JP3604086B2 - Valve structure - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a gate valve and a globe valve in which a fluid to be handled has toxic or flammable properties and is required to prevent leakage from the valve. More particularly, the present invention relates to a valve stem and a valve stem with improved maintainability. The present invention relates to a valve structure capable of preventing a screw portion from being exposed to wind and rain and completely preventing external leakage of a fluid.
[0002]
[Prior art]
In the case of a gate valve or a globe valve, the handle is turned to open or close the valve. At this time, it is necessary to prevent the valve stem connected to the handle from rotating together. FIG. 8 shows a method of attaching a rotation preventing detent to the valve stem as a conventional structure in which the valve stem is prevented from rotating during valve operation. FIG. 9 shows another structure in which a side surface of a valve body typified by a gate valve has a square convex or concave shape, a square guide is opened on the inner surface of the valve box, and a convex shape machined on the side surface of the valve body. Alternatively, the concave shape is fitted into the rectangular guide of the valve box, and the rotation of the valve stem is prevented at the connection between the valve stem and the valve body, and the rotation reaction force is transmitted to the valve body. The structure which prevented is shown.
[0003]
FIG. 10 shows a structure in which the valve stem is prevented from being exposed to the elements by covering with a bellows-like boot.
[0004]
By the way, in the rotation preventing structure shown in FIG. 9, a convex or concave rectangular guide is formed on the inner surface of the valve box and the side surface of the valve body by a method typified by a gate valve, and is processed on the side surface of the valve body. Processing is complicated by fitting a convex or concave rectangular guide into the rectangular guide of the valve box, preventing rotation of the valve body with the valve box, and preventing rotation of the valve body at the connection with the valve body. Therefore, a simple structure is desired.
[0005]
On the other hand, leakage from the valve stem penetration part is generally kept airtight by using packing. For this reason, when the fluid used is toxic or flammable, it is desired to improve the reliability of the hermetic structure from the problem that external leakage occurs due to delay in retightening, forgetting to retighten, or deterioration of the packing.
[0006]
[Problems to be solved by the invention]
In such a conventional technique, in the case of the structure shown in FIG. 8, since the rotation preventing detent 12 is attached to the valve stem 11, the detent 12 is integrally formed with the lifting and lowering of the valve stem 11 during the valve operation. Raises and lowers, a space for raising and lowering the detent 12 is required, and there is a problem that the total length of the valve becomes longer. Further, in order to prevent the valve stem 11 from being exposed to the elements, it is necessary to cover the entire valve or to attach a cover such as a bellows-shaped boot covering the valve stem on the upper and lower surfaces of the detent 12. There is an inconvenience that is also disadvantageous economically.
[0007]
In FIG. 9, since the side surface 21 of the valve body is formed into a square convex or concave shape, complicated processing such as milling or Zeiper processing is required. Further, the valve box 22 can be machined to a guide length which does not come off when the valve body 23 moves up and down by a valve operation with a rectangular guide 24 in which the side surface of the valve body 23 is formed into a convex or concave shape. Required.
[0008]
The rectangular guide processing of the valve box 22 guides the lifting and lowering of the valve element 23 with respect to the convex or concave shape formed on the side surface 21 of the valve element, and prevents the valve element 23 from rotating. Like the convex or concave processing of the side surface 21, complicated processing such as milling or Zeper processing is required. For this reason, the method of fitting into the convex or concave rectangular guide 24 shown in FIG. 2 to prevent the guide and rotation of the valve body 23 is particularly effective in a small-diameter valve having a small processing space, in which the guide section between the valve body and the valve box is provided. Has a complicated structure and is economically disadvantageous.
[0009]
FIG. 10 shows a structure in which the valve stem 31 is simply prevented from being exposed to the elements by the bellows-like boot 32. Leakage from the valve stem penetration portion is kept airtight only by the packing 33. Therefore, it is possible to retighten the packing 33, but there is a problem that external leakage occurs due to a delay in the retightening execution time, forgetting to retighten, or deterioration of the packing.
[0010]
As described above, in the connection structure between the valve box and the valve lid that has been conventionally used, even if the flange type is a seal welding type and external leakage from the flange portion can be prevented, leakage from the packing portion occurs. Can also be expected. That is, it was difficult to prevent leakage of the fluid to the outside. Further, even if a cover is attached with a bellows-shaped boot or the like to protect the valve stem from the weather, external leakage cannot be completely prevented when leakage from the packing portion occurs. Furthermore, if a detent is attached to the valve stem to prevent the rotation of the stem, members that cover the valve stem, such as bellows-shaped boots, are required on the upper and lower surfaces of the detent, which is disadvantageous economically. is there.
