US3075737A - Valve actuating mechanism or the like - Google Patents

Description

F. J. CANTALUPO ETAL 3,075,737

VALVE ACTUATING MECHANISM OR THE LIKE Filed July 20, 1959 Jan. 29, 1963 26 i6 7 L7 mm 1 i iizaez fors.

United States Patent 3,075,737 VALVE ACTUATING MECHANISM OR THE LIKE Francis J. Cantalupo and John P. Doelger, Chicago, Ill., assignors to Crane Co., Chicago, 111., a corporation of Illinois Filed July 20, 1959, 'Ser. No. 828,201 1 Claim. (Cl. 251-26) This invention relates generally to a globe valve type such as a stop-check valve actuating mechanism or the like, and more particularly it is especially concerned with valve structures and mechanism for use on boiler feed water service or other fluid lines and contemplates the use of such mechanism on valves, for example, of relatively large sizes such as 16-inches and upwards and on extremely high fluid pressures, say, of the order of 3000 pounds per square inch, and temperatures in the range of 700 to 900 degrees Fahrenheit. It is suitable either for remote or manual operation, and preferably for a piston type valve for boiler feed service.

In order to acquire a better appreciation of the background of this invention, it should be understood at the outset that as said fluid operating pressures have been increasing for greater efliciency in power plants, such as central stations, manufacturers processing plants and the like, it has become increasingly difiicult to provide the necessary end thrust required for closing the valves in an absolutely tight condition. One of the principal reasons previously for the inability to obtain desirable valve tightness has been due largely to the relatively high boiler feed line pressures to which the valve is subjected.

Ordinarily the closing operation would require such a high end thrust as to make conventional actuation such as by electric motors, hydraulic pistons and the like impractical because of the power required. Therefore it is an object of this invention to make use of the maximum line fluid pressure encountered and apply it to piston actuated means permitting convenient use of a pilot control valve to regulate flow output to the main valve piston. Further, as hereinafter made clear, check valves are used to utilize the highest fluid pressure encountered whether it be above or below the main valve seat.

A beneficial condition insofar as the valve actuation itself is concerned is one in which the line fluid pressure itself is employed or harnessed so as to aid in the valve seating operation.

Accordingly, it is one of the more important objects of our invention to provide for such actuating mechanism in which line fluid pressure available is so employed. It will of course be understood that on a boiler, the boiler feed Water pressure is always available and therefore it is one of the principal objects of this invention to provide a valve which preferably utilizes the boiler feed water pressure or other available fluid pressure for providing the necessary axial thrusts to close and open the valve.

A further object is to provide for a main valve actuating construction in which the valve disc or closure member is intentionally made larger in diameter at its upper portion with the purpose in mind that such larger diameter will aid in providing a suflicien-t difierential area to seat the valve tightly regardless of the fluid pressure encountered in the system.

It is therefore a further object of this invention to provide in cooperation with the main valve a multi-way control valve in which the latter member will introduce the high fluid pressure to the top side of the closure member at the area of said larger diameter whereby to close the main valve and to also provide means for conveniently relieving the fluid pressure from the top side of the main valve closure member thereby to allow the fluid pressure of the piping system to act upon the underside and smaller diameter of the closure member to open the main 3,075,737 Patented Jan. 29, 1963 ice valve. It follows, as hereinafter made clear, that it is then no longer necessary to move the main valve closure member against the relatively high differential fluid pressures.

Another object of this invention is to provide a multiway control valve, say, one having three-way controls, and so arranged that the main valve closure member is balanced from a fluid pressure standpoint and thereby permits relatively easy operation insofar as the amount of power required to operate it is concerned.

It is a further object of our invention to provide for a valve operating mechanism in which because of the use of high fluid pressure available in closing the valve the use of a relatively small motor is adequate to operate the multi-way control valve against high pressures as of the order of those above referred to and which permits automatic operation electrically.

