JPH11141731A - Disassembling or remounting method of hydraulic structure of hydraulic operation type large size valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a disassembling or remounting method of a hydraulic structure of a hydraulic operation type large size valve which saves a labor and has a good operating efficiency. SOLUTION: At the time a hydraulic structure 19 for operating a valve stem 13 is disassembled from or remounted on a valve casing 10, in a hydraulic operation type large size valve arranged so that the hydraulic structure 19 is disposed at a lowest position in a upside-down state, first of all, a portal shaped jack 50 is arranged at a lower flange 23 of a yoke unit 21 in the state of a coupling for connecting the valve stem 13 and a piston rod of a hydraulic structure 19 being disassembled. This jack 50 is engaged with a coupling groove provided at a lower end of the valve stem 13 and the valve stem 13 is jack upper. Thereafter a detail structural parts provided at an upper end of a piston rod is disassembled or remounted in the state of the valve stem 13 being jack upped.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for removing or re-installing a hydraulically operated large valve hydraulic mechanism, and more particularly, to a method for removing a hydraulically operated large valve from a valve box in which the hydraulic mechanism is mounted at the lowest position in an inverted state. The present invention relates to a method for removing or reattaching a hydraulically operated large valve hydraulic mechanism suitable for removing or reattaching the hydraulic mechanism.

[0002]

2. Description of the Related Art In thermal or nuclear power plants, a large number of hydraulically operated large valves are installed in high-temperature, high-pressure steam or condensate piping. FIG. 1 shows a schematic structure of a large valve of this type. A valve seat 11 is attached to the valve box 10.
The valve body 12 moves up and down via the valve rod 13 to open and close the fluid passage 14. The fluid inlet 15 and the outlet 16 of the valve box 10 are connected to a pipe (not shown) by welding. An upper cover 1 for maintenance and inspection is provided at an upper portion of the valve box 10.
7 are provided. The lower portion of the valve stem 13 projects outside the valve box 10 via a seal portion 18, and the lower end thereof is connected to the hydraulic mechanism 1.
9 is connected to the piston rod 20.

The yoke portion 21 is a member for connecting the valve box 10 and the hydraulic mechanism 19, and includes an upper flange 22 connected to the valve box 10, a lower flange 23 connected to the hydraulic mechanism 19, and upper and lower parts thereof. It comprises a plurality of connecting members 24 connecting the flanges. The hydraulic mechanism 19 mainly includes a hydraulic unit 25 and a spring housing 26, and moves a piston rod 20 up and down by operating a piston 28 in a cylinder 27 of the hydraulic unit 25 with hydraulic pressure. The upper end of the piston rod 20 is connected to the valve stem 1 via the coupling portion 29.
3 is connected to the lower end.

A transmission member 30 and an spring 31 whose upper ends are connected to a coupling portion 29 are housed in the spring housing 26, and the spring 31 acts to constantly push the transmission member 30 downward. . Since the transmission member 30 is integrated with the piston rod 20 and the valve rod 13, when no hydraulic pressure is applied to the hydraulic unit 25, the transmission member 30 is lowered by the action of the spring 31, and as a result, the valve rod 13 and the valve The body 12 is also lowered and the valve is closed. A switch bar 32 is attached to the coupling part 29, and the other end of the switch bar 32 is connected to a switch box 33 fixed to the spring housing 26. The switch bar 32 moves up and down integrally with the piston rod 20 and the valve rod 13, and this movement activates a limit switch (not shown) built in the switch box 33, and the signal thereof controls the hydraulic circuit of the hydraulic unit 25. You.

FIG. 2 shows a detailed structure of the coupling portion 29. As shown in FIG. The upper end of the piston rod 20 is a bolt 34, and the connection ring 36
And the collar 40 are integrated with the upper end of the piston rod 20. A spacer 37 and a coupling 38 are overlapped on the connecting ring 36, and the connecting ring 36 and the spacer 38 are connected.
37, the coupling 38 and the upper end of the transmission member 30 are fastened and fixed by stud-through bolts 41. The coupling 38 is divided into two parts, and the upper part thereof is engaged with the coupling groove 39 at the lower end of the valve rod 13. With the above structure, the piston rod 20 and the valve rod 13 are connected,
It moves up and down as one. This type of hydraulically operated large valve installed in a power generation facility is huge, for example, having a diameter of 600
In the case of mm, the weight reaches about 20 tons and the total length reaches about 5 m. Also, in consideration of the convenience of disassembly, inspection and arrangement, there are overwhelmingly many cases installed in an inverted state as shown in FIG.

[0006] Meanwhile, inspection and repair of the power generation equipment are periodically performed, and inspection and repair of the above-mentioned hydraulically operated large valve are also performed at this time. In particular, the hydraulic unit 25 is detached from the valve box 10 and manufactured by the manufacturer.
After being carefully inspected and fine-tuned here, it is returned to the site and reinstalled. Hydraulic unit 25 to valve box 10
When removing the piston rod from the valve rod 13, it is necessary to separate the piston rod 20 from the valve rod 13. The procedure of the separating operation will be described with reference to FIG. First, the stud 41 is removed, and the split coupling 38 shown in FIG.
3 Remove from the coupling groove 39 at the lower end. The position of the coupling groove 39 at this time is shown by a two-dot chain line in FIG. In this state, even if the spacer 37 is to be removed, the lowermost end of the valve stem 13 becomes an obstacle and cannot be removed. Similarly, the nut 35 cannot be removed. For this reason, it is necessary to secure the gap g shown in FIG. 3 in order to remove the spacer 37 and the nut 35. By securing the gap g, the spacer 37, the nut 3
5 Piston rod 2 in order of connecting ring 36 and collar 40
The detailed components at the top end can be removed and the hydraulic unit 25 including the piston rod 20 can then be disconnected from the yoke section 21.

As a method for securing the gap g, the valve stem 1
There is no effective means other than pulling the upper part 3 upward. Conventionally, as shown in FIG. 4, first, after removing the upper lid 17 of the valve box 10, the chain block 44 is set on the hook 43 of the crane. The valve block 12 and the valve rod 13 are pulled up by the chain block 44. However, this method is troublesome as described below, and the work efficiency is extremely poor.

First, it is necessary to remove the upper lid 17.
The upper lid 17 has a diameter of about 1,300 mm and a weight of about 3 tons in the case of the above-described large valve having a diameter of 600 mm.
A great deal of labor is required for the lifting operation of the 7 itself. In addition, top cover 1
Removal of several tens of bolts fixing the 7 to the valve box 10 also requires a great deal of labor. Second, the valve element 12 and the valve rod 13
When the chain is pulled up by the chain block 44, the core of the chain block 44 and the core of the valve stem 13 often do not coincide with each other. If work is easily performed in this state, the valve stem 13 will be lifted obliquely. -There is a possibility of causing damage to the valve part 18 and the valve stem 13. For this reason, skill and meticulous adjustment are required for the alignment work for raising the valve stem 13 vertically. Third, when the upper lid 17 is opened, dust and foreign matter may enter the valve box 10 from the opening, and may cause a failure in the valve function after restoration. For this reason, it is necessary to cure the valve body 11 and the valve rod 13 so that dust and foreign matter do not enter the valve box 10 from the opening when the valve body 11 and the valve rod 13 are pulled up. Fourth, after the inspection and repair of the hydraulic mechanism 19 are completed, when re-attaching, it is necessary to remove curing, pull down the valve body 12 and the valve rod 13 and re-attach the upper lid 17 in the opposite manner to the above. is there.

[0009]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art, and to provide a method for removing or reattaching a hydraulic mechanism of a hydraulically operated large valve which requires less labor and has good work efficiency. To provide.

[0010]

According to the present invention, there is provided a method for removing or re-installing a hydraulic mechanism of a large-sized hydraulically operated valve, wherein the hydraulic mechanism for operating a valve rod is installed at the lowest position in an inverted state. When removing or re-attaching the hydraulic mechanism from the valve box of a large-type large valve, first, the coupling for connecting the valve rod and the piston rod of the hydraulic mechanism is removed, and the gate is formed on the lower flange of the yoke portion. Is arranged, the jack is engaged with the coupling groove of the valve stem, the valve stem is jacked up, and the detailed components at the upper end of the piston rod are removed or reattached with the valve stem jacked up. It is characterized by doing so.

[0011]

FIG. 5 shows an embodiment of the present invention. With the coupling 38 connecting the valve rod 13 and the piston rod 20 of the hydraulic mechanism 19 removed, a portal jack 50 is disposed on the lower flange 23 of the yoke portion 21;
This gate type jack 50 is connected to the coupling groove 39 of the valve stem 13.
And the valve rod 13 is jacked up, and the detailed components at the upper end of the piston rod 20 are removed or reattached with the valve rod 13 jacked up.

FIGS. 6 and 7 show the details. The gate-type jack 50 is engaged with a coupling groove 39 at the lower end of the valve rod 13 to sandwich the lower end of the valve rod 13, and a pair of connecting plates 5 for connecting these flat plates 51 by bolts 53.
2 and a pair of support columns 56 for supporting the flat plate 51 from below.
And a pair of portable jacks 55.

First, with the coupling 38 shown in FIG. 2 removed, a pair of flat plates 51 are applied to the coupling groove 39 to clamp the lower end of the valve rod 13. A notch 54 corresponding to the coupling groove 39 is formed in the flat plate 51 in advance. Next, the flat plates 51 are connected to each other by bolts 5 using the connecting plate 52.
Connect and fix with 3. Next, the pair of support columns 56 and the pair of portable jacks 55 are arranged below the flat plate 51 in a sufficiently contracted state, and the rod ends of the portable jacks 55 are brought into contact with the lower surface of the flat plate 51. The state at this time is the state shown in FIG. Next, the valve jack 13 is jacked up to a required height by further operating the portable jack 55. Next, the rotating nut 57 of the pair of support columns 56 is turned to extend the bolt 58 upward until the upper end plate 59 of the bolt 58 contacts the lower surface of the flat plate 51. The state at this time is the state shown in FIG.

Next, when the portable jack 55 is retracted, the load of the valve body 12 and the valve rod 13 is applied to the supporting column 56 via the flat plate 51.
To the side and the stem 13 maintains the same height. For this reason, the contracted portable jack 55 can be removed and used for other purposes. Also, by removing the portable jack 55, the work area on the lower flange 23 of the yoke portion 21 becomes somewhat larger.

Next, the work of removing the detailed components at the upper end of the piston rod is performed. First, after removing the spacer 37,
By removing the nut 35 and then removing the connecting ring 36 and the collar 40 in this order, the hydraulic unit 25 including the piston rod 20 can be separated from the transmission member 30 and pulled out of the spring housing 26. The extracted hydraulic unit 25 is transported from the site to a manufacturing maker to perform predetermined inspection and repair. During this time, the valve body 12 left on the valve body side
And the valve stem 13 maintains the jack-up state by the portal jack 50 as it is.

The hydraulic mechanism 19 that has been inspected and repaired is mounted again in the reverse order. That is, the piston rod 20 is inserted into the internal space of the transmission member 30 from below,
In the following, color 40, connecting ring 36, nut 35, space
The detailed parts are mounted in the order of Ser. The pair of portable jacks 55 are arranged below the flat plate 51 in a sufficiently contracted state, and the rod end of the portable jack 55 is brought into contact with the lower surface of the flat plate 51 to reduce the load of the valve body 12 and the valve rod 13 to the flat plate 51.
Is moved to the portable jack 55 side via. Next, the bolts 58 are sufficiently shortened downward by turning the rotating nuts 57 of the pair of support columns 56 of the gate jack 50 in the downward direction.
Next, by shortening the portable jack 55,
The flat plate 51 receiving the load of the valve body 12 and the valve rod 13 also descends, and engages with the flat plate 51 to integrate the valve body 12 and the valve rod 1.
3 also falls at the same time.

When the lowering operation of the gate jack 50 is continued and the sheet of the valve body 12 comes into contact with the valve seat 11, the valve body 1
2. The lowering of the valve stem 13 and the flat plate 51 integrated therewith is stopped. Accordingly, by continuously performing the downward shortening operation of the portable jack 55, the tip of the rod of the portable jack 55 is separated from the lower surface of the flat plate 51.
At this stage, the portable jack 55 and the support column 56 can be removed from above the lower flange 23. Next, the bolt 53 of the connecting plate 52 connecting the pair of flat plates 51 is removed, and the flat plate 51 is removed from the coupling groove 39 of the valve stem 13. Thereafter, the coupling portion 29 is connected by the coupling 38, and the reattachment operation is completed.

According to the above-described embodiment, the hydraulic mechanism 19 can be removed and reattached without removing the upper lid 17 of the large valve, so that the working efficiency is high. In addition, foreign matter can be prevented from entering the valve box 10 from the opening caused by removing the upper lid 17, and curing of the opening is not required.

The portal jack 50 of the above embodiment is mainly composed of independent members of the flat plate 51, the supporting column 56, and the portable jack 55. However, the invention is not limited to this. For example, the supporting column 56 has a jack function. In this case, the use of the portable jack 55 may be omitted. Further, a portal type jack in which these members are integrated may be used.

[0020]

According to the present invention, it is possible to reduce the time and labor required for a hydraulically operated large valve valve box which is installed upside down with the hydraulic mechanism for operating the valve rod at the lowest position, and the hydraulic efficiency is improved. Removal or reattachment of the mechanism can be performed.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a schematic structure of a large hydraulically operated valve.

FIG. 2 is a cross-sectional view showing a detailed structure of a coupling portion of a large hydraulically operated valve.

FIG. 3 is a cross-sectional view showing a state where a coupling part of a large hydraulically operated valve is removed.

FIG. 4 is a sectional view showing a state of removal or re-attachment of a hydraulic mechanism according to the related art.

FIG. 5 is a sectional view showing an outline of an embodiment of the present invention.

FIG. 6 is a cross-sectional view showing a state of removing the coupling unit according to the embodiment of the present invention.

FIG. 7 is a view taken in the direction of arrows AA in FIG. 6;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Valve box 11 ... Valve seat 12 ... Valve element 13 ... Valve stem 17 ... Upper lid 19 ... Hydraulic mechanism 20 ... Piston rod 21 ... Yoke part 23 ... Lower flange 29 ... Cup Ring part 38 Coupling 39 Coupling groove 50 Gate type jack

Claims (1)

[Claims] When removing or re-attaching the hydraulic mechanism from a valve box of a hydraulically operated large valve installed in an inverted state with the hydraulic mechanism for operating the valve stem at the lowest position, first, the valve stem and With the coupling connecting the piston rod of the hydraulic mechanism removed, a portal-type jack is arranged on the lower flange of the yoke part, and this jack is engaged with the coupling groove of the valve stem to remove the valve stem. A method for removing or reattaching a hydraulically operated large valve hydraulic mechanism, wherein a detailed component at the upper end of the piston rod is removed or reattached in a state in which the valve is jacked up and the valve stem is jacked up.