US3376936A - Bypass valve for removing paraffin in oil wells - Google Patents

Description

D. R. TOMLIN 3,3765936 BYPASS VALVE FOR REMOVING PARAFFIN IN OIL WELLS April 9, 1968 sheet@ m/IL/Mm/ 25 MSVWS n D 3 |rv4/ d. w M

INVENTOR.

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April 9,. 1968 l l D. IFe. ToMLlN 3,376,936

BYPASS VALVE FOR REMOVING PARAFFIN IN OIL WELLS Filed D60. 13, 1966 5 Sheets-Sheet E 0a ve Tom/in INVENTOR.

April 9, 1968 D. R. TOMLIN BYPASS VALVE FOR REMOVING PARAFFIN IN OIL WELLS 3 Sheets-Sheet 3 Filed DeC. 13, 1966 R. m, 0 0 fy M n s. l r .w @W m W v 8 m.. F o/MLMQMV. /xx ,r MAI. 11%, ,W///% f 'Il lill. l "gt llllllllljlll United States arent 3,376,936 BYPASS VALVE FOR REMQVING PARAFFIN IN OIL WELLS Dave R. Tomlin, Odessa, Tex., assigner to Paraiiin Tool & Equipment Co., a corporation of Texas Continuation-impart of application Ser. No. 401,110,

Oct. 2, 1964. This application Dec. 13, 1966, Ser.

6 Claims. (Cl. 166-226) ABSTRACT F THE DISCLOSURE A bypass valve installed in the power oil string of an oil well employing a hydraulic pumping system which enables a paraffin removing solution to be pumped down the power oil string and bypassed laterally outwardly thereof for effectively removing panaiiin deposits in the production string or tube without the necessity of pulling the production tube or power oil string. The bypass valve may also be employed with conventional type pumps when hollow pump rods or sucker rods are used in order to enable a paraffin removing solution to be pumped down the hollow rod :and bypassed laterally outw-ardly thereof into Contact with a paraflin deposit for removing such a deposit.

This application is a continuation-in-part of pending application Ser. No. 401,110 filed Oct. 2, 1964 for Parafiin Removing Tool for Tubing now abandoned.

The invention involves the provision o-f an outlet means for a paraffin removing 'agent oriented in an oil well tubing string for discharging the paraiiin removing agent in a region subject to the formation of paraiiin deposits to remove such deposits from the oil well tubing string. The outlet means includes a valve 'arrangement operable from the ground level for selectively opening and closing the outlet means for selectively enabling discharge of paraffin removing agents into the paraffin deposit region. The outlet means in the form of a bypass valve may be inserted into .the power oil string for a bottom-hole hydraulic pump or incorporated into a hollow pump rod of a conventional type pump with the bypass valve serving to control passage of iiuid through the outlet means into the paraiiin deposit region.

An object of the present invention is to provide a bypass valve for installation in :the power oil string of a hydraulic pumping system of an oil well where the power oil string is disposed inside of the production string or the production string is inside of the power oil string and also for installation in conjunction with a conventional type pump when hollow pump rods are used interiorly of the production string.

It is well known that paraffin deposits tend to occur at varying depths in tubing. By way of example, oil iiowing upwardly through a tubing is chilled or cooled where the tubing passes through fresh water sands which are considerably cooler than the oil thereby causing paraifin to deposit on the tubing strings and these deposits may occur at substantially any depth. It is most common for paraffin deposits to occur at an area from just below the group surface down Vto a depth of normally not over 3,000 ot 3,500 feet. In most cases, the paraflin deposit will occur in the production string with very little deposit occurring on the power oil string and the removal of the paraffin deposit is necessary in order to maintain efficient ric flow from the production string. Customarily, the paraffin problem has been solved by pulling the string of tubing and the pump, cleaning the tubing while out of the well by employing various well-known procedures and then returning the string of tubing into the well bore which obviously is a costly and time-consuming operation. In some installations, the production string itself forms the well casing and may be cemented in the well bore and cannot be pulled. In such cases, the removel of paraffin deposits is a costly procedure and many devices have been provided in attempts to eiiiciently remove the paraffin deposits.

