US2419243A - Method of making valves - Google Patents

Description

- F. AI -LEN EI'AL 2,419,243

METHOD OF MAKING VALVES April 22, 1947.v

I s SheetsShe et 1 Filed Aug. 24, 1944 4b mmmm I '3 M67ZZ0715 April 22, 1947. E ALLEN, r 2,419,243

METHOD OF MAKING VALVES Filed Aug. 24, 1944 3 Sheets-Sheet 3 Patenteci Apr. 22, 1947 METHOD OF MAKING VALVES Earle F. Allen, Wellesley Hills, and Lewis M. Burrows, North Quincy, Mass.,assignors to Manning, Maxwell 85 Moore, Incorporated, New York, N. Y., a corporation of New Jersey Application August 24, 1944, Serial No. 550,966

4 Claims.

This invention pertains to gate valves, and relates more particularly to a novel method of making such valves. In a gate valve the valve head slides relatively to the valve seat, usually moving in a direction substantially perpendicular to the axis of the seat orifice. To support the valve head, when closed, against the imposed fluid pressure, it is usual to arrange the head between two spaced, opposed seat surfaces, one at the delivery end of the inlet passage and the other at the inlet end of the outlet passage, Heretofore, due to difficulties of manufacture, it has not usually been possible to have the valve head seat tightly against both seat surfaces at the same time, and thus the packing, through which the valve stem passes, is often subjected to excess pressure with consequent leakage along the valve stem.

Under conditions of modern engineering practice where very high pressures, high fluid velocities, and high temperatures are encountered, it has become substantially necessary to provide valve seats of wear-resistant material, different from that of the casing proper, united leak-tight to the material of the casing, and likewise to provide the valve head with wear-resistant, seatengaging faces.- However, this involves added difficulties-in manufacture, especially in the manufacture of valves of the smaller sizes, and especially in the formation and finishing of the seat surfaces. In this connection it may be noted that the opposed seat surfaces ofa gate valve are often inclined relatively to" each other to accommodate a wedge-shaped valve head, and that in the smaller sized valves in particular the space available within the valve casing for machine operations is limited. Even under the best conditions of prior practice the contacting surfaces of the valve head and seat are so inaccurately fitted that substantial force is requisite to open and close the valve, necessitating the provision of a heavy valve stem and an actuating lever or wheel of large radius, thus unduly adding to the size and weight of the valve Morover, in the endeavor to provide suificient space with which to perform the essential operations, the valve bodies or casings have heretofore been made unnecessarily large (as respects flow capacity) thus increasing the external dimensions of the i-valve and its weight and cost.

"Preferably the valve. head is swivelled to .the stem to avoid cramping, and in order to guide the valve head as it moves toward and from closed position, it is necessary to provide the casing with a guideway, preferably of generally rectangular transverse section. The provision of an accurately finished guideway of such shape in a forging or cored casting is a difficult and expensive operation; after forming the guideway the seat-receiving bores must then be formed by counterboring with a hooked tool, and the neck and outside-thread on the casing must be formed accurately concentric with the axis of the guideway. The seat-receiving bores must be accurately located with respect to the axis of the guideway,

and even if the seat-receiving bores are initially accurate, the subsequent spinning operation for expanding the seat ring to make it leak-tight often changes the plane of the seat. Moreover, in valves as customarily made heretofore and which have a union bonnet, a substantial body of metal is necessary to provide the threaded portion of the casing neck, the union nut is large and heavy, the packing receiving space is restricted, and the packing nut cooperates with a discontinuous thread on'the yoke, and after a relatively short use becomes oval from wrench ressure.

To avoid some of theabove difficulties, it has heretofore been proposed to make the valve casing in'severalparts and to unite them after installing the valve seats, but so far as is known to me, noprior practical, commercial methodshave been adequateto provide a valve having the desired accuracy of seating to insure ease of operation of the valve, nor to provide concomitant, leak-tight seating of the valve head against both seat-surfaces.

