JP3094224B2 - Ball valve and its strainer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a ball valve having a built-in strainer capable of removing impurities and the like contained in a flowing fluid.

[0002]

2. Description of the Related Art Conventionally, a ball valve of this type has a structure shown in FIG. This conventional ball valve has a pair of ball seats 5 on an inner peripheral surface of a flow path 50a of a valve body 50.
1, 51, and the ball seats 51, 5
The ball 52 having the through hole 52a is provided between
3. A cylindrical strainer 5 which is rotatably interposed by the rotation operation 3 and has an opening 54a in the through hole 52a.
4 is provided so that it can be inserted and removed.
A strainer insertion / removal hole (not shown, but the strainer 54 on the paper surface of FIG. 10 is described in the side wall of the valve body 50 facing the opening 54a of the strainer 54 when the valve is closed when the 2a and the flow path 50a are not communicated. The measurement wall of the valve body 50 in the up-down direction at the position in which it is set is formed.

[0003]

However, according to the above-mentioned conventional ball valve, when the strainer 54 is replaced, the ball 52 is rotated to close the flow path 50a, and then the strainer is inserted into and removed from the strainer insertion hole. A cap to be screwed on and a through hole 52a as a means for preventing the strainer 54 from coming off.
Must be removed in order, the strainer 54 must be replaced, and the C-type retaining ring 56 and the cap must be mounted again in that order.
Since a special tool is required for attaching and detaching the strainer, there is a problem that the work of inserting and removing the strainer 54 becomes extremely complicated.

[0004] Therefore, the present invention has been made to solve the above-mentioned conventional problems, and an object of the present invention is to provide a ball valve capable of simplifying the operation of inserting and removing a strainer and reducing the number of parts. .

[0005]

In order to solve the above-mentioned problems, a ball valve according to the present invention comprises a through hole formed between a pair of ball seats mounted on an inner peripheral surface of a flow path of a valve body. 9
has a, with balls 9 for opening and closing the flow path 2 is interposed by the rotation, the through hole 9a of the ball 9, in the ball valve strainer 13 is disposed, the baud
The strainer 13 and the rotation of the ball 9
An operation that allows the distal end portion 17a of the operation member 17 for performing an operation to be inserted and removed.
A hole 9b is formed so as to cross the through hole 9a.
On the other hand, in the valve body 1, the mounting hole 9
b, an insertion hole 20 substantially coinciding with FIG.
When the member 17 rotates with respect to the valve body 1, the ball 9
Is rotated, and the operating member 17 is connected to the flow path 2.
Is configured to be insertable into and removable from the valve body 1 in the closed state, and the strainer 1
3 is configured to be removable.

In the ball valve having the above structure, when the operation member 17 for rotating the ball 9 is inserted and removed in the closed state of the flow path 2 (valve closed state), the strainer 13 is inserted accordingly. When the strainer 13 is mounted on the ball 9, the movement is restricted by the operation member 17. In this regard, the operating member 17 forms a means for fixing the strainer 13.

[0007]

Embodiments of the present invention will be described below with reference to the drawings.

<First Embodiment> In FIGS. 1 to 3,
Reference numeral 1 denotes a valve body in which a flow path 2 is formed in the pipe axis direction. The valve body 1 includes a body 1a in which a valve chamber 3 is formed in the flow path 2 and a threaded portion 1c at one end of the body 1a. It comprises a ball pressing portion 1b screwed through an O-ring 4, and screw portions 5 and 6 are formed on the inner peripheral surfaces at the other ends of the ball pressing portion 1b and the body portion 1a, respectively.

Reference numeral 7 denotes a mounting hole formed in the other end of the body portion 1a in the radial direction, which is normally closed. However, if necessary, a pressure gauge or the like is provided via a screw portion 7a provided at both ends. Mounted.

Reference numeral 8 denotes a pair of ball seats mounted on the inner peripheral surface of the other end side of the body portion 1a and the ball retainer 1b, and a tapered surface 8a whose diameter increases toward the end portion is formed on the inner peripheral surface inside the pair. And made of a synthetic resin or the like.

