JP3421223B2 - Gland packing unit for valves - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gland packing unit for a valve having a gland packing for sealing between an outer peripheral surface of a valve stem and an inner peripheral surface of a through hole of an upper lid through which the valve stem is inserted. Is.

[0002]

2. Description of the Related Art FIG. 14 is a vertical sectional view of a general valve having a conventional gland seal portion. In FIG. 14, reference numeral 1 denotes a valve stem having a valve plug 2 attached to the lower end thereof, which is vertically moved by an actuator connected to the upper end thereof to open and close the flow passage formed in the valve body 3. Reference numeral 15 is a stem connector that connects the valve stem 1 and the stem 16 of the actuator. The upper lid 4 attached to the valve body 3 is formed with a through hole 4A through which the valve stem 1 passes. A neck bush 5, a plurality of gland packings 6, a lantern ring 7, a plurality of gland packings 6, and a packing follower 8 are sequentially fitted into the through hole 4A.
As the gland packing 6, for example, various kinds of packing such as rubberized asbestos thread lattice knitted graphite packing and Teflon thread knitted packing are used. 9 is a packing flange,
The packing follower 8 is pressed downward by the tightening force of the nut 11 against the stud bolt 10. And
By pressing the packing follower 8 downward to compress the gland packing 6, between the inner peripheral surface of the gland packing 6 and the outer peripheral surface of the valve stem 1, and between the outer peripheral surface of the gland packing 6 and the inner peripheral surface of the through hole 4A. A surface pressure is generated between the two, and a ground seal is provided so as to prevent the fluid in the flow path from leaking to the outside.

FIG. 15 is an enlarged sectional view of a conventional gland seal portion in such a valve. In FIG. 15, an aggregate of packings including the neck bush 5, a plurality of gland packings 6, a lantern ring 7 and the like is collectively shown as a gland packing 12, and the upper lid 4 is slightly different in shape from that of FIG. It appears as a thing. However, the structure is basically the same as that of the gland seal portion of FIG. In such a gland seal portion, the gland packing 12 is regularly replaced in order to prevent fluid leakage for a long period of time.

[0004]

Since the gland seal portion in the conventional valve is constructed as described above, when replacing the gland packing 12 with a new one, first, the valve body 3 and the upper lid 4 are to be replaced. The upper lid 4 is removed from the valve body 3 by removing the bolt and the nut connecting the and. Then, the valve stem 1 is pulled out from the upper lid 4, the nut 11 is removed from the stud bolt 10, and the packing flange 9 and the packing follower 8 are removed from the upper lid 4. After that, the jig is used to pick up the gland packing 12 from the inside of the through hole 4A, and then the gland packing 12 is replaced with a new gland packing 12.

However, since the gland packing 12 has been strongly pressed into the through hole 4A for a long period of time,
There is a possibility that the gland packing 12 comes into close contact with the inner surface of the through hole 4A and is difficult to remove, and that when the new gland packing 12 is inserted into the through hole 4A, it may enter obliquely. Moreover, in order to replace the gland packing 12, it is necessary to remove the upper lid 4 and the valve stem 1 from the valve body 3, and this involves a large-scale disassembly work. Therefore, there is a problem that it takes a long time to replace the gland packing 12 on site. Furthermore, a plurality of nuts 11
At the time of tightening (two nuts 11 in this example), it was necessary to tighten the nuts 11 in a well-balanced manner in order to apply an appropriate pressing force to the gland packing 12.

The present invention has been made to solve such a problem, and an object thereof is to obtain a gland packing unit for a valve, in which the gland packing is assembled and replaced very easily and surely.

Another object of the present invention is to provide a gland packing unit for a valve, which can reduce the size of the gland seal portion, and hence the entire valve.

