GB2161587A - Top entry ball valve and a clamp therefor - Google Patents

Abstract

A top entry valve includes a valve body 1 formed with an open top valve chest 2, a ball closure 3 mounted in the valve chest, a seat ring 11 at the low-pressure side, and a seat ring assembly 12 comprising another seat ring 13, a belleville spring 14 and a seat ring holder 15 at the high-pressure side. The seat ring assembly 12 can be easily assembled with and disassembled from the valve chest 2 through the open top with the aid of a clamp which compresses the belleville spring 14, the spring being allowed to expand after mounting in the chest. The clamp comprises a pair of clamping members 20 fastened together with bolts 27, tightening of which causes the members 20 to pivot on a fulcrum a. <IMAGE>

Description

SPECIFICATION Top entry ball valve and a clamp therefor The present invention relates to a top entry ball valve and a clamp therefor.

In conventional top entry ball valves, it is most common that the surfaces for receiving the valve seats on the rims of the valve ports at the high- and low-pressure sides of a valve chest are tapered so as to allow a ball valve to fit snugly on the valve seat rings. These conventional top entry ball valves have a disadvantage that the optimum depth by which the ball valve is allowed to fit between the seat rings is limited within a narrow range. A ball valve fitting deeply requires too much torque. On the other hand, a ball valve fitting shallowly provides only imperfect sealing. It is difficult, therefore, to keep the operation efficiency and sealing performance in an ideal condition. It is also difficult to machine the tapered surfaces so as to provide satisfactory surface accuracy.

In another type of conventional top entry ball valve in which the opposite surfaces for receiving the valve seats are parallel to each other, a valve seat ring assembly, which is a combination of a valve seat ring, a belleville spring and a valve seat ring holder, is provided at the high-pressure side so as to allow the ball valve to fit closely on the valve seat ring. The valve seat ring holder is screwed into the valve port at the high-pressure side so that an operator can turn the valve seat ring holder so as to move it toward and away from the ball valve. This type of conventional top entry ball valve has disadvantages in that it is intricate in construction because the valve body must be tapped and that fine particles conveyed through the valve port are apt to stick to the tapped surface and thereby cause difficulties in the disassembly.

It is an object of the present invention to provide a top entry ball valve in which the valve seat ring assemly can be easily mounted and removed into and out of the space between the ball valve and the surface for receiving the valve seat at the high-pressure side without the necessity of machining the valve body.

It is another object of the present invention to provide a clamp for mounting and removing the seal ring assembly into and from the valve body.

In order that the present invention may be more readily understood, reference will now be made to the accompanying drawings, in which: Fig. 1 is a vertical sectional view of a ball valve according to the present invention; Fig. 2 is a cross-sectional side view of the valve body; Fig. 3 is a partially broken away horizontal sectional view thereof; Fig. 4 and 5 are partially cutaway vertical sectional views illustrating how the first embodiment of the clamp is used; Fig. 6 is a partially cutaway side view thereof; Fig. 7 is a sectional view of the second embodiment of the clamp; Fig. 8 is a front view thereof; Fig. 9 is a sectional view of the third embodiment of the clamp; Fig. 10 is a front view thereof; Fig. 11 is a sectional view of the fourth embodiment of the clamp; Fig. 1 2 is a front view thereof;; Fig. 1 3 is a sectional view of the fifth embodiment of the clamp; Fig. 1 4 is a front view thereof; Fig. 1 5 is a sectional view of the sixth embodiment of the clamp; Fig. 1 6 is a front view thereof; Fig. 1 7 is a sectional view thereof, illustrating how it is used; Fig. 1 8 is a plan view thereof; Fig. 1 9 is a sectional view of the seventh embodiment of the clamp, illustrating how it is used; Fig. 20 is a sectional view of the eighth embodiment of the clamp, illustrating the actual use; Fig. 21 is a sectional view of the ninth embodiment of the clamp; and Fig. 22 is a plan view thereof.