Reference numeral 9 denotes a substantially spherical ball rotatably interposed between the ball seats 8. A cylindrical through hole is provided to open and close the flow paths 2 and 2 located at both ends of the ball 9. 9a is drilled. That is, as shown in FIG. 1, when the flow paths 2, 2 and the through holes 9a are substantially in the same direction, the flow paths 2, 2,
When the passages 2 and 2 and the through-hole 9a are substantially orthogonal to each other as shown in FIG. 3, the passages 2 and 2 9 and the ball seats 8, 8, the through holes 9 a
And a valve-closed state in which the valve is not communicated.

As shown in FIG. 4, a recess 10 having a surface 10a substantially parallel to the axis of the through hole 9a and a surface 10b substantially perpendicular to the axis of the through hole 9a is formed at the bottom of the ball 9. On the other hand, the valve chamber 3 of the valve body 1 is formed with a protruding piece 1d which is disposed in the recess 10 and can come into contact with the surfaces 10a and 10b. During this state, the rotation is restricted within a range of about 90 degrees.

Further, a substantially oval mounting hole 9b is formed in the ball 9 so as to intersect the through hole 9a in plan view. The mounting hole 9b is formed so as to penetrate the inner peripheral surface of the facing through hole 9a through the through hole 9a from one direction perpendicular to the axis of the through hole 9a.

Reference numeral 13 denotes a strainer mounted in the mounting hole 9b of the ball 9, which is disposed at a predetermined interval.
It comprises a pair of frame members 14a, 14b molded into a shape substantially matching the inner surface of the frame member b, and a mesh body 15 adhered to the inner surfaces of the frame members 14a, 14b.

The frame member 14a is formed of an annular body inserted into the mounting hole 9b on one side with the through hole 9a interposed therebetween. The frame member 14b is formed of an annular body inserted into the mounting hole 9b on the other side. It consists of a bottomed concave body with its open end closed, and a net 15 is attached to the inner surface of each annular body.

Further, the net-like body 15 has a concavely curved surface by being attached only to one side from the long axis of the frame member 14, and in the present embodiment, the valve is in a valve-open state. The concave portion is disposed so as to be located on the downstream side with respect to the flow direction of the fluid in the flow path 2. Since the inner diameter of the through hole 9a and the major axis of the mounting hole 9b are formed to have substantially the same dimensions, the mesh 15 is disposed so as to block the through hole 9a.

Reference numeral 17 denotes an operation member for rotating the ball 9 and is formed in a flange shape. That is, the operation member 17 has a shape (substantially oval shape in plan view) substantially coinciding with the mounting hole 9b, and a tip portion 17a insertable into the mounting hole 9b, and concentric with the tip portion 17a and Tip 17
a cylindrical neck portion 17 having an outer diameter substantially the same as the minor diameter of a
b, a disc-shaped flange portion 17c concentric with the neck portion 17b and inserted into an accommodating portion 1e projecting annularly from the wall surface of the valve body 1, and a corner protruding from above the flange portion 17c, And an operation unit 17d for a wrench or the like that has been cut.

When the flange 17c of the operating member 17 is inserted into the housing 1e and the tip 17a is inserted into the mounting hole 9b, the lower surface of the tip 17a is connected to the strainer inserted into the mounting hole 9b. 13 is in contact with the upper surface. Therefore, play of the strainer 13 in the mounting hole 9b is restricted.

Further, the distal end portion 17a and the mounting hole 9b of the operating member 17 are formed in a non-circular shape in a plan view (that is, in the direction of the rotation axis of the ball 9).
The ball 9 rotates along with the rotation around the axis (that is, the flange portion 17c of the operation member 17 rotates within the housing portion 1e of the valve body 1).

A peripheral groove is formed on the outer peripheral surface of the flange portion 17c of the operation member 17, and an O-ring 18 is mounted on the peripheral groove, so that the outer peripheral surface of the flange portion 17c and the inside of the housing portion 1e are formed. A seal with the peripheral surface is provided.

In the housing portion 1e of the valve body 1,
A bottom plate portion 19 having an insertion hole 20 through which the distal end portion 17a of the operation member 17 can be inserted is formed with a predetermined thickness, and the predetermined thickness of the bottom plate portion 19 is substantially equal to the axial length of the neck portion 17b of the operation member 17. The operation member 17 is inserted into the valve body 1 by being formed to be the same or shorter, and the flange portion 17c
In contact with the lower surface of the bottom plate 19 and the upper surface of the bottom plate portion 19,
The lower surface of the bottom plate portion 19 and the upper surface of the tip portion 17a are substantially in agreement or slightly separated. Therefore, the operation member 17
The distal end portion 17a of the operating member 17 is completely housed in the valve chamber 3, and the operating member 17 has its distal end portion 17a
Can smoothly rotate without interfering with the insertion hole 20.

