GB2075153A - Valves - Google Patents

Abstract

Valves used, for example, as valves for foam fire extinguishing systems which have a simplified valve structure and a simplified fluid path are disclosed. A valve chamber (3) and an accumulator chamber (4) are formed within a valve body (1) and a clapper (11) of a specified shape is rotatably mounted on the valve body. Fluid inlet means (12) is also provided in the valve for introducing fluid from a primary side (5) into the accumulator chamber. The clapper is rotated in response to a difference in pressure between the fluid at the primary side and the fluid within the accumulator chamber to open or close the valve. <IMAGE>

Description

SPECIFICATION Valve The present invention relates to a valve.

In general, a valve is provided to allow fluid flowing through a pipe to enter or leave therethrough, or to control the flow of the fluid, and is made of bronze, cast steel, forged steel, stainless steel, etc. Some valves are manually operated to open or close and some valves are adapted to be controlled by a pressure of fluid to open or close.

Heretofore, there has been a-valve of a type which is capable of being opened or closed by the pressure of fluid as illustrated in Fig. 25.

The valve illustrated in Fig. 25 comprises a valve body 21 and a clapper 26. The valve body 21 has an upper valve chamber 22 and a lower valve chamber 23 formed therein. The lower valve chamber 23 is provided with a primary pipe connection 24 at a lower portion thereof and with a secondary pipe connection 25 at a side portion thereof. These connections 24 and 25 are arranged perpendicularly to each other. On the other hand, the upper valve chamber 22 is coupled to a control pipe (not shown) connected to a control means and to an introducing pipe (not shown) for introducing fluid from the primary side into the valve chamber 22. A piston type clapper 26 is rotatably provided between the upper and lower valve chambers 22 and 23.When the lower face of the clapper 26 is brought into contact with a base portion of the primary pipe connection 24 the valve is closed and when the lower face is disengaged from the base portion the valve is opened.

In this arrangement, when the pressure of the upper valve chamber 22 is reduced by operating the control means, the clapper 26 is pushed upwardly by the pressure of the fluid at the primary side to release the closing of the primary pipe connection 24 and open the valve. When the pressure of the upper valve chamber 22 is restored to its original value, the clapper 26 is lowered by its own weight or the action of a spring until the lower face thereof abuts against the base portion of the primary pipe connection 24 to close the valve again.

This conventional valve, however, has disadvantages such that a large pressure loss is caused by a bent flow path of fluid because the primary pipe connection 24 is perpendicular to the secondary pipe connection 25 and that various troubles are caused and the life of the valve is shortened because pressurized fluid gives a large shock to the lower face of the clapper 26 and therefore the clapper 26 and the valve body supporting the same are liable to be fatigued. In addition, there is another problem that a burden of a fluid pressurizing source is considerably large.

These disadvantages are common to valves wherein the clapper is reciprocated. For this reason, a valve of this type needs to be complicated in the structure of the valve body and the clapper and should be large in size with a view to obtain a necessary strength.

Thus, the manufacturing, maintenance, inspection, etc. of the valve requires considerable time and labour. Furthermore, since this type of known valve requires separate provision of the introducing pipe for controlling opening and closing of the valve, the structure is further complicated and the manufacturing cost is increased.

On the other hand, there has been a valve in which the primary pipe connection is not perpendicular to the secondary pipe connection. This valve has a piston type clapper mounted in an upper and a lower valve chamber so as to move up and down and has a partition dividing the lower chamber into a primary side and a secondary side. A through hole is provided at a suitable position of the partition to communicate the primary side with the secondary side. The valve is closed when the clapper is located at the through hole. The opening and closing operations of this valve is carried out in response to decrease and increase of the pressure within the upper valve chamber as in the first known valve as described above.

This known valve, however, is complicated in the valve structure because the valve chamber is divided into two parts by the partition, so that the manufacturing, maintenance and inspection are not easy. In addition, the flow path at the connecting portion between the primary and the secondary portion is bent so that a large pressure loss is caused, too. Thus, this known valve again has disadvantages involved in the foregoing example of the known valve. As to the introducing pipe, there is a problem similar to that of the foregoing example of the known valve.

