Piping system, steam turbine plant, and method of cleaning piping system

1. A piping system of a steam turbine plant, comprising:

a piping member including a first pipe section including a first passage, a second pipe section including a second passage, a connection section arranged between the first pipe section and the second pipe section and including a connection passage that is configured to connect the first passage and the second passage, and a third pipe section including a third passage connected with the connection passage through an opening, the first pipe section being supplied with steam;

a steam stop valve connected with the third pipe section and in which steam supplied to a steam turbine flows; and

a turbine bypass valve connected with the second pipe section and connected with an outlet of the steam turbine, wherein

an angle made by a first central axis of the first pipe section and a second central axis of the second pipe section is larger than an angle made by the first central axis and a third central axis of the third pipe section.

2. The piping system according to claim 1 , wherein

the first central axis and the second central axis are parallel to each other.

3. The piping system according to claim 1 , wherein

the first central axis and the second central axis coincide with each other.

4. The piping system according to claim 1 , wherein

the first central axis and the third central axis are perpendicular to each other.

5. The piping system according to claim 1 , wherein

the opening is arranged above a central axis of the connection section.

6. The piping system according to claim 1 , wherein

an inlet of the steam stop valve into which the steam from the third pipe section flows is arranged above a central axis of the connection section.

7. The piping system according to claim 1 , wherein

the second pipe section is arranged above the first pipe section.

8. A steam turbine plant comprising:

the piping system according to claim 1 .

9. A method of cleaning a piping system of a steam turbine plant,

the piping system including:

a piping member including a first pipe section including a first passage, a second pipe section including a second passage, a connection section arranged between the first pipe section and the second pipe section and including a connection passage that is configured to connect the first passage and the second passage, and a third pipe section including a third passage connected with the connection passage through an opening, an angle made by a first central axis of the first pipe section and a second central axis of the second pipe section being larger than an angle made by the first central axis and a third central axis of the third pipe section;

a steam generation device connected with the first pipe section;

a steam stop valve connected with the third pipe section having had an inside cleaned and in which steam supplied to a steam turbine flows; and

a turbine bypass valve connected with the second pipe section and connected with an outlet of the steam turbine,

the method comprising the steps of:

closing the steam stop valve; and

supplying steam from the steam generation device and cleaning the first pipe section and the second pipe section.

10. The method of cleaning a piping system according to claim 9 , comprising:

conducting a test to close the steam stop valve;

closing the steam stop valve after completion of the test; and

supplying steam from the steam generation device in a state where the steam stop valve is closed and performing the cleaning.

11. The method of cleaning a piping system according to claim 9 , comprising:

conducting connection between the second pipe section and the turbine bypass valve in a state where the turbine bypass valve is disassembled; and

assembling the turbine bypass valve after the cleaning.