US3583416A

US3583416A - Stem assembly for a valve and a method of replacing a valve stem while the valve is closed

Info

Publication number: US3583416A
Authority: US
Inventors: Edward M Nebesnik; Daniel J Ranalli
Original assignee: United States Steel Corp
Current assignee: United States Steel Corp
Priority date: 1969-08-29
Filing date: 1969-08-29
Publication date: 1971-06-08
Anticipated expiration: 1988-06-08

Abstract

A stem assembly for a valve and a method of replacing the valve stem while the valve is closed and in operative position is disclosed. The stem assembly is utilized for a gate valve having a body provided with a fluid passage through the body, a seat ring in the fluid passage and a gate disposed in the fluid passage in closed sealing engagement with the seat ring. The gate has a stem lug provided with a shoe notch. The shoe notch has a throat and a locking portion of greater width than the throat. The stem assembly has shoe means having a shoe stem and a shoe on one end of the shoe stem. The shoe has a width adapted to be inserted through the throat and into the locking portion and a length adapted upon rotation of this shoe to a locking position to engage the locking portion. A locking means is adapted to slide over the shoe stem and has a leg adapted to pass through the throat and into the locking portion to engage the shoe and the throat when the shoe is in the locking position. An outer stem member is adapted to receive the shoe stem and to engage the locking means and securing means are utilized for securing the outer stem member to the shoe stem. The method includes the steps of removing the broken stem shoe from the notch by use of one means of a burning means, a chipping means, or a drilling means; moving a shoe means having a shoe stem and a shoe on one end of the shoe stem (provided with a width less than the throat and a length greater than the throat width) into the notch so that the width passes through the throat into the locking portion; rotating the shoe means so that the length engages the locking portion; moving a locking means having a leg adapted to pass through the throat into the notch so that the leg passes through the throat and into the locking portion to engage the shoe and the throat when the shoe is in the locking position; moving an outer stem member provided with a shoe stemreceive aperture over the shoe stem and into engagement with the locking means; and securing the outer stem member to the shoe stem.

Description

United States Patent [72] Inventors Edward M. Nebesnik; The stem assembly is utilized for a gate valve having a body Daniel .I. Ranalli, both oi, Clairton, Pa. provided with a fluid passage through the body, a seat ring in [2!] Appl. No. 854,127 the fluid passage and a gate disposed in the fluid passage in [22] Filed Aug. 29, 1969 closed sealing engagement with the seat ring. The gate has a [45] Patented June 8, 197] stem lug provided with a shoe notch. The shoe notch has a [73] Assignee United States Steel Corporation throat and a locking portion of greater width than the throat. The stem assembly has shoe means having a shoe stem and a shoe on one end of the shoe stem. The shoe has a width STEM ASSEMBLY FOR A VALVE AND A METHOD adapted to be inserted through the throat and into the locking F REPLACING A VALVE STEM WHILE THE portion and a length adapted upon rotation of this shoe to a VALVEISCLOSED locking position to engage the locking portion. A locking Claims, 11 Dflwing 8 means is adapted to slide over the shoe stem and has a leg 52 user 137/15, adapted to Passlhroughthethwatandinwthelocking P 137/315 mg tion to engage the shoe and the throat when the shoe is in the l6 3 0 locking posiiion- Stem member is adapted to receive i izlrft if Search F n l/ 159 the Shoe Stem and to engage the locking means and securing 315, 382.5; 251/193, 29l; 287/!03 A, 53 H; 85/! nltieans are utilized for securing the outer stern member to the 5 0e stem. 29/40] The method includes the steps of removing the broken stem 56] R mg Cited shoe from the notch by use of one means of a burning means, a chi in means, or drillin means; movin a shoe means 1 306 I00 g fg g jgs tf PATENTS 85/] H Ux hav ir ig 5 shoe stem and a Sh( )8 on one end o f the shoe stem 1'958497 5/1934 Rivers 85/ H UX (provided with a width less than the throat and a length 2373020 4/1945 Doster 37/315 greater than the throat width) into the notch so that the width 2626:775 1/1953 Lange 37/3 I 5 x passes through the throat into the locking portion; rotating the Primary Examiner-William F. ODea Assistant Examiner David R. Matthews Attorney- Robert J. Leek, Jr.

