MXPA98006805A - Means of operation of valve exte - Google Patents

Abstract

The present invention relates to external valve operating means for operating a valve maintained under internal pressure and having a valve body and a rotary valve stem, comprising: a removable and adjustable and hollow operating seal cover that has an upper opening and a lower opening and wherein the inner surface has threads for the threaded engagement with the valve body; an external valve stem impeller having a lower end in an operative engagement that matches an upper part of said valve stem, said external valve stem impeller has an upper end projecting through said upper opening of said operation seal cover, said upper end of said external valve driver being shaped to be engaged by a tool so that said valve stem can be rotated to operate the valve, a first O-ring seal between the lower end of said external valve stem impeller and said operating seal cover in the vicinity of said upper opening so as to form a seal therebetween which is maintained by any internal non-ventilated valve pressure; O-ring seal positioned between a lower part of said operation seal cap and said valve body adjacent to the threaded engagement, and means for venting said external valve operating means whereby said operation seal cap can be moved to along said lower end of said external valve stem impeller and the part of said valve body adjacent said threaded engagement to allow a partial disengagement of said threaded engagement so that the ventilation means are established between said seal cover and said valve body when said second seal is in an unsealed contact with said valve body for ventilate the internal pressure within said external valve operating means before the removal of the same

Description

OPERATING MEANS OF EXTERNAL VALVE Background of the Invention 1. Field of the Invention The present invention relates generally to valves with rotating rods carrying fluids under pressure and, more particularly, to novel valve cover assemblies for use on such valves. 2. Discussion A number of known types of valves, such as ball valves, for example, carrying fluids under pressure employ rotating valve rods as a means of operating the valves. More specifically, the flow of fluid through such a valve can be controlled by the rotation of its rod by means of a tool.

Such valves typically employ a valve body through which a fluid conduit extends. The valve stem passes through a separate conduit, or valve stem conduit, in the valve body. Since one end of the valve stem protrudes from the outside of the valve body, to allow for manipulation, and the other end is connected to the flow control means in the inner fluid conduit, the valve stem conduit must extending from the outside of the valve body through to the fluid conduit inside the valve body. As such, a valve stem seal, often consisting of a ring at 0, is employed to seal the valve stem conduit as well as to provide a bearing to withstand the internal pressure load acting on the valve stem.

If the valve stem seal fails, the internal pressure will force the fluid being carried by the valve through the valve stem conduit to the outside of the valve body. Depending on the nature of the valve stem seal failure, fluid can either drip, flow or spray out of the valve body. This runoff can easily cause damage to the surrounding components or to dangerous conditions. To guard against such a result, valve covers of known type are typically placed on the valves to provide a cover * sealed around the valve stem and opening of the valve stem conduit in the valve body. In the event that valve stem seal failure occurs when such a valve cover is in place, fluid runoff has been contained within the valve cover.

Handling a valve using a valve cover requires removal of the valve cover to access the valve stem. This takes an additional time, effort and additional tools. Removed valve covers can also be lost, misplaced or not replaced by mistake. In addition, repeated removals and replacements of a cap can cause the cap seal itself to wear prematurely. For these and other reasons there is a possibility of fluid leakage from the valve cover.

It is therefore an object of the present invention to provide a valve cover in combination with an external valve stem drive which together permits manipulation of the valve stem without removing the valve cover or endangering the seal of the valve. valve cover.

Synthesis of the Invention The present invention provides an external valve operating means for operating a valve maintained under internal pressure, wherein the valve is of the type having a rotary valve rod. The external valve operating means covers and seals the area surrounding the valve stem and allows the valve stem to rotate without removing the external valve operating means or compromising the seal.

A stationary and hollow operation seal cap is attached to the valve body with threads to allow its removal. A ventilation O-ring, seated in the stationary operation seal cap, forms a seal with the valve body when the stationary operating seal cap is screwed onto or otherwise comfortably secured in the valve body. The seal releases or vents the internal pressure with the release of the stationary operation seal cover.

An external valve stem drive fastens its lower end to the valve stem, while its upper end protrudes through an opening in the top of the stationary operation seal cover. The upper end of the outer rod drive is shaped such that it can be grasped or otherwise engaged and driven by a suitable tool which, as a result, effects the tumbling of the valve rod. An O-ring seal is placed between the external valve stem drive and the stationary operation seal cap as to form a seal. This seal is maintained when the external valve stem drive is rotated.