One object of the present inventionis to provide a novel method of makingvalves such that casing; to provide a novel method of making a gate valve whereby-finished, opposed seat surfaces may be so arranged that their planes intersect to form a true dihedral angle bisected by the axis of the valve stem; to provide a method of making gate valves having opposed seat surfaces such that when the valve head is seated it engages both seat surfaces with substantially equal and leak-tight pressure; to provide a method of making valves'such that by reason of accuracy of finish and relative location of the valve head and seat, a minimum force is necessary to close and open the valve'so that thereby the valve-actuating stem and operating 'lever or wheel maybe made smaller and lighter in weight than usual; and to provide a; method of making valves-such as--- to permit'thevalve casing to be made to the minimum external dimensions necessary to provide for the desired capacity, when in use, and without reference to the machine operations required during manufacture.

Other and further objects and advantages of the invention will be pointed out in the following more detailed description and by reference to the accompanying drawings wherein Fig. 1 is a side elevation of the body portion of the casing before assembly with the other parts;

Fig. 2 is a vertical section through-thebody of the casing in the vertical plane defined by the axes of the inlet and outlet passages;

Fig. 3 is :a plan view of the casing body shown in Fig. 1;

Figs. 4 and 5 are side elevations of an inlet and outlet plug before assembly with the body portion of the casing;

Fig. 5 is an end elevation of the plug shown in Fig. 5, showing one of the Valve seat surfaces;

Fig. 6 is a side elevation of a bottom closure for the casing;

Fig. 7' is a front elevationof a jig useful in assembling the casing body with certain parts of the valve bonnet structure;

Fig. 8 is a side elevation of the jig shown in Fig. '7 with the casing body and the bonnet posts assembled in the jig;

Fig; 9 is a plan view of a gauge employed in assembling the inlet and outlet plugs with the :body portion of the casing;

Fig. 10 is a front elevation, partly in vertical section, showing the inlet and outlet plugs assembled with the easing' body and arranged in a weldins j Fig. 11 is a front elevation of the casing, the jig being omitted, showing the inlet and outlet plugs tack-welded to the casing body;

Fig. 12 is an elevation from the right-hand. side of Fig. 11 showing the tack-welding of the outlet plug to the casing body;

Fig. 13 is a vertical section, in the plane defined by the axes of the inlet and outlet passages, showing the complete valve structure resultant from the present improved method of procedure; and

Fig. 14 is a section on the line l4-l4' of Fig. 13.

Referring to the drawings, the numeral 1 designates a block designed to constitute the center part of the valve casing or body. This block, as

illustrated, is made from square bar stock of appi'opr"'-te material, for example carbon steel, the corners being turned off and the upper portion, for example approximately one-half the length of the block, having its corners rounded off to provide a cylindrical base 4 for the bonnet portion of the valve. This block is provided with an axial bore 5 (Fig. 2) of generally rectangular transverse section and which may be made without difficulty by a broaching operation since the bore extends completely through the block. This bore 5 has longitudinally extending finished guide channels 6 for guiding the valve head in its movements toward and from the valve seat. The block 15 also has the transverse passage or bore l whose opposite ends constitute socket-s designed to receive the inlet and outlet plugs hereinafter described, the passage 1 intersecting the bore 5 to form the valve chamber 8.

In the upper or bonnet portion of the block the bore 5 is enlarged by a counterbore Ill to form a shoulder designed as hereinafter described, to support a back-seat, and above this shoulder there is formed an annular ribl I internally screw threaded, for the reception of a ring (hereinafter described) forming a base for the packing material. Above this rib l l the block is further counten-bored to alarger diameter, as shown at l2, to form a pacln'ng chamber.

