion 29 in Fig. 1. As a result, the opening between the piston 7 at its forward lower edge, and the inner corner 30 of the seat 5 are most exposed to wear. The lower edge of the piston, indicated at 31 in Fig. 4, may be worn deeply and the valve seat at 30 may also wear for the fluid will flow at its greatest velocity at this portion, due to the restricted opening there. The area at the end of the piston and its seat will not be materially worn, as the comparative size of the passage across the end of the piston will be large. It will therefore be noted that, with this valve the lower edge of the valve and the adjacent portion of the seat may wear materially, and also the up er edges may also be thus worn, without a ecting the close seal obtained by the valve when it is seated. This feature of my valve is of great value in use with sandy fluids as it enables a blowout preventer to successfully function where other types of valves would be so worn as to fail in closing the passage.
Having thus described my invention, what I claim as new is:
1. A valve for well casin s comprising a body having a passage theret rough, a cylindrical chamber transversely of the body, a valve seat at one end of said chamber within the wall of said passage, a cylindrical valve, a strip of packing on the forward end and spaced from the upper and lower sides of said valve to contact with said seat, and means to move said valve.
2. A valve for well casings comprising a body having a passage therethrough, a cylindrical chamber transversely of the body, a circular recess in the wall of said passage at one end of said chamber forming a valve seat, a cylindrical valve, a circular strip of packing on the forward end thereof to contazt with said seat, and means to move said va ve.
` 3. A valve for well casings comprisin a body having-a passage therethrough, a cy drical chamber transversely of the body, a valve seat at one end of said chamber within the wall of said assage, a cylindrical piston valve having a uid-tight fit with the inner walls of said chamber, a strip of packing set in the forward end base of said piston valve, and means to move said valve.
4. Ina valve for well casing, a body having a passage therethrough, a cylindrical valve chamber projecting from one side thereof transversely of said passage, a valve seat in the wall of said body, a c lindrical valve r in said valve chamber, a ac 'ng rin set in the forwardcnd face of said valve, an packing strips in the outer surface' of said valve longitudinally thereof connecting with said I testimony whereof I hereunto aiix my signature this 11th day of May, A. D. 1928. WALTER E. -KNG.