JP2005114116A - 2-way ball valve - Google Patents

Abstract

[PROBLEMS] To prevent valve operation torque from increasing with a relatively simple structure and to be able to face even when the pressure on the secondary side is higher than the primary side or the flow direction of the fluid changes. Provides a two-way ball valve.
A clearance between a valve body and a ball plug is sealed by a primary side seat ring and an O ring, and the primary flow path and a ball cavity are blocked in a fully open state or an intermediate opening state. When switched to the fully closed state, the primary fluid pressure rises, so that the O-ring 26 is elastically deformed in the diameter-expanding direction by the fluid pressure, and a gap G ₁ is generated between the O-ring 26 and the annular groove 30. When the gap G ₁ is generated, the primary flow path 5A and the ball cavity 6 communicate with each other through the gap Go-G ₁ -G, and the pressure in the ball cavity 6 is equalized with the primary fluid pressure.
[Selection] Figure 2

Description

  The present invention relates to a two-way ball valve including a spherical ball plug having a through channel, and more particularly to a floating type two-way ball valve.

  As a valve used to control various fluids, for example, a cooling medium for air conditioning, a two-way ball valve is conventionally known. This type of two-way ball valve can be broadly classified according to the ball plug support system: a floating type that is rotatably supported by a pair of seat rings and a trunnion type that is rotatably supported by a valve shaft There are two types. In the floating type, since the ball plug receives the primary fluid pressure and is pressed against the secondary seat ring when fully closed, the seal is mainly achieved by contact between the ball plug and the secondary seat ring. On the other hand, the trunnion type adopts a structure in which both ends of the trunnion are pivotally supported by holes provided in the valve body, so that the ball seat plug is closed by the primary side fluid pressure when fully closed compared to the floating type. For this reason, the seal is usually achieved by contact between the ball plug and the primary side seat ring. Of these, the present invention particularly relates to the former floating type two-way ball valve.

In a floating type two-way ball valve, there are two main factors that increase the operating torque of the valve. The first factor is the degree of variation in dimensions of parts such as the valve body, ball plug, and seat ring. That is, if the degree of variation is large, the frictional force between the parts inevitably increases, so that the valve operating torque increases.
The second factor is a pressure difference generated between the primary fluid pressure and the pressure in the ball cavity when the valve is fully closed. That is, when the valve is closed, the primary side fluid pressure differs from the pressure in the ball plug and the ball cavity, and a differential pressure is generated. Since this differential pressure is usually high on the primary side, the ball plug is pressed against the secondary side seat ring. As a result, the operating torque of the valve increases as compared to when the valve is fully open or at an intermediate opening.

Then, as a prior art which solves such a problem, the ball valve described in patent documents 1 and 2, for example is known. The applicant has not been able to find prior art documents closely related to the present invention by the time of filing other than the prior art documents specified by the prior art document information described in this specification.
JP 2003-113948 A JP 11-218240 A

  The two-way ball valve disclosed in Japanese Patent Application Laid-Open No. 2003-113948 supports a ball valve body that is also incorporated in a valve body so as to be rotatable by a pair of seat rings, and each seat ring and the inner wall of the valve body The gap is sealed with an O-ring.

  The ball valve disclosed in Japanese Patent Application Laid-Open No. 11-218240 includes a valve casing that forms a primary side flow path and a secondary side flow path, and a ball plug that is incorporated in the valve casing via a pair of seat rings. And a means for rotating the ball plug, and forming a valve hole that allows the primary side channel and the secondary side channel to communicate with each other at a non-facing position. A space that does not communicate with the secondary flow path is formed on the opposite side of the primary flow path, and a fluid difference between the primary side and the secondary side is introduced by guiding and introducing the fluid of the primary flow path into this space. The ball plug can be reliably operated without increasing the opening / closing operation torque even when the pressure is large or the diameter is large.

  The ball valve described in Japanese Patent Laid-Open No. 2003-113948 obtains a reliable seal by elastic deformation of the O-ring, so there is no need to increase the dimensional accuracy of the parts, and the first factor described above However, the second factor could not be dealt with at all, and there was still room for improvement. Further, there is a problem that even when the pressure on the secondary side is higher than that on the primary side, or when the flow direction of the fluid changes (when there is a possibility of backflow), it cannot be opposed at all.