As illustrated in Fig. 26, there has further been a valve wherein the primary pipe connection 24 and the secondary pipe connection 25 are provided in the valve body and connected to each other linearly and the clapper 26 is mounted rotatably. This known valve, however, cannot be controlled to open and close by a fluid pressure.

Under these circumstances, there has been a demand for a valve capable of being opened and closed by a fluid pressure and having a clapper which is not moved reciprocatingly.

According to the present invention from one aspect there is provided a valve which comprises: a valve body; a valve chamber and an accumulator chamber formed within said valve body; pipe connections for a primary side and a secondary side, respectively, which are provided on a valve chamber side of the valve body; a control pipe connection provided on an accumulator chamber side for reducing a pressure within said accumulator chamber; a clapper having a sectorial shape in section and rotatably mounted on said valve body with a center of the arc of the sectorial shape as a fulcrum for partitioning between said valve chamber and said accumulator chamber; and fluid inlet means for introducing fluid from the primary pipe connection into said accumulator chamber.

According to the present invention from another aspect there is provided a valve which comprises: a valve body; a valve chamber and an accumulator chamber formed within said valve body; a primary pipe connection and a secondary pipe connection provided on a valve chamber side of said valve body; a control pipe connection provided on an accumulator chamber side of reducing a pressure within said accumulator chamber; a clapper rotatably mounted on said valve body; and a fluid inlet mechanism for introducing fluid from the primary pipe connection into said accumulator chamber, said clapper comprising a valve portion for opening and closing a primary inlet or a secondary outlet and a partition portion for partitioning between said valve chamber and said accumulator chamber and said valve body having an inner wall curved so as to correspond to a rotation locus of a tip end portion of said partition portion.

The present invention will now be described by way of example with reference to Figs. 1 to 24 of the accompanying drawings, in which: Figure 1 is a front view of a valve of a first embodiment of the present invention; Figure 2 is a right side elevational view of the valve illustrated in Fig. 1; Figure 3 is a partly cut-away plan view of the valve illustrated in Fig. 1; Figure 4 is an enlarged sectional view of the valve illustrated in Fig. 1; Figure 5 is a perspective view of a clapper usable for the valve illustrated in Fig. 1; Figures 6A to 6C are sectional views showing an operation of the valve illustrated in Fig.

1; Figures 7A to 7C are a modified form of the embodiment illustrated in Fig. 1, showing an operation thereof; Figure 8 is an enlarged sectional view of a valve of a second embodiment of the present invention; Figure 9 is a sectional view of a modified form of the second embodiment; Figure 10 is a similar sectional view of another modified form of the second embodiment; Figure ii is a sectional view of a valve of a third embodiment of the present invention; Figure 12 is a partly cut-away plan view of a valve of a fourth embodiment of the present invention; Figure 13 is an enlarged sectional view of the valve illustrated in Fig. 12; Figure 14 is a front view of a valve of a fifth embodiment of the present invention; Figure 15 is a left side elevational view of the valve illustrated in Fig. 14;; Figure 16 is an enlarged sectional view of the valve illustrated in Fig. 14; Figure 17 is a perspective view of a clapper usable for the valve illustrated in Fig. 14; Figures 18A to 18C are sectional views showing an operation of the valve illustrated in Fig. 14: Figure 19 is a sectional view of a modified form of the fifth embodiment; Figures 20 to 23 are sectional views of other various modifications of the fifth embodiment, respectively; and Figure 24 is a front view of a further modification of the valve applicable to the first to fifth embodiments; and Figs. 1 to 5 illustrate a first embodiment of the present invention. In these figures, a valve of the present invention includes a specific clapper 11 formed in a sectorial shape in section and rotatably mounted in a valve body 1.The opening and closing of the valve body 1 is effected by a pressure of fluid flowing into the valve.

The material of the body 1 is selected from bronze, cast iron, cast steel, forged steel, etc.

according to the pressure or temperature of the fluid flowing thereinto. The body 1 comprises members coupled to each other through a gasket 2 and has a valve chamber 3 and a pressure accumulator chamber 4 formed within the valve body 1. On the side of the valve chamber 3 of the valve body 1, there are provided inlet and outlet pipe connections, i.e., a pipe connection 5 for a primary side and a pipe connection 6 for a secondary side. A control pipe connection 7 is provided on the side of the accumulator chamber 4 for reducing the pressure inside of the accumulator chamber 4. These connections 5, 6 and 7 are connected to pipes (not shown), respectively. For example, where the valve of the embodiment is used for a foam fire extinguishing system, the primary pipe connection 5 is connected to a source for supplying a fire extinguishing liquid such as a stock solution tank, cistern, pump, etc., and the secondary pipe connection 6 is connected to a bubble head, and the control pipe connection 7 is connected to a self-resettable detector head, a manually actuatable valve, an electromagnetic valve, etc.

The clapper 11 has a sectorial form in section as described above and mounted within the valve body 1 so as to be rotated around a fulcrum, a center of the arc of the sectorial shape. In this embodiment, the clapper 11 is pivotally mounted on a shaft 8 provided in the valve body 1 at a position near the secondary pipe connection 6. The clapper 11 slidably contacts the gasket 2 positioned therearound and is brought into contact with an annular seat ring 9 for valve packing to block the fluid path when the valve is in its closed position as illustrated in Fig. 4.

A broken line in Fig. 4 shows a position of the clapper when it has been rotated to an open position. Numeral 10 in Fig. 4 designates means for pressing the seat ring 9.

The clapper 11 has a communicating aperture 1 2 which constitutes a fluid inlet means, i.e., a means for introducing the fluid from the primary pipe connection 5 into the accumulator chamber 4 and is provided at a position allowing the valve chamber 3 to communicate with the accumulator chamber 4 irrespective of the position of the clapper 11.

The opening/closing speed of the clapper 11 is varied depending on the diameter of the communicating aperture 12.

Although the valve packing, i.e., seat ring 9, is provided on the valve body 1 in this embodiment and a further embodiment as will be described later, the seat ring 9 may alternatively be provided on the clapper 11.

The operation of the valve of the present embodiment will now be described referring to Figs. 6A to 6C. In these figures, it is assumed that the valve is used for a foam fire extinguishing system.

As illustrated in Fig. 6A, the valve is normally in its closed position in which the fluid through the primary pipe connection 5 is introduced into the valve chamber 3, the communicating aperture 12, the accumulator chamber 4, the control pipe connection 7 and the control pipe and blocked by the selfresettable detector head, the manual actuatable valve, the electromagnetic valve, etc. to press them. The pressurized fluid within the valve chamber 3 and the accumulator chamber 3 presses the clapper 11 while imparting a clockwise turning moment as viewed in the drawing to the clapper 11. Therefore, the flow path within the valve body 1 is checked by the clapper 11 and the valve is kept in its closed position.More particularly, the pressurized fluid within the accumulator chamber 4 urges the clapper 11 by clockwise turning moment, whereas the pressurized fluid introduced into a space within the valve chamber 3 defined by the valve body 1 and the clapper 11 urges the clapper 11 by counterclockwise turning moment. However, since there is no pressurized fluid within the seat ring 9, the clockwise turning moment prevails over the counterclockwise turning moment by a pressure corresponding to the area within the seat ring 9 where there is no pressurized fluid. In addition, the clapper 11 is further urged by clockwise turning moment of its own weight, so that the clapper 11 is held in its closed position without forming a flow path from the primary side to the secondary side.

When the self-ressetable detector head, the manually actuatable valve, etc. is opened, the pressure of the fluid within the accumulator chamber 4 is reduced. Since the fluid amount discharged through the detector head, manually actuable valve, etc. is larger than the fluid amount flowing into the accumulator chamber 4 through the communicating aperture 12, the pressure within the accumulator chamber 4 against the clapper 11 becomes smaller. As a result, the clapper 11 is pressed so as to rotate counterclockwise, by the pressurized fluid within the valve chamber 3. This counterclockwise turning moment prevails over the clockwise turning moment by the weight of the clapper 11, to rotate the clapper 11. As a result, the valve is moved into an open position to allow the fluid of the primary side to flow to the secondary side (Fig. 6B).The ratio of the opening area of the control pipe connection 7 to the opening area of the communicating aperture 1 2 which is smaller than that of the connection 7 may be suitably selected according to a desired rotating speed of the clapper 11, i.e