JP2001289334A - Ball valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a ball valve having a seat ring easy to be exchanged and provided with a fire guard function. SOLUTION: This ball valve is formed of a ball having a through hole for flowing of the fluid, a body 2 having a support part 2d provided in the inner surface of a hall housing space 2f formed inside and for supporting the ball 1 freely to be rotated from both sides thereof and formed with the spherical outer surface 2b, a fluid flow hole 2a provided freely to be communicated with the through hole 1a, and a ball insertion hole 2h formed in a direction crossing the fluid flow hole 2a, a seat ring 3 for water-tightly surrounding a boundary part 2c between the ball 1 and the support part 2d, and a rotary mechanism 4 for sealing the ball insertion hole 2h and for rotating the ball 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a method for installing a pipe,
The present invention relates to a ball valve for controlling a flow of a fluid in a pipe.

[0002]

2. Description of the Related Art Conventional ball valves are of the side entry type.
(Fig. 5) and top entry type (Fig. 6). Body of side entry type ball valve (B1) (22)
Is composed of a female body half (22a) and a male body half (22b), a ball storage space (22d) is formed on the mating surface thereof, and a fluid for flowing fluid to the center of the two. Through hole
(22c) is formed to penetrate.

A through hole (21a) is formed in the ball (21). The ball (21) is accommodated in a ball storage space (22d) through a seat ring (23) so as to coincide with the fluid flow hole (22c). Have been. The female female half (22a) and the male male half (22b) are fixed with bolts (29), and by tightening the bolts (29), the through holes (21a) of the ball (21) are fixed. The contact pressure between the hole edge and the seat ring (23), and between the seat ring (23) and the hole edge of the fluid flow hole (22c) is increased to ensure watertightness.

[0004] Such a side entry type ball valve (B
The problem with (1) is that the body (22) is centered and the female body half (22
a) and the male body half (22b). That is, when replacing the seat ring (23) that has deteriorated due to long-term use, first replace the ball valve with piping.
(B1) is removed, the bolt (29) is removed, the body (22) is disassembled, and the seat ring (23) is replaced. Then install the new seat ring (23) and re-insert the body (2
2) will be assembled and assembled into the pipe as before. Seat ring (23) for side entry ball valve (B1)
There was a problem that it took time and effort to replace the.

On the other hand, a top entry type ball valve (B2) as shown in FIG. 6 can eliminate the above-mentioned problem. That is, the body (32) of the top entry type ball valve (B2) is integrally formed by casting, and communicates with the ball storage space (32d) formed in the body (32), and the body (32) Fluid through-holes (3
An entry hole (32b) for mounting the ball rotation mechanism (34) is formed at a right angle to 2c). Therefore, in this case, if the entry hole (32b) is removed from the ball rotation mechanism (34) while the top entry type ball valve (B2) is attached to the pipe, the seat ring (33) can be replaced.

However, the top entry type ball valve (B2) has another problem. That is, a draft is formed on the inner peripheral surface of the space (32b) for inserting and removing the ball (31) and the seat ring (33) from the ball storage space (32b). Then, adjust the seat ring (3
3) is processed with water tightness.

However, when the seat ring (33) is machined in accordance with the draft angle, if the machining is not accurate, the seat ring (33) will not fit into the draft angle in a watertight manner. The ball (31) supported by () is not disposed at a predetermined position, so that the fluid flow hole (31c) and the ball (31)
However, there is a problem in that the through holes (31a) formed in the holes do not coincide with each other and thus are not aligned. Therefore, accuracy is required for the draft and the processing of the seat ring (33), and the processing cost increases.

[0008] Further, as a problem common to both, there is a problem of loss of sealing performance in the event of a fire, that is, a problem of so-called fire guard performance. All of the above conventional examples are heat-sensitive seat rings
The balls (21) and (31) are supported by the hole edges of the fluid flow holes (21c) and (31c) of the bodies (22) and (32) via (23) and (33).
That is, even if the ball valves (B1) and (B2) are closed, if a fire occurs and the ball valves (B1) and (B2) become hot due to the flame, the seat rings (23) and (33) are burned out, A gap is created between the ball (21) (31) and the hole edge of the fluid flow hole (21c) (31c), or the ball (21) (31) falls off and fluid leaks out from here. is there.

If the fluid is like water, it will not spread fires or disasters, but if the leaked liquid is flammable or highly toxic, or corrosive, then only fire But a secondary disaster caused by leaked liquid. Therefore, in the conventional ball valves (B1) and (B2), there was a problem that a fire guard system had to be separately installed in the pipe.

[0010]

The problem to be solved by the present invention is as follows.
First, we have developed a ball valve that has fire guard properties and, second, does not require a draft or the like and does not require special processing on the seat ring despite its top entry type that is easy to maintain. Is to do.

[0011]

According to a first aspect of the present invention, there is provided a ball valve (A) comprising: (a) a ball (1) having a through hole (1a) through which a fluid flows; ) The ball (1) protrudes from the inner surface of the ball storage space (2f)
(2d) that is rotatably supported from both sides and has an outer surface (2b) formed in a spherical shape, and a through hole (1
a) and a ball insertion / removal hole (2h) formed to be orthogonal to the fluid flow hole (2a). (2)
And (c) water-tight contact with the outer surface (1b) of the ball (1) and the outer surface (2b) of the support (2d), surrounding the boundary (2c) between the ball (1) and the support (2d). Seat ring (3) and (d) ball insertion hole
(2h) and a rotation mechanism (4) for rotating the ball (1).

The body (2) according to the present invention has an integral structure,
A ball insertion / removal hole (2h) for inserting / removing the ball (1) at right angles to the fluid flow hole (2a) is provided.When replacing the worn seat ring (3), use a ball valve (A ) With the rotating mechanism (4) removed from the ball insertion hole (2h), take out the ball (1) and the seat ring (3), and replace the seat ring (3) with a new seat ring (3) Ball valve (B1) like the conventional side entry type ball valve (B1).
There is no need to dismantle (B1), and the seat ring (3) can be easily replaced without any trouble. In addition, for the reason described later, a draft such as the conventional top entry type ball valve (B2) is not required, and machining is very simple.

In addition to the above, the most important point in the present invention is that the ball valve (A) can have "fire barrier properties". In other words, the ball supporting structure of the present invention is not a seat ring (3) as in the prior art, but a supporting portion (FIG. 1) for supporting the ball (1) so as to sandwich the ball (1) from both sides in the "closed state" as shown in FIG. Part of the ball (1) fits into the fluid flow hole (2a) of 2d), and in this state, the ball (1) is supported from both sides by the hole edge of the fluid flow hole (2a). Therefore, a fire occurs when the ball valve (A) is closed, and at that time, even if the seat ring (3) burns out, the ball (1) does not fall out of the support portion (2d). , Ball (1) and ball support surface (2e)
Fluid outflow from between the fluid flow hole (2a) and the edge of the fluid flow hole (2a) opened to the minimum can be minimized.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIG. The body (2) of the present embodiment is an integrally molded product having a ball storage space (2f) formed therein, and a support portion (2d) protruding so as to face the inner surface thereof. Support (2
The opposing surface of d) is a ball support surface (2e) that supports the ball (1) from both sides, and the fluid flow hole (2a) is open, and the support portion (2d)
The outer surface (2b) is also formed in a spherical shape for the reason described later.

At both ends of the body (2), flanges (2g) connected to flanges (not shown) of piping are formed.
A fluid flow hole (2a) is formed between the flange (2g) and the ball support surface (2e) of the support portion (2d) so as to penetrate therethrough.

A ball insertion hole (2h) is formed in the body (2) in a direction perpendicular to the center axis of the fluid passage hole (2a), and the ball insertion hole (2h) is It communicates with the ball storage space (2f). This allows the ball (1) to be inserted into and removed from the ball storage space (2f) through the ball insertion hole (2h).

The ball (1) is a sphere, which is fitted between the support portions (2d) and is used while being rotatably supported. The spherical outer surface (1b) has a ball support surface of the support portion (2d). The fluid flow hole (2a) opening in (2e) is rotatably contacted with the edge of the fluid flow hole (2a) and is supported from both sides. Further, a through-hole (1a) is formed at the center thereof so as to coincide with the fluid flow hole (2a), and a rotation mechanism is formed on the outer surface (1b) of the rotating mechanism perpendicular to the through-hole (1a).
One recess (1d) into which the rotation drive section (7) of (4) fits is formed. The width between the hole edges (1c) of the through holes (1a) is substantially equal to the width between the support portions (2d), and is very small.
The ball (1) is fitted between the support portions (2d) with a gap (of course, not limited to this, but preferably in a water-tight or nearly water-tight fitting state).

The seat ring (3) is a ring made of Teflon (registered trademark) or carbon. If necessary, a reinforcing ring (3b) is attached to the outer periphery of the seat ring body (3a). In the present embodiment, a reinforcing ring (3b) is provided on the outer periphery of a ring-shaped seat ring body (3a) made of Teflon or carbon.
Are shown. Seat ring body (3
The inner peripheral surface of a) is formed in a mountain shape in order to contact the outer surface (2b) of the support portion (2d) and the outer surface (1b) of the ball (1) in a watertight manner. The water-tight contact surfaces are (3c) and (3d). This seat ring (3) is attached so as to surround the boundary part (2c) between the support part (2b) and the ball (1), and it is completely watertight over the entire circumference so that fluid does not leak. It is in a state where it is

The rotation mechanism (4) includes a handle (6) and a handle (6).
The stem (5) to which is attached, the stem holder (8) for rotatably holding the stem (5), and the stem holder (8) are attached and fitted into the ball insertion hole (2h) of the body (2). It is composed of a fixed stem block (9). At the lower end of the stem (5), a rotation drive section (7) projects, and fits into a recess (1d) formed in the ball (1).

Next, a method of replacing the seat ring (3) of the ball valve (A) according to the present invention will be described. First, handle
(6) is operated to bring the ball valve (A) into a fluid flowing state, that is, an open state. This state is the state of FIG. 2, in which the hole edge (1c) of the through hole (1a) of the ball (1) coincides with the fluid flow hole (2a) opened on the ball support surface (2e) of the support portion (2b). Ball
By pulling out (1), the ball (1) together with the seat ring (3) can be pulled out of the body (2).

Next, remove the bolt and remove the stem block (9).
Remove from the body (2). Since the rotation drive section (7) is merely fitted in the recess (1d), it can be easily removed. This allows the ball (1) to be seen from the ball insertion / removal hole (2h). In this state, the ball (1) is forcibly pulled out from the ball insertion / removal hole (2h) using a jig (not shown). In this case, the seat ring (3) slides on the spherical outer surface (2b) of the support portion (2d) with the water-tight contact surface (3d) at the end opposite to the drawer side in accordance with the drawing of the ball (1). Seat ring as shown in 4
(3) inclines so that the drawer side end comes off the ball (1). When the ball (1) is further pulled out, the end of the seat ring (3) on the side opposite to the pull-out side is completely disengaged from the support portion (2d), and is smoothly drawn out in an inclined state as shown in FIG. here,
Since the outer surface (2b) of the support portion (2d) is formed in a spherical shape, the seat ring (3) can slide on the outer surface (2b) of the support portion (2d) without resistance.

When the ball (1) of the seat ring (3) is completely removed, the seat ring (3) is replaced with a new seat ring (3).
A new seat ring (3) is attached to both sides of the ball (1) so as to surround the through hole (1a). In this state, the ball (1) is inserted into the ball insertion hole (2h) of the body (2).
At this time, if the seat ring (3) is mounted at a right angle to the through hole (1a), the seat ring (3) comes into contact with the hole edge of the support (2d) and the ball ( Since 1) cannot be placed between the supports (2d), the seat ring
The insertion side end (lower end in the figure) of (3) is moved toward the center of the ball (1), and the upper end is mounted to be inclined away from the center of the ball (1) (see FIG. 3).

By doing so, the ball (1) is supported by the support (2d).
When passing through the upper hole edge (10), the lower part of the seat ring (3) can pass without contacting or in contact with the upper hole edge (10). When the ball (1) is pushed in while the seat ring (3) is fitted, the water-tight contact surface (3c) or (3d) of the seat ring (3) or both water-tight contact surfaces (3c) (3d)
Is the outer surface (1b) of the ball (1) or the outer surface (2b) of the support (2d).
Alternatively, while contacting both (1b) and (2b), and the inner diameter thereof gradually increases and moves, the through hole (1a) gradually moves from the inclined state.
The posture is changed to a state parallel to the hole edge (1c) of the ball, and eventually the ball passes through the hole edge of the support portion (2d) together with the ball (1), and the ball
(1) fits between the support portions (2d). As a result, the hole edge (1c) of the through hole (1a) of the ball (1) and the ball support surface (2e) of the support portion (2d)
And the entire circumference of the boundary portion (2c). The inner diameter of the watertight contact surfaces (3c) and (3d) of the seat ring (3) is slightly smaller than the outer diameter of the contact portion of the ball (1) and the outer portion of the contact portion of the outer surface (2b) of the support (2d). It is formed small, and the water-tight contact surfaces (3c) and (3d) are pressed against the contact portion of the ball (1) and the contact portion of the outer surface (2b) of the support portion (2d), thereby ensuring high water tightness. Finally, the rotation mechanism (4) is fitted into the ball insertion / removal hole (2h) and fixed by bolts, and the replacement maintenance of the seat ring (3) is completed.

The opening and closing of the ball valve (A) is performed by turning the handle (6). That is, when changing from the above-mentioned open state to the closed state, the handle (6) of the rotating device (4) is moved from the open state to 9
When turned 0 degrees, the ball (1) along with the stem (5)
Will also rotate. Thus, by rotating the ball (1), the through-hole (1a) came off the fluid flow hole (2a), and the spherical outer surface (1b) was opened on the ball support surface (2e) of the support portion (2d). The hole of the fluid flow hole (2a) fits exactly. In this state, since a part of the ball (1) has entered the fluid flow hole (2a), even if a fire occurs, the ball valve (A) is exposed to the high heat of the flame and the seat ring (3) is burned out. Even if the ball (1) does not come off from between the support portions (2d),
Leakage of a very small amount of fluid from between the hole edge of the fluid flow hole (2d) and the outer surface (1b) of the ball (1) does not leak out in large amounts. That is, it is possible to provide “fire guard”.

In the ball valve (A) of the present invention as described above, the water-tight structure of the seat ring (3) is such that the outer surface (2b) of the support portion (2d) having a spherical structure and the ball (1) The water-tight contact surface of the seat ring (3) that contacts the outer surface (1b) with an appropriate pressure
Due to the relationship with (3c) and (3d), there is no tapered structure as in the conventional example (B2). Therefore, processing is also simplified.

[0026]

According to the ball valve of the present invention, when the ball is removed to replace the seat ring, the seat ring can be easily removed together with the ball without removing the ball from the pipe or dismantling the body, thereby simplifying maintenance. In addition, it is not necessary to perform special processing for the seat ring and the body in spite of such a structure, so that the processing cost can be reduced. In addition to this, the most important point of the present invention is that the ball does not fall into the fluid passage hole of the support portion in the closed state and does not come off, so that a fire guard function may be additionally provided. I can do it.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a closed state of a ball valve of the present invention.

FIG. 2 is a sectional view of the ball valve of the present invention in an open state.

FIG. 3 is an enlarged cross-sectional view before a ball having a seat ring attached thereto is press-fitted between support portions in the present invention.

FIG. 4 is an enlarged cross-sectional view of the present invention in which a ball with a seat ring is being pressed between support portions.

FIG. 5 is a sectional view of a conventional side entry type ball valve.

FIG. 6 is a sectional view of a conventional top entry type ball valve.

[Explanation of symbols]

 (1) Ball (1a) Through hole (2) Body (2d) Support (2f) Ball storage space (3) Seat ring (4) Rotation mechanism

Claims (1)

[Claims] 1. A ball having a through hole through which a fluid flows, and a ball protruding from an inner surface of a ball storage space formed inside the ball so that the ball can be rotated from both sides. A support portion that supports and has an outer surface formed in a spherical shape, a fluid flow hole that is provided so as to match the through hole of the ball and that is opened on the ball support surface, and that is orthogonal to the fluid flow hole. (C) a seat ring that surrounds a boundary portion between the ball and the support portion and contacts the outer surface of the ball and the outer surface of the support portion in a water-tight manner, and (d) the ball. A ball valve comprising: a rotation mechanism that closes an insertion hole and rotates a ball.