The ball valve disclosed in Japanese Patent Application Laid-Open No. 11-218240 has a problem that although the second factor can be eliminated, the first factor cannot be dealt with at all. In addition, since it is necessary to form an L-shaped valve hole in the ball plug, the valve casing needs to be manufactured in a special shape when it is attached in the middle of a straight pipe.
Further, like the ball valve described in Japanese Patent Application Laid-Open No. 2003-113948, there is a problem that the pressure cannot be opposed at all when the pressure on the secondary side becomes higher than the primary side or the flow direction of the fluid changes. It was.

  The present invention has been made to solve the above-described conventional problems, and the object of the present invention is to solve the first and second factors at the same time with a relatively simple structure and to operate torque. Another object of the present invention is to provide a two-way ball valve that can reduce the pressure of the secondary side and can cope with a case where the pressure on the secondary side is higher than that on the primary side or the flow direction of the fluid changes.

  In order to achieve the above object, a first invention includes a valve body in which a primary flow path, a secondary flow path, and a ball cavity positioned between both flow paths are formed, and the ball cavity. A ball plug that is rotatably incorporated in a primary side and a secondary side seat ring to cut off and communicate the primary side flow path and the secondary side flow path, and a rotating means for rotating the ball plug. In the provided two-way ball valve, when the primary fluid pressure in the valve body becomes higher than the pressure in the ball cavity when fully closed, the pressure difference between the ball plug and the primary seat ring or the primary A gap is formed between the side seat ring and the inner wall of the valve body, and a part of the primary side fluid is guided from the primary side flow path to the ball cavity via the gap.

  According to a second invention, in the first invention, when the fluid pressure in the secondary channel becomes higher than the pressure in the ball cavity when fully closed, the differential pressure causes the ball plug and the secondary seat ring to Or a gap is formed between the secondary side seat ring and the inner wall of the valve body, and a part of the secondary side fluid is guided from the secondary side flow path to the ball cavity via the gap. Is.

  According to a third aspect of the present invention, there is provided a valve body in which a primary side flow path, a secondary side flow path, and a ball cavity positioned between both flow paths are formed, and a primary side and a secondary side in the ball cavity. In a two-way ball valve provided with a ball plug that is rotatably incorporated via a side seat ring and blocks and communicates the primary side flow path and the secondary side flow path, and a rotating means for rotating the ball plug A first annular groove is formed on the inner wall of the valve body on the primary side from the primary seat ring, and a first seal member is inserted into the annular groove so that the primary fluid in the valve body is fully closed. When the pressure becomes higher than the pressure in the ball cavity, a gap is generated between the first seal member and the first annular groove by expanding the first seal member in the radial direction by the differential pressure. Let this gap and the valve Via the gap between the body and the primary seat ring is part of the primary side fluid that was guided to the ball cavity from the primary flow path.

  According to a fourth invention, in the third invention, a second annular groove is formed on the inner wall of the valve body on the secondary side from the secondary seat ring, and a second seal member is provided in the annular groove. When the secondary fluid pressure in the valve body becomes higher than the pressure in the ball cavity when fully inserted, the second seal member is expanded in the radial direction by the differential pressure. A gap is formed between the member and the second annular groove, and a part of the secondary fluid is circulated through the gap and a gap between the valve body and the secondary seat ring. The ball is guided from the side channel to the ball cavity.

  According to a fifth aspect of the present invention, there is provided a valve body in which a primary side flow path, a secondary side flow path, and a ball cavity positioned between both flow paths are formed, and a primary side and a secondary side in the ball cavity. In a two-way ball valve provided with a ball plug that is rotatably incorporated via a side seat ring and blocks and communicates the primary side flow path and the secondary side flow path, and a rotating means for rotating the ball plug An annular groove and a communication path are formed between the primary seat ring and the valve body, and a seal member is inserted into the annular groove so that the primary fluid pressure in the valve body is in the ball cavity when fully closed. When the pressure is higher than the internal pressure, the differential pressure causes the seal member to be expanded in the radial direction to create a gap between the seal member and the annular groove, and the primary side via the gap and the communication path Part of the fluid Serial is from the primary flow path which was guided to the ball cavity.