Referring now to Fig. 1, a ball valve in accordance with the present invention includes a valve body 1 having a valve chest 2 therein. The valve chest 2 has an open top 4 through which a ball valve 3 can be put into and taken out of the valve chest 2. A surface 7 for receiving a valve seat ring 11 on the rim of a valve port 5 at the low-pressure side of the valve chest 2 is parallel to a surface 8 for receiving a valve seat ring assembly 1 2 on the rim of a valve port 6 at the high-pressure side of the valve chest 2.Stepped portions 9 and 10 in the form of semicircular arcs are formed substantially on the lower halves of the surfaces 7 and 8, respectively, to keep in position the valve seat ring 11 and the valve seat ring assembly 1 2. As shown in Fig. 2, the upper end faces of the stepped portions 9 and 10 are disposed below, and at a distance of Ax from, a horizontal plane which contains the axis of the valve ports 5 and 6.

The valve seat ring 11 supported by the stepped portion 9 is interposed between the surface 7 and the ball valve 3. The valve seat ring assembly 1 2 supported by the stepped portion 10 is interposed between the surface 8 and the ball valve 3. The valve seat ring assembly 1 2 is a combination of a valve seat ring 13, a belleville spring 14 and a valve seat ring holder 15, the last of which is an annular member having the same inside diameter as that of the valve port 6 and having an annular flange 1 6 projecting inwardly from its inner rim so as to accommodate the valve seat ring 1 3 and the belleville spring 14 therein.When the ball valve 3, valve seat ring 11 and valve seat ring assembly 1 2 are accommodated in the valve chest 2 as shown in Fig. 1, the belleville spring 14 normally urges the valve seat ring 1 3 inwardly for disengagement from the valve seat ring holder 1 5 so as to leave a space of Al therebetween.

An annular groove 1 7 is provided in the outside surface of the annular flange 1 6.

When the belleville spring 14 is in an uncompressed condition, the valve seat ring assembly 1 2 is too thick to be put into the valve cfiest 2. On the other hand, when the ball valve 3, valve seat ring 11 and valve seat ring assembly 1 2 are already in the valve chest 2, it is difficult to take them out of the valve chest 2 because of large frictional force caused by the resilience of the belleville spring 14.

The above-described difficulties are eliminated, e.g., by any one of clamps shown in Figs. 4 to 22.

Referring now to Figs. 4 to 6, the first embodiment of the clamp according to the present invention comprises a pair of clamping members 20 facing each other. Substantially the lower half of each clamping member 20 constitutes a clamping portion 21, while the upper half constitutes an operating portion 22 for opening and closing the clamping portions 21.

Each clamping portion 21 is provided with a semicircular concave 23 having such a radius of curvature as to fit accurately on the periphery of the valve seat ring assembly 1 2.

Grooves 24 are formed in the inside rims of the concaves 23.

A projection 26 is provided on the top of each operating portion 22. The surfaces of the projections 26 facing each other are slightly bulged toward, and allowed to abut on, each other. Bolts 27 extend through one clamping member 20 near the shoulders of the operating portion 22, and are threaded into the other clamping member 20. Holes provided in the former clampingmember 20 for allowing the bolts 27 to extend therethrough are slightly larger than the body size of the bolts 27.

In operation, the bolts 27 are loosened, and the concaves 23 of the clamping members 20 are rested on the periphery of the valve seat ring assembly 1 2 so as to allow the groove 24 of one clamping member 20 to receive a rim of the annular groove 1 7 and allow the groove 24 of the other clamping member 20 to abut on the end face of the valve seat ring 1 3 facing the ball valve 3 as shown in Fig. 4.

Then the bolts 27 are threaded into one clamping member 20 while the boltheads abut on the other clamping member 20. Consequently, the clamping portions 21 are allowed to pivot on a fulcrum a (Fig. 5) in such directions as to come close to each other and thereby compress the belleville spring 14 as to decrease the total thickness of the valve seat ring assembly 1 2.

The valve seat ring assembly 1 2 held by the clamp in the above-described manner is put into the valve chest 2 together with the ball valve 3 and the valve seat ring 11. When the valve seat ring assembly 1 2 is placed in position, the clamp is disengaged therefrom so as to allow the belleville spring 14 to urge the valve seat ring holder 1 5 and the valve seat ring 1 3 toward engagement with the surface 8 and the ball valve 3, respectively.