Accordingly, it is a most significant object of the present invention to provide a structure which will facilitate the removal of paraffin deposits from tubing without the necessity of pulling the tubing or thepump by providing a bypass valve in the power oil string or other tubular member within the production string or associated with the production string in such a manner that a paraffin removing agent, as for ex-ample oil at an elevated temperature. to be pumped down a tubing string and discharged onto the paraffin deposit for cleaning and removing the paraffin deposit after which the bypass valve may return to its normally closed position for enabling the power oil string to return to its normal operation.

Still 4another object of the invention is to provide a device for facilitating removal of paraffin deposits which may be readily installed within the power oil string whether it be tubing, macaroni string or hollow rod. In making lthe installation of this invention at any depth felt necessary to be below the paraffin deposit allows the parafiin removing agent to be circulated down through the power oil string and back up through the production string or in reverse, the paraffin removing agent can be pumped down through the production string and back up the power oil string inasmuch as the structure of the present invention enables circulation of the paraffin removing agent in either direction.

A still further object of the present invention is to provide a device in accordance with the preceding objects which includes a bypass valve which selectively directs the paraffin removing agent out of the pipe string or inner tubing at selected upper or lower locations within the tubing to be cleaned.

Still a further object of the present invention is to provide a device in accordance with the preceding objects which shall have an improved double-acting valve construction effecting a positive sealing action in either of its positions of adjustments to enable the fiow of paraffin removing agent to be discharged to the best advantage with any tubing or pipe string to be cleaned.

Still another important object of the present invention is to provide a device in accordance with the preceding objects which may be easily and economically introduced into a power oil string or the like and which can be easily actuated at ground level for efiiciently removing paraiiin deposits.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and in which:

FIGURE 1 is a vertical view illustrating schematically the installation of the bypass valve of the present invention installed in the power oil string of a hydraulic pumping system;

FIGURE 2 is a vertical sectional view, 0n an enlarged scale, of the bypass valve illustrating the valve in normally closed position so that the power oil string may operate in a conventional manner;

FIGURE 3 is a vertical sectional view similar to FIG- URE 2 but with the bypass valve in the open position to enable a paraffin removing agent to be pumped down the power oil string and out through the bypass valve for cleaning a parat'rin deposit or the How may be reversed;

FIGURE 4 is a transverse, sectional view taken substantially upon a plane passing along section line 4-4 of FIGURE 3 illustrating the structural relationship of the components of the present invention;

FIGURE 5 is a vertical sectional view of a modilied embodiment of the invention in which the valve element is illustrated in an intermediate position;

FIGURE 6 is an exploded perspective view of the elements of the valve illustrated in FIGURE 5;

FIGURE 7 is a sectional view similar to FIGURE 5 but illustrating another embodiment of the invention; and

FIGURE 8 is a sectional view similar t0 FIGURE 3 but illustrating the components reversed to provide a structure so that the valve is in opened position when the movable component thereof is elevated rather than moved downwardly as in the structure of FIGURES 2 and 3.

Referring now specifically to the drawings, FIGURE 1 illustrates schematically the installation of the present invention in an oil well employing a hydraulic pumping system such as various wellltnown installations. One manufacturer of such systems is Kobe, Inc., of Huntington Park, Calif., and FIGURE 1 illustrates perhaps the simplest installation in which a well casing 10 is disposed within a well bore and the well casing 10 itself forms the production tubing and during normal operation of the hydraulic pumping system, parain deposits 12 will be formed on the interior surface of the production tubing. A conventional well head 14 is disposed at the upper end of the well casing or production tubing 10 together with a pipe 16 extending therefrom to a suitable storage tank or the like for material owing through the production tubing 10. Disposed concentrically within the production tubing 10 is a power oil string or tubing 18 which extends upwardly through the well head 14 and communicates with a hydraulically operated bottom hole pump at the lower end thereof in a conventional manner. The upper end of the power oil string 18 is provided with a T- coupling or the like 22 communicated with a power oil pipe 24 at one side thereof and a parain removing agent pipe 26 as the other branch thereof with each of the branches having suitable conventional valves 28 which also may be provided in the production pipe 16 with a suitable piping arrangement being provided for selectively pumping power oil down through the power oil string 18 and discharging production oil and power oil through the production pipe 16 or pumping a paraffin removing agent down through the power oil string 18 with the paraffin removing agent and the parafiin removed thereby being discharged through the production pipe 16 as it rises from the production tubing 10. The reverse procedure may be employed, that is, the parain removing agent may be pumped downwardly through the pipe 16, production tubing 10 and back up through the power oil string 1S. In addition, the present invention may be installed in various conventional installations regardless of whether the casing is a fixed casing and serves as a production tube or the production tube is inserted into the casing and regardless of the orientation of the power oil string in relation to the production string or tubing.