A further object of this invention is to provide an actu ting mechanism for valves or the like in which the main valve may be conveniently operated by fluid pressure even in the event of electrical power failure.

Further, it is an object of the invention to provide an actuating construction in which a plurality of relatively small manually operated valves can be used to isolate the control valve for repair and then by suitable manipulation as hereinafter described permit the operation of the main valve while repairs are being made on the control valve.

A further object is to provide for a structure in valve operating mechanism in which considerable economies can be effected within the purview of constructing valves for high pressure boiler feed service by reason of the reduction in the size of the motor operating mechanisms heretofore required.

Another object is to provide for a construction in which despite the use of a stepped cylinder it does not contribute substantially to the overall size of the valve nor to its height. Yet it is one which lends itself readily to reductions in actual costs considerably less than valves presently available.

Another object of our invention is to provide for an actuating mechanism making it possible to seat the valve tightly against extremely high test pressures usually required by specification of the manufacturer and one in which no difliculty will be experienced in seating the valve tightly against any test pressures which might be required by an operator in order to meet severe field conditions.

Other objects and advantages of the invention will become more readily apparent upon proceeding with the following description read in light of the acompanying draw= ing, in which:

FIG. 1 is a piping assembly in partial section of a pre ferred embodiment of a valve actuating mechanism in corporating our invention;

FIG. 2 is a fragmentary sectional assembly view of the pilot valve mechanism;- and FIG. 3 is a sectional assembly view of a check valve assembled with the mechanism.

Referring to FIG. 1, a main valve to be actuated generally designated 1 is shown, the design being suitable for boiler feed water service, the valve body or casing being provided at its end portions with the inlet connection 2 and the outlet connection 3 and with a pair of cylinders having a differential cross-sectional area within the main valve casing chamber. While these respective connections are shown as being of the welded end type, it will of course be appreciated that other forms of pipe connections may be used without detracting from the invention. In boiler feed water service, it will of course be understood that line fluid pressure is applied on the underside of the valve closure member generally designated 4, the fluid flow thus being in the direction indicated by the arrow inscribed on the outside of the valve casing to avoid an incorrect installation of the valve. The upper or end opposite the seating surface of the closure member 4 is provided with the larger area piston and it is this additional area above the closure member that provides sufficient differential area to close and seat the valve tightly at all pressures within the piping system. The valve closure reciprocally movable member is provided with a free movable double piston, axially aligned in the valve casing cylinder and having at its lower peripheral end portion and adjacent to the lower end of the smaller area piston the annular valve seating surface 5 which contacts the seat 6 of the casing 1 when the valve is in the closed position as shown. As also indicated, the respective seat contact areas may be of a special hard seating material in order to allow for improved performance when encountering the more severe field services.

At an intermediate portion of the valve closure member 4, a plurality of fluid sealing rings 7 and 8 are provided which may of course be variable in their number, material and arrangement, depending upon the type of service for which the valve is intended. These rings function to seal the two positions and to prevent excessive escape of fluid past the large piston into the annular chamber immediately adjacent the smaller piston. Since it is essential that any pressure in this'chamber be relieved so as to obtain the advantage of the differential pressure area, this chamber is relieved through piping to the low pressure side of the system as subsequently explained. At its upper end, a cap ring 9 is used to hold a sealing member 11 in position, the latter construction preferably being of the pressure seal type, as, for example, employing a sealing structure similar to that shown in the Marburg Patent No. 2,330,130, granted September 21, 1943. The said sealing member is held in position in the usual manner by the bolt studs 12a, all of which is more clearly set forth in the said patent. Obviously, other forms of construction for closing and sealing the valve chambers may be used without affecting the invention.