For disassembly, the order of procedure has only to be reversed.

Referring now to Figs. 7 and 8, the second embodiment of the clamp according to the present invention is similar to the first embodiment in that it comprises a pair of clamping members 20, the lower half of each clamping member 20 constitutes a clamping portion 21, the upper half constitutes an operating portion 22 for opening and closing the clamping portions 21, each clamping portion 21 is provided with a semicircular concave 23, and grooves 24 are formed in the inside rims of the concaves 23.

The difference between the first and second embodiments consists in the construction of the operating portions 22. A first bolt 29 is threaded into and through the projection 26 of one operating portion 22 so as to allow the end of the bolt 29 to abut on the inside surface of the projection 26 of the other operating portion 22. A pair of second bolts 30 extend through one clamping member 20 near the shoulders of the operating portion 22, and are threaded into the other clamping member 20. Holes provided in the former claming member 20 for allowing the bolts 30 to extend therethrough are slightly larger than the body size of the bolts 30.

Instead of a pair of bolts 30, this embodiment may be provided only with a single bolt 30 as shown with a dot-dash line in Fig. 8.

In operation, the concaves 23 of the clamping members 20 are rested on the periphery of the valve seat ring assembly 1 2 in the same manner mentioned in reference to the first embodiment. Then the first bolt 29 is threaded into and through one projection 26 so as to force it away from the other. Consequently, the clamping portion 21 abutting on the boltheads of the bolts 30 is allowed to pivot on the upper inside edges of the boltheads in such a direction as to come close to the other clamping portion 21 and thereby compress the belleville spring 14. Procedures to be carried out thereafter are the same as mentioned in reference to the first embodiment.

Referring now to Figs. 9 and 10, the third embodiment of the clamp according to the present invention has one clamping member 20 adapted to pivot on a pair of pins 31 provided on the other clamping memmber 20.

A bolt 32 is threaded into and through one projection 26 and inserted into a hole provided in the other projection 26. This hole is slightly larger than the body size of the bolt 32. A nut 33 is screwed on the bolt 32 to prevent the latter projection 26 from coming close to the former projection 26. The clamping portions 21 are C-shaped as shown in Fig.

10.

Referring now to Figs. 11 and 12, the fourth embodiment of the clamp according to the present invention has projections provided directly on the tops of the clamping portions 21. These projections have tapered sides 34 and threaded semicylindrical sides 35 formed above the tapered sides 34. When the clamping members 20 are put together, a space equal to that left between the clamping portions 21 is left between the mating faces in the portion having the tapered sides 34, while the mating faces in the portion having the threaded semicylindrical sides 35 are brought into contact with each other, with the lower ends of the contact surfaces serving as a fulcrum a on which the clamping portions 21 are allowed to pivot.

A locknut 36 is screwed on the threaded portion 35 so as to allow a tapered sleeve 37 formed on the lower half of the locknut 36 to fit on the tapered portion 34. When the locknut 36 is tightened so as to drive it toward the clamping portions 21, the tapered sleeve 37 forces the tapered portion 34 to bend the clamping portions 21 on the fulcrum a in such directions as to come close to each other.

Referring now to Figs. 1 3 and 14, the fifth embodiment of the clamp according to the present invention has a tapered hole 38 formed by the inside surfaces of the projections 26. A tapered pin 39 adapted to fit in the tapered hole 38 is threaded into and through a coupling member 40. Inward flanges 41 provided on the lower ends of the coupling member 40 fit in grooves provided in the outside surfaces of the projections 26.

A lug 42 for fitting a handle thereon is provided on the top of the tapered pin 39.

In operation, a handle (not shown) is fitted on the lug 42 and the tapered pin 39 is turned so as to be driven downwardly and forced into the tapered hole 38. Consequently, the clamping portions 21 are allowed to pivot on the grooves receiving the inward flanges 41 of the coupling member 40 in such directions as to come close to each other.