Further, the insertion hole 20 is formed so as to substantially coincide with the mounting hole 9b in a plan view when the pipe axis direction of the flow path 2 and the axial direction of the through hole 9a are substantially orthogonal. Therefore, the operating member 17 can be inserted and removed from the valve main body 1 only in such a state, while in other states, the upper surface of the distal end portion 17a of the operating member 17 is
, And the detachment of the operating member 17 from the valve body 1 is regulated.

Further, a tapered surface 19a is formed on the lower surface of the bottom plate portion 19 of the housing portion 1e so as to become thinner toward the edge of the insertion hole 20, and the operating member 17 is in the valve open state shown in FIG. 3 is allowed to move upward (in the axial direction). still,
The O-ring 18 attached to the flange portion 17c has the tapered surface 19a in which the O-ring 18 attached to the flange portion 17c is located shortly before the distal end portion 17a of the operation member 17 that rotates while moving upward is inserted into the insertion hole 20.
Preferably, it is formed so as to be completely separated from e.

However, a cap body 22 is screwed into a threaded portion formed on the outer peripheral surface of the housing part 1e.
Since there is only a small gap between the back surface of the second member 2 and the upper surface of the flange portion 17c of the operation member 17, the upward movement of the operation member 17 is restricted when the cap body 22 is securely screwed to the valve body 1. You.

The first embodiment of the ball valve according to the present embodiment has the above-described configuration.
The following procedure is performed. First, after turning the operation member 17 to close the valve, the cap body 22 is removed, and the operation member 17 is pulled upward. At this time, since the insertion hole 20 of the bottom plate portion 19 and the distal end portion 17a of the operation member 17 coincide with each other in a plan view (the direction in which the operation member 17 is pulled out), the operation member 17 is moved without causing interference. Can be easily extracted from

Next, when the operation member 17 is removed, the strainer 13 is pulled out through the insertion hole 20. At this time, as in the case of the operation member 17, the insertion hole 20
And the frame member 14 of the strainer 13 coincide with each other in plan view, so that the strainer 13 can be easily pulled out from the mounting hole 9b of the ball 9 without causing interference.

When the strainer 13 is inserted, the reverse procedure is performed. That is, after inserting the strainer 13 into the mounting hole 9b of the ball 9 through the insertion hole 20, and then inserting the distal end portion 17a into the mounting hole 9b and inserting the operating member 17 into the valve body 1, The cap body 22 is screwed to the valve body 1.

Therefore, according to the ball valve according to the present embodiment, by using the operating member 17 as the fixing means of the strainer 13, it is not necessary to use a conventional C-shaped snap ring, and the operation of inserting and removing the strainer 13 is simplified. And the number of parts can be reduced.

Further, by adopting a structure in which the insertion / removal location of the operating member 17 and the insertion / removal location of the strainer 13 are adopted, there is an advantage that the assembly and disassembly of the ball valve can be performed extremely easily.

Further, since the mesh member 15 employed in the strainer 13 has a structure in which a flat mesh member is simply curved into a concave curved surface, the strainer 13 can be manufactured easily and at low cost. , The size can be reduced.

Further, when the valve is changed from the open state to the closed state,
It is conceivable that the operating member 17 jumps out of the valve main body 1 due to the residual pressure remaining in the valve chamber 3. However, in the ball valve according to the present embodiment, the cap body 22 as a detachment restricting means is provided. Therefore, such a situation can be avoided.

In addition, when the residual pressure remains in the valve chamber 3, as shown in FIG. 5, if the cap member 22 is loosened to reduce the screwing amount, the operation member 17 can The inside of the space formed between the back surface and the upper surface of the flange portion 17c of the operation member 17 can be raised, and the O-ring 18 attached to the flange portion 17c moves with the valve member 1 as the operation member 17 rises.
The O-ring 18 is moved up in the accommodation portion 1e of the
Completely separated from. Therefore, the O-ring 18
Is released, the excess pressure in the valve chamber 3 is released, and even if the cap body 22 is removed thereafter, there is no danger that the operating member 17 will jump out.