ABSTRACT: A stem assembly for a valve and a method of replacing the valve stem while the valve is closed and in operative position is disclosed.

shoe means so that the length engages the locking portion; moving a locking means having a leg adapted to pass through the throat into the notch so that the leg passes through the throat and into the locking portion to engage the shoe and the throat when the shoe is in the locking position; moving an outer stem member provided with a shoe stem-receive aperture over.the shoe stem and into engagement with the locking means; and securing the outer stem member to the shoe stem.

e-Q 44 30 i 0 g 4/ 5-; 42 g 46a j 46 32 E jrFh/JZ 34 E 30a 28c 28c 36 76 2a 20 4a Mm 22 l2 --/4 46b Q l8 /s Q 16 W PATENTED JUN '8 l97| SHEET 2 [IF 2 FIG. 4B.

FIG. 4A.

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STEM ASSEMBLY FOR A VALVE AND A METHOD OF REPLACING A VALVE STEM WHILE THE VALVE IS CLOSED BACKGROUND OF THE INVENTION l'leretofore, when the original stem ofa gate valve ofthe rising-stem type became defective while the gate was in the closed position, it was necessary to close down the facilities served by the gate valve during the valve repair work, thereby resulting in loss of production, high labor cost, and attendant increased production cost for the shutdown facility and the product produced thereby.

OBJECTIVES OF THE INVENTION It is the general object of this invention to avoid and overcome the foregoing and other difficulties of and objections to prior art practices by the provision of an improved replacement stem assembly for a valve and an improved method of replacing the defective valve stem, which stem assembly and method:

a. permits valve stem replacement while the valve gate is in the closed position in the body of the gate valve;

b. is simple and rugged in construction; and

c. eliminates costly shutdown ofplant facilities for the valve stem replacement.

BRIEF SUMMARY OF THE INVENTION The aforesaid objectives of this invention and other objectives which will become apparent as the description proceeds are achieved by providing an improved stem assembly for a gate valve having a broken or defective stem and a method of replacing the defective stem while the gate of the valve is in the closed position.

The stem assembly is utilized for a gate valve having a body provided with a fluid passage through the body, a seat ring in the fluid passage and a gate disposed in the fluid passage in closed sealing engagement with the seat ring. The gate has a stem lug provided with a shoe notch. The shoe notch has a throat and a locking portion of greater width than the throat. The stem assembly has shoe means having a shoe stem and a shoe on one end of the shoe stem. The shoe has a width adapted to be inserted through the throat and into the locking portion and a length adapted upon rotation of this shoe to a locking position to engage the locking portion. A locking means is adapted to slide over the shoe stem and has a .leg adapted to pass through the throat and into the locking portion to engate the shoe and the throat when the shoe is in the locking position. An outer stern member is adapted to receive the shoe stem and to engage the locking means, and securing means are utilized for securing the outer stern member to the shoe stem.

The method includes the steps of removing the broken stem shoe from the notch by use of one means ofa burning means, a chipping means, or a drilling means; moving a shoe means having a shoe stem and a shoe on one end of the shoe stem (the shoe being provided with a width less than the throat width and a length greater than the shoe width) into the notch so that the shoe width passes through the throat into the locking portion; rotating the shoe means so that the shoe length engages the locking portion; moving a locking means having a leg adapted to pass through the throat into the notch so that the leg passes through the throat and into the locking portion to engage the shoe and the throat when the shoe is in the locking position; moving an outer stem member provided with a shoe stem-receive aperture over the shoe stem and into engagement with the locking means; and securing the outer stem member to the shoe stem.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS For a better understanding of this invention, reference should be had to the accompanying drawings wherein like numerals of reference indicate similar parts throughout the several views and wherein:

FIG. I is a vertical sectional view ofa gate valve showing the gate in closed position and a broken stem;

FIG. 2 is a fragmentary enlarged vertical sectional view of the improved stem assembly of the present invention and a portion of the stem lug of the valve gate;

FIG. 2A is a fragmentary cross sectional view of an alternative threaded connection between the shoe stem and the outer stem member;

FIG. 3A is a side elevational view of the shoe means of the improved stem assembly;

FIG. 3B is a side elevational view of the shoe means taken along the line 3B3B of FIG. 3A in the direction ofthe arrows;

FIG. 4A is a side elevational view of the locking means of the improved stem assembly;

FIG. 4B is a side elevational view of the locking means taken along the line 48-48 of FIG. 4A in the direction of the arrows;

FIG. 4C is a bottom view of the locking means taken along the line 4C-4C of FIG. 4A in the direction ofthe arrows;

FIG. 5 is a fragmentary side elevational view ofa portion of the shoe stem and the outer stem member, of the stem assembly;

FIG. 6 is a view similar to FIG. 2 of an alternative embodiment ofthe stem assembly;

FIG. 7 is a view similar to FIGS. 2 and 6 of another alternative embodiment ofthe stem assembly.