[0011]
In addition, the structure in which the rotation of the valve stem is transmitted to the valve body and fitted into a convex or concave rectangular guide formed on the side surface of the valve body on the inner surface of the valve box to prevent the rotation of the valve body with the valve box is processed. However, since it is complicated and economically disadvantageous, it is necessary to simplify the structure and make it economically advantageous.
[0012]
Therefore, the present invention has been made in view of the above circumstances, and a small and lightweight valve body can be taken out integrally with a valve stem by using a flange type as a seal welding type or an integral type, and leakage from a packing portion can be leaked to the outside. It is an object of the present invention to disclose a valve structure which is free from the elements, protects the valve stem from the elements, protects the valve stem from the weather, easily tightens the packing, and is particularly effective when the fluid to be handled is toxic or flammable. .
[0013]
[Means for Solving the Problems]
In order to achieve the above-mentioned object, in the present invention, a gate valve or a globe valve installed in a piping section of a pressure fluid and flowing or closing the flow of fluid in the piping section by opening and closing the valve is provided. The purpose is to prevent external leakage from the valve caused by installation, and to reduce the size by integrating it as an integral type or a seal welding type from the flange structure for connecting the valve box and the valve lid. I do. Specifically, a rod-shaped pin is inserted into a drilled hole formed in a valve box, a semicircular groove is formed in the valve body side, and fitted into a pin attached to the valve box. That is, since the rotation of the valve stem is prevented by the connection portion between the valve stem and the valve body, and the rotation reaction force is transmitted to the valve body, the rotation of the valve body is prevented by the valve box. The effect is that the valve stem and the valve body can be taken out without removing the valve body and the valve stem from the yoke and the valve lid.
[0014]
Further, as a means for providing a seal structure having high reliability with respect to external leakage, in the present invention, O-rings are attached to the upper and lower ends of the packing retainer, and external leakage from the outer periphery of the packing is performed by the O-rings at the lower end. The upper end is fitted into the lower end of the stem nut to prevent external leakage from the inner periphery of the packing with an O-ring. According to the valve structure by this means, the packing can be retightened, and the entire valve stem can be housed in a completely closed container, thereby exhibiting high sealing performance against external leakage. Also, the valve stem is prevented from being exposed to the weather.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. FIGS. 1 and 2 show an example of a valve element of a gate valve. A semi-circular groove 43 formed on a side surface of a valve element 42 is formed on an inner surface of a valve box 41. A partial structure for preventing the rotation of the valve body 42 (co-rotation at the time of valve operation) by inserting the pin 44 of FIG.
[0016]
In the valve box 41, drill holes are formed at two positions perpendicular to the flow at a position where the valve body 42 is accommodated in the valve box 41 at a center position of the valve rod 41 in order to insert the rod-shaped pin 44. I do. After drilling, a semicircular groove can be formed in the inner surface of the valve box 41 by processing the inner diameter to a diameter that allows the valve element 42 to be accommodated in the valve box 41, and the depth of the drill hole is adjusted by the valve element 42 and the valve seat. If it is processed deeper than the position where 45 contacts, the lower end of the rod-shaped pin 44 to be inserted into the valve box can be fixed by a drilled hole that is not processed into a semicircle.
[0017]
On the other hand, the upper part of the rod-shaped pin 44 inserted in the valve box 41 is fixed by a valve lid 47 having an inner diameter in which the valve body 42 is accommodated in the valve box 41. A semi-circular groove equal to or slightly larger than the outer diameter of the rod-shaped pin inserted into the valve box 41 is formed in the outer diameter of the valve body 42, and the semi-circular groove of the valve body 42 is inserted and fixed in the valve box 41. When fitted into the rod-shaped pin 44, the rotation of the valve rod 48 during the operation of the valve can be prevented. That is, by adopting the above-described rotation preventing structure for the valve stem 48 and the valve body connecting portion 49, the rotation reaction force is transmitted to the valve body 42, so that the rotation of the valve body 42 is prevented by the valve stem 41.
[0018]
Since the rotation prevention structure of the valve body 42 and the guide structure of the vertical movement of the valve body at the time of valve operation are formed by drilling holes, milling processing and zeper processing required for conventional square groove processing are not required, and processing is performed. The shape is simplified, which is economically advantageous. Although FIG. 4 showing this structural example is a gate valve, a similar structure can be applied to a globe valve.
[0019]
Further, in the embodiment shown in FIG. 3, a drill hole is drilled from the bottom 51 of the valve box 53, a rod-shaped pin 52 is inserted, and the drilled hole is closed by welding, so that the valve lid and the valve box have an integrated structure. The most economical structure with a valve box.
