JPS5827175Y2 - Valve stem free test device - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an apparatus for performing a stem-free test on a swing valve, butterfly valve, etc. while the valve remains fully open.

Conventionally, a swing valve is used as the main blocking valve in geothermal power generation turbines.

The function of the swing valve will be described below with reference to the embodiment of the present invention illustrated in the drawings.

The valve 2 and the small valve 5 are opened and closed by operating an oil cylinder (not shown) via an oil cylinder connecting lever 4 connected to a valve 2 suspended from a valve shaft 1 with a key 3. .

The valve stem 1 is supported by a bush (corresponding to bush 6.7).

In this way, the valve stem 1 needs to rotate smoothly in the bush following the movement of the oil cylinder (not shown), but the steam flowing through the valve contains impurities, which may accumulate as scale. The smooth movement of the valve stem may be hindered due to factors such as dirt, dirt, and bending of the valve stem.

If the valve shaft becomes stuck to the support bush and does not move, it will not be possible to shut off the steam flowing into the turbine, and there is a risk that the turbine will run out of control and be damaged.

In order to prevent such dangers, we regularly conduct stem-free tests in which the valve shaft is rotated to open and close the valve.

When performing such a stem-free test, the turbine output is reduced during the stem-free test in a turbine equipped with two or more main blocking valves in order to temporarily fully close the valves.

Also, for turbines equipped with only one main blocking valve, it is not possible to perform a stem-free test in which the valve is fully closed (2.

The purpose of the present invention is to solve these drawbacks and provide a mechanism or device that allows stem-free testing of the main stop valve even in a turbine equipped with only one main stop valve. shall be.

In other words, in the present invention, we have stopped the conventional method of stem-free testing in which the valve shaft was rotated to open and close the valve, and instead we tested the stem-free test by rotating the bushing that supports the valve shaft without rotating the valve shaft. A stem-free test is performed by moving the valve stem and bushing to confirm that there is no sticking between the valve stem and bushing.

The present invention will now be described in detail with reference to preferred embodiments illustrated in the accompanying drawings.

1 and 2 show a swing valve equipped with the device of the invention.

The valve seat 8 is driven into a valve chamber 9, and the valve 2 is suspended from a valve shaft 11 and opened and closed by an arm 10 to adjust the width of the steam passage formed between the valve seat 8 and the valve seat 8.

The valve stem 1 is supported by a bushing 6.7.

The stem-free test device of the present invention includes a bush 6°7, intermediate bushes 11 and 12, an outer bush 13, a bearing cover 14,
It is composed of a bracket 15, levers 16, 16, a hydraulic cylinder 19 serving as a driving device, and a piston 18.

The bushing 6.7 is screwed into the intermediate bushings 11, 12 and is integral with the intermediate bushings 11.12.

The outer bushing 13 is fixed to a bearing cover 14 and a bracket 15 by shrink fitting.

The outer bushing 13 and the intermediate bushings 11 and 12 are rotatable with respect to each other.

The intermediate bushes 11, 12 can each rotate integrally with the bush 6.7.

A lever 16 is attached to each intermediate bush by shrink fitting, and the lever 16 is connected to a hydraulic cylinder 19 by a link 17 and a connecting piece 20.

Upper and lower chambers 21.2 of the piston 18 in the hydraulic cylinder 19
2 are connected to hydraulic pressure switching valves (not shown) through oil passages so that pressure oil can be injected and discharged, respectively.

Now, operate the hydraulic switching valve to open the lower chamber 22 of the piston 18.
Pressure oil is injected into the upper chamber 21, and the pressure oil in the upper chamber 21 is discharged (discharge port 2
3. Refueling port 24), the piston will be pushed upward by hydraulic pressure.

This movement of the piston is transmitted to the intermediate bushes 11, 12 by the connecting piece 20, link 17 and lever 16.

The intermediate bushes 11, 12 rotate integrally with the bush 6.7 between the valve shaft 1 and the outer bush 13 in the direction in which the valve 2 is closed.

Conversely, when the pressure oil in the lower chamber 22 of the piston 18 is discharged and the pressure oil is injected into the upper chamber 21, the intermediate bushes 11, 1
2. Bushes 6 and 7 rotate in the direction in which valve 2 opens.

By performing this series of operations, a stem-free test can be performed to confirm that the valve stem 1 is not stuck while the valve 2 remains fully open.

Although the present invention has been described above with respect to swing valves, the present invention is generally applicable to butterfly valves in general that require a stem-free test, and also to valves that open and close by moving the valve shaft up and down, rather than by rotating the valve shaft. The present invention can be applied to all types of valves in which a stem-free test is performed by rotating or moving up and down a bush that supports a valve stem.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view of a swing valve having the device of the present invention, and FIG. 2 is a cross-sectional view thereof. 1...Valve stem, 2...Valve, 3...
・Key 4...Oil cylinder connection lever, 5...
・Small valve, 6, 7... Bush, 8... Valve seat, 9... Valve chamber, 10... Arm, 1
1゜12...Middle bushing, 13...Outer bushing, 14...Bearing cover 15...
...Bracket, 16...Lever 18...
...Piston, 19...Cylinder, 20...
...Connection piece, 21, 22...chamber.

Claims (1)

[Scope of utility model registration request] A bushing supporting the valve shaft is integrated with an intermediate bushing extending outward from these bushings, and a hydraulic mechanism for rotating the bushing via a lever connected to the intermediate bushing is disposed outside. A device that performs a stem-free test with the valve fully open.