Even if the cap body 22 is not attached, the valve main body must be moved before the tip 17a of the rotating operation member 17 coincides with the insertion hole 20 so that the operation member 17 can be detached. The operation of the O-ring 18 is completely separated from the housing portion 1e by the action of the tapered surface 19a formed in the first member 1. Therefore, the excess pressure in the valve chamber 3 is released before the operation member 17 can be detached. Thus, it is possible to preferably prevent the operating member 17 from jumping out of the valve body 1.

Incidentally, with the operation part 17d of the operation member 17,
If the operation member 17 is rotated, the ball 9 is rotated to switch between a communication state and a non-communication state between the flow path 2 and the through hole 9a, so that the flow path 2 can be opened and closed. Then, the surface 10 of the concave portion 10 formed in the ball 9
Since the projecting piece 1d of the valve body 1 abuts on a and 10b, it is possible to suitably switch between the valve open state and the valve closed state. At this time, a handle having a square hole may be externally fitted to the operation portion 17d, and the ball 9 may be rotated through the handle.

The first embodiment of the ball valve according to the present invention comprises:
As described above, a second embodiment will now be described.

<Second Embodiment> FIGS. 6 to 8 show a second embodiment of a ball valve according to the present invention, and the same components as those in the first embodiment are denoted by the same reference numerals. The description is omitted.

A characteristic part of the ball valve according to this embodiment is in a housing part 1e of the valve body 1. Projecting pieces 1f,... Are formed in the accommodating portion 1e at four equal positions. Then, the female screw 25,
25 (not shown in FIG. 8) are formed, and through holes 26, 26 are formed in the other opposing pair of projecting pieces 1f, 1f.
(Not shown in FIG. 8).

A screw 27 is screwed into the female screw 25,
By disposing the screw 27 in the vicinity of the upper surface of the flange portion 17c of the operation member 17, the operation member 17 is restricted from being detached from the valve body 1, and is replaced with the cap body 22 in the first embodiment. Form a departure control means.

A pin 28 as a position restricting means is fitted in the through hole 26, and an operation portion 17d of the operation member 17 is provided.
It is configured to be able to contact the pin 29 that is fitted into the hole 17e formed in the hole 17e. When the two are in contact with each other, the distal end portion 17a of the operation member 17 and the insertion hole 20 are approximately 5 mm apart.
It is set to shift by degrees. In such a case, the flow path 2,
2 and the through hole 9a intersect at 95 degrees (85 degrees), the flow paths 2 and 2 are blocked by the outer peripheral surface of the ball 9 and the ball sheets 8 and 8, and become incommunicable with the through hole 9a. The valve is closed.

Accordingly, the operating member 17 is moved from the position P where the flow path 2 is opened to the position Q where the pins 28 and 29 abut against each other.
The rotation from the position Q to the insertion / removal position R is restricted, so that the distal end portion 17a of the operation member 17 coincides with the insertion hole 20 and the operation member 17 is Inadvertent detachment can be prevented.

When inserting and removing the strainer 13,
As shown in FIG. 8C, the pin 28 may be pulled out, and the position regulation of the operation member 17 may be released.

In the ball valve of the second embodiment, a reduction step is formed at the tip of the tip 17a of the operating member 17, and the frame 14a of the strainer 13 is fitted over the reduction step. The operating member 17 and the strainer 13
And are fixed integrally. Therefore, the operation of inserting and removing the operation member 17 and the strainer 13 can be performed at the same time, and the operation of inserting and removing the strainer 13 can be simplified, which is extremely useful as a ball valve. In addition, as in the second embodiment, the operating member 17 and the strainer 1
3 are separately manufactured, connected and fixed to each other, and formed together with the operation member 17 and the strainer 13, for example, the frame member 14 and the operation member 17 of the strainer 13 are combined together. The same member may be used to be integrally formed.

<Other Embodiments> The present invention is not limited to the above-mentioned two embodiments, and specific specific matters of the shape of the valve body 1, the strainer 13, the operating member 17, etc. The design can be arbitrarily changed within the scope of the design.