[0020]
FIG. 4 shows that the sealing structure of the valve stem 61 by the packing 61 and external leakage from the packing part are prevented, the packing 61 can be tightened, and the reliability of the external leakage is improved by covering the entire outside of the valve stem 62. 2 shows a partial structure.
[0021]
The lower end of the valve stem 62 is connected to a valve body (not shown), and by rotating the handle 63, the stem nut 64 rotates. The stem nut 64 is fitted into the yoke 65 and fixed so as not to move up and down, and the valve stem 62 is joined to the stem nut 64 with a screw. It will slide up and down, and the opening and closing operation of the valve can be performed.
[0022]
On the other hand, the valve stem 62 penetrates through the inside of the valve box, and a packing 61 for closing a gap between the penetration parts is inserted in order to prevent leakage from the penetration part. The packing 61 has a structure in which a packing holding plate 67 is pressed by a packing tightening bolt 66 and tightened via the packing holding 68 to prevent leakage from a gap in the through portion.
[0023]
However, also in this structure, the elasticity of the packing 61 is reduced due to the deterioration of the packing 61 with long-term use, and regular tightening is required to prevent leakage. In particular, when the fluid to be used is toxic or flammable, a high sealing structure is desired with respect to external leakage due to delay in the retightening of the packing 61, forgetting to retighten, or deterioration of the packing.
[0024]
Therefore, in this embodiment, O-rings are attached to the upper end portion 69 and the lower end portion 70 of the packing retainer 68 to prevent external leakage from the outer periphery of the packing at the lower end portion 70 and to prevent external leakage from the inner periphery of the packing at the upper end portion 69. Leakage can be prevented. Further, in order to make the structure capable of tightening the packing 61, the lower end 71 of the stem nut is fitted around the outer periphery of the upper end 69 of the packing retainer 68, and the gap is sealed with an O-ring. .
[0025]
Further, since the stem nut 64 covers the entire threaded portion of the valve stem 62, the valve stem 62 can be housed in a completely sealed container by closing the upper end 72 of the stem nut with the plug 73. And external leakage can be prevented.
[0026]
However, as shown in FIG. 5, the upper end 72 of the stem nut 64 is not limited to a structure in which the lid is closed with a plug 73 as a separate body. It may be a structure.
[0027]
In order to prevent external leakage from the packing, as shown in FIG. 6, an O-ring can be attached to the outer diameter 82 and the inner diameter 83 of the packing retainer 81, but the valve rod 84 can be completely covered. Because of this, the valve stem 84 may be exposed to the elements, and the outer surface of the valve stem 84 may be damaged. Therefore, when the valve stem 84 comes into contact with the seal and moves up and down during the operation of the valve stem, the seal portion is damaged by rust or damage generated on the outer peripheral surface of the valve stem 84, which is not practical.
[0028]
Further, in order to prevent the outer surface of the valve stem from being damaged, it is conceivable to attach a cover such as a bellows-like boot, but the length of the bellows-like boot is required in consideration of a work space for mounting the boot. There are disadvantages in that the overall length is lengthened and that the bellows-like boots need to be removed during the disassembly and inspection work.
[0029]
For this reason, the present invention, as in the above-described embodiment, stores the entire valve rod in a completely closed container, prevents the valve rod from being exposed to wind and rain, and prevents external leakage from the packing. And the packing can be further tightened.
[0030]
FIGS. 7A and 7B show the overall structure of the gate valve and the globe valve using the present invention. As described in the embodiment with reference to FIG. 4, the valve body 91 has a semicircular groove formed in the inner surface of the valve box, and the rod-shaped pin 72 is inserted into this groove to guide the valve rod 95 up and down. The inside diameter of the valve cover 93 is larger than the outside diameter of the valve body 91, and is set to a size that allows the valve body 91 to be inserted through the inside diameter of the valve cover 93 during assembly. Since the packing sheet 94 is screwed into the valve cover 93 by a screw, the valve body 91 and the valve stem 95 can be assembled into the valve box 96, and the packing sheet 94 can be screwed into the valve cover 93 through the valve stem 95. The packing tightening bolt 97 tightens the packing 100 by tightening the packing holding plate 98 via the packing holding 99. For this reason, the inner diameter of the packing holder 98 is made larger than the outer diameter of the packing holder 99, and the packing holder 98 and the packing holder 99 are joined by the detachable two-part ring 101.