In the first invention, when the primary fluid pressure in the valve body becomes higher than the pressure in the ball cavity, the differential pressure causes a gap between the ball plug and the primary seat ring or between the primary seat ring and the valve body inner wall. A gap is formed between the two and a part of the primary fluid is guided to the ball cavity through the gap, thereby making the pressure in the ball cavity equal to the primary fluid pressure. Therefore, it is possible to prevent an increase in valve operating torque caused by the first and second factors.
In the second invention, since the secondary fluid can be guided to the ball cavity, in addition to the effect of the first invention described above, the secondary fluid pressure becomes higher than the primary fluid pressure, It can cope with backflow.
In the third invention, the same effect as in the first invention described above can be obtained.
In the fourth invention, similarly to the above-described second invention, it is possible to cope with the case where the secondary fluid pressure becomes higher than the primary fluid pressure or the fluid flows backward.
In the fifth invention, the same effect as in the first invention described above can be obtained.

Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings.
1 is a cross-sectional view of a first embodiment of a two-way ball valve according to the present invention when fully open, FIG. 2 is an enlarged cross-sectional view of part A in FIG. 1, and FIG. 3 is an enlarged cross-sectional view of part B in FIG. FIG. In these drawings, a two-way ball valve generally indicated by reference numeral 1 includes a valve body 2 connected in the middle of piping, a ball plug 3 rotatably incorporated in the center of the valve body 2, and the ball plug. 4 is configured as a rotating means for rotating 3 within an angle range of approximately 90 °.

  The valve body 2 is composed of a straight pipe having both ends open, one end of the inside forms a primary flow path 5A, the other end of the inside forms a secondary flow path 5B, and the center in the inside is the ball. A ball cavity 6 for accommodating the plug 3 is formed. Further, the valve body 2 is composed of two members, an upstream valve body 2A and a downstream valve body 2B, which are integrally connected by screwing of the male screw 11 and the female screw 12 and the joint portion is sealed by the seal member 13. Has been. The upstream valve body 2A has the primary flow path 5A and the ball cavity 6 formed therein, and a cylindrical portion 14 is integrally projected upward at the center of the upper surface. A taper screw 16 to which an upstream pipe (not shown) is connected is formed on the inner peripheral surface of the upstream opening 15 of the upstream valve body 2A, and the female screw 11 is formed on the inner peripheral surface of the downstream opening 17. Has been.

  The downstream valve body 2B forms the secondary flow path 5B inside, and the external thread 12 that engages with the female thread 11 of the upstream valve body 2A is formed on the outer peripheral surface of the upstream opening end 18. A taper screw 20 to which a downstream pipe (not shown) is connected is formed on the inner peripheral surface of the downstream opening 19.

  The ball plug 3 is substantially spherical and has a through passage 23 formed therein. A pair of primary and secondary side seat rings 24 and 25 and a first side ring 24 are formed in the ball cavity 6 of the valve body 2. The second O-rings (seal members) 26 and 27 are rotatably incorporated, and the outer peripheral surface forms a spherical seat portion and is pressed against the seat rings 24 and 25. The through-flow passage 23 is formed of a through-hole formed so as to pass through the center of the ball plug 3 and perpendicular to the axis of the four, and the inflow side opening 23a has a predetermined flow characteristic, for example, a cross-sectional shape is a ball. The outflow side opening 23b is formed in a circular shape in a generally fan shape in the rotation direction of the plug 3 (arrow C direction).

  The primary and secondary seat rings 24 and 25 are respectively formed in annular seat ring grooves 28 and 29 formed on the inner walls of the upstream valve body 2A and the downstream valve body 2B as shown in FIGS. The ball valve 3 is pressed against the spherical seating portion by being inserted and screwed into the upstream valve body 2A. The ball cavity 6 and the seat ring grooves 28 and 29 communicate with each other. Appropriate gaps G are respectively set between the outer peripheral surfaces of the primary and secondary seat rings 24 and 25 and the inner wall of the valve body 2.