As indicated, the lower end portion of the cap 11 is provided with an undersurface 12, serving as a stop for the said closure member, contacting the upper surface portion 13. The closure member 4 is preferably provided with a welded strut 14 spanning the closure member chamber 15. This strut merely functions as means for removing the closure member when necessary, and also it carries the indicator rod (not shown) to show the respective position of the valve as well as to cooperate with electric switches (not shown) for visually indicating to the operator such valve position. It will of course be appreciated that this structural detail also may vary considerably, depending upon the type of the closure member desired and the kind of service for which the valve is intended. It will be appreciated that the casing cham: ber portion 16 immediately above the closure member cooperates with the inlet of the valve, as indicated at 17, through the plurality of valves and piping together with the piston and the motor prime mover to effect the desired reciprocating movement of the valve closure member 4 by means hereinafter described in greater detail. The main valve is provided with the usual outlet or discharge chamber as shown.

Directing attention now to the pilot valve asembly, generally designated 18, preferably mounted independently of the main valve body 1, it consists of a cylindrical casing 19 mounted by means of a supporting bracket 21 upon the upper portion 22 of the said main valve body and of the general configuration indicated at 23. The bracket is attached by means of a plurality of bolts 24 to an outer surface of the said main valve body casing portion 22 as illustrated' At the upper portion of the pilot valve cylindrical casing 19, a prime mover, such as a conventional electric motor, generally designated 25 is mounted to cooperate therewith and positioned in superposed coaxial relationship by means of the vertical supporting brackets 26. The pilot valve motor as indicated is connected in the usual manner to a source of electric power generally designated S, being suitably actuated predeterminately by switch means (not shown), forming part of an electric control panel (also not shown). The lower protruding rotatable shaft coupling 27 of the motor is adjustable on the threaded shaft 28 connected to the ball bearing screw 29. The latter member, for example, is of the conventional type known to the trade as the Saginaw screw, having at the lower end portion thereof the stern nut 31 and the stem 32 connected to the pilot valve piston generally designated 33. It should be understood that the structure of the Saginaw screw is such that rotation of the threaded shaft 28 through the screw 29 imparts a reciprocating movement to the piston stem 32 and the connecting piston 33 depending upon the direction of rotation of the shaft 28. The piston is shown in the raised position in FIG. 2. The piston is provided with the usual sealing rings 34 and 35 at upper and lower portions respectively. As indicated, the piston is reciprocally movable in the cylinder casing 19, actuated through the screw 29 as above referred to. A flanged cap 36 serves as a closure for the cylinder casing 19 held in sealing relation thereto by the bolts 40. The piston 33 is provided with an annular intermediate relieved portion 37 for flow purposes hereinafter explained in detail. As shown, the upper portion of the piston 33 is provided with a bleeder port 38 connecting the upper chamber 39 with the inner chamber 41 of the piston 33 to balance the fluid pressure and the stem 32 is suitably connected by means of threads 42 to the piston 33.

For journally receiving the stem 32 in leakproof assembly, a conventional stufiing box (not shown) is provided in the cap 36 for which the gland flange 43 cooperates with the gland studs 44 for compressing the stuffing box packing by means of the adjustment provided by the gland nuts 45.

It will be noted that the cylindrical casing 19 is provided with a plurality of ports, two on difierent horizontal planes and one on a vertical axis, as indicated at 46 and 48, respectively, and in a vertical plane at 47, suitably connected to piping as indicated respectively at 49, S2, and 51, each one of the sections of piping having the flow therethrough controllable by means of preferably manually operated stop valves at 53, 55, and 54, respectively.

Now tracing the path of the piping 49 extending beyond the valve 53, it will be noted that the connection is made by means of a short length of tubing 56 connected to a T 57, having the usual run and the lower depending suitably bent inlet conduit or pipe 58. The latter is connected by means of the tubing to the conventional hall check valves 59 connected by tubing 61 and arranged in tandem to communicate with the chambers 10 and 17 extending around the closure or disc 4 when the valve is in the position shown in FIG. 1. The check valves permit only unidirectional flow in the high pressure conduit 58 and are preferably, but not necessarily, of the spring-loaded ball type with a body, a cap 20 in which a spring 50 is used to hold a steel ball 30 to its seat. The ball is preferably retained within the pronged cage as shown. Each of the check valves has the body reduced at 64 and has the lower tubular portion 62 connected at 63 (see FIG. 1) to the chambers 10 and 17. These check valves are used to utilize the higher fluid pressure in the line as contained in the chambers 10 and 17 constituting the upstream and downstream portions respectively of the valve casing. The limit ends of attachment of the check valves to the main valve casing 1 are made at 70. The details of the check valves employed are shown enlarged and in substantial detail in FIG. 3.

