USRE17724E - Valve - Google Patents

Description

5. J. NORDSTROM 2 Shee zs-Sheet l VALVE July 8, 19308 Original Filed Feb'. 1. 192a ATTORNEY July 8 1930. s. J. NQRDSTROM I VALVE inal Filed Feb. 1, 19 Z s-Sheet 2 ATTORNEY Reiuued (July 8, 1930.

svnn sonar nonnsrnom, or rmnmonr, camroanm, nssrenoa'ro m'nnoo-nonn- STBOM VALVE COEPANY, OF DELAWARE SAN FRANCISCO, OALIFOBNIA, A, CORPORATION OF vanvn Original 1T0. 1,634,721, dated July 5, 1927, Serial No. 85,119, :lled. Iebrnary 1, 1926. Application for reissue flied June 24, 1928. Serial No. 873,418.

The invention relates to an improvement in valves, and more particularly to an improvement in plug valves of the type in which lubricant is used for the purpose of lubricating the bearing or seating surfaces of the valve.

One object of the present invention is to provide a plug valve of this type with improved means by which the pressure under which the plug is held againstits seat may be made to var from maximum when the plug is in closed position to minimum when the plug is in open position, the pressure at all times, however, being sufficient to, hold the plug against its seat, exce t when the plug is lifted for the purpose introducing fresh lubricant between the hearing or seating surfaces. A. further ob'ect of the invense a novel valve structure which 'will tend to prevent rotation of compressible packing, when the stem is rotated. A still further objectof the invention is to provide a plug valve with means whereby the sealing packing may be renewed while the valve is in service with the plug in either open or closed position. These objects are accomplished in the improved .plug valve hereinafter fully described and particularly pointed out in the appended claims.

In the accom' anying drawings illustrating the preferre form of the invention, Fig. 1 is a lon 'tudinal section throu h the improved va ve with the plug in c osed posidrawings comprises the usual casing 5 pro-- vided with a longitudinal passageway 6 therethrou h having an inlet 7 and an outlet 8. Forme transversely of the passageway 6 in the casing 4 is a valve seat or bore 9 which is preferably tapered'and in which is seated a plug 10 having a valve stem 11 the outer end of which is squared at 12 to receive a wrench b which the plug may be turned to open an close the valve. In the plug 10 is a hole 13 adapted to register with the passageway 6 when the plug is turned to open position. The valve parts thus far described are of usual construction and mode of operation.

The means for holding the plug 10 firmly against its seat 9 comprises a flexible ring or diaphragm 14, a threaded collar 15, en-

gaging with the threads 16 formed on the base of the valve stem 11 anda ring or collar of resilient packing 17 arranged to be adjustably compressed by means of the gland 18. The construction and mode of operation of these parts are such that the plug is held against its seat with greater force when it is in closed osition than when it is in open position, but 1s at all times held against its seat with suflicient force to prevent the fluids from entering the joint between the plug 10 and the seat 9.- 1 p The diaphragm 14 is in the form of a'ring located in an annular recess 20 formed in one side of the casing 5. around the larger'end of the ta ered valve seat 9. When the plug 10 is held Fig. 1, a sli ht s ace separates the top of the plug rom t e bottom 23.0f the recess 20, which space is availed of'to secure the varying pressure with which the plug is held against its seat when it is in closed and open firmly against its seat, as shown in.

positions, as will presently be described. it

Interposed between the upper surface 23 of the recess 20 and the lower surface of the outer rim of the ring 14' is a narrow gasket- '24, and inteljaoeed between the upper surface and the outer of the ring 14and the lower surface ofthe hub part .25 of the valve cover 26 is anarrow ring gasket 27.

The valve cover 26 is secured to the casing by means of the cap screws 28 and thereby tightly holds the, ring 14 in' the recess 20 and so prevents lateral or rotative move ment thereof while permitting the inner edge or rim of the ring to travel longitudinally or axially of the valve stem 11.

The internally threaded collar 15 is integral with the inner edge of the flexible ring 14 and projects outwardly, surrounding the" the cooperating threads on thetbase of the' valve stem and the collar 15. The result is that when the plug is turnedin a counterclockwise direction through an arc of 90 from its closed position, as shown in Fig. 1, to its-open position with the hole 13 in alinement with the passageway 6 through the casing, the travel of the threads 16 on the stem 11 in the threads of the collar 15 will cause the collar 15 to move toward the plug and engage with the top surface 22 thereof when the plug reaches its open position. Thus the open position of the plug is determined by the engagement of the inner end of the collar 15 with the upper end of the p ug.