Although the principles of this invention are broadly applicable to valves, this invention is particularly adapted for use in conjunction with a gate valve and hence it has been so illustrated and will be so described.

DETAILED DESCRIPTION With specific reference to the form of this invention illustrated in the drawings and referring particularly to FIG. I, a gate valve is indicated generally by the reference numeral 10.

This gate valve has a body I2 (FIG. I) provided with a fluid passage 14 through the body 12; a seat ring means comprising a pair of seat rings 16 disposed in generally tapered juxtaposition in the fluid passage 14 and a wedge-shaped gate 18 disposed in the fluid passage 14 in closed sealing engagement with the seat rings 16. The gate 18 has a stem lug 20 (FIGS. I and 2) provided with a shoe notch 22 of generally inverted T- shaped cross section. The shoe notch 22 has a throat 24 of a width W (FIG. 2 and a locking portion 26 of greater width WI (FIG. 2) than the throat 24.

As shown in flG. I, the body 12 is secured to a bonnet 28 by bolts 30 and nuts 32, extending through aligned holes in a body flange 12a and a bonnet flange 2811 with a bonnet gasket 28b disposed therebetween. The upper portion of the bonnet 28 is secured to a gland 34 (with stem packing 36 disposed between the gland 34 and the upper portion ofthe bonnet 28) by a plurality of gland eyebolts 30a, extending from lugs 28c on the upper portion of the bonnet 28 through suitable holes in the gland 34. Nuts 32 secure the gland eyebolts 30a in position. A split yoke 40 is connected by bolts and nuts (not shown) at its lower end to the upper portion ofthe bonnet 28, is integrated by bolts 30 and nuts 32 and carries a yoke sleeve 4]. A yoke nut 42 is rotatable in the yoke sleeve M by means of a handwheel 44 and engages the upper threaded portion 460 of a stem 46 to reciprocate the gate I8 between the open and closed positions. A nut 32a secures the handwheel 44 to the yoke nut 42 and the stem 46 reciprocates through a clearance hole 33 in the handwheel 44.

As shown in FIG. 1 the stem 46 carries on its lower end a T- shoe 46b, which T-shoe 46b is disposed in the shoe notch 22. This stem 46 has broken adjacent the shoe notch 22 (as indicated by the broken line in FIG. I) and while the gate 18 is disposed in the closed sealing position.

It will be understood by those skilled in the art that the upper portions of the defective stem 46 may be removed after removal of the handwheel 44, the yoke 40, the gland 34, the stem packing 36 aNd the bonnet 28, thereby exposing the recessed broken portions of the T-shoe 46b in the notch 22. From a consideration of FIG. I it will be apparent that the now exposed cavity 48, adjacent the broken T-shoe 46b in the notch 22, is too small to permit direct removal of the broken T-shoe.

METHOD The method of removing the broken stem shoe 46b from the generally inverted T-shaped notch 22 in the stem lug 20 on the gate 118 while the gate 13 is in the closed sealing engagement with the seat rings I6 in the fluid passage I4 includes removing the broken stem shoe 46b (FIGS. 1, 2) from the notch 22 by use of one means of a burning means, such a an oxoacetylene torch or the like, a chipping means, such as a pneumatic chipping hammer or the like, or a drilling means, such as an automatic drill or the like, (all not shown).

Thereafter. a shoe means 50 (FIGS. 2, ISA-3B), a shoe stem 52 and a shoe 54 on one end of the shoe stem 52, which shoe 54 is provided with a width W2, FIG. 38 less than the width W of the throat 24 (FIG. 2) and a length W3 (FIGS. 2, 38) greater than the width W of the throat 24 is moved through the throat 24 so that the shoe width W2 passes through the throat 24 into the locking portion 26 of the notch 22. The shoe means 50 is then rotated in either counterclockwise or clockwise direction so that the length W3 of the shoe 54 engages the locking portion 26.

A locking means 56 (FIGS. 2, 4A-4C), having a shoe stem aperture 57 and a leg 58 adapted to pass through the throat 24 of the notch 22 is moved through the throat 24 and into a locking position to engage the shoe 54 and the throat 24 when the shoe 54 is in the locking position. Two legs 58 are shown in FIGS. 4B4C.