Thus the check valve tubes 62 are attached in such manner to the main valve that the highest fluid pressures whether they be outwardly and below the seat in the chamber 17 or inwardly and above the seat in the charnher 10, the highest fluid pressure will always actuate one check valve or the other whereby to utilize the highest pressure to operate the main valve disc. Continuing with the description of the piping, the upper portion of the T 57 has the outlet tubing 66 preferably formed with a return bend as at 67, e7 to connect with the conventional selectively operated stop valve 68. The latter valve is provided with a tubing connection 69 made with the cross fitting 71 and communicating through the cross fitting with the tubing 72 and another stop valve '73 also of the conventional type above referred to. Immediately below the valve 73, another short length of tubing 74 is provided for attachment to a T 75 having its side opening con nected by means of the tubing 99 with the casing annular chamber immediately below the sealing rings 8, in order to dispose of leakage past the rings 7 and 8. Depending from the said T is a curved tube 76 connecting with the run of another T 77, as illustrated, and the latter member on its downstream side of the run is connected with a piece of tubing 89 extending to the low pressure side of the piping system or a suitable receptacle (not shown).

Referring again to the T 57, it will noted that the flow control into the connecting tubing 56 is efiected by means of the selectively operable stop valve 53 indicated by its handle as being in the open position. As previously stated, the latter valve is connected by means of the conduit 49 to communicate with the inlet opening 46 in the Wall of the cylindrical casing 19. At its lowermost end portion, the casing 19 is is provided with the axially parallel tubing 51 and the control valve 54 has the latter member connected by means of the tubing 78 connected with the T 77. The valve 54 by its handle extending parallel to the run is also indicated as being in open position. At a side lower peripheral portion of the easing 19, the transversely extending conduit 52 and the control valve 55 are connected with the tubing 7 to enter the side outlet at 81 Within the cross 71. As shown, the latter member at its opposite end portion is connected by means of the tubing 82 so as to extend through the wall 22 of the casing and communicate with the chamber 16 above the main valve closure member 4, as shown.

In connection with considering the function of the selectively operable valves in the operating system designated 53, 54, 55, 68, and 73, it should be understood that the direction of the handles in indicative of whether or not the valve is opened or closed. The transverse position of the handle indicates the valve is closed and where the handle extends parallel to the run the valves are open. For example, in the drawing FIG. 1, the valves 53, 54, and 55 are all indicated as being open, since the handles are parallel with the run of the respective valves. In this same stage of operation, the handles of the valves 63 and 73 extend transversely and indicate therefore that the valves are closed.

In FIG. 2, it will be appreciated that in the position shown for the pilot valve piston 33, the main valve closure disc 4 will be opened when the pilot valve piston is in the raised position shown in this figure, in which case, the ports respectively designated at 51 and 52 are connected to the low pressure side of the fluid operating system.

In considering the operation of the valve actuating mechanism, let it be assumed that the automatic operation is to be employed in which case the pilot valve motor 25 will come into use. It will be noted that the main valve 4 is in a seated position, and therefore, the valve is in a closed position. With such positioning of the main valve, the first step in such actuation will be to activate the pilot valve motor 25 to drive the pilot valve piston 33 upward. This wiil close off the high pressure side of the system, the piston then occupying the position shown in FIG. 2. In this position, the fluid pressure above the closure member at 16 is relieved to the low pressure side of the system. It will be appreciated that at this stage 6 of operation of the main valve, the line fluid pressure Within chamber 17 being below the closure member 4 will lift the said closure member and maintain it in the open position.