  Further, the inner wall of the valve body 2 has first and second annular grooves 30 and 31 for housing the first and second O-rings 26 and 27, and an inner peripheral wall 32 for regulating the inner periphery of these grooves. 33 is formed. The first annular groove 30 is formed on the upstream side of the seat ring groove 28 and communicates with the seat ring groove 28 and the ball cavity 6 through the gap G. The second annular groove 31 is formed on the downstream side of the seat ring groove 29, and communicates with the seat ring groove 29 and the ball cavity 6 through the gap G.

  The bottom surfaces 30a and 31a of the first and second annular grooves 30 and 31 are formed on slopes that are inclined so that the depth increases from the inside toward the outside, and the innermost depth is the first depth. The outer diameters of the first and second O-rings 26 and 27 are set smaller than the outer diameter, and the outermost depth is set larger than the outer diameters of the first and second O-rings 26 and 27. When the first and second O-rings 26 and 27 are fitted into the first and second annular grooves 30 and 31 in a natural state, the inner peripheral walls 32 of the first and second annular grooves 30 and 31 are provided. , 33 and compressed by the primary and secondary seat rings 24, 25 and pressed against the groove bottom surfaces 30a, 31a to seal the first and second annular grooves 30, 31. 2 and 3 show this state.

  The inner peripheral wall 32 that defines the inner periphery of the first annular groove 30 faces the primary side seat ring 24 while maintaining an appropriate gap Go, so that the primary side flow path 5A and the first annular groove 30 are opposed to each other. Is in communication. For this reason, the primary fluid pressure is constantly applied to the first O-ring 26. Similarly, the inner peripheral wall 33 that defines the inner periphery of the second annular groove 31 faces the secondary side flow ring 5B and the second flow path 5B by facing the secondary side seat ring 25 with an appropriate gap Go. The annular groove 31 is communicated. For this reason, the secondary fluid pressure is constantly applied to the second O-ring 27.

  In FIG. 1, the ball plug 3 further has a concave portion 35 formed at the center of the upper surface, and the lower end portion 4a of the four is fitted in the concave portion 35 while being prevented from rotating. Said 4 penetrates the said cylinder part 14 rotatably through the O-ring 36, and an upper end is connected with drive devices, such as a drive motor and a pneumatic operating device which abbreviate | omitted illustration, or about 90 degrees by manual operation. It is comprised so that it may rotate within the angle range.

  The fully open state shown in FIG. 1 of the two-way ball valve 1 having such a structure, that is, the axis of the valve body 2 coincides with the axis of the through passage 23 of the ball plug 3, and the primary side passage 5A and the secondary side In a state where the flow paths 5B communicate with each other via the through flow path 23, the fluid 40 supplied to the upstream pipe flows through the two-way ball valve 1 to the downstream pipe. When the ball plug 3 is rotated 90 ° in the direction of arrow C from this fully open state, the inflow side opening 23a and the outflow side opening 23b move to the outside of the seat rings 24 and 25, and the primary and secondary flow paths In order to block the communication between 5A, 5B and the through passage 23, the two-way ball valve 1 is fully closed to block the passage of the fluid 40.

When the two-way ball valve 1 is switched to the fully closed state, the fluid pressure (P ₁ ) on the primary side becomes higher than the fluid pressure (P ₂ ) on the secondary side, so the pressure difference (P ₁ -P ₂ ) The plug 3 is pressed against the secondary side seat ring 25. At this time, since the primary fluid pressure (P ₁ ) is also applied to the first O-ring 26 in the first annular groove 30, the first O-ring 26 is expanded by the fluid pressure (P ₁ ). It is elastically deformed in the radial direction, moves toward the outer periphery of the first annular groove 30 as indicated by a two-dot chain line in FIG. 2, and is released from the pressed state by the primary side seat ring 24. For this reason, a gap G ₁ is formed between the first O-ring 26 and the first annular groove 30, whereby the primary-side flow path 5 A and the ball cavity 6 are separated by a gap Go-first annular groove 30 -gap G. ₁ —Gap G—Communication through the seat ring groove 28. Therefore, a part of the fluid 40 on the primary side flows into the ball cavity 6 and the fluid pressure (P ₃ ) in the ball cavity 6 is equalized with the primary fluid pressure (P ₁ ) (P ₁ = P _3). ). As a result, since the ball plug 3 is released from the load due to the differential pressure, it is not strongly pressed against the secondary side seat ring 25 and the operating torque of the two-way ball valve 1 is increased when the valve is opened from the fully closed state. Can be prevented. Further, if the operating torque does not increase, the seat rings 24 and 25 are less worn, and the durability of the two-way ball valve 1 can be improved.

