JPH07280132A - Valve position indicator device for back washing valve - Google Patents

Abstract

PURPOSE:To easily detect the drop of a valve and valve rod. CONSTITUTION:Regarding a back washing valve formed out of a butterfly valve, an adjusting bolt 14 capable of free advance and retreat in the axial direction of a valve rod 10 is provided on the bottom of a valve box 9 faced to the lower edge of the rod 10. Furthermore, the bolt 14 is kept in contact with the lower edge of the valve rod 10 for the support thereof at the set position. Also, a detection pin 21 capable of free advance and retreat in the axial direction of the rod 10 is laid on the bottom of the box 9 in parallel to the bolt 14 and in contact with the lower edge of the rod 10. The positional change of the rod 10 is detected via the advance and retreat amount of the pin 21.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a valve body position indicating device for a backwash valve using a butterfly valve.

[0002]

2. Description of the Related Art FIGS. 3 to 6 show the construction of a cooling water pipe line to a turbine condenser of a power plant. 3 to 6, the cooling water pipeline for the turbine condenser 1 is the introduction pipe 2
The inflow pipe 3, the outflow pipe 4, and the discharge pipe 5 are connected to the backwash valve 6. The inflow pipe 3 communicates with one side of the turbine condenser 1 via the first valve 7a, and the outflow pipe 4 is connected to the second valve 7
It communicates with the other side of the turbine condenser 1 via b.

The backwash valve 6 is a four-port two-position switching valve composed of a butterfly valve, and the first port 6a and the second port 6b of the backwash valve 6 facing each other have an inflow pipe 3 and an outflow pipe 4, respectively. And the introduction pipe 2 and the discharge pipe 5 are connected to the other opposing third port 6c and fourth port 6d, respectively. The lower end of the introduction pipe 2 opens below the water surface, and a pump 8 and a third valve 7c are interposed in the middle thereof.

The backwash valve 6 includes a valve box 9 having a first port 6a, a second port 6b, a third port 6c and a fourth port 6d, and an axial center of a valve rod 10 disposed inside the valve box 9. It has a valve body 11 that rotates around and is configured to switch between a normal state and a backwash state by switching the position of the valve body 11. In the normal state, the introduction pipe 2 and the inflow pipe 3 communicate with each other, the outflow pipe 4 and the discharge pipe 5 communicate with each other, and in the backwash state, the introduction pipe 2 and the outflow pipe 4 communicate with each other, and the inflow pipe 3 and the discharge pipe 3 communicate with each other. 5 communicate.

The bosses 9a and 9b of the valve box 9 are bushes 12
The valve rod 10 is rotatably held via the bottom cover 13 and the boss 9b on the bottom side is closed by the bottom cover 13. The bottom cover 13 is provided with an adjusting bolt 14 that is screwed into the screw hole so as to be able to extend and retract in the axial direction of the valve rod 10.
4 makes the tip end contact the lower end surface of the valve rod 10 and
And the valve body 11 is held at a predetermined position.

[0006]

In the conventional structure described above, the contact surface between the lower end surface of the valve rod 10 and the tip of the adjusting bolt 14 is worn or corroded due to long-term use, and the valve rod 10 and Since the valve element 11 shifts from the set position and falls down, the adjustment bolt 14 is appropriately adjusted to return the valve rod 10 to the predetermined position. However, if the detection of the positional deviation of the valve rod 10 is delayed, the contact between the valve body 11 and the seat portion is not performed well, the seat portion and the lining are damaged, and the valve box 9 and the valve body 11 are corroded. There was a problem.

An object of the present invention is to solve the above-mentioned problems, and an object thereof is to provide a valve body position indicating device for a backwash valve which can easily detect the depression of the valve body and the valve stem at any time. .

[0008]

In order to solve the above-mentioned problems, a valve body position indicating device for a backwash valve according to the present invention is a backwash valve comprising a butterfly valve, wherein the bottom face of the valve box has a lower end surface of a valve rod. The adjustment bolt is installed to face the valve rod so that it can move back and forth in the axial direction of the valve rod, and the adjustment bolt is brought into contact with the lower end surface of the valve rod to support the valve rod at the set position and The valve element position indicating means that can be moved back and forth in the axial direction of the valve rod is arranged parallel to the adjusting bolt and in contact with the lower end surface of the valve rod, and protrudes in the axial direction of the valve rod outside the valve box. The position change of the valve body is detected by the protrusion amount of the valve body position indicating means.

[0009]

In the above structure, when the positions of the valve rod and the valve disc in the valve box are displaced due to the abrasion of the contact surfaces of the adjusting bolt and the valve rod, the axial direction of the valve disc position indicating means that abuts the valve rod. The amount of protrusion of the valve rod changes, so that the amount of depression of the valve rod and the valve body can be detected by the displacement thereof. Then, the adjusting bolt is adjusted according to the detected amount of depression, and the valve rod and the valve body are returned to the set positions.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a valve body position indicating device for a backwash valve according to the present invention will be described below with reference to the drawings. First, FIGS.
The members that perform the same operations as those described in 1 are assigned the same reference numerals and the description thereof will be omitted.

In FIG. 1, the boss portions 9a and 9b of the valve box 9 are shown.
Holds the valve rod 10 rotatably via a bush 12, and closes the boss portion 9b on the bottom side with a bottom cover 13. The bottom cover 13 is provided with an adjusting bolt 14 that is screwed into a screw hole so as to be able to move back and forth in the axial direction of the valve rod 10, and the adjusting bolt 14 has its tip abutted against the lower end surface of the valve rod 10 so that the valve is closed. The rod 10 and the valve element 11 are held in place.

In the through hole 13a of the bottom cover 13, a detection pin 21 which constitutes a valve body position indicating means is arranged in parallel with the adjusting bolt 14, and the detection pin 21 can freely move in the axial direction of the valve rod 10. The head portion 21a is in contact with the lower end surface of the valve rod 10. The lower end side of the detection pin 21 forms an indicator 21b having a diameter smaller than that of the head 21a. The indicator 21b penetrates the pressing plate 22 fixed to the bottom cover 13 and projects to the outside of the valve box 9, and the indicator 21b may be provided with a scale or the like. Holding plate 2
2 and the head 21a of the detection pin 21 between the spring 23
The spring 23 biases the detection pin 21 toward the lower end surface of the valve rod 10. In addition, the detection pin 2
1 is kept watertight by a seal 24 arranged around the head 21a.

The operation of the above configuration will be described below. If the contact surface between the adjusting bolt 14 and the valve rod 10 is worn or corroded by the controlled fluid and the valve rod 10 and the valve element 11 fall in the axial direction of the valve rod 10 due to long-term use, The detection pin 21 abutting the lower end surface of the rod 10 is pushed out in the axial direction of the valve rod 10 against the urging force of the spring 23, and the protrusion amount of the indicator 21b protruding outside the valve box 9 changes. The amount of depression of the valve rod 10 and the valve body 11 can be detected at any time by the displacement. Then, the adjustment bolt 14 is adjusted according to the detected amount of depression, and the valve rod 10 and the valve body 11 are returned to the set positions.

FIG. 2 shows another embodiment of the present invention. Members having the same functions as those of the previous embodiment are designated by the same reference numerals and the description thereof will be omitted. In FIG. 2, a detection bolt 31 serving as a valve body position indicating means is screwed on the female screw portion 13b of the bottom cover 13, and the detection bolt 31 is provided.
Is movable in parallel with the adjusting bolt 14 and in the axial direction of the valve rod 10. The detection bolt 31 has an indicator 31a on the head side located outside the valve box 9, and an abutment pin portion 31b with a small diameter on the tip side. The contact pin portion 31b has a through hole 13c formed at the bottom of the female screw portion 13b.
And abuts on the lower end surface of the valve rod 10. Further, the contact pin portion 31b is watertightly held by the seal 32 arranged around the contact pin portion 31b.

The detection bolt 31 is used for the valve rod 1 under normal conditions.
0 is separated from the lower end surface of the valve rod 10, and only when the displacement of the valve rod 10 is detected, the contact pin portion 31b is pushed toward the lower end face of the valve rod 10 by screwing with the female screw portion 13b. Abut the lower end surface of the. In this state, the amount of protrusion of the indicator 31a in the axial direction of the valve rod 10 is measured, and the amount of displacement of the valve rod 10 is detected by comparison with a set amount or a previously measured amount. Other functions and effects are similar to the above.

[0016]

As described above, according to the present invention, the amount of protrusion of the valve body position indicating means in the axial direction changes with the variation of the valve stem, and the displacement thereof causes the valve rod and the valve body to move. The amount of depression can be detected.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a valve body position indicating device for a backwash valve according to an embodiment of the present invention.

FIG. 2 is a sectional view showing a valve body position indicating device for a backwash valve in another embodiment of the present invention.

FIG. 3 is an overall configuration diagram of a cooling water pipeline for a conventional turbine condenser.

FIG. 4 is a cross-sectional view of a conventional backwash valve.

FIG. 5 is a front view of a conventional backwash valve.

FIG. 6 is a vertical sectional view of a conventional backwash valve.

[Explanation of symbols]

 9 valve box 10 valve stem 11 valve body 13 bottom cover 14 adjustment bolt 21 detection pin 21b indicator

Claims (1)

[Claims] 1. A backwash valve comprising a butterfly valve,
An adjustment bolt is placed on the bottom of the valve box so as to face the lower end surface of the valve rod so that it can be extended and retracted in the axial direction of the valve rod, and the adjustment bolt is brought into contact with the lower end surface of the valve rod to set the valve rod. The valve body position indicating means, which is supported at the position and is movable in the axial direction of the valve stem at the bottom of the valve casing, is arranged parallel to the adjusting bolt and in contact with the lower end face of the valve stem. A valve body position indicating device for a backwash valve, characterized in that a change in the position of the valve body is detected by the amount of protrusion of the valve body position indicating means protruding outside in the axial direction of the valve rod.