The embodiment of the invention illustrated in FIG- URES 1-4 is generally designated by numeral 100 and is installed in the power oil string 18 by incorporating the structure into the power oil string when it is being made up. The device is in the form of a bypass valve structure operable from ground level and includes a coupling 102 at the upper end thereof for detachable engagement with an upper section of the power oil string and a coupling 104 at the lower end thereof for detachable Connection with the lower section of the power oil string with such couplings being conventional screw-threaded type couplings. In the embodiment illustrated in FIGURES 1-4, the bottom hole pump 20 is supported in or adjacent the bottom of the production tubing 10 inasmuch as the bottom hole pump 20 is not suspended or supported by the power oil string 18 with the power oil string 18 serving only to convey power oil to the hydraulic pump 20.

The valve assembly 100 includes an external sleeve or barrel 106 and an internal sleeve or piston 108 which is longitudinally movable within the barrel 106. The upper end of the piston 108 is connected with the coupling 102 in any suitable manner such as by a screw-threaded connection and a continuous longitudinal bore 110 is provided longitudinally through the piston 108 with the bore being of constant cross-sectional dimension. The portion of the piston 108 received within the barrel 106 has an outside diameter substantially equal to the internal diameter of the barrel 106 and longitudinally spaced pairs of O-ring seals 112 are provided on the piston 108 for sliding sealing engagement with the interior of the barrel 106.

The lower end of the piston 108 is beveled or chamfered at 114 and the upper end of the lower portion or enlarged portion of the piston 108 is likewise beveled or chamfered as at 116. Above the upper chamfered shoulder 116, the piston 108 is provided with a plurality of radial openings 118 which are spaced longitudinally from the upper pair of O-rings 112.

The cylindrical barrel 106 is provided with a plurality of radial openings 120 extending therethrough in a recessed or relieved portion 122 of the interior surface of the barrel 106 which defines an annular chamber communicating with the openings 120 and extending both above and below the openings 120. The upper end of the barrel 106 is provided with a tubular closure member or plug 124 screw-threaded to the upper end ofthe barrel 106 at 126 and closely slidably receiving the reduced upper end portion of the piston 108 as illustrated in FIGURE 2. The lower end of the closure plug 124 is beveled or chamfered as at 128 for matching engagement and forming a limit for upward movement of the piston 108 by engaging the chamfered shoulder 116 0n the lower end portion of the piston 108. When this condition exists as illustrated .in FIGURE 2, the pairs of seals 112 are disposed above and below the openings 120 and thus seal off the openings 120 to prevent ow of fluid outwardly therethrough. Thus, power oil under pressure passing through the power oil string 18 will continue down through the power oil string 18 to the bottom hole pump 20 for operation thereof in an obvious manner.

The lower end of the barrel 106 is connected to the coupling 104 by a screw-threaded connection 130 and the upper end of the coupling 104 is provided with a chamfered shoulder 132 and the lower end thereof is provided with a threaded section 134 for engagement with the lower section of the power oil string 18 with a bore 136 extending throughout the length of the coupling 104. When the piston 108 is moved downwardly to the position illustrated in FIGURE 3, the chamfered end 114 of the piston 108 will engage the shoulder 132 and both pairs o-f seals 112 will then be below the openings 120 thereby enabling fluid passing downwardly through the power oil string 1S to -be bypassed laterally outwardly through the aligned holes 118 and 120 as illustrated in FIGURE 3.

The interior of the plug 124 is provided with one or more O-ring seals to assist in sealingly engaging the plug 124 with the upper end of the piston 108 and to permit sliding of the piston 108. Thus, in accordance ywith this embodiment of the invention, the bypass valve assembly 100 is disposed in the production tubing 10 at a region below the paratlin deposit 12 which is usually produced by cooling of the production oil as it fiows upwardly through the formation and especially through water bearing sands and the like. The paraffin removing agent such as heated petroleum may be circulated by any suitable pump means (not shown) down through the power oil string 18 by closing the valve 28 in the power oil line 24 and opening a similar valve in the paraffin removing agent pipe 26. Thus, the parailin removing agent is discharged from the bypass valve 100 through the aligned openings or orifices 118 and 120 and into engagement with the production tube 10 and back up through the production tube 10 thus removing the parailin deposit 12 where it may be recirculated back into the heating device by suitable valving in the production pipe 16 or may be pumped directly into the storage tank (not shown). The Iwell casing or production tubing 10 may be itself cemented into the well bore or a separate production tubing may be employed in a well casing or well bore but in any event, the tubing string through which the oil is produced from the formation is designated by numeral 10 and is subject to the formation of parailn deposits 12 therein as the oil is cooled through its upward passage through the formation.

