JPH06323106A - Pressure test method for main steam lead pipe of turbine - Google Patents

Abstract

PURPOSE:To reduce the manhours for working and manufacturing an engine frame which is required for a test on site by omitting installation of a blank cap for pressure test. CONSTITUTION:A main steam lead pipe 1 is connected to regular positions of a main stop valve/main steam control valve 4 and a turbine casing inlet 3. A pressure test jig 5 is arranged on the turbine casing inlet 3, while a pressure test cover 6 and pressure test jigs 7, 8 are arranged on the main stop valve/main steam control valve 4. A pressure test jig 9 is arranged on the main steam lead pipe 1. Water is poured into the main steam lead pipe 1 for carrying out pressure test.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used for performing a pressure resistance test of a main steam lead pipe in a main steam system of a steam turbine in which a main steam stop valve / steam control valve, a main steam lead pipe and a main steam lead pipe are connected. The present invention relates to a pressure resistance test method in which a test pressure is simultaneously applied to the inlet of a bin.

[0002]

2. Description of the Related Art Generally, welding of electric works is regulated by law. For example, for a pressure-resistant part such as a boiler for a thermal power plant for power generation and a containment container for a nuclear power plant for power generation, the welded part is the Minister of International Trade and Industry. It is stipulated that this product must be used only after it has passed the inspection and passed, and the welding inspection, etc., is performed by a designated publicly known organization.

As the inspection range, the steam turbine piping is intended for on-site welding spots having a pipe diameter of 150 mmφ or more and a pressure of 10 kg / cm ² (circumferential weld) or more. Of these, the pressure resistance test of the main steam lead pipe is a pressure resistance test performed at the site, and conventionally, as shown in FIGS. 3 and 4, both ends of the main steam lead pipe 1, that is, the main steam stop valve and steam control It is usual that a blind plug for pressure resistance test is attached to the portion connected to the valve 4 and the turbine casing inlet 3 and the main steam lead pipe 1 is used alone. FIG. 4 shows the frame 2 supporting the main steam lead pipe 1a lowered for the pressure resistance test.

[0004]

According to this prior art method, pressure-proof test blinds are attached to both ends of the main steam lead pipe 1, and the main steam lead pipe 1 is independently subjected to a pressure test. Therefore, there are the following problems.

(1) Extra work of attaching and detaching the blind plug for pressure resistance test occurs. (2) Since the blind plugs are attached to both ends of the main steam lead pipe, it is necessary to suspend the main steam lead pipe including the working space below the normal position. Extra work such as installation, removal and construction of the frame will occur.

(3) The ceiling crane is occupied for the pressure resistance test of the main steam lead pipe, which hinders the progress of the surrounding work. (4) Since the main steam lead tube is used for a local pressure resistance test, the main steam stop valve / steam control valve at both ends of the main steam lead tube and the welding connection at the turbine casing inlet are also subjected to the pressure resistance test. However, an alternative test (radiation transmission test) must be performed.

Therefore, an object of the present invention is to eliminate the installation of blind plugs for pressure test and reduce the work man-hours and frame-manufacturing man-hours required for carrying out the test at the site. It provides a pressure test method for a tube.

[0008]

In carrying out a pressure resistance test of a main steam lead pipe incorporated in a main steam system of a steam turbine, a main steam stop valve, a steam control valve, and a main steam lead according to the present invention. It is characterized in that the test pressure is simultaneously applied to the tube and the inlet of the turbine to perform the test at one time.

[0009]

The present invention is a method for simultaneously applying a test pressure to the main steam stop valve / steam control valve, the main steam lead pipe and the turbine casing inlet, and a pressure resistance test is applied to the main steam lead pipe. It is possible to omit the provision of a blind plug, and it is possible to reduce the number of man-hours required for carrying out the test. Further, it is not necessary to fabricate the frame prior to the execution of the test, and the man-hour for frame production can be reduced.

[0010]

EXAMPLE FIG. 1 illustrates the method of the present invention. The main steam lead pipe 1 is connected to the main steam stop valve / steam control valve 4 and the turbine casing inlet 3 at regular positions. A pressure resistance test jig 5 is attached to the turbine casing inlet part 3 as a main steam stop valve.
A pressure resistance test lid 6 and pressure resistance test jigs 7 and 8 are attached to the steam control valve 4. Further, a pressure resistance test jig 9 is attached to the main steam lead pipe 1.

In the figure, reference numeral 10 is a tank, 11 is a water filling pump, and 12 is a water filling main valve. FIG. 2 shows an embodiment of a pressure resistance test jig 5 used in the turbine casing inlet portion 3, which is composed of a connecting member 13 and a plug 14.

After the standard is completed as described above, a breakdown voltage test is carried out. Water-filled pump 11 stored in tank 10
Is injected into the main steam lead pipe 1, and a test pressure is applied to the entire region. Finish the test after confirming that there is no leakage at all points.

[0013]

According to the method of the present invention, in carrying out the pressure resistance test of the main steam lead pipe, it is not necessary to remove the temporary receiving frame of the main steam lead pipe as a preparatory restoration work.
It is also possible to omit the production. As a result, it is possible to reduce the work man-hours and the frame manufacturing man-hours.

Further, during the pressure resistance test of the main steam lead pipe, the ceiling crane is not occupied and the progress of the peripheral process is not hindered. Furthermore, by carrying out the pressure resistance test at the site collectively, there are no alternative test points, and the quality can be improved.

[Brief description of drawings]

FIG. 1 is a system configuration diagram for carrying out a withstand voltage test according to the present invention.

FIG. 2 is a configuration diagram showing an example of a pressure resistance test jig for a turbine casing entrance portion.

FIG. 3 is a system configuration diagram for performing a pressure resistance test by a conventional method.

FIG. 4 is a perspective view showing an example of a temporary frame structure by a conventional method.

[Explanation of symbols] 1 Main steam lead pipe 3 Turbin casing inlet 4 Steam stop valve / steam control valve 5, 7, 8, 9 Pressure resistance test jig 6 Pressure resistance test lid 11 Water filling pump

Claims (1)

[Claims] 1. A main steam stop valve, a steam control valve, a main steam lead pipe, and a turbine casing are used for conducting a pressure resistance test of a main steam lead pipe incorporated in a main steam system of a steam turbine. A pressure resistance test method characterized in that a test pressure is simultaneously applied to the inlets to perform a test at once.