Now, let the automatic operation of the valve, which is the normal method of actuation, be applied.

In this case, the hand-operated valves 53, 54, and 55 are open and the valves 63 and 73 are closed. The main valve piston is to be actuated in the desired direction by means of the control valve actuator 18. The highest fluid pressure from the main valve passes upward from the lower or the upper check valve through conduit 58, T 57, valve 53, conduit 49, through the opening 46, into the control valve annular chamber 37. With the piston 33 in the position shown in FIG. 1, the high fluid pressure from the annular chamber 37 moves dirictly to opening 4-8, conduit 52, valve 55, conduit 79 into the cross 81, into conduit 71 to enter the chamber 16 of the main valve casing above the disk 4 which thus forces the disk to the seated position, as illustrated.

Now let it be assumed that the main valve is to be opened and the piston 33 would then be in the raised position shown in FIG. 2, relieving the high pressure fluid from the chamber 16, through the conduit 71, the cross 81, the conduit 79, valve 55, the conduit 52, through the opening 48 into the control valve chamber 41 through the opening 47, into conduit 51, valve 54, conduit 78, T 77 and conduit to the low pressure side of the system which may be either a receptacle, pump, or other portion of the low pressure side of the system.

The high pressure fluid at such stage of operation remains in the annular chamber 37 being sealed against substantialy escape by means of sealing rings 34 and 35.

Now let it be assumed that with the automatic operation still in effect it becomes necessary to close the valve. Assume that the hand-operated valves 53, 54, and 55 are in the open position and hand-operated valves designated 68 and 73 are closed, at which point the pilot valve motor 25 is actuated by suitable push button switch (not sworn) to drive the pilot valve piston 33 downward to the lowermost position illustrated in FIG. 1. Such positioning will thus allow the line high fluid pressure to enter through the conduit 58 into the conduit 49 and the bent conduit 66 and 67 moving respectively through the valve 68 (now opened) and thence into the conduit 82 communicating with the interior chamber 16, thus to allow high pressure to enter the main valve above the closure member to close the main valve and maintain it in such position so long as the differential pressure condition remains unchanged.

Let it now be assumed there is to be fluid actuation in connection with a valve in which there is to be only manual operation as distinguished from the previously described automatic operation. Under such condition, the first valves to be closed will be the hand-operated valves 53, 54, 55, and 73. By closing valves 53, 54, and 55, the pilot valve is completely out oif and isolated from the system. Opening the hand-operated valve designated 68 allows the line fluid high pressure to enter the main valve casing chamber 16 above the closure member 4 and thus promptly close the said main valve.

With the main valve in the closed position as illustrated, assume that it is now desired to open the said valve. With such intention, the hand-operated valves 53, 54, and 55 are turned to the closed position (handles extend transverse to run) so as to isolate the pilot valve from the system and hand-operated valve 68 is also permitted to remain in the closed position. But, the hand-operated valve 73 is opened, which latter condition allows for the fluid pressure above the closure member 4 in chamber 16 to be relieved to the low pressure side through the conduit 74 and 76, passing through the Ts 75 and 77, discharging through the exhaust conduit 7 8 into the low pressure side or suitable receptacle. In this position of the several valves actuated, the high pressure of the main 7 valve will lift the disc 4 and keep it in the open position as previously described in connection with the automatic operation.

It will be appreciated that the ball check valves 59 being pressure responsive prevent reverse or backflow of fluid into the respective valve chambers 10 and 17.

While only a single embodiment of the general actuating mechanism has been shown and described, it will be appreciated that this is only for purpose of illustration and the extent of the invention should be measured by the scope of the appended claim.