In accordance with the present invention, an inlet plug 23 (Figs. 4, 5 and 5 and an outlet plug Hi are provided. These plugs are identical in construction, each being made from cylindrical stock turned down to provide the circular outer end portion l5 and the cylindrical inner end portion 56, the inner end portion being of a diameter such as to fit snugly in one end, respectively, of the transverse passage 1 in the block I. Each of the plugs 53 and I l, respectively, is furnished with an axial bore ll (Fig. 5 and, as here illustrated, yith an internally screw-threaded outer socket portion 28 (Fig. 14) designed to receive the screw threaded end of a pipe. However, if preferred, these inlet and outlet plugs may be shaped to receive a welded-on pipe connection.

When, as herein specifically illustrated, the valve is a gate valve having opposed inclined seat surfaces, the inner end surface IS of each of the plugs 13 and it is inclined at the desired angle to the axis of the plug. Whether or not these ends are inclined or sloped it is preferred, in accordance with the present invention, to provide an annular recess in the inner end of each plug, these recesses being coaxial with the bore ll of the respective plug, and in the recess there is disposed a seat annulus 20 (Fig. 10) of hard wearresistant material. Before assembly of the parts, the inner ends of these plugs l3 and M are freely exposed so that it is possible to apply any usual type of wear-resistant seat material to the plug without difliculty. Thus, for example, the annulus 29 may be made of Stellite, flowed into position while molten and at a temperature such as to cause it to fuse and form a molecular union with the material of the plug proper. After the seat annulus has thus been permanently installed leak-tight in the recess in the inner end of the plug, its exposed face is finished as accurately as desirable, for example by grinding, to form a seat surface 2i (Figs. and 5). This seat surface is accurately fiat and disposed at the desired slope, for instance with reference to the axis of the plug. As illustrated in Fig. 5 the inner end of each plug is provided with a flat surface 22 of segmental shape, with its base substantially tangent to the periphery of the seat surface 21 and intersecting the plane. of the seat surface in a line which is accurately perpendicular to the plane defined by the axis of the passage I! and the axis of the annular valve seat surface 2|.

When making a valve such as specifically illustrated herein and whose bonnet structure comprises parallel posts, the present invention contemplates the preparation of two such posts 23 and 24 (Fig. 8) which are identically alike and preferably formed from cylindrical bar stock. The lower ends of these posts are preferably slightly beveled, as shown at E5 in Fig. 8, and the posts are screw threaded at their intermediate portions, as shown at 25 (Fig. 8), with radial shoulders above the screw threads, above which the posts are of reduced diameter, as shown at 28, the upper ends of the posts being screw threaded, as shown at 29 (Fig. 13).

In accordance with the present invention, it is preferred to provide a spacer or dummy valve head 35 (Fig. 10) for use in assembling the parts (although, if desired, an actual valve head may be employed), shaped to slide accurately in the guideways 6 of the valve casing and having opposed seat-engaging surfaces 3| and 32, respectively (Fig. -10) which are accurately finished and sloped at the same identical angles as the valve seat surfaces of the completed valve. This spacer block or dummy (or actual head) 36 is furnished with a rigid stem te preferably having a screw threaded portion 39*. By means of this stem the spacer bloclr or dummy head may be introduced into the bore 5 and properly disposed between the seat surfacesZl at the ends of the spaced opposed plugs l3 and i4 and held rigidly in place during the welding operation as hereinafter described.