Referring now specifically to FIGURES and 6, the bypass valve assembly 29 includes a cylindrical barrel 30 whose internally threaded upper and lower ends are provided With closure plugs 32 and 34 respectively. The upper plug 32 has an axial bore 36 therethrough which may be provided with an O-ring 40 for sealing purposes, with a tube 42 being slidable through the O-ring and the bore.

The upper end of tube 42 is externally screw-threaded for engagement with a coupling member 44 by which it is secured to the lower end of the power oil string such as 18 and the lower end of tube 42 will either be screwthreaded into a piston type valve member 48 or the tube 42 and valve 48 may be constructed of unitary construction. In any event, the piston type valve 48 is slidably disposed within the interior of the barrel 30.

The exterior surface of the valve 48 is provided with an O-ring seal 50 for sealing engagement with the internal surface of the barrel 30 at any position of the piston type valve 48 in the barrel 30. The piston type valve 48 has a bore 46 extending therethrough which communicates directly `with the tube 42 and the lower end portion of the bore 46 is angulated as at 52 and the angulated end portion 52 opens through a beveled or conical side surface 54 which forms the lower end portion of the valve 4S.

The upper end of the valve 48 is also provided with a beveled or conical surface 56 for orientation in adjacent relation or in seating engagement with an inclined seating surface 60 on the inner end of the plug 32. The sealing method for the valve 48 may be either in the form of annular ribs 58 which are concentrically disposed with the conical valve seating surface 60 or with an O-ring as described in more detail in conjunction with FIGURE 7. The lower closure plug 34 is likewise provided with an axial bore or passage therethrough whose upper end is counterbored to provide a conical valve seat 66 receiving the valve surface 54 at the lower end of the valve 48. At its lower end, the closure member 34 is provided with a diametrically reduced externally threaded end portion 68 to which the lower section or" the power oil string 18 may be connected.

Adjacent the upper end of the barrel 30 as illustrated in FIGURE 5, there is provided a discharge port or ports 72 therein and a similar port is pro-vided in the tube 42 and when' the valve 48 is in the lowered position away from seating engagement with the valve surface 60, the ports 62 and 72 will be communicated so that fluid may flow outwardly therethrough as illustrated in FIGURE 5.

In its lowermost position, the valve 4S will seat against the valve surface 66 thereby closing off the bore 46 and bypassing iluid outwardly through the opening or ori-tice 62 and correspondingly out through the opening or orifice 72 or permitting reverse llow if desired.

.FIGURE 7 illustrates a structure similar to that ein` ployed in FIGURES 5 and 6 and the same reference numerals will be applied thereto. In this embodiment of the invention, the valve 48' has the bore 46 extending straight through so that it will register with the bore 64 through the lower plug 34 when the valve 48' is lowered to seating engagement with the inclined sur-face 66 thereon. The upper inclined surface 56 of the valve member 48 is provided with an O-rin-g seal 58 in lieu of the sealing -rings 58 or the O-ring may be disposed between the concentric rings 58.

In FIGURE 8, it is pointed out that by inverting the external sleeve or barrel 106, the over-all operation of the assembly is reversed. In this condition, when the barrel 106 and the piston 108 are in their extended positions or stretched out positions, the ports 120 in the barrel 106 are opened and when the piston 108 is forced downwardly or inwardly, the lports 120 will be closed. Thus, when the ports 120 are opened, circulation would pass through the bore 110 and out through the ports 120 and back up the production tubing or string in which the valve assembly is enclosed. When the valve assembly is telescoped together by moving the piston 108 downwardly, the ports will be closed inasmuch as the O- ring seals 112 will be disposed above and below the ports 120 respectively. Then las power oil comes down through the power oil string, only enough fluid would pass through the ports 118 to fill the area between the interior surface of the barrel y106 abo-ve the upper seal 112 and then the power voi-l would pass on down through the valve assembly into the bottom hole pump 20 in a c0nventional manner.