[0031]
In the valve operation, the stem 102 is rotated by rotating the handle 102 to move the valve stem 95 up and down. For this reason, the stem nut 103 is fitted into the yoke 104, is fixed by a lock nut 105 so as not to move up and down, and the valve stem 95 is joined to the stem nut 103 by a screw. The rod 95 has a structure of sliding up and down by sliding on a screw surface. In this structure, since the outer diameter of the stem nut lower end portion 106 is equal to the outer diameter of the packing presser 99, the valve body 91 and the valve stem 95 are assembled into the valve box 96 through the inner diameter of the packing presser plate 98, and the packing sheet 94. Can be screwed into the valve lid 93 through the valve stem 95, and can be assembled through the valve stem 95 in the order of the packing 100 and the packing retainer 99. The stem nut 103 can be rotated and fitted into the upper end of the yoke 104 while being engaged with the valve stem screw portion. The stem nut 103 is fitted into the yoke 104, and the lock nut 105 is passed through the stem nut 103 and the yoke 104 is inserted. Screwing the yoke 104 and the stem nut 103 can be fixed. Therefore, the entire valve stem is housed in a completely closed container, and the packing 100 can be tightened. In disassembling and assembling the valve, the valve stem 95 can be removed without removing the valve lid 93 and the yoke 104 from the valve box 96. Since the valve body 91 and the valve body 91 can be taken out, it has a structure that is easy to handle during inspection work with excellent maintainability.
[0032]
【The invention's effect】
As described above, according to the present invention, a structure that prevents external leakage, has excellent maintainability, is easy to handle during inspection work, simplifies the structure, and is economically advantageous. It is possible to provide a gate valve or a globe valve having a very good function. In particular, for a valve having a small processing space for a small-diameter valve, the most economical effect can be obtained by adopting a method of drilling a hole in the valve box and valve body guide processing.
[0033]
Since the valve body and the valve stem can be removed integrally, maintenance time can be reduced. By making the guide circular, drilling is performed. Therefore, in a small-diameter valve having a small processing space, conventional milling or zipper processing is not required, which leads to a reduction in processing time. By completely enclosing the valve stem in a sealed container, external leakage from the valve can be completely prevented and the valve stem can be protected from the weather, which is particularly effective when the fluid to be handled is toxic or flammable.
[Brief description of the drawings]
FIG. 1 is an enlarged view (longitudinal sectional view) of a lower structure showing a detent structure according to an embodiment applied to a gate valve.
FIG. 2 is a cross-sectional view of the same; FIG. 3 is an enlarged view of a lower structure (a vertical cross-sectional view) showing a modification of the embodiment;
FIG. 4 is an enlarged view (longitudinal sectional view) of the upper structure showing the external leakage structure.
FIG. 5 is an enlarged view (longitudinal sectional view) of the upper structure showing a modification of the embodiment.
FIG. 6 is an enlarged view of a main part showing a structure for preventing leakage from packing of the embodiment. [FIG. 7] (1) is an overall view applied to a globe valve, and (2) is an overall view applied to a gate valve [ FIG. 8 is an enlarged view of a main part showing a conventional detent structure. FIG. 9 is an enlarged view of a main part showing another conventional detent structure. FIG. 10 is an enlarged view of a main part showing a conventional valve stem coating structure. Figure [Explanation of symbols]
41 valve box 42 valve element 43 semicircular groove 44 detent pin 45 valve seat 47 valve lid 48 valve rod 61 packing 63 handle 64 stem nut 65 yoke 66 packing tightening bolt 67 packing holding plate 68 packing holding 69 upper end O Ring 70 Lower O-ring

Claims (4)

A semicircular groove is formed on the inner surface of the valve box by drilling, and a rod-shaped pin is inserted and fixed along the semicircular groove, and a semicircular groove is machined on the side surface of the valve body to form the semicircular groove. A stem nut is provided which is fitted with the pin inserted into the valve box, and which is fitted in a yoke of the valve box so as not to move up and down , and a valve stem joined by screws is raised and lowered by rotation of a handle, a packing interposed in the gap of the valve stem and the valve body to the outer periphery of the upper end portion of the gland that enables Zoshime with covering the valve stem is fitted into the lower end of the stem nut, the at the upper end of the packing gland An O-ring is provided between the lower end of the stem nut and an O-ring between the lower end of the packing retainer and the valve box . The valve structure according to claim 1, wherein the rod-shaped pin is inserted by drilling a hole from the bottom of the valve box. 3. The valve according to claim 1, wherein the O-ring on the upper end side of the packing retainer is provided between the O-ring and a lower end of a stem nut that covers an elevating screw portion of the valve stem, and the upper end of the stem nut is closed by a plug. Construction. 3. The valve structure according to claim 1, wherein an upper end of the stem nut is closed in advance.

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