The outer end of the valve cover 26 forms with the valve stem 11 an annular space in which the ring of resilient-packing 17 is located. The outer end 32 of the packing ring 17 and the inner end 33 thereof are beveled and the inner end 34 of the gland 18 and the outer end 35 of the collar 15 are correspondingly beveled, so that as the packing 17 is compressed it fills the space between the stem 11 and the cover 26 and exerts its ressure on the outer end of the collar 15 to old the plug 10 firmly against its seat 9. The land 18 is of usual construction and is held in place on the cover 26 by means of the studs 36 and nuts 37. The amount of compresvsion exerted on the packing 17 by the gland 18 may be regulated by turning the nuts 37 in the proper direction in a clockwise direction to increase the compression and therefore the pressure exerted by the packing 17 on the collar 15, and in a counter-clockwise direction to decrease the compression and thereby lessen the pressure exerted'by the packin 17 on the collar 15. By properl regulatlng the compression of the'packing 17 the closed position of the plug 10. may be approximately determined. By turning the lug from its open to its closed position a ew times and gradually tightening down on the nuts 37 so that'when the plug reaches substantially its closed position considerable turning force is required to turn it completely into its closed position, the closed position of the plug. is approximately determined. It will thus be understood that the open posi- 14 a distance substantially 42 and tion of the plug is determined by the engagement between the inner end 30 ofthe collar 15 and the top surface of the plug and that the closed position of the plug is determined substantially positively by the adjustable compression of the packing 17. The operator readily perceives the fact that the plug is approximately in its closed position by the force required to turn the plug.

While the plug is being turned from its open to its closed position the travel of the threads 16 on the valve stem in the threads on the collar 15 causes the collar to move away from the larger end of the plug and toward the packing 17 thereby compressing the packing 17. The pressure exerted by the packing 17 upon the collar 15 is communicated to the threads 16 and so to the plug 10 to force the latter tightly against its seat 9 when the plug is turned to closed position. Under these conditions the packing 17 exerts its maximum pressure upon the plug 10. When the plug is turned from its closed to its open position the collar 15 moves from the packing 17 toward the upper end of the plug 10 and thereby lessens the compression upon the packing 17. Under these conditions the packing 17 exerts its minimum pressure upon the plug. It will be observed, however, that this pressure is sufiicient to hold the plug firmly inits seat against any tendency the fluid passing through the line may have to lift the plug from its seat.

In this type-of valve the contacting surfaces ofthe plug 10 and its seat 9, which are known as the hearing or seating surfaces of the valve, are normally held slightly separated by a thin film of lubricant which facilitates the turning of the plug and at the same time prevents foreign matter from lodging on the bearing surfaces. It is to be understood therefore that when the plug is described as held firmly against its seat, a thin film of. lubricant under normal conditions of operation separates the adjacent surfaces of the plug and its valve seat. From time to time it is necessary to renew or increase this film of lubricant by slightly increasing theamount of separation between the plug and its seat and introducing a fresh supply of lubricant between them. In the present invention the plug is separated from its seat for the purpose of lubrication (the packing 17 yielding sufficiently) by putting pressure on the supply of lubricant introduced into the chamber 39 formed between the smaller end 40 of the plug 10 and the adjacent part 41 of the valve casing. The lubricant is introduced into the chamber 39 through two channels 42 and 44 formed longitudinally in the surface of the plug 10. The upper ends of the grooves or channels communicate by the transverse hole 45 with the inner end 40fof a reservoir 47 formed axially in the valve stem 11. The

Ill

I outer end of the reservoir 47 is threaded to receive a screw 48 by which the lubricant in the reservoir may be put under pressure.

This pressure being communicated to the lubricant in the chamber 39, thereby lifts the plug 10 from-its seat and causes the lubricant in the grooves or channels 42 and 44 to ooze laterally therefrom so that when the plug is turned in either direction the excess lubricant is smeared asa thin film between the contacting, or more properly speaking, adjacent surfaces of the plug 10 and its seat 9. Backflow of lubricant through the reservoir 47 is prevented by the check valves 49 of usual construction and mode of operation.