The purpose of the ability to change the barrel 106 would be to allow the too-l to work in wells where the power oil string is in tension during normal pumping activities which would have the valve assembly telescoped out or stretched or when the power oil string is not in tension allowing the portion where Valve assembly is installed to have the valve assembly telescoped together during normal pumping activities.

Assuming that the tubing 10 which comprises the oil flow conducting casing of the well bore or is merely the flow tubing within a well casing is encountering trouble from paraffin deposits forming therein which is readily apparent by diminution of ilow at the surface or by an increase in the power required for the pumping operation 4or the like, it is then necessary to remove the paraffin deposit. I-f it is not already known, it is then determined at what depth the parailin deposits are occurring. A pipe line or string such as string 18 of the requisite length is made up such that when it is inserted in the tubing string 10, the valve assembly such as that illustrated in FIG- UR'ES 5 and 6 incorporated therein so that it will be positioned with its exhaust port 72 exposed just below the par-atlin deposit and with the lower end closure plug 34 or other additional pipe sections attached thereto opening below the region of paraffin deposit. Thus, the barrel 30 is now tixedly positioned in the tubing string 10 and the pipe 1'8 may be shifted vertically with respect to the barrel 30 thus moving the valve member 48 within the barrel 30.

Normally, it is best to bring parailn accumulation di- -rectly to the surface if possible. Therefore, when the valve member 48 is moved downwardly from its uppermost position, this will permit flow of the paraffin removing agent, such as heated oil, to flow downwardly through the tube 42, emerging from port 62 to pass outwardly through the discharge po-rt 72 into the tubing 10 and rising to the surface thereby melting and carrying paran deposits out of 7 the tubing through the pipe 16 into a storage area or tank as desired.

It will be noted that this form of the invention has a double-acting valve member 48 which will be sealed when in its uppermost position by the rib elements 58 or an O- Vring seal to establish a iiuid-tight seal with the inner wall on the barrel 30. The seal prevents pressurized fluid from coming out of port 62 and out port 72 when the valve body is in its uppermost position. Such pressurized fluid will then pass down through the bore 46 out through the angled end portion 52 and down through the passages 64 which enables the valve assembly of FIGURES and 6 to be employed with a hydraulic pumping system.

Alternately when the valve member 48 is in its lowered position, the surfaces 54 and 66 will seat thereby completely closing `the discharge from the passage 52 since the latter now is masked by the seat 66. Consequently, the flow of fluid arriving in the valve through the pipe line 18 will be discharged through the ports 62 and through the ports 72 out into the production tubing 10, well bore or the like and then pass upwardly for discharge through the line 16. Thus, the valve 48 closes off the ports 72 when in the uppermost position and closes off the through passage when in the lowermost position.