We claim:

Valve actuating apparatus for a globe valve or the like;

the combination of a valve body with a pair of axially aligned cylinders having different cross-sectional areas therewithin;

' the said body having an inlet and outlet and a valve chamber therebetween defined by said cylinders and an annular valve seating surface in said chamber adjacent a lower end of the smaller area cylinder remote from the larger area cylinder;

the said seating surface lying between the upstream and downstream portions of the valve body;

a freely movable stepped piston with respective fluid sealing rings for substantially sealing said larger and smaller areas of the axially aligned cylinders;

the said stepped piston forming an intermediate annular chamber between said larger and smaller areas of the axially aligned cylinders in said valve chamber, the said intermediate chamber including means continuously relieving fluid pressures therefrom;

a valve closure member therefor reciprocally movable in said valve chamber With said stepped piston for predetermined fluid sealing engagement with said valve seating surface;

a pressure-sealing cap ring covering an outer portion of said valve chamber to seal said larger area of the axially aligned cylinder;

said apparatus including a fluid actuating system with high pressure and low pressure sides comprising a fluid supply line predeterminately communicating with said valve chamber at said upstream and downstream portions of said valve seating surface;

check valve means connected to said valve chamber upstream and downstream of said valve seating surface;

the said system embodying a pilot valve assembly, the said assembly including a prime mover and piping therefore connected to said fluid supply line, the said piping connecting a plurality of manually operated stop valves, the said stop valves selectively communicating through the said piping with the said valve chamber to supply or release line fluid from the supply line to that portion of the valve chamber between the double piston and said pressure-sealing cap ring;

the said check valve means being interconnected and mounted on said fluid supply line;

a piston control pilot valve for controlling the direction of reciprocal movement of said valve closure member, the said pilot valve being connected to said supply line and interposed between said pilot supply lineand said valve chamber, the latter chamber being connected by said piping to said pilot valve upon predetermined actuation of said manually operated stop valves;

the piston of said pilot valve being reciprocally actuated by said prime mover;

the said pilot valve having three fluid connections with said actuating system, one of said connections communicating with that portion of said valve chamber between said stepped piston and said cap ring, another of said connections communicating with said fluid supply line and the third connection being to the low pressure side of said fluid actuating system, two of said manually operated stop valves controlling fluid flow between said pilot valve and said first named valve body and the other of said manually operated stop valves controlling fluid flow to the low pressure side of said fluid actuating system; the said latter mentioned stop valves when in the closed position cutting off said pilot valve from communications with said actuating system while permitting manual operation of the said globe valve; the said plurality of manually operated stop valves also including a pair of stop valves communicating with said valve chamber above said stepped piston, one of said latter valves being mounted on the said fluid supply line, the other being connected to the low pressure side of the system; the system and piping providing that upon closing the first named three stop valves of said pilot valve and opening said one of latter valves on the fluid supply line and closing the other of the said pair of valves connected to the low pressure side of the system line fluid pressure is applied toact on the larger area of said stepped piston to close and seat the closure member on said annular seating surface; the said system and piping also providing that upon closing said one of the pair of valves on the fluid suply line and opening said one of said pair of valves connected to the low pressure side of the system, line fluid pressure which is applied on the smaller area of said stepped piston is effective to unseat and open said closure member; the said pilot valve piston being substantially sealed and having a relieved portion forming an annular chamber in the pilot valve, the latter chamber at a predetermined lowered axial position of the pilot valve piston providing a fluid connection between said fluid supply line and said valve chamber above said stepped piston, the said pilot valve piston at said latter axial position thereof communicating below said pilot valve annular chamber with said low pressure side of said system; the said valve closure member being seated on said annular valve seating surface in the latter position of the pilot valve piston; the said pilot valve piston at a predetermined raised axial position thereof closing off said pilot valve annular chamber from communication with said fluid supply line and providing at said piston axial position for relief of fluid pressure in the valve chamber above said stepped piston in cooperation with said third connection of the pilot valve leading to the low pressure side of the said system; the said valve closure member being unseated relative to said annular valve seating surface in said raised axial position of the pilot valve piston, line fluid pressure acting against said smaller area of the stepped piston.

References (Iited in the file of this patent V UNITED STATES PATENTS 570,727

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