Referring now to Figs. 1 5 and 16, the sixth embodiment of the clamp designed for a large-sized ball valve includes a pair of clamping plates 51 and 51' facing each other, a clamping bolt 52, and a pair of fulcrum bolts 53 extending parallel with each other.

The clamping plate 51 is mounted on the valve seat ring 11 disposed at the low-pressure side, while the clamping plate 51' is mounted on the valve seat ring assembly 1 2 disposed at the high-pressure side. The lower ends of the clamping plates 51 and 51' terminate in fitting members 57 and 57' having semicircular concaves which are complementary to the peripheral surfaces of the valve seat ring 11 and the valve seat ring holder 1 5 (Fig. 17), respectively. Tongues 60 and 60' provided on the semicircular concaves of the fitting members 57 and 57' are adapted to fit in the annular grooves 1 7 (Fig.

17) provided in the peripheral surfaces of the valve seat ring 11 and the valve seat ring holder 15, respectively.

The clamping bolt 52 extends through holes 61 and 61' provided in the upper central portion of the clamping plates 51 and 51'. Holes 62 and 62' for allowing the fulcrum bolts 53 to extend therethrough are disposed below the holes 61 and 61' and symmetrically about the vertical center line.

Before the clamping bolt 52 is allowed to extend through the clamping plates 51 and 51', two locknuts 63 and 63' are screwed on the clamping bolt 52 and disposed about the middle thereof. A bracket 64 is secured to the middle portion of the clamping bolt 52. Four coupling bolts 65 extend through the bracket 64 and are connected to the ball valve 3. Two of the coupling bolts 65 are disposed across the clamping bolt 52 from the remaining two.

Thus the sixth embodiment of the clamp according to the present invention can be positioned in the right place by connecting it to the ball valve 3 by means of the bracket 64 and the coupling bolts 65. The clamping bolt 52 is prevented from revolution even when the locknuts 63 and 63' are turned. The bracket 64 can be gripped by hooks for raising the ball valve 3.

A clamp designed for a comparatively smallsized ball valve may be devoid of the bracket 64 and the coupling bolts 65, in which case the clamp should be provided with some suitable means for preventing the clamping bolt 52 from revolution even when the locknuts 63 and 63' are turned. For example, key seats to receive keys may be formed in the holes 61 and 61'.

Nuts 67 and 67' are screwed on both end portions of the fulcrum bolts 53 projecting outwardly from the clamping plates 51 and 51'. These nuts serve to hold two clamping plates at a given distance from each other.

In order to take off the ball valve 3, the valve seat ring 11 and the valve seat ring assembly 1 2 from the valve body 1, a bonnet 50 (Fig. 1) is removed from the valve body 1, and the parts of the clamp are assembled into a complete unit as shown in Figs. 1 7 and 1 8.

Then the locknuts 63 and 63' are turned so that they may be allowed to recede from each other. The clamping plates 51 and 51' are pushed in such a manner that the upper portions thereof recede from each other. Since the pressure thus applied by the locknuts 63 and 63' to the clamping plates 51 and 51' are sustained by the nuts 67 and 67', the clamping plates 51 and 51' function as levers with the nuts 67 and 67' functioning as fulcrums. Consequently, the clamping plates 51 and 51' undergo forces having such directions as to bring the fitting members 57 and 57' close to each other. Thus the ball valve 3 is clamped by the valve seat ring 11 and the valve seat ring assembly 1 2 When the bracket 64 is gripped by hooks and raised, the ball valve 3, the valve seat ring 11 and the valve seat ring assembly 12 slip out of the valve chest 2.

In order to put the ball valve 3, the valve seat ring 11 and the valve seat ring assembly 12 into the valve chest 2, these three components are incorporated in one beforehand by means of the above-described sixth embodiment of the clamp and inserted into the valve chest 2. Then the ball valve 3 is released from the clamping force which has been applied thereto by the clamp, and the clamp is detached.