The joint between the valve cover 26 and the casing 5 is hermetically sealed by means of the compression of the gaskets 24 and 27 by the cover 26. Leakage by way of the cooperating threads on the valve stem and collar 15 is prevented by means of the com-. pression of the packing 17 Leakage through these parts is further prevented by, introducing lubricant into them from the reservoir 47 through the radial hole 50 which I passesthrough the threads 16 and the base of the valve stem into the inner end 'of the reservoir 47 The pressure under which the lubricant in the reservoir 47 is forced into the interstices between the cooperating threads on the stem 11 and on the collar 15 surface of the outer rim of the ring 14.

thereby eifectively seals these passages against leakage. Thus it will be observed that the present invention provides a valve in which leakage from the valve outwardly is positively avoided. The sealing of the joint between the plug 10 and its seat 9 by a film of lubricant prevents leakage past the plug. when it has been turned to closed position". The packing 17 will not tend to rotate together with the stem 12, since this acking has only a minor portion of its surace area in contact with the stems Thus the outer periphery of packing 17 is pressed in contact with the stationary inner periphery'of cover 26, and the upperand lower packing faces are in frictional contact with the normally stationary gland 18 and ring 15. When the improved valve constructed as described above is assembled, the threaded collar 15 is screwed down on the threaded section 16 of the valve stem 11 until the inner end 30 of the collar 15 encounters the top surface 22 of the plug 10. The gasket 24 is then placed against the under surface of the outer rim of the flexible ring or diaphragm 14 and the gasket 27 is placed on the up or he parts are then inserted into the valve casing 5 with the plug in open position, that is, with the hole 13 therein in alinement with the passageway 6 through the casing. Inasmuch as the ring or diaphragm 14 at this time is substantially straight and parallel is in engagement with the inner end 30 of the collar 15, the plug 10 will be held raised from its seat until the packing 17 is in place and a is put under pressure by means of the gland 18. Thereupon the plug 10 is forced into its seat, the flexibility of the ring or diaphragm 14 permitting this. Under these conditions the inner end 30 of the collar 15 is still in contact with the top surface 22 of the plug. The nuts 37 are then adjusted until the compression of the packing 17 is properly regulated to permit the 'plug 10 to be turned into approximately its closed position and no more. As the plug is turning from its open to its closed position, the inner end 30 of the collar 15 leaves the top surface 22 of the plug 10, as shown in Fig. 1, and. so increases the pressure under which the plug is held against its seat.

I claim:

1. A valve comprising, a casing having a passageway therethrough, a plug seated in the casing and having a hole adapted to regof the'collar, and means for lifting the plug from its seat so that a film of lubricant may be spread between the plug and itsseat.

2. A valve comprisin a casing having a passageway therethroug a lug seated in the casing and having a hole a apted to register with the passageway, one side of the casing being provided with an annular recess above the larger end of the plug, a flexible ring seated in the recess, means for holding the outer edge of the ring tightly against the casing, an internally threaded collar mounted on the inner-edge of the ring and extending outwardly, a stem projecting outwardly from the plugland having a threaded sect-ion engaged y t e collar, :1. ring of flexible packing surroundin the stem and bearin upon the outer end of t e collar, and means or compressing the packing to determine the closed position of the plug, the open position of the lug being determined by the engagement of the inner end of the collar with the upper surface of the plug.

3. A valve comprising; a casing having a passageway therethroug a plug seated in the casin and having a hole adapted to register wit the passa ewa one side of the casing being provide wit an annular recess above the larger end of the plug, "a flexible ring located in the recess, a narrow ring gasket ocated between the outer rim of the flexible ring and the casing, a cover for the casing,

- a narrow ring gasket located between the cover and the upper surface of the outer rim 5 of the flexible ring, an internally threaded collar mounted 'on the inner edge of the flexible r1ng, the inner end of the collar and the upper end of the plug determining the open 4 position of the plug, a valve stem projectmg outwardly from the larger end of the plug and having a threaded section engaged by the collar, and means for exerting a yielding pressure on the collar to determine the closed position of the plug.

4. A valve comprisin a casing having a passageway therethroug a plug seated in the casing and having a hole adapted to register with the passageway, a valve stem projecting outwardly from the larger end of the plugsure longitudinally on the collar.