T facilitate the assembly of the posts 23 and 24 with the block I, there is preferably provided a jig (illustrated in Figs. '7 and 8) comprising a rigid block 32 having a downwardly directed cylindrical boss 33 shaped to fit snugly within the bore l2 in the casing body member I. Parallel rigid rods 34 and 35 extend downwardly from the block 32, preferably being welded to the latter. To the lower end of the rod 35 there is secured a bottom member 36, preferably pivoted at 3'! to the rod 35. A latch 38 is pivoted to the lower part of the rod 3d and is designed to engage the free end of the member 36 so as releasably to hold the latter in substantially horizontal position, perpendicular to the axis of the member 33. The member 38 has a screw-threaded bore coaxial with the part 33 and which receives a screw 39 having a knurled actuating head, and is provided at its upper or inner end with a disk member at having an upwardly directed plug or boss 4i de signed to enter and lit snugly within the lower end of the bore in the casing body. The jig also comprises an upwardly directed post l2 rigidly secured to the block 32 and which is rigidly united, as by welding, to a cross-head 43 provided at its opposite ends with screw openings for the reception of the screw-threaded upper ends 39 of the posts 23 and 24. Nuts 45 are provided for engagement of the screw-threaded upper ends 2% of the posts so as to secure the posts rigidly, and in accurately parallel relation, to the cross-head 43. The openings in the cross-head are relatively located so that when the posts and 24 are thus mounted in the cross-head, the axes of these posts lie in the same diametrical plane of the casing body with the peripheries of the lower ends of the posts contacting the periphery of the bonnet portion of the casing body. Having secured the posts in the jig in this way, the body of the casing is then introduced between the rods 34 and 35 by first disconnecting the latch 38 from the member 36 and swinging the latter downwardly so that the body may be pushed upwardly to telescope over the member 33 of the jig. The member 35 is then swung up and engaged with the latch 38 and the screw 39 is turned so as to cause the member 4| to enter the lower part of the bore 5 in the casing body and to press the casing body firmly upwardly against the member 33'. With the parts locked in this position, the lower ends of the posts 23 and 24 are welded to the casing body so as to form fillets 45 of welding material (Fig. 8) partially surrounding the lower ends of the posts and integrally joining them with the casing body. The nuts 44 may now be retracted to release the posts from the cross-head 43, and by disengaging the latch 33 the jig may be opened to permit withdrawal of the casing body with posts 23 and 24 firmly attached and in proper position. f

To assist in assembling the plugs l3 and M with the casing body, there is provided a gauge mem her 46' (Fig. 9) comprising'a disk-like portion: having a coaxial cylindrical boss. 41 which is designed to fit snugly within the lower end .of the bore 5 in the casing body, andwhich has, at its. diametrically'opposite (sides, fiat, parallel, vertical surfaces 48 which are spaced accurately .at equal distances from the center of the boss ll,

This gauge is introduced into the lower part of the casing body, and the plugs Ill and M are inserted in the opposite ends of the bore I, respectively, and are pushed inwardly and rotated until the fiat surfaces 22 of the two plugs engage the fiat surfaces 48 of the gauge. This gauge thus determines the distance between the valve seats and accurately locates the planes of the valve seats so that they make a true dihedral angle whose apex line is in the vertical plane of the axis of the valve body. 1 With the parts in this position, they are placed in a suitable jig comprising members 49, 50 and 5! which may be moved inwardly to apply heavy pressure. The dummy valve head at is then in-' troduced into the bore 5 and inserted between the opposed valve seats. A cross-head 52 (which may be a part of the completed valve structure) (Fig. 13) is now mounted 0n the upper ends of the posts 23 and 24 and locked in position by nuts 53, the cross-head having a central screwthreaded opening into which the screw-threaded part 30 of the stem of the dummy valve head has already been threaded. A suitable wrench or hand wheel may be applied to the upper end of the stem 36* of the dummy valve head, and by this means the dummy valve head may be forced down very firmly between the Valve seats. Pressure is now applied by means of the parts 49, 5B

and 5|, and while the parts are thus held under high pressure, welding material 56 (Figs. 11 and 12) is applied so as to unite each plug to the body of the casing. Preferably the welding material is first applied as shown in Figs. 11 and 12 at four preferably spaced points so as to tack-weld the parts together and thus insure their proper relationship before the main body of the welding material is applied. Before applying the main body of welding material, the dummy head may again be tightened so as to insure proper location of the parts before they are finally united. With the parts thus firmly held and accurately located; welding material 51 is applied so as to form an annular fillet uniting each plug firmly, permanently and leak-tight to the body of the casing. After the plugs l3 and 14 have thus been secured in position, a closure member 59 is secured to the lower end of the casing body by welding material Bil.