For a more complete understanding of the nature and scope of the invention, reference is now made to the following detailed description of the embodiments thereof taken in conjunction with the accompanying clauses and the accompanying drawings.

Brief Description of the Drawings Figure 1 is a vertical cross-sectional view of a known type of quarter-turn ball valve in the open position incorporating a preferred embodiment of the external valve operating means of the invention; Figure 2 is an enlarged view of the embodiment of the external valve operating means of Figure 1.

Description of Preferred Additions A quarter-turn ball valve of the prior art incorporating the external rod drive valve cap of the invention is generally indicated with the number 3 in Figure 1. The valve 3 incorporates a valve body indicated generally with the number 5. The valve body 5 includes a lower ball valve member that receives the part 6 and an upper valve rod that receives the part 7. Within the ball valve member receiving portion 6 of the body 5 is contained a ball valve member 8 and 9-9 ball seals. A valve rod 88 and the valve stem packing or seal configuration indicated generally with the numeral 13 are contained within the valve stem receiving part 7.

The ball valve member 8 is rotated about the axis YY, and includes a fluid conduit 15 therethrough to communicate with the fluid line inlet and outlet ports 19 and 21 when in the open position as shown in FIG. shown in FIG. 1. Fluid flows through conduit 15 in a direction parallel to axis XX when the ball valve member is in an open position. Alternatively, as will be well understood, a quarter-turn rotation of the ball valve member 8 places the ball valve member in the closed position which prevents communication and therefore fluid flow between the line inlet and outlet ports of fluid 19 and 21. The 9-9 ball seals, made of Teflon or other suitable materials, prevent the fluid from flowing around the ball member 8.

The bottom of the valve stem 11 engages the groove 23 in the upper part of the ball member 8 to rotate the ball member 8 as the valve rod 11 is turned around the Y-Y axis. The upper part of the valve stem 11 extends beyond the valve stem seal configuration, indicated generally with the number 13 and the valve body 5 and is shaped to allow contact to rotate the valve stem 11.

The valve stem seal configuration 13 is located in the annular recesses in the upper valve stem receiving part 7 of the valve body 5. A primary seal sheave 29, made of Teflon or other strong material suitable for the passage of fluid through the valve 3, is seated at the upper end of the annular bottom recess 31 as for sealing, against the flange 33 of the valve stem 11. The ring at 0 37 is seated in the annular recess 35., located above the ring part 36. The ring at 0 37 is also made of Teflon or some other suitable material to prevent runoff of the fluid. The O-ring 37 has an interference fit both on its inner circumference with the valve stem 11 and its other outer circumference with the side wall of the annular recess 35 and therefore serves to prevent the passage of fluid in case of failure of the fluid. primary seal sheave 29. Above the annular recess 35 is an annular recess of larger diameter 39. Resting on the shoulder formed between the annular recess 35 and the larger diameter annular recess 39 is gland 41 which serves as a guide of rod. A retaining ring 47 fits within an annular groove in the valve stem 11 to ensure that the valve stem seal configuration is in place.

The valve stem receiving part 7 of the valve body 5 has the threads 49 on its outer surface. These threads match the threads 50 on the inner surface of a valve cover - a component of the external valve operating means forming a preferred embodiment of the present invention, shown generally at point 51. Figure 1 and Figure 2 show the valve operating means 51 in a threaded contact with the valve body 5 with an interengagement of the threads 49 and 50.

Figure 2 shows an enlarged view of the external valve operating means 51. The stationary operating seal cap 53 has a circumferential inner annular recess 55 within the periphery of its bottom aperture. Within the annular recess 55 the O 57 ventilation ring is seated, which is made of Teflon or some other suitable material to prevent the passage of the fluid. As shown in Figure 2, when the stationary operation seal cap 53 is in full threaded contact with the valve body 5, the ventilation O-ring 57 forms a circumferential seal to contain any fluid release from the valve 3 inside the external valve operating means 51. The removal of the external valve operating means 51 may be required by the service requirements of the valve 3. The seal formed by the O 57 ventilation ring is broken when the stationary operation seal cap 53 is released by rotation to the point where the ventilation O-ring 57 passes over the tapered or chamfered shoulder 59. The threads 49 and 50 are still partially engaged at this point so that the pressure within the external valve operating means is released before the external valve operating means 51 can be removed from the valve body 5.