  In addition, since the first annular groove 30 is normally sealed by the first O-ring 26, the parts such as the valve body 2, the ball plug 3, and the seat rings 24 and 25 can be easily manufactured and the dimensions of these parts vary. It is possible to prevent an increase in operating torque due to the degree of. Therefore, the ball plug 3 can be operated smoothly and reliably from this point.

  In addition to the primary side, the secondary O-ring 27 and the second annular groove 31 on the secondary side have the same structure as the first O-ring 26 and the first annular groove 30 on the primary side. Therefore, even when the secondary fluid pressure becomes higher than the primary fluid pressure, and the ball plug 3 is pressed against the primary seat ring 24 by the differential pressure, the secondary fluid is guided into the ball cavity 6 and The secondary fluid pressure and the fluid pressure in the ball cavity 6 can be equalized. Therefore, it is possible to cope with a case where the fluid pressure on the secondary side is higher than that on the primary side or the flow direction of the fluid 40 is changed.

FIG. 4 is a cross-sectional view of an essential part showing a modification of the embodiment shown in FIG.
In this embodiment, the bottom surface 30a of the first annular groove 30 formed in the valve body 2 is formed on a surface perpendicular to the axis of the valve body 2, and the primary side surface 24a of the primary seat ring 24 is formed on the inner periphery. It is formed on a tapered surface inclined more toward the outer periphery. Even in such a structure, since the cross-sectional shape of the first annular groove 30 is formed in a trapezoidal shape that is wider from the inner peripheral side toward the outer peripheral side, the primary side fluid pressure is changed when switched to the fully closed state. When the height is increased, the first O-ring 26 can be expanded in the diameter expanding direction and moved in the outer circumferential direction of the first annular groove 30, and it is clear that the same effect as the first embodiment described above can be obtained. Will.

FIG. 5 is a cross-sectional view of a main part showing a second embodiment of the present invention.
In this embodiment, in addition to the first embodiment shown in FIG. 1, the inner wall 41 of the valve body 2 (the inner peripheral wall of the portion where the seat ring groove 29 and the first annular groove 30 are formed). And the outer peripheral surface of the primary side seat ring 24 is formed with a communication passage 42 that allows the ball cavity 6 and the first annular groove 30 to communicate with each other, and the first O-ring 26 is expanded in the diameter direction by the primary side fluid pressure. When elastically deformed, the pressure in the first annular groove 30 is released to the ball cavity 6 by the communication path 42. The first annular groove 30 is not limited to the groove depth increasing from the inner peripheral side toward the outer peripheral side, and may be a uniform depth as shown in FIG.

  As shown in FIG. 7, the communication passage 42 has a required number of grooves (FIGS. (A) and (b)), small holes (FIG. (C) or notches (not shown) formed in the primary side seat ring 24. (D)).

  In such a structure, when the two-way ball valve is switched from the fully open state or the intermediate opening state to the fully closed state, the fluid pressure in the first annular groove 30 is released to the ball cavity 6 through the communication passage 42, and the primary side The fluid pressure and the fluid pressure in the ball cavity 6 can be quickly equalized.

8 to 10 show modifications of the third embodiment described above.
In FIG. 8, a groove-shaped communication passage 50 for communicating the ball cavity 6 and the first annular groove 30 is formed on the inner wall 41 of the valve body 2.

  9A and 9B, a ring-shaped collar 51 is fitted around the outer periphery of the primary side seat ring 24 and the first annular groove 30, and the ball cavity 6 and the first cavity 51 are connected to each other by a communication passage 52 provided in the collar 51. The annular groove 30 is communicated with each other.

  As the collar 51, various shapes are conceivable as shown in FIGS. That is, FIG. 4A shows a ring shape in which a part of the circumferential surface is cut open, and the cut open portion serves as a communication path 52. In FIG. 5B, a plurality of grooves (dents) formed in the inner peripheral surface in a ring shape having no open portion are used as the communication path 52. FIG. 4C shows V-shaped irregularities formed alternately and continuously on the inner periphery and the outer periphery. In this case, the uneven portion on the outer peripheral side forms the communication path 52. FIG. 4D shows a wire formed in a ring shape by being spirally wound. In this case, a gap between adjacent coils forms the communication path 52.

  Even in such a structure, it will be apparent that the primary fluid pressure can be quickly released into the ball cavity 6 when switched to the fully closed state.

FIG. 11 is a cross-sectional view of a main part showing a fourth embodiment of the present invention.
In this embodiment, a movement restricting portion 60 that restricts the movement of the primary seat ring 24 to the downstream side is integrally provided on the inner wall of the valve body 2 and is switched to the fully closed state so that the primary fluid pressure is high. When this happens, the ball plug 3 is moved downstream by the fluid pressure, and a gap G ₄ is generated between the outer peripheral surface of the ball plug 3 and the inner peripheral surface of the primary side seat ring 24. .

Even in such a structure, the primary fluid can be guided into the ball cavity 6 through the gap G ₄ when switched to the fully closed state, so that the primary fluid pressure and the pressure in the ball cavity 6 are made equal. It will be clear that it can be done.

FIG. 12 is a cross-sectional view of an essential part showing a fifth embodiment of the present invention.
In this embodiment, a primary side seat ring 61 formed of an elastic material is fitted into a seat ring groove 28 formed on the inner wall of the valve body 2. The primary side sheet ring 61 is formed by bending a metal plate having a V-shaped cross section so that the groove 62 faces outward, so that the primary side bent piece 61a and the secondary side bent piece 61b In the opened state, the connecting portion of the primary side bent piece 61a and the secondary side bent piece 61b is pressed against the outer peripheral surface of the ball plug 3, and the tip of the primary side bent piece 61a is the groove 28 for seat ring. , The seat ring groove 28 is sealed, and the primary-side flow path 5A and the ball cavity 6 are kept out of communication. The tip of the secondary bent piece 61b is separated from the inner wall of the valve body 2 with an appropriate gap.

When the two-way ball valve is switched to the fully closed state, the primary side fluid pressure rises, so that the primary side seat ring 61 is elastically deformed to the secondary side by this fluid pressure. For this reason, the primary side bent piece 61a is separated from the bottom surface of the seat ring groove 28 as shown by a two-dot chain line, and thereby the primary side flow path 5A and the ball cavity 6 are communicated with each other through the seat ring groove 28. . As a result, a part of the primary fluid flows into the ball cavity 6 through the seat ring groove 28, and the pressure in the ball cavity 6 is equalized with the primary fluid pressure. Therefore, it is obvious that even in such a structure, it is possible to prevent the operating torque from increasing as in the first to fourth embodiments.
Further, in the present embodiment, since the primary side seat ring 61 also functions as an O-ring, the number of parts can be reduced, and the internal processing of the valve body 2 is compared with the above-described embodiment. There is an advantage that it can be manufactured easily and inexpensively. The primary side seat ring 61 is not limited to a V-shaped cross section, and may be U-shaped.

  In the embodiment shown in FIGS. 4 to 12, only the primary-side seal structure has been described, but the secondary-side seal structure is exactly the same as that of the primary side in order to prevent backflow. It is preferable.