After the parts have cooled, the valve body is removed from the jig, the dummy valve head with 'its stem is removed, and the true valve head 6|,

having swivel connection to the lower end of the valve stem 63, is introduced into the valve chamber. Preferably the upper surface of this valve head 6| (as shown at 62) is designed to make leak-tight contact with a back-seat 64 when the valve is wide open. This back-seat is an annulus resting upon the shoulder ll of the valve body, and is held in position by a screw-threaded annulus 65 which also constitutes a base or support for the packing material '66 which occupies the chamber l2. This packing material is compressed by a gland 61 having oppositely directed ears which are normally engaged by nuts, 68011 the posts '23 and 2'4, these nuts being capable of being backed ofi sufficiently to permit the gland to be turned a part rotation and thereby to disenage its ears from the nuts to permit full retraction of the gland from the stuffing box or chamber l2. Above the nuts 68 there is arranged the cross-head 52, held in place by the nuts 53 and which, as herein shown, has a screw-threaded central aperture for the reception of an internally screw-threaded nut 54 which engages the screw thread 69 on the valve stem 63. A hand wheel 10 at the upper end of the valve stem provides for turning the valve stem and thus actuating the valve.

By the procedure above outlined, it is possible to make a valve, even of small capacity, having a unitary, leak-proof casing and accurately finished and accurately located Wear-resistant seat surfaces molecularly united to the body of the valve so that leakage can not develop between the seat and the body regardless of temperature or pressure conditions. It is also possible to make a valve having such an accurately finished wearresistant seat and whose external dimensions are substantially less than those of valves of similar capacity made in accordance with usual procedures and which must be of undesirably large eX- ternal dimensions in order to provide the requisite internal working space for the installation and finishing of a wear-resistant seat.

By this method it is possible to make a gate valve having opposed seat surfaces, whether parallel or relatively inclined, which are so accurately finished and relatively located as to insure leak-tight seating of both sides of the valve head simultaneously, while at the same time so reducing friction between the valve head and the seat surfaces (by reason of the relative rigidity of the opposed seats and fine finish thus made possible), that the seating and retraction of the valve head is very easy as compared with ordinary practice. It is thus possible to employ a smaller, less expensive and lighter valve stem and a smaller valve-actuating handle than is customary in valves of the same capacity.

It may be noted that substantially all of the constituent parts of this valve may be made from bar stock and by simple turning or equivalent operations, thus greatly reducing the cost of manufacture as compared with valves which require castings or forgings which must be subjected to expensive machine operations in reducing them to the final shape and dimensions.

We claim:

1. That method of making a gate valve which comprises as steps providing a unitary block of material having therein a valve chamber, axially aligned inlet and outlet sockets which open into said chamber and a gauge-receiving socket, providing an inlet plug and an outlet plug each having an axial flow passage, a portion of each plug being of an external diameter such as to fit into the inlet and outlet socket, respectively, of the block, providing the inner end of each plug with an. annulus of Wear-resistant material, each annulus having an accurately finished surface constituting a valve seat, the seat surface of each plug being disposed in a plane which is inclined at a predetermined angle to the axis of the flow passage in the plug, providing each plug with a positioning surface disposed in a plane perpendicular to the axis of its fiow passage and which intersects the plane of the valve Seat in a line which is perpendicular to a plane defined by the axes of the flow passage and valve seat, providing a gauge which fits into the gauge-receiv ing socket and which has parallel spaced vertical surfaces for engagement with the positioning surfaces of the respective plugs, placing the gauge in its socket in the block, introducing the plugs into the inlet and outlet passages, respectively, and causing their positioning surfaces to engage the opposite vertical surfaces of the gauge, respectively, providing a rigid spacer member having accurately formed seat-engaging surfaces whose respective planes are inclined to the axes of the inlet and outlet sockets, respectively, at the same angles as the seats in the completed valve, advancing the spacer member between the seats within the valve chamber until its seat-engaging surfaces firmly contact the respective valve seats, applying pressure to the parts such as to cause intimate contact of the seat surfaces of the plugs with the seat-engaging surfaces of the spacer member, tack-welding the plugs to the block while maintaining such pressure, applying further force tending to advance the spacer member between the valve seats, completing the welding of the plugs to the block, allowing the parts to cool, and relieving the pressure and retracting the spacer member from between the valve seats.