In distinction to this, the structure in FIGURE 7 has the bore 46' extending straight through the valve 48 to meet directly with the bore 64 when the valve member 48' rests against seat 66. This allows iiuid flow through bore 46 down through bore 64 until pipe 18 fills with uid then the uid would pass out through ports 62 and thus out through ports 72 at any time the valve 48 was moved downwardly away from seating and sealing engagement with the inclined seating surface 60. The reason that the oil will ow out through the ports 62 and 72 is that the Huid or oil would flow to the point of least resistance. Substantially less pressure would be required to circulate the flow out through the ports 62 and 72 as compared with forcing it down the pipe line 18 into the hydraulic pumping system or down through a pipe such as pipe 18 to a point adjacent the bottom of the production tube. This would enable the structure of FIGURE 7 and the structure of FIGURES 2-4 to be employed in a conventional type of pump employing a sucker rod in that the sucker rod or pump rod may `be hollow and actually be constituted by the pipes 18 with the bypass valve assembly being incorporated therein or being substituted for certain sections of a sucker rod pipe when desired to clean paraffin from the wall of the production tubing, well bore or the like. Quite obviously, the valve members may be constructed of various materials of metal, rubber, neoprene or the like with the shifting of the valve member either 48, 48 or 108 enabling alternate fiow longitudinally through the valve assembly or bypassing ow laterally outwardly for circulation of paraffin removing agent. The ow through structure enables the bypass valve to be installed to allow normal activity of the producing system when the bypass valve is in its elongated position or in its collapsed position. Also, the structure of this invention allows circulation of a parat-lin treating agent down through the tube 18, out through the bypass valve and back up the production tubing or enabling reverse flow of the paraffin removing agent down through the production tubing 10, in through the bypass valve and up through the pipe string 18. Any of many well-known structures may be employed for shifting the valve member longitudinally as will be recognized by the industry depending upon the particular requirements of each individual installation and it also will be recognized that this structure enables circulation of paraffin treating agents without the necessity of the removal of various piping, tubing or the like. Assuming that the device illustrated in FIGURES 1-4 is operating normally in a hydraulic pumping system and it is desired to remove the paraffin deposit, it is only necessary to close off the power oil supply line, open the heated oil line or paraffin removing agent line and pump the paraffin removing agent down through the power oil line 18 with the bypass valve assembly positioned in open condition. Thus the paraffin removing agent will pass down the oil string 18 into the bypass valve assembly and then pass out through the ports therein for removing the paraffin deposit in an obvious manner. While this paraffin removing operation will mean that the hydraulic pumping sytsem is temporarily deactivated, the bypass valve assembly will not require removal of any components from the well bore and enables the paraffin to be pumped directly to the ground surface. This also enables reduction in the quantity of paraffin removing agent employed since the paraffin removing agent does not go all the way to the bottom of the well and then reverse direction but reverses direction at a point closely spaced below the paraflin deposit.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention as claimed.

What is claimed as new is as follows:

1. In an oil well tubing string having a region therein subject to the formation of paraffin deposits, a parain removing assembly comprising a pipe having an outlet means positionable in said tubing string at said paraffin deposit region, means supplying a paraffin removing agent through said pipe and outlet means to said paraffin deposit region, said outlet means comprising a body having a valve chamber therein with which said pipe communicates, upper and lower outlet ports communicating said valve chamber with the interior of said tubing string, a valve shiftable within said chamber and operable to se lectively open said upper and lower ports, said valve comprising a body having a passage therethrough, said pipe being in communication with the upper end of said passage, a valve seat on the lower surface of said valve body upon which the lower end of said passage opens, said lower outlet port having a valve seat engageable by said valve body seat and blocking flow through said passage.

2. The combination of claim 1 wherein said pipe has an opening into said valve chamber above said valve body, said upper port being communicatable with said pipe opening, said chamber body having an end wall with an opening through which said pipe is slidably disposed, said valve body being shiftable into a position in said valve chamber in which said pipe opening is closed by said end wall.

3. The combination of claim 2 wherein said valve body and end wall have cooperating sealing means.

4. A parafn removing assembly for an oil well tubing string having a region therein subject to the formation of parain deposits, pipe means extending longitudinally of the tubing string for conveying a paraffin removing agent to a point below the paraffin deposits, and valve means incorporated into said pipe means for discharging the paraffin removing agent from the pipe means to said paraffin deposit region, said pipe means being the power oil string in a hydraulic pumping system including a bottom hole pump, said valve means being in the form of a bypass valve shiftable between a closed position which enables power oil to pass therethrough to said bottom hole pump and an open position which enables the paraffin removing agent to be conveyed down the power oil string and bypassed into the paraffin deposit region while leaving the portion of the power oil string below the bypass valve filled with power oil.

5. The structure as defined in claim 4 wherein said valve means includes an external barrel having radial discharge port means in one area thereof, a tubular valve member slidable in said barrel, said Valve member having a straight through passage in communication with the power oil string, said valve member having radial discharge port means in one area thereof, said port means in the valve member being communicated with the port means in the barrel when in open position to enable 'luid flow between the through passage and exterior of the barrel, said port means in the valve member being in noncommunicating relation to the port means in the barrel when in closed position.

6. The structure as defined in claim 5 wherein said valve member is 'longitudinally shiftable in said barrel when moving from open to closed position, and seal means sealingly associated -between the valve member and barrel for isolating the port means in the barrel when the valve member is in closed position.

References Cited UNITED STATES PATENTS Fording 1616-73 X Boynton 166-2261X Savitz 166-73 X Lewis 166-73 Conrad 1616-226 X Mitchell 166--57 Williams 1616-226 X CHARLES E. OCONNELL, Primary Examiner.

DAVID H. BROWN, Assistant Examiner.

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