Thereafter, an outer stem member 60, FIGS. 2 and 5, provided with a shoe-stem receiving aperture 62 is moved over the shoe stem 52 and into engagement with a seat portion 64 (FIGS. 2, 3A-3B) on the upper portions of the locking means 56. Finally, as shown in FIG. 2, securing means, such as pins 66 are driven through registering holes 60A (FIGS. 2, and 52A (FIG. 2, 3A-3B) in the outer stem member 60 and the shoe stem 52 respectively and are peened over to secure them therein. As shown in FIGS. 2, 5, the outer stern member 60 has an upper threaded portion 60a for engagement with the yoke nut 42.

In FIG. 2A the outer stem member 60 is connected to the shoe stem 52 by a threaded connection 67 and secured thereat by a fastener, such as an allen setscrew 69 or the like.

ALTERNATIVE EMBODIMENTS It will be understood by those skilled in the art that, alternatively as shown in FIG. 6, the improved stem assembly of the present invention may be provided with an outer stem member 60 having a reduced portion 60b on one end. The reduced portion 60b carries the shoe 54. In this embodiment, the locking means 56 has registering half sections 560 adapted to be disposed about the reduced portion 60b and inserted through the throat 24 into engagement with the shoe 54. Locking securing means, such as bolts 30 and nuts 32 or the like are employed for securing the half sections 56a together. In addition, the locking means 56 may be secured to the reduced portion 600, as by an allen setscrew 68 or the like.

It will be noted from a consideration of FIG. 7 that the outer stem member 60 carries (as by welding or the like) the locking means 56 on one end, in this case the lower end. A set screw 68a or the like may be utilized to secure the locking means 56 to the shoe stem 52. Alternatively, a similar set screw 68b or the like may be employed to secure the outer stem member 66 to the shoe stem 52.

Referring now to FIG. I, it will be apparent that when the gate 18 is in the raised or open position (not shown in FIG. I) the seat ring 64 of the locking means 56 will engage a backseat bushing 76 on the upper portion of the bonnet 28 thereby permitting the replacement of the stem packing 36. I

SUMMARY OF THE ACHIEVEMENT OF THE OBJECTIVES OF THE INVENTION It will be recognized by those skilled in the art that the objects of this invention have been achieved by providing an improved replacement stem assembly for a broken stem 46 (Flg. I) of a gate valve and an improved method of removing the broken shoe stem 52 from the notch 24 of the stem lug 20 within the limited confines of the upper bonnet cavity 48 while the gate I8 is in closed sealing engagement with the seat rings 16 of the body 12. The improved stem assembly and method permit replacement of the valve stem 46 while the gate 18 is in closed position in the body 12 of the valve, is simple and rugged in construction, and eliminates costly shutdown of plant facilities during the replacement of the defective valve stem 46 by the improved stem assembly of the present inventron.

While in accordance with the patent statutes, preferred and alternative embodiments of this invention have been illustrated and described in detail, it is particularly understood that the invention is not limited thereto or thereby.

We claim:

I. For a gate valve having a body provided with a fluid passage through said body, a seat ring in said fluid passage and a gate disposed in said fluid passage in closed sealing engagement with said ring, said gate having a stem lug provided with a shoe notch, said shoe notch having a throat and a locking portion of greater width than said throat, a stem assembly havmg:

a. shoe means having a shoe stem and a shoe on one end of said shoe stem;

I. said shoe being adapted to be inserted through said throat and into said locking portion and further adapted upon rotation of said shoe to a locking position to engage said locking portion;

b. a locking means adapted to slide over said shoe stem and having a leg adapted to pass through said throat and into said locking portion to engage said shoe and said throat when said shoe is in said locking position;

c. an outer stem member adapted to receive said shoe stem and to engage said locking means; and

d. securing means for securing said outer stem member to said shoe stem.

2. The stem assembly recited in claim I wherein said securing means has a pair of registering holes in said outer stem member and said shoe stern and pin means extending through said registering holes.

3. The stem assembly recited in claim 1 wherein said securing means has a threaded connection between said outer stem member and said shoe stem.

4. The stem assembly recited in claim 3 and having a fastener extending through said outer stem member and engaging said shoe stem.

5. The stem assembly recited in claim I wherein said outer stem member has a reduced portion on one end, said reduced portion carries said shoe, said locking means has a registering half section adapted to be about said reduced portion and inserted through said throat into engagement with said shoe, and locking securing means for securing said half sections together.

6. The apparatus recited in claim 5 wherein said locking means is secured to said reduced portion.

7. The stem assembly recited in claim I wherein said outer stem member carries said locking means on one end.

8. The apparatus recited in claim 1 wherein said gate valve has a bonnet connected to said body and is provided with a back seat bushing and said locking means has a back seat engageable with said back seat bushing when said gate is open to permit repacking of said gate valve.