5, A valve comprising, a casing having a passageway therethrough, a plug seated in the casing, one side of the casing being provided with an annular recess, a flexible ring located within the recess, a cover for holding the outer edge of the ring tightly against the casing to prevent rotation thereof, a valve stem projecting from the larger end of the plug, the outer end of the cover surrounding the stem roviding a space for packing, resilient packing in the space supported by the exible ring and interposed between the inner end of the. packing and the larger end of the plug, means for exerting an adjustable pressure on thepacking, cooperating threads on the collar and on the valve stem whereby the pressure exerted by the packing on the collar is increased or diminished according to the direction of rotation of the plug, and means for lifting the plug from its seat against the resilient packing so that the seating surfaces may be lubricated.

6. A valve comprising, a casing having a passageway therethrough, a plug seated in the casing, one side of the casing being provided with an annular recess, a flexible ring located within the recess, a cover for holding the outer edge of the ring tightly against the casing to prevent rotation thereof, a valve stem projecting from the larger end of the plug, the outer end of the cover surrounding the stem providin a space for packing, resilient packing in t e space provided therefor, a collar supported from the flexible ring and interposed between the inner end'of the packingand the larger end of the plug, means for exerting an ad ustable pressure on the packgrovided therefor; a collar a raver.

ing, cooperating threads on the collar and on the valve stem whereby the pressure exerted by the packing on the collar is increased or diminished according to the direction of rotation of the plug, means for lifting the plug from its seat against the resilient packing so that the seating surfaces may be lubricated, and means for lubricating the cooperatin threads and the resilient packing.

A valve comprising, a casing having a passageway therethrough, a plug provided with a stem seated in the casing and having a hole adapted to register with the passageway, one side of said casing being provided with a recess through which the stem of the plug projects, a flexible ring positioned within the recess and held against rotation, a collar carried on the inner edge of said ring and surrounding the base of the valve stem, cooperating threads on the inner surface of the collar and on the base of the stem, a resilient packing'bearing upon the outer end of the collar, and means for compressing the packing. I

8. A valve comprising, a casing having a passageway therethrough, a plug seated in the casing and having a hole adapted to register with the passageway, a valve stem extending from the plug outwardly through the casing, said c-asin having an annular recess surrounding the ase of the valve stem, an annular diaphra m located in the recess,

means for holding t e outer rim of the dia- I phragm firmly against the casing, a collar supported by the inner edge of the diaphragm and surrounding the base of the valve stem, cooperating threads on the collar and the valve stem, and resilient means for exerting pressure on the collar to hold the plug against its seat, there being suflicient play between the bottom of the collar and the top of the plug to permit the plug to be turned from. closed position, through a predetermined arc to open position.

9. A valve comprising a casing or-body having a passageway therethrough, a plug rotatably disposed within the casing and having a hole adapted to register with the passageway, a member extending into the easing axially of the plug and operably connected to the same whereby the plug can be turned by rotation of the member, said member having a threaded portion, means sealed with respect to the casing and 7 having a threaded engagement with the threaded portion of said member, and common means to supply lubricant under pressure to the valve working surfaces and to said threaded en gagement for sealing the latter against leaka e.

10. A valve comprising a casing or body having a passageway therethrough, a plug rotatably disposed within the casing and having a hole adapted to register with the passageway, a member extending into the casing axially of the plug and operably connected to the same where y the plug can be turned by rotation of the member, said member having a threaded portion, a collar internally 5 threaded and engaging the threads of said member, means or supplying lubricant to said threaded engagement, and means for sealing said collar relative to the casing, said last named means permitting relative movement between the collar and easing upon rotation of said member.

11. A valve comprising a or body havin a passageway therethroug a plug rotata ly disposed within the casing and having a hole adapted to register with the passageway, one side of the casing being provided with a recess adjacent one end of the plu a flexible ring or diaphragm located wit 1n the recess, means for sealing the outer 2ov rim of the ring with respectto the casing, an internally threaded collar mounted on the inner edge of the ring, and a member rotatable for turning the plug, said member having a threaded portion engaged by the threads of the collar. v v

. 12. A valve comprising a casin or body havin a passageway therethroug a plug rotata 1y disposed within the casing and having a hole a apted to register with the pasgosageway, one side of the casing being provided with a recess adjacent one end of the I plug, a flexible ring or diaphragm located within the recess, means for sealin the outer rim of the ring with respect to t e casing,

5 an internally threaded collar mounted on the inner edge of the rin a member rotatable for turning the plug an having a threaded portion en age by the threads of the collar, and means. or supplying lubricant to said thread- 40 ed engagement.

In witness whereof, I have hereunto set my hand. SVEN JOHAN NORDSTROM.

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