JP2011021672A - Ball valve, and method of inspecting leakage in the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a ball valve in which fluid is not required to flow in a pipe at leakage inspection, and which allows the leakage inspection to be conducted easily. <P>SOLUTION: This ball valve includes a valve body 12 interposed in the midway of a pipe with fluid flowing therethrough, and having a fluid passage 11 therein, two ball valve elements 14 arranged in series in the fluid passage 11, and housed turnably in the valve body 12, to open and close the fluid passage 11, a fluid supply source 25 provided in the valve body 12 between the both ball valve elements 14, for supplying fluid into the fluid passage 11, and a connection part 24 for connecting a leakage detecting means 23 having a pressure gage 26 for detecting pressure of the fluid in the fluid passage 11. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a ball valve for controlling a flow of a fluid that is interposed in a pipe through which a fluid flows and flows in the pipe, and a method for inspecting a leak of the ball valve.

  As shown in FIG. 5, various piping systems 50 provided in a chemical plant, a power plant or the like are usually provided in the middle of a piping 51 of the piping system 50, and fluids such as gas and liquid flowing in the piping 51. A plurality of valves V1 to V4 for controlling the flow are provided. As the valves V1 to V4, a ball valve 40 as shown in FIG. 4 may be used (see Patent Document 1).

  As shown in FIG. 4, the ball valve 40 is disposed in the middle of the pipe 51 of the pipe system 50, and is disposed in the fluid passage 41 and the valve body 42 having the fluid passage 41 through which the fluid flows. In order to open and close 41, a ball valve body 44 having a through hole 43 and rotatably accommodated in the valve body 42 is provided. A ring-shaped valve seat 45 that supports the ball valve body 44 and a ring-shaped valve seal 46 that seals between the valve body 42 and the ball valve body 44 are accommodated in the valve body 42. A stem 47 extending upward is connected to the upper portion of the ball valve body 44, and a lever 48 is connected to the tip of the stem 47.

  In such a ball valve 40, the through hole 43 of the ball valve body 44 and the fluid passage 41 in the valve body 42 communicate with each other (see FIG. 4A), so that the fluid flows downstream, and the ball valve body. The supply of fluid is stopped by closing the fluid passage 41 in the valve body 42 by 44 (see FIG. 4B).

Special Table 2003-515078

  Incidentally, a leak (internal leak) may occur in the ball valve 40 due to deterioration of the valve seal 46 and the like.

  As a conventional method for inspecting a leak of the ball valve 40, a predetermined pressure is applied to the fluid passage 41 in a state where the ball valve 40 to be inspected is fully closed, and a subsequent pressure change in the fluid passage 41 or the like is used. Some of them determine whether or not a leak has occurred in the ball valve 40 (ball valve body 44). In this leak inspection method, in order to apply a predetermined pressure for leak inspection of the ball valve 40 in the fluid passage 41 of the ball valve 40, it is necessary to flow a fluid into the pipe 51, which is a very troublesome operation. Need.

  Accordingly, an object of the present invention is to provide a ball valve that does not require a fluid to flow through a pipe at the time of leak inspection and can easily execute the leak inspection.

  In order to achieve the above object, the present invention is provided in the middle of a pipe through which a fluid flows, and has a valve body having a fluid passage therein, and is arranged in series with the fluid passage for opening and closing the fluid passage. Two ball valve bodies that are rotatably accommodated in the valve body, a fluid supply source that is provided in the valve body between these ball valve bodies and supplies fluid into the fluid passage, and the fluid passage And a connecting portion for connecting a leak detecting means having a pressure gauge for detecting the pressure of the fluid inside.

  A common opening / closing operation means for opening / closing the both ball valve bodies may be provided.

  According to the present invention, in the method for inspecting a leak of the ball valve, both the ball valve bodies are fully closed, the leak detection means is connected to the connection portion, and a fluid supply source of the leak detection means is used. The fluid is supplied into the fluid passage between the ball valve bodies to increase the pressure of the fluid in the fluid passage between the ball valve bodies to a predetermined pressure, and after the predetermined time has elapsed, the leak When the pressure of the fluid in the fluid passage between the two ball valve bodies detected by the pressure gauge of the detection means is smaller than a predetermined reference value, it is determined that a leak has occurred in the two ball valve bodies. is there.

  According to the present invention, there is no need to flow a fluid into the pipe during the leak inspection, and it is possible to provide a ball valve that can easily execute the leak inspection.

FIG. 1 is a side sectional view of a ball valve according to an embodiment of the present invention, showing a fully opened state. FIG. 2 is a side sectional view of the ball valve showing a state where the leak detecting means is mounted, and shows a state where the ball valve is fully closed. FIG. 3 is a side sectional view of a ball valve according to another embodiment, showing a fully opened state. 4 (a) and 4 (b) are side sectional views of a conventional ball valve, FIG. 4 (a) shows a fully opened state, and FIG. 4 (b) shows a fully closed state. FIG. 5 is a schematic diagram of the piping system.

  Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

  As shown in FIG. 1, the ball valve 10 is provided in the middle of the piping of the piping system, and is disposed in series with the valve body 12 having a fluid passage 11 through which a fluid flows, and the fluid passage 11. In order to open and close 11, two ball valve bodies 14 having a through hole 13 and rotatably accommodated in the valve body 12 are provided. In the valve body 12, a pair of left and right ring-shaped valve seats 15 that sandwich and support each ball valve body 14 from both sides, and a pair of left and right ring shapes that seal between the valve body 12 and each ball valve body 14. The valve seal 16 is accommodated. A stem 17 extending upward is connected to an upper portion of each ball valve body 14. The ball valve 10 according to this embodiment is a floating type in which the ball valve body 14 is supported by a valve seat 15.

  The valve body 12 includes an accommodating portion 18 that accommodates the ball valve body 14, the valve seat 15, and the valve seal 16, an end connecting portion 19 that is attached to one end of the accommodating portion 18, and to which piping is connected. It has an intermediate connection part 20 that is attached to the other end and connects the other ends of the accommodating part 18. The end connection portion 19 and the intermediate connection portion 20 are attached to the housing portion 18 using bolts 21.

  The valve body 12 (the accommodating portion 18, the end connecting portion 19, and the intermediate connecting portion 20) is made of forged steel or other material. The material of the valve body 12 is determined based on the temperature of the fluid flowing in the piping (in the fluid passage 11), the pressure of the fluid flowing in the piping (in the fluid passage 11), and the like.

  Each ball valve body 14 is attached to the accommodating portion 18 of the valve body 12 so as to rotate about 90 degrees in order to open and close the fluid passage 11.

  Further, the ball valve 10 according to the present embodiment is provided on the valve body 12 (intermediate connection portion 20) between the ball valve bodies 14, and a pressure gauge 22 that detects the pressure of the fluid in the fluid passage 11 (see FIG. 1). Or a connecting portion 24 for connecting a leak detecting means 23 (see FIG. 2) to be described later. The connection portion 24 of the present embodiment is provided in a hole 24a formed through the intermediate connection portion 20 of the valve body 12, and is a plug-in connection type connector (FIG. 5) into which a plug of the pressure gauge 22 or the leak detection means 23 is inserted. Not shown). When the leak inspection is not performed, a pressure gauge 22 or a cap (not shown) is attached to the connector of the connection portion 24.

  As shown in FIG. 2, the leak detection means 23 according to this embodiment includes a fluid supply source 25 that supplies fluid into the fluid passage 11 and a pressure gauge 26 that detects the pressure of the fluid in the fluid passage 11. . The fluid supply source 25 supplies the same type of fluid that flows in the pipe (in the fluid passage 11) into the fluid passage 11. As the fluid supply source 25, an air compressor, a gas compressor, a water pump, or the like can be used.

  As shown in FIGS. 1 and 2, the ball valve 10 according to the present embodiment includes a common opening / closing operation means 27 for opening / closing the both ball valve bodies 14. The opening / closing operation means 27 according to this embodiment is rotatably connected to a lever 29 having one end connected to the stem 17 of one of the ball valve bodies 14 and the other ball valve body having the other end. The bar member 28 is rotatably connected to a lever 29 connected to the 14 stems 17. By moving the bar member 28, both ball valve bodies 14 can be simultaneously opened and closed to the same opening degree via the lever 29.

  The ball valve 10 according to the present embodiment causes the fluid to flow downstream by communicating the through hole 13 of the ball valve body 14 and the fluid passage 11 of the valve body 12 (see FIG. 1). The fluid supply is stopped by closing the passage 11 (see FIG. 2). The ball valve 10 adjusts the flow rate of the fluid to be supplied by changing the rotation angle of the ball valve body 14 in a state where the through hole 13 of the ball valve body 14 and the fluid passage 11 of the valve body 12 are communicated. It is supposed to be.

  Next, the leak inspection method of this embodiment will be described.

  A leak (internal leak) of the ball valve 10 is usually caused by deterioration of the ball valve body 14, the valve seal 16, the stem 17, and the like. Such deterioration of the ball valve body 14, the valve seal 16, the stem 17, etc. is due to the high temperature of the fluid flowing in the piping (in the fluid passage 11) and the pressure of the fluid flowing in the piping (in the fluid passage 11). High or deterioration due to lifetime (aging deterioration) occurs as a factor.

  When inspecting the leakage of the ball valve 10, first, the ball valve 10 is fully closed as shown in FIG. That is, the fluid passage 11 is closed by both ball valve bodies 14.

  Next, the pressure gauge 22 (a cap when the pressure gauge 22 is not attached to the connecting portion 24) is removed from the connecting portion 24, and the leak detecting means 23 (fluid supply source 25, pressure gauge 26) is connected to the connecting portion 24. Connecting.

  Then, a leak inspection is executed. The leak inspection is executed as follows, for example.

  First, a fluid is supplied into the fluid passage 11 between the ball valve bodies 14 by the fluid supply source 25 of the leak detection means 23, and the pressure of the fluid in the fluid passage 11 between the ball valve bodies 14 is reduced to a predetermined pressure. Increase the pressure. After a predetermined time has elapsed since the pressure of the fluid in the fluid passage 11 between the ball valve bodies 14 is increased to a predetermined pressure, the fluid passage between the ball valve bodies 14 by the pressure gauge 26 of the leak detection means 23. 11 detects the pressure of the fluid in When the pressure (detected value) of the fluid in the fluid passage 11 between the ball valve bodies 14 detected by the pressure gauge 26 is smaller than a predetermined reference value, a leak (internal leak) occurs in the ball valve 10. Judge that

  When it is determined that a leak has occurred in the ball valve 10, the entire ball valve 10 is replaced or repaired.

  According to the ball valve 10 according to the present embodiment, a valve body 12 having a fluid passage 11 inside is provided in the middle of a pipe through which a fluid flows, and the fluid passage 11 is arranged in series to open and close the fluid passage 11. For this purpose, two ball valve bodies 14 rotatably accommodated in the valve body 12 and a fluid supply source for supplying fluid into the fluid passage 11 are provided in the valve body 12 between these ball valve bodies 14. 25 and a connecting portion 24 for connecting a leak detecting means 23 having a pressure gauge 26 for detecting the pressure of the fluid in the fluid passage 11, the ball valve 10 (both ball valve bodies 14) is connected by the fluid supply source 25. The pressure of the fluid in the fluid passage 11 between the two ball valve bodies 14 is measured by the pressure gauge 26. Bets can be, it is possible to easily perform a leakage inspection of the ball valve 10.

  That is, according to the ball valve 10 according to the present embodiment, the fluid supply source 25 supplies the fluid into the fluid passage 11 between the ball valve bodies 14, so that the inside of the fluid passage 11 between the ball valve bodies 14. Since a predetermined pressure for leak inspection of the ball valve 10 can be applied to the pipe 51, it is not necessary to flow a fluid into the pipe 51 during the leak inspection.

  Further, since the common opening / closing operation means 27 for opening / closing both the ball valve bodies 14 is provided, both the ball valve bodies 14 can be simultaneously opened / closed to the same opening degree by the common opening / closing operation means 27. It is possible to open and close both ball valve bodies 14 by a single operation.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above embodiments, and various other embodiments can be adopted.

  For example, the opening / closing operation means 27 is not limited to that of the above embodiment. For example, as shown in FIG. 3, the opening / closing operation means 30 includes a housing 31 provided at the top of the valve body 12 and a gear (in the illustrated example, a bevel gear) 32 mounted on the stem 17 of each ball valve body 14. And a shaft member 33 rotatably supported by the housing 31, and a drive gear (bevel gear in the illustrated example) 34 that is attached to the shaft member 33 and meshes with each gear 32. . By rotating the shaft member 33, both ball valve bodies 14 can be simultaneously opened and closed to the same opening degree via the drive gear 34 and the gear 32. By using such an opening / closing operation means 30, the opening degree (rotation angle) of each ball valve element 14 can be adjusted accurately, and the flow rate of the fluid flowing in the fluid passage 11 can be accurately controlled. It becomes possible.

  The ball valve 10 is not limited to a floating type. For example, the ball valve 10 may be a trunnion type that supports a ball valve body using a trunnion.

DESCRIPTION OF SYMBOLS 10 Ball valve 11 Fluid passage 12 Valve body 14 Ball valve body 23 Leak detection means 24 Connection part 25 Fluid supply source 26 Pressure gauge 27 Opening / closing operation means 30 Opening / closing operation means

Claims (3)

  A valve body interposed in the middle of a pipe through which a fluid flows, and having a fluid passage therein, is arranged in series with the fluid passage, and is rotatably accommodated in the valve body to open and close the fluid passage. Two ball valve bodies, a fluid supply source for supplying a fluid into the fluid passage, and a pressure gauge for detecting the pressure of the fluid in the fluid passage. A ball valve comprising a connecting portion for connecting a leak detecting means.   2. The ball valve according to claim 1, further comprising a common opening / closing operation means for opening / closing the both ball valve bodies. In the method for inspecting a leak of the ball valve according to claim 1 or 2,
The ball valve bodies are fully closed, and the leak detection means is connected to the connection portion.
A fluid is supplied to the fluid passage between the ball valve bodies by the fluid supply source of the leak detection means, and the pressure of the fluid in the fluid passage between the ball valve bodies is increased to a predetermined pressure.
When the pressure of the fluid in the fluid passage between the ball valve bodies detected by the pressure gauge of the leak detection means after a predetermined time has passed is smaller than a predetermined reference value, the both ball valve bodies leak. This is a ball valve leak inspection method.

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