9. The apparatus recited in claim 7 wherein said locking means is secured to said shoe means.

10. The method of removing a broken stem shoe from a notch in a stem lug on a gate of a gate valve when said gate is in closed sealing engagement with a seat ring disposed in a fluid passage provided in a body of said gate valve, said body being provided with a limited work cavity adjacent said notch, said notch having a throat and a locking portion of greater width than said throat, said method including the steps of:

a. removing said broken stem shoe from said notch by use of one means of a burning means, a chipping means, and a drilling means;

b. moving a shoe means having a shoe stem and a shoe on one end of said shoe stem into said notch so that said width passes through said throat into said locking portion;

c. rotating said shoe means so that said shoe engages said locking portion;

d. moving a locking means having a leg adapted to pass through said throat into said notch so that said leg passes through said throat and into said locking portion to engage said shoe and said throat when said shoe is in said locking position;

e. moving an outer stem member provided with a shoe stem receiving aperture over said shoe stem ment with said locking means; and

l. securing said outer stem member to said shoe stem.

11. The method recited in claim 10 and including the step of threadably securing said outer stem member to said shoe stem.

12. The method recited in claim ll including the step of fastening said outer stem member to said shoe stem.

13. The method recited in claim 10 wherein said outer stern member has a reduced portion on one end and carries said shoe on the end of said reduced portion. and said locking means has registering half sections and including the steps of:

a. moving said half sections through said throat into said locking portion in engagement with said shoe, and

b. securing said half sections together.

14. THe method recited in claim 10 wherein said outer stem member carries said locking means on one end and includes the step of:

a. positioning said outer stem member and said locking means about said shoe stem so that said locking means secures said shoe in said locking means.

15. The method recited in claim 10 and including the step of securing said outer stem member to said shoe stem by pinning.

and into engage-

Claims

2. The stem assembly recited in claim 1 wherein said securing means has a pair of registering holes in said outer stem member and said shoe stem and pin means extending through said registering holes.
3. The stem assembly recited in claim 1 wherein said securing means has a threaded connection between said outer stem member and said shoe stem.
4. The stem assembly recited in claim 3 and having a fastener extending through said outer stem member and engaging said shoe stem.
5. The stem assembly recited in claim 1 wherein said outer stem member has a reduced portion on one end, said reduced portion carries said shoe, said locking means has a registering half section adapted to be about said reduced portion and inserted through said throat into engagement with said shoe, and locking securing means for securing said half sections together.
6. The apparatus recited in claim 5 wherein said locking means is secured to said reduced portion.
7. The stem assembly recited in claim 1 wherein said outer stem member carries said locking means on one end.
8. The apparatus recited in claim 1 wherein said gate valve has a bonnet connected to said body and is provided with a back seat bushing and said locking means has a back seat engageable with said back seat bushing when said gate is open to permit repacking of said gate valve.
9. The apparatus recited in claim 7 wherein said locking means is secured to said shoe means.
10. The method of removing a broken stem shoe from a notch in a stem lug on a gate of a gate valve when said gate is in closed sealing engagement with a seat ring disposed in a fluid passage provided in a body of said gate valve, said body being provided with a limited work cavity adjacent said notch, said notch having a throat and a locking portion of greater width than said throat, said method including the steps of: a. removing said broken stem shoe from said notch by use of one means of a burning means, a chipping means, and a drilling means; b. moving a shoe means having a shoe stem and a shoe on one end of said shoe stem into said notch so that said width passes through said throat into said locking portion; c. rotating said shoe means so that said shoe engages said locking portion; d. moving a locking means having a leg adapted to pass through said throat into said notch so that said leg passes through said throat and into said locking portion to engage said shoe and said throat when said shoe is in said locking position; e. moving an outer stem member provided with a shoe stem receiving aperture over said shoe stem and into engagement with said locking means; and f. securing said outer stem member to said shoe stem.
11. The method recited in claim 10 and including the step of threadably securing said outer stem member to said shoe stem.
12. The method recited in claim 11 including the step of fastening said outer stem member to said shoe stem.
13. The method recited in claim 10 wherein said outer stem member has a reduced portion on one end and carries said shoe on the end of said reduced portion, and said locking means has registering half sections and including the steps of: a. moving said half sections through said throat into said locking Portion in engagement with said shoe, and b. securing said half sections together.
14. THe method recited in claim 10 wherein said outer stem member carries said locking means on one end and includes the step of: a. positioning said outer stem member and said locking means about said shoe stem so that said locking means secures said shoe in said locking means.
15. The method recited in claim 10 and including the step of securing said outer stem member to said shoe stem by pinning.