It is sectional drawing in the time of a full open which shows 1st Embodiment of the ball valve which concerns on this invention. It is an expanded sectional view of the FIG. 1A section. It is an expanded sectional view of the FIG. 1B part. It is sectional drawing of the principal part which shows the modification of embodiment shown in FIG. It is sectional drawing of the principal part which shows the 2nd Embodiment of this invention. It is sectional drawing of the principal part which shows the modification of 2nd Embodiment. (A)-(d) is a figure which shows a primary side seat ring, respectively. It is a figure which shows the modification of the 3rd Embodiment of this invention. It is a figure which shows the modification of the 3rd Embodiment of this invention. (A)-(d) is a figure which shows a seat ring, respectively. It is sectional drawing of the principal part which shows the 4th Embodiment of this invention. It is sectional drawing of the principal part which shows the 5th Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Two-way ball valve, 2 ... Valve main body, 3 ... Ball plug, 4 ... Valve shaft, 5A ... Primary side flow path, 5B ... Secondary side flow path, 6 ... Ball cavity, 24 ... Primary side seat ring, 25 ... secondary side seat ring, 23 ... through flow path, 23a ... inflow side opening, 26 ... first O-ring, 27 ... second O-ring, 42, 50, 52 ... communication path, 60 ... movement restriction part , 61 ... primary seat _{ring, G, Go, G 1,} G 2, G 3, G 4 ... gap.

Claims (5)

A valve body in which a primary flow path, a secondary flow path, and a ball cavity located between both flow paths are formed, and a primary side and a secondary side seat ring in the ball cavity In a two-way ball valve provided with a ball plug that is rotatably incorporated and blocks and communicates the primary side flow path and the secondary side flow path, and a rotation means for rotating the ball plug,
When the primary fluid pressure in the valve body becomes higher than the pressure in the ball cavity when fully closed, the differential pressure causes a difference between the ball plug and the primary seat ring or between the primary seat ring and the valve body inner wall. A two-way ball valve is characterized in that a gap is formed in the first and second parts of the primary fluid through the gap to be guided from the primary channel to the ball cavity. The two-way ball valve according to claim 1,
When the fluid pressure of the secondary side flow path becomes higher than the pressure in the ball cavity when fully closed, the differential pressure causes a difference between the ball plug and the secondary side seat ring or the secondary side seat ring and the valve body. A two-way ball valve characterized in that a gap is formed between inner walls, and a part of the secondary fluid is guided from the secondary channel to the ball cavity via the gap. A valve body in which a primary flow path, a secondary flow path, and a ball cavity located between both flow paths are formed, and a primary side and a secondary side seat ring in the ball cavity In a two-way ball valve provided with a ball plug that is rotatably incorporated and blocks and communicates the primary side flow path and the secondary side flow path, and a rotation means for rotating the ball plug,
A first annular groove is formed on the inner side of the valve body on the primary side from the primary seat ring, and a first seal member is fitted into the annular groove,
When the primary fluid pressure in the valve body becomes higher than the pressure in the ball cavity when fully closed, the first seal member and the first A gap is formed between the annular groove and a part of the primary fluid from the primary channel through the gap and a gap between the valve body and the primary seat ring. A two-way ball valve characterized by leading to. The two-way ball valve according to claim 3,
Forming a second annular groove on the secondary side of the secondary seat ring on the inner wall of the valve body, and inserting a second seal member into the annular groove;
When the secondary fluid pressure in the valve body becomes higher than the pressure in the ball cavity when fully closed, the second seal member and the second seal member are expanded by radially expanding the second seal member by the differential pressure. A gap is generated between the second annular groove, and a part of the secondary fluid is passed through the gap between the gap and the valve body and the secondary seat ring. A two-way ball valve characterized by being guided to the ball cavity. A valve body in which a primary flow path, a secondary flow path, and a ball cavity located between both flow paths are formed, and a primary side and a secondary side seat ring in the ball cavity In a two-way ball valve provided with a ball plug that is rotatably incorporated and blocks and communicates the primary side flow path and the secondary side flow path, and a rotation means for rotating the ball plug,
An annular groove and a communication path are formed between the primary seat ring and the valve body, and a seal member is inserted into the annular groove.
When the primary fluid pressure in the valve body becomes higher than the pressure in the ball cavity when fully closed, a gap is formed between the seal member and the annular groove by expanding the seal member in the radial direction by the differential pressure. And a part of the primary fluid is guided from the primary flow path to the ball cavity via the gap and the communication path.

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