[0008]

A gland packing unit for a valve according to a first aspect of the present invention seals between an outer peripheral surface of a valve stem and an inner peripheral surface of a through hole of an upper lid through which the valve stem is inserted. A gland packing unit for a valve having a gland packing for, which has a cylindrical shape that can be inserted between an inner peripheral surface of the through hole and an outer peripheral surface of the valve stem, and an outer peripheral surface of the valve stem. A packing case for accommodating the gland packing in a packing accommodating portion formed on the inner peripheral surface so as to face each other at a predetermined interval, and the gland packing accommodated in the packing case are compressed in the axial direction of the valve stem. Possible cap and the gland packing of the valve stem
Apply an elastic material that presses in the axial direction to the outside of the gland packing.
Located on the side of the gland packing and the elastic surface
Between the surface facing the material and the gland packing on one end side.
Inner flange part that contacts is formed, and the elastic
A cylindrical elastic force transmission with an outer flange that contacts the material
Free movement of the reaching member along the axial direction of the valve stem
To prepare for.

A gland packing unit for a valve according to a second aspect of the present invention is located on the bottom side of the through hole.
The elastic material by contacting the elastic material.
A contact member for pressing in the axial direction of the valve stem is provided .

[0010]

[0011]

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Reference examples and embodiments of the present invention will be described below. Reference example 1. FIG. 1 is a diagram for explaining a reference example 1 of the present invention, in which the same parts as those in the conventional example of FIG.

In FIG. 1, a female screw portion 4B is formed on the inner surface of the through hole 4A of the upper lid 4, and this female screw portion 4B is formed.
The gland packing unit Y1 can be screwed on. The unit Y1 is a packing case 21.
And the cap 22 and the above-mentioned gland packing 12 are combined. Packing case 21
Has a cylindrical shape that can be inserted into the through hole 4A, an outer screw surface 21A that is screwed with the female screw portion 4B is formed on the upper outer peripheral surface thereof, and a female screw portion 21B is formed on the inner peripheral surface from above. Are formed. An inner flange portion 21C is formed at the lower end of the packing case 21, and an outer flange portion 21D is formed at the upper end. The inside of the packing case 21 above the inner flange portion 21C serves as a packing accommodating portion, and the gland packing 12 is accommodated in this accommodating portion. Seal rings 23 and 24 are attached to the outer peripheral surface of the packing case 21 and the upper surface of the outer flange 21D.

The cap 22 is formed into a cylindrical shape through which the valve stem 1 is inserted, and the outer peripheral surface of the cap 22 is fitted with a female screw portion 21B of the packing case 21.
A is formed. An outer flange portion 22B is formed on the upper end of the cap 22. Also, the cap 22
A seal ring 25 is attached to the inner peripheral surface of the.

Next, the operation will be described. First, when assembling the unit Y1 itself, the packing case 21
After inserting the gland packing 12 from above, the male screw portion 22A of the cap 22 is screwed onto the female screw portion 21B of the packing case 21. In that case, the cap 22
Is loosely screwed to prevent the gland packing 12 interposed between the lower end of the cap 22 and the inner flange portion 21C of the packing case 21 from being strongly compressed.

Unit Y assembled in this way
When assembling 1 to the upper lid 4, first, the unit Y
While passing the valve stem 1 inside 1, the male screw portion 21A of the packing case 21 is screwed onto the female screw portion 4B of the upper lid 4 to fix the packing case 21 to the upper lid 4. After that, as shown in FIG. 1, the cap 22 is strongly tightened with respect to the packing case 21, and the gland packing 12 is strongly compressed vertically between the lower end of the cap 22 and the inner flange portion 21C of the packing case 21. To do. By compressing the gland packing 12 in this way, the gap between the inner circumferential surface of the gland packing 12 and the outer circumferential surface of the valve stem 1 and the outer circumferential surface of the gland packing 12 and the inner circumferential surface of the packing case 21 are Sufficient surface pressure is generated between them to prevent fluid from leaking between them. The upper lid 4 and the packing case 21 are sealed by a seal ring 23 and a threaded portion of the female screw portion 4B and the male screw portion 21A. The seal ring 24 seals between the seal case 21 and the cap 22, and the seal ring 25 seals between the cap 22 and the valve stem 1. The unit Y1 is assembled to the valve in this way and used.

Thereafter, when replacing the packing unit Y1 assembled in this way with a new one,
The unit Y1 is removed by loosening the cap 22 to release the compression of the gland packing 12, and then rotating the packing case 21 to remove it from the upper lid 4. Then, the new unit Y1 is assembled to the upper lid 4 in the same manner as the above-described mounting work.

As described above, the reference example 1 has the gland packing 12, the packing case 21, and the cap 2.
Since the unit 2 is attached to or removed from the upper lid 4 as one unit Y1, the replacement of the gland packing 12 does not require a large-scale disassembly work for removing the upper lid 4 and the valve stem 1 from the valve body 3 as in the conventional case.
Further, it is possible to secure a replacement work space for the unit Y1 without removing the actuator for moving the valve stem 1 up and down. That is, as shown in FIG. 14, after removing the stem connector 15 that connects the stem 16 of the actuator and the valve stem 1, the stem 16 of the actuator is pushed up and the valve stem 1
Of the stems 1, 1 by pushing down
A space for exchanging the unit Y1 can be ensured during the period of time 6. As a result, the gland packing 12 can be replaced very easily in the field.

Moreover, a proper pressing force can be applied to the gland packing 12 only by tightening the cap 22 against the packing case 21, and the gland packing 12 can be properly pressed as in the conventional example shown in FIG. There is no need for the troublesome work of tightening the plurality of nuts 11 in a well-balanced manner in order to apply pressure, and there is no problem that an appropriate pressure cannot be applied to the gland packing 12 due to individual differences among workers. Therefore, the gland packing 1
Assembling and replacing 2 will be reliable.

Further, since the stud bolts 10 and the nuts 11 as in the conventional example of FIG. 15 do not project above the upper lid 4, there is an extra space above the upper lid 4, and that much space is provided.
It is possible to suppress the height of the entire valve including the actuator to be low, downsize the entire valve, and lower the center of gravity thereof. The lower center of gravity of the valve means
This is advantageous in suppressing the occurrence of vibration.

Further, by handling the gland packing 12 while being accommodated in the packing case 21, it is possible to avoid touching the gland packing 12 directly with an operator when exchanging the gland packing 12. As a result, It is possible to prevent the liquid in the valve from adversely affecting the human body. Further, the gland packing 12 can be managed in inventory in units of the unit Y1.

Reference Example 2. 2 to 4 are diagrams for explaining the second reference example of the present invention. 2 is a sectional view of a gland seal portion including the gland packing unit Y2 of Reference Example 2, FIG. 3 is a sectional view of the unit Y2, and FIG. 4 is an exploded sectional view of the unit Y2.

The unit Y2 is different from the unit Y1 of the reference example 1 described above only in the position where the seal ring 24 is provided. In the unit Y2, the seal ring 24 is attached to the outer peripheral surface of the cap 22, and the packing case 21
A seal is provided between the cap and the cap 22.
Other configurations are the same as those of the unit Y1.

In this reference example 2 , the seal ring 2 is used.
Since 4 is interposed between the inner peripheral surface of the packing case 21 and the outer peripheral surface of the cap 22, the seal ring 24 separates the packing case 21 and the cap 22 from each other regardless of how much the cap 22 is screwed into the packing case 21. The space can be sealed to reliably prevent the liquid from leaking.

Embodiment 1 . FIG. 5 is a sectional view of a gland seal portion for explaining the first embodiment of the present invention. The gland packing unit Y3 according to the first embodiment includes a spring guide (elastic force transmitting member) 31 and a coil spring (elastic material) 32 that are vertically movable inside the packing case 21 according to the first reference example of FIG. It has a configuration that incorporates.

The spring guide 31 has a cylindrical shape, an inner flange portion 31A is formed at the upper end thereof, and an outer flange portion 31B is formed at the lower end thereof. The gland packing 12 is housed between the inner flange portion 21C of the packing case 21 and the inner flange portion 31A of the spring guide 31, and the spring 32 is arranged between the outer flange portion 31B of the spring guide 31 and the lower end of the cap 22. It is housed in. Therefore, the spring 32
Is the gland packing 1 across the spring guide 31.
2 will be deployed outside. Spring guide 3
1, the valve stem 1
A seal ring 33 for sealing between the outer peripheral surface of the inner flange portion 31A and the outer peripheral surface of the inner flange portion 31A is attached.
A seal ring 34 for attaching a seal to the inner peripheral surface of the cap 22 is attached.

Next, the operation will be described. In the case of the first embodiment, when the cap 22 is screwed into the packing case 21, the upper end of the spring 32 is pressed downward by the cap 22, and the lower end of the spring 32 causes the outer flange portion 31B of the spring guide 31 to move. When pressed downward, the inner flange portion 31A of the spring guide 31 presses the gland packing 12 downward. That is, when the cap 32 is screwed in, the gland packing 12 is compressed via the spring 32 and the spring guide 31.

As described above, in the first embodiment, since the spring 32 is compressed, the compression force of the gland packing 12 is sufficiently secured, and the surface pressure on the inner peripheral surface and the outer peripheral surface of the gland packing 12 is increased. It is possible to stably suppress a decrease in the surface pressure of the sealing surface with time. Therefore, the maintenance and inspection work for maintaining the surface pressure of the sealing surface can be reduced. Further, since the spring 32 is provided in the outer peripheral portion of the gland packing 12 over the substantially entire length thereof, a sufficiently large spring 32 can be provided while suppressing an increase in the size of the unit Y3.

Embodiment 2 . FIG. 6 is a sectional view of a gland seal portion for explaining the second embodiment of the present invention. In the gland packing unit Y4 of the second embodiment, the inner peripheral surface of the cap 22 in the gland packing unit Y3 of the first embodiment shown in FIG. The upper end of the spring guide 31 is opposed. A seal ring 35 is attached to the inner peripheral surface of the cap 22 for sealing the outer peripheral surface of the valve stem 1.

In the second embodiment, the cap 22 is strongly screwed into the packing case 21 so that the lower end of the cap 22 is brought into contact with the upper end of the spring guide 31, and the gland packing is provided only through the spring guide 31. It is also possible to press 12.

Third Embodiment 7 to 9 are diagrams for explaining the third embodiment of the present invention. 7 is a sectional view of a gland seal portion including the gland packing unit Y5 of the third embodiment, FIG. 8 is a sectional view of the unit Y5, and FIG. 9 is a unit Y5.
FIG. The unit Y5 is provided at the lower end portion of the cap 22 in the unit Y4 of the second embodiment shown in FIG.
A recess 22C that fits into the upper end of the spring guide 31
Is formed.

In the third embodiment, the cap 2
By the inner peripheral surface of the concave portion 22C of 2, the spring guide 3
1 guides the vertical movement of the upper end portion of the gland packing 1 to smoothly move the spring guide 31 up and down.
2 can be pressurized efficiently and with good balance.

Fourth Embodiment FIG. 10 is a diagram for explaining the fourth embodiment of the present invention. The gland packing unit Y6 according to the fourth embodiment includes a packing case 41, a spring guide 42,
The base (contact member) 43, the gland packing 12, and the spring 32 are provided. The packing case 41 has a cylindrical shape, and an outer screw surface 41 </ b> A that is screwed into the female screw portion 4 </ b> B of the upper lid 4 is formed on the outer peripheral surface thereof. An inner flange portion 41B is formed on the upper end of the packing case 41, and a seal ring 4 for sealing between the inner peripheral surface and the outer peripheral surface of the valve stem 1 is formed.
4 is attached. A seal ring 45 is attached to the outer peripheral surface of the packing case 41 to seal the inner peripheral surface of the through hole 4A of the upper lid 4.

The spring guide 42 has a cylindrical shape that fits inside the packing case 41, and has an outer flange portion 42A formed at the upper end thereof and an inner flange portion 42B formed at the lower end thereof. The base 43 has a ring shape that fits in the stepped portion on the bottom side of the through hole 4A, and the inner peripheral surface of the packing case 41 and the spring guide 4 are provided on the upper surface of the flat plate portion 43A that is placed on the stepped portion of the through hole 4A.
An annular convex portion 43B is formed between the outer peripheral surface and the outer peripheral surface of the second convex portion 43B.

The gland packing 12 is housed between the inner flange portion 41B of the packing case 41 and the inner flange portion 42B of the spring guide 42, and the spring 3
2 is accommodated between the outer flange portion 42A of the spring guide 42 and the convex portion 43B of the base 43. Therefore, the spring 32 is arranged outside the gland packing 12 with the spring guide 42 interposed therebetween.

Next, the operation will be described. In the fourth embodiment, when the male screw portion 41A of the packing case 41 is screwed into the female screw portion 4B of the upper lid 4, the spring 32 is compressed between the spring guide 42 and the base 43, and the reaction force thereof causes the spring guide to move. The upper end of 42 is pressed upward, and the lower end of the spring guide 42 presses the gland packing 12 upward. That is, when the packing case 41 is screwed in, the gland packing 12 is pressed through the spring 32 and the spring guide 42. Therefore, the packing case 41 according to the fourth embodiment functions similarly to the cap 22 according to the first to third embodiments described above, and the spring guide 42 corresponds to the first embodiment.
Therefore, it functions similarly to the packing case 21 of the third embodiment.

As described above, in the fourth embodiment, since the spring 32 is compressed, the compression force of the gland packing 12 is sufficiently secured, and the surface pressure on the inner peripheral surface and the outer peripheral surface of the gland packing 12 is increased. It is possible to stably suppress a decrease in the surface pressure of the sealing surface with time. Therefore, the maintenance and inspection work for maintaining the surface pressure of the sealing surface can be reduced. Further, since the spring 32 is provided in the outer peripheral portion of the gland packing 12 over the substantially entire length thereof, a sufficiently large spring 32 can be provided while suppressing an increase in the size of the unit Y6. Moreover, since the compressive force is not applied to the gland packing 12 and the spring 32 until the packing case 41 is screwed into the upper lid 4, the unit Y6 can be smoothly inserted into the through hole 4A.

Fifth Embodiment 11 to 13 are diagrams for explaining the fifth embodiment of the present invention. 11 is a sectional view of a gland seal portion including the gland packing unit Y7 of the fifth embodiment, FIG. 12 is a sectional view of the unit Y7, and FIG. 13 is an exploded sectional view of the unit Y7. The unit Y7 is shown in FIG.
In the gland packing unit Y6 of the fourth embodiment, a bulging portion 43C that bulges upward facing the spring guide 42 is formed on the upper surface of the base 43.

In the fifth embodiment, the packing case 41 is strongly screwed into the upper lid 4 so that the base 4
It is also possible to bring the bulging portion 43C of No. 3 into contact with the lower end of the spring guide 42 and pressurize the gland packing 12 via the base 43 and the spring guide 42.

[0040]

As described above, according to the invention of claim 1, a packing case for accommodating the gland packing,
Since the unit configuration is equipped with a cap that compresses the gland packing in the packing case in the axial direction of the valve stem, the gland packing can be installed and removed very easily and reliably, and the gland seal part There is an effect that it is possible to reduce the size and, in turn, the size of the entire valve.

Further , since the gland packing is provided with the elastic material that presses in the axial direction of the valve stem, the compression force of the gland packing can be sufficiently secured by the pressing force of the elastic material, and the gland packing can be secured. It is possible to stabilize the surface pressures on the inner peripheral surface and the outer peripheral surface and suppress the decrease in the surface pressure of the sealing surface with time.

Further , an elastic material is provided on the outer peripheral portion of the gland packing, and the pressing force of the elastic material is transmitted to the gland packing by the cylindrical elastic force transmitting member, so that the elastic material is provided on the outer peripheral portion of the gland packing. The gland packing unit can be deployed over a range of almost the entire length, and as a result, a sufficiently large elastic material can be deployed while suppressing an increase in size of the gland packing unit.

According to the second aspect of the present invention, the elastic member is pressed by the abutting member located on the bottom side of the through hole, so that the gland packing unit can be mounted without applying a pressing force to the gland packing or the elastic material. The effect is that it can be smoothly inserted into the through hole.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a gland seal portion including a gland packing unit according to a first reference example of the present invention.

FIG. 2 is a sectional view of a gland seal portion including a gland packing unit according to a second reference example of the present invention.

3 is a cross-sectional view of the gland packing unit of FIG.

FIG. 4 is an exploded cross-sectional view of the gland packing unit of FIG.

FIG. 5 is a cross-sectional view of a gland seal portion including the gland packing unit according to the first embodiment of the present invention.

FIG. 6 is a sectional view of a gland seal portion including a gland packing unit according to Embodiment 2 of the present invention.

FIG. 7 is a sectional view of a gland seal portion including a gland packing unit according to a third embodiment of the present invention.

8 is a sectional view of the gland packing unit of FIG.

9 is an exploded sectional view of the gland packing unit of FIG.

FIG. 10 is a sectional view of a gland seal portion including a gland packing unit according to a fourth embodiment of the present invention.

FIG. 11 is a sectional view of a gland seal portion including a gland packing unit according to a fifth embodiment of the present invention.

12 is a sectional view of the gland packing unit of FIG.

13 is an exploded sectional view of the gland packing unit of FIG.

FIG. 14 is a vertical cross-sectional view of a valve having a conventional gland seal portion.

FIG. 15 is an enlarged cross-sectional view of a conventional gland seal portion.

[Explanation of symbols]

1 valve stem 2 valve plug 3 valve body 4 Upper lid 4A through hole 12 Grand packing 21 packing case 22 Cap 31 Spring guide (elastic force transmission member) 31A inner flange 31B Outer flange part 32 Spring (elastic material)

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-8-312833 (JP, A) JP-A-5-149440 (JP, A) JP-A-63-180785 (JP, A) 10864 (JP, U) Actually open 61-194867 (JP, U) Actually open 61-23584 (JP, U) Actually open 58-74651 (JP, U) Actually open 59-32782 (JP, U) Actual development Sho 55-144249 (JP, U) Actual public Sho 52-52254 (JP, Y2) (58) Fields investigated (Int.Cl. ⁷ , DB name) F16K 41/00-41/18 F16J 15/00

Claims (2)

(57) [Claims] 1. A gland packing unit for a valve, comprising a gland packing for sealing between an outer peripheral surface of a valve stem and an inner peripheral surface of a through hole of an upper lid through which the valve stem is inserted. A packing accommodating portion formed in the inner peripheral surface so as to be insertable between the inner peripheral surface of the valve stem and the outer peripheral surface of the valve stem and facing the outer peripheral surface of the valve stem at a predetermined interval. A packing case accommodating the gland packing, a cap capable of compressing the gland packing accommodated in the packing case in the axial direction of the valve stem, and a gland packing in the axial direction of the valve stem.
Elastic material to be pressed is placed outside the gland packing
Then, the facing surface between the outer peripheral surface of the gland packing and the elastic material
In between, the inner flap that abuts the gland packing on one end side
Is formed, and abuts on the other end with the elastic member.
A cylindrical elastic force transmission member having an outer flange is formed as described above.
A gland packing unit for a valve, which is movable along the axial direction of the valve stem . 2. The bullet located at the bottom side of the through hole,
The elastic material by contacting it with the elastic material.
A contact member that presses in the axial direction of the frame is provided.
The gland packing unit for the valve according to claim 1.
To.