Referring now to Fig. 19, the seventh embodiment of the clamp according to the present invention includes a turnbuckle 72 with a bolt 70 having a right-handed screw thread at one end and another bolt 70' having a lefthanded screw thread at the other. The outside end portions of the fulcrum bolts 70 and 70' are threaded into nuts 71 and 71' secured to the inside surfaces of the clamping plates 51 and 51', respectively. The space between the locknuts 63 and 63' is left unchanged, and the turnbuckle 72 is operated so as to press the lower ends of the clamping plates 51 and 51' toward each other.

Referring now to Fig. 20, the eighth embodiment of the clamp according to the present invention includes a turnbuckle 74 with a bolt 73 having a right-handed screw thread at one end and another bolt 73' having a lefthanded screw thread at the other. The turnbuckle 74 is operated so as to press the lower ends of the clamping plates 51 and 51' toward each other. the bracket 64 is secured to the fulcrum bolts 53.

The ninth embodiment of the clamp according to the present invention shown in Figs. 21 and 22 is applicable to any one of the abovedescribed sixth to eighth embodiments. One end portions of auxiliary plates 76 and 76' are allowed to fit in notches 75 and 75' (Figs.

16 and 21) formed in the side edges of the clamping plates 51 and 51' when it is difficult to take off the ball valve 3, the valve seat ring 11 and the valve seat ring assembly 1 2 from the valve chest 2 by means of any one of the above-described sixth to eighth embodiments because, e.g., the material to be conveyed through the ball valve 3 sticks to or is caught in a gap. Lifting bolts 78 and 78' are threaded into and through tapped holes 77 and 77' formed in the other end portions of the auxiliary plates 76 and 76'. The lower ends of the lifting bolts 78 and 78' are allowed to touch the upper surface of the valve body 1. Upload is exerted on the auxiliary plates 76 and 76' when the lifting bolts 78 and 78' are turned so as to drive them toward the valve body 1. Consequently, the clamp as a whole is pulled up.

Claims (5)

1. A top entry ball valve comprising: a valve body formed with a valve chest having an open top; a valve mounted in said valve chest so as to be removable from said valve chest via said open top; said valve body having an opposed pair of seat receiving surfaces formed thereon so as to be parallel to each other; a seat ring disposed between said valve and one of said seat receiving surfaces at the lowpressure side of the ball valve; a seat ring assembly comprising another seat ring, a belleville spring and a seat ring holder and disposed between said valve and the other of said seat receiving surfaces at the high-pressure side of the ball valve; one or both of said seat rings and said ring holder being arranged so as to allow said belleville spring to expand when said seat ring assembly is mounted in said valve chest.

2. A clamp for use with the top entry type ball valve as claimed in claim 1, comprising; a pair of clamping pieces adapted to engage on the outer periphery of said seat ring and said seat ring holder, one of said clamping pieces being adapted to engage in an annular groove formed in the outer periphery of said seat ring holder; and a fastening means for fastening said pair of clamping pieces together to bring said seat ring toward said seat ring holder while compressing said belleville spring.

3. A clamp for use with the top entry ball valve as claimed in claim 1, comprising: a clamping plate mounted on said seat ring disposed at the low-pressure side; another clamping plate mounted on said seat ring assembly disposed at the high-pressure side; said clamping plates having semicircular concaves at the lower ends, said concaves being complementary to the peripheral surfaces of said seat ring and said seat ring holder, respectively, and provided with tongues adapted to fit in annular grooves formed in the peripheral surfaces of said seat ring and said seat ring holder, respectively; a clamping bolt extending through holes formed in the upper central portions of said clamping plates; two locknuts screwed on said clamping bolt and disposed between said clamping plates; ; a pair of fulcrum bolts extending parallel with each other through holes formed in said clamping plates below said clamping bolt symmetrically about the vertical center lines of said clamping plates; and nuts screwed on both end portions of each of said fulcrum bolts projecting outwardly from said clamping plates.

4. A top entry ball valve constructed substantially as hereinbefore described with reference to the accompanying drawings.

5. Clamps for use with top entry type ball valves as claimed in claim 1, constructed and adapted to operate substantially as hereinbefore described with reference to the accompanying drawings.