Protruding through the upper opening 61 at the top of the stationary operation seal cover 53 is an external valve stem drive, indicated generally at point 63. The bottom part 65 of the external valve stem drive 63 has an internal recess 67 which is coformed to match with and to urgeably engage the upper part of the valve stem 11. An annular flange 69 is formed integrally on the bottom of the external valve stem drive 63.

The ring seal at 0 71 is seated in the annular space formed by the lower shoulder 73, located between the bottom part 65 and the annular flange 69, and the upper shoulder 75, located within the periphery of the upper opening 61 of the stationary operation cover 53. A ring seal in 071 is also made of Teflon or some other suitable material to prevent the passage of fluid. The ring seal at 0 71 is compressed by axially pulling the external rod drive 63 and the stationary operating seal cap 51 by engaging the threads 49 and 50. The O-ring seal 71 maintains its seal when turned the external valve stem drive 63.

The upper part 77 of the external valve stem drive 63 was shaped to allow gripping and tumbling by a tool. This results in the rotation of the valve stem 11 which in turn allows manipulation of the clamped valve.

Having described the invention generally in detail with reference to the drawings, including the presently preferred embodiments thereof, those skilled in the art will be able to practice the invention either according to the embodiments described or according to other embodiments without departing from the spirit and scope of the appended claims.

Claims (5)

R E I V I N D I C A C I O N S

1. An external valve operating means for operating a valve maintained under internal pressure and having a valve body and a rotatable valve rod, which comprise: a hollow stationary operating seal cap having an upper opening and a bottom opening and wherein the inner surface has threads for the threaded contact with the valve body; an external valve stem drive having a lower end in operative contact coincident with the valve stem and an upper end projecting through said upper opening of said stationary operation seal cover, said upper end of the valve stem drive external being shaped to engage by a tool whereby said valve stem can be rotated to operate the valve, - an O-ring seal placed between the lower end of said external valve stem drive and said stationary operation seal cap in the vicinity of said upper opening so as to form a seal there which is maintained when said external valve stem drive is rotated; Y means for venting external valve operation sayings.

2. The external valve operating means as claimed in clause 9, characterized in that said stationary operating seal cap is generally bell-shaped with the upper opening there having an inwardly extending circumferential flange that contacts the the upper part of the O-ring seal and said lower end of said external valve stem drive is in the form of an outwardly extending circumferential flange whose upper side engages the bottom of said O-ring seal.

3. The external valve operating means of clause 2, characterized in that the O-ring is compressed between said circumferential flange extending inwardly of said stationary operating seal cap and said circumferential flange extending outwardly from said thrust bearing. external valve stem by engaging said valve stem with said external valve stem drive and the simultaneous threaded engagement of said valve body with the stationary operating seal cap.

4. The external valve operating means as claimed in clause 2, characterized in that the ring at 0 is compressed between the circumferential flange extending inwardly of said stationary operating seal cap and said circumferential flange extending towards outside said outer valve rod drive by fluid pressure within said external valve operating means.

5. The external valve operating means as claimed in clause 1, characterized in that said means for venting said external valve operating means comprises: an inner annular recess within the periphery of said bottom aperture of said stationary operation seal cap; Y a ventilation 0-ring seated in said annular recess to form a seal with the valve body when said stationary operation seal cap is in full threaded contact with the valve body and to release the seal with the partial threaded disengagement from said valve. stationary operation seal cap with valve body. E S U M E N External valve operating means that form a seal around the rotary valve stem of a valve operating under internal pressure are described. This seal prevents the escape of fluids in case the primary seals of the valve fail. The external valve operating means allow the valve stem to rotate without removing or compromising the seal. A stationary operation seal cap is in threaded engagement with the valve body. With partial disengagement of the stationary operation seal cover, the pressure inside the external valve operating means is ventilated. An external valve stem drive protrudes through the top of the stationary operation seal cover. A ring in O forms a seal between the two. The bottom of the external shank drive matches the rotary valve shank while the upper part of the external shank drive is shaped to allow gripping by a tool. The rotation of the external rod drive through the tool effects the rotation of the valve stem while the seal surrounding it is maintained.