2. That method of making a valve having a body defining a valve chamber which comprises as steps forming, from a solid length of bar stock, a block having intersecting longitudinal and transverse bores which extend completely through the block and whose intersection forms the valve chamber, shaping one end portion of the longitudinal bore to a non-circular transverse section and so as to provide longitudinally extending guideways for the valve head, forming a pair of seat plugs from bar stock each having an axial passage and having one end externally shaped to fit into one end respectively of the transverse bore in the block, molecularly uniting an annulus of hard wear-resistant metal to the inner end of each plug, finishing each annulus to form an accurately shaped surface constituting a valve seat, providing each plug with a positioning surface accurately located relatively to its seat surface, providing a spacer shaped to slide in the guideways in the block and having accurately formed seat-engaging surfaces, assembling the block and plugs by inserting the plugs in the opposite ends of the transverse bore respectively, engaging the positioning surface of each plug with gauging means thereby accurately to position the seat surfaces of the plugs, moving the spacer along the guideways until its seat-engaging surfaces engage the seats of the respective plugs, and holding the parts in thus assembled position while uniting the plugs and block by welding.

3. That method of making a valve having a body defining a valve chamber which comprises as steps forming, from a solid length of bar stock, a block having intersecting longitudinal and transverse bores which extend completely through the block and whose intersection forms the valve chamber, shaping one end portion of the longitudinal bore to a non-circular transverse section and so as to provide longitudinally extendin guideways for the valve head, forming a pair of seat plugs from bar stock each having an axial passage and having one end externally shaped to fit into one end respectively of the transverse bore in the block, each plug having an accurately finished surface at its inner end constituting a valve seat, the seat surface of each plug being disposed in a plane which is inclined at a predetermined angle to the axi of the flow passage in the plug, providing a gauge which fits in the lower end of the longitudinal bore in the block, the gauge having parallel vertical surfaces and the plugs having complemental vertical surfaces at their inner ends for engagement with the vertical surfaces of the gauge, placing the gauge in the lower end of the longi.. tudinal bore in the block, introducing the inner ends of the plugs into the opposite ends respectively of the transverse bore-and causing the aforesaid vertical surfaces of the plugs to engage the opposite vertical surfaces of the gauge, respectively, and holding the parts in thus assembled relation while Welding the plugs to the block.

4. That method of making a valve having a body defining a valve chamber which comprises as steps forming, from a solid length of bar stock, a block having intersecting longitudinal and transverse bores which extend completely through the block and Whose intersection forms the valve chamber, shaping one end portion of the longitudinal bore to a non-circular transverse section and so as to provide longitudinally extending guideways for the valvehead, forming a pair of seat plugs from bar stock each having an axial passage and having one end externally shaped to fit into one end respectively of the transverse bore in the block, providing a spacer having finished seat-engaging surfaces and which is shaped to slide in the valve head guideways, disposing the plugs with their inner ends in the opposite ends respectively of the transverse bore in the block and so that the planes of the seat surfaces of the respective plugs intersect to form a dihedral angle, sliding the spacer along the valve head guideways until it is disposed between the seat surfaces of the respective plugs, clamping the plugs, block and spacer together in such a way as to cause the seat surfaces of the plugs to contact the spacer under heavy pressure, welding the plugs to the block while the parts are thus clamped, and after the welding metal has cooled withdrawing the spacer from the seat surfaces.

EARLE F. ALLEN.

LEWIS M. BURROWS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,034,418 Plant Mar. 17, 1936 1,293,874 Murray Feb. 11, 1919 1,658,374 Ericsson Feb. 7, 1928 1,679,324 Murray July 31, 1928 1,828,478 Sparks Oct. 20, 1931

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