Further, in the above embodiment, the rotation operation of the ball 9 is performed by using one operation member 17, but the present invention is not limited to this.
b may be a through hole, and two operating members 17, 17 may be arranged at both ends of the mounting hole 9b, and the rotating operation of the ball 9 may be performed with either operating member 17. In such a case, the housing portion 1e, the bottom plate portion 19, the insertion hole 20
The configuration relating to the insertion of the operating member 17 is such that the rotation centers of the two operating members 17 and 17 coincide with each other.
Are arranged to face each other.

Further, even if two operating members 17 are not provided,
For example, as shown in FIG. 9, the mounting hole 9b is formed so as to penetrate the ball 9, and when the flow path 2 is closed, the opening end 9c of the mounting hole 9b (the opening into which the distal end portion 17a of the operating member 17 is inserted). The second insertion hole 3 is located at a position facing the opening end opposite to the end).
0 may be formed, and a cap body 31 as a plugging means may be detachably attached to the second insertion hole 30.

The cap body 31 is connected to the cap body 2
2, a second housing 1g which is annularly protruded from the wall surface of the valve body 1 and is concentric with the housing 1e.
Is screwed onto a threaded portion engraved on the outer peripheral surface of the.

Further, the second housing portion 1g and the cap body 3
1, a flange body 32 composed of a large-diameter portion 32a housed in the second housing portion 1g and a small-diameter portion 32b inserted into the mounting hole 9b and the second insertion hole 30 is interposed. ,
The tip of the flange body 32 contacts the lower surface of the strainer 13 and has a function of restricting the movement of the strainer 13. Further, an O-ring 34 is mounted in a circumferential groove formed on the outer periphery of the large diameter portion 32a, thereby sealing the outer peripheral surface of the large diameter portion 32a and the inner peripheral surface of the second housing portion 1g.

Therefore, if the cap body 31 is loosened and the screwed amount of the cap body 31 is reduced, the flange body 32 moves downward even when the residual pressure remains in the valve chamber 3. Then, since the O-ring 34 is separated from the second housing portion 1g, the excess pressure can be released. And then,
If the cap body 31 is removed and the flange body 32 is removed, the strainer 13 can be removed therefrom.

In the embodiment shown in FIG. 9, when the strainer 13 is formed integrally with the operation member 17, there is no possibility that the strainer 13 moves freely in the mounting hole 9b. You may. In such a case, a seal is achieved between the second housing portion 1f and the cap body 31. On the other hand, when the strainer 13 is not integrally formed with the operation member 17, a movement regulating means for the strainer 13 is necessary. In such a case, instead of the flange body 32, for example, a back surface of the cap body 31 is provided. It may be an elastic body such as a coil spring which is attached and the other end of which can be brought into contact with the lower surface of the strainer 13.

[0050]

As described above, in the present invention, a C-shaped retaining ring is formed in a through hole of a ball in order to use a ball seat ball in which the ball is rotatably interposed as a means for preventing the strainer from coming off. Compared with the conventional ball valve fitted into the concave groove, a special effect that the strainer can be easily and quickly attached and detached can be obtained.

Further, since the number of parts is reduced as compared with the related art, there is also an effect that the overall configuration can be simplified.

[Brief description of the drawings]

FIG. 1 is a front sectional view of a ball valve in an open state according to an embodiment of the present invention.

FIG. 2 is an exploded perspective view of a schematic configuration of the ball valve of the embodiment.

FIG. 3 is a front sectional view of the ball valve of the embodiment in a valve closed state.

FIG. 4 is a bottom view of a main part of the ball valve of the embodiment,
(A) is a valve open state, (b) is a valve closed state.

FIG. 5 is a front sectional view of the ball valve according to the embodiment in a state where the operation member is raised;

FIG. 6 is a front sectional view of a ball valve according to another embodiment in a valve open state.

FIG. 7 is a front sectional view of a ball valve according to another embodiment in a valve closed state.

FIG. 8 is a plan view of a main part of a ball valve according to another embodiment,
(A) is the valve open position, (b) is the valve closed position, and (c) is the insertion / removal position.

FIG. 9 is a front sectional view of a main part of a ball valve according to another embodiment in a valve closed state.

FIG. 10 is a front sectional view of a conventional ball valve.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Valve main body, 1d ... Protrusion piece, 1e ... Housing part, 1f ... Protrusion piece,
1g: second storage section, 2: flow path, 8: ball seat, 9 ...
Ball, 9a: through hole, 9b: mounting hole, 10: recess, 1
3 ... strainer, 14 ... frame member, 15 ... mesh body, 17
... operating member, 17a ... tip, 17b ... neck, 17c ...
Flange section, 17d operating section, 18 O-ring, 19 bottom plate section, 19a tapered surface, 20 insertion hole, 22 cap body (removal restriction means), 27 screw (removal restriction means), 2
8 ... pin (position regulating means), 30 ... second insertion hole, 31 ...
Cap body (closing means)

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-2000-46211 (JP, A) JP-A-50-82028 (JP, U) JP-A-2-125709 (JP, U) Registered utility model 3014633 (JP) , U) (58) Fields investigated (Int. Cl. ⁷ , DB name) F16K 5/00 F16K 51/00

Claims (7)

(57) [Claims] A through hole (9) is provided between a pair of ball seats (8, 8) mounted on an inner peripheral surface of a flow path (2) of a valve body (1).
a), a ball (9) for opening and closing the flow path (2) by rotation is interposed, and a strainer (13) is disposed in a through hole (9a) of the ball (9). In the ball valve, the ball (9) has an attachment hole (9b) through which the strainer (13) and a tip (17a) of an operating member (17) for rotating the ball (9) can be inserted and removed. ) Are formed so as to intersect with the through-holes (9a), while the insertion holes (20) in the valve body (1) substantially coincide with the mounting holes (9b) in the closed state of the flow path (2). ) Is formed, and the ball (9) is rotated by rotating the operation member (17) with respect to the valve body (1). In the closed state of (2), the valve body (1) is configured to be insertable / removable, and to insert / remove the operating member (17). There, the strainer (13)
Characterized in that the ball valve can be inserted and removed. 2. A position (Q) for closing the flow path (2) between a position (P) where the flow path (2) is opened and an insertion / removal position (R) of the operation member (17). ) Is set, and the valve body (1) is provided with position regulating means (2) in order to regulate the rotation of the operating member (17) from the position (Q) to the insertion / removal position (R).
8. The ball valve according to claim 1, wherein (8) is detachably mounted. 3. The mounting hole (9b), which is formed through the ball (9) and is the valve body (1), wherein the mounting hole (9b) is closed when the flow path (2) is closed. 3) The second insertion hole (30) is formed at a position facing the second insertion hole (30), and the plug means (31) is detachably attached to the second insertion hole (30). Ball valve. 4. A through hole (9) is provided between a pair of ball seats (8, 8) mounted on the inner peripheral surface of a flow path (2) of a valve body (1).
a), a ball (9) for opening and closing the flow path (2) by rotation is interposed, and a strainer (13) is disposed in a through hole (9a) of the ball (9). An operating member (17) for rotating the ball (9) is configured to be insertable into and removable from the valve body (1) in a closed state of the flow path (2). The operating member (1
With the insertion / removal of 7), the strainer (13) is configured to be insertable / removable, and further, the insertion / removal position (R) of the operation member (17) from the position (P) where the flow path (2) is opened. By the time, the position (Q) for closing the flow path (2) is set,
The operating member (1) is moved from the position (Q) to the insertion / removal position (R).
7) A ball valve characterized in that a position regulating means (28) is detachably attached to the valve body (1) so as to regulate the rotation of (7). 5. A detachment restricting means (22) is provided on the valve body (1) to restrict the operation member (17) from detaching from the valve body (1) when the flow path (2) is closed. 5. The ball valve according to claim 1, wherein the ball valve is detachably mounted. 6. The ball valve according to claim 1, wherein the strainer (13) and the operating member (17) are integrally formed. 7. A through hole (9) for a ball (9) rotatably interposed between a pair of ball seats (8, 8) mounted on the inner peripheral surface of a flow path (2) of a valve body (1). 9a) A strainer for a ball valve arranged in 9a), wherein the ball (9) has a shape.
The ball (9) is disposed so as to be able to be inserted into and removed from the mounting hole (9b) intersecting the formed through hole (9a) and to block the through hole (9a). Surface mesh (1
5) A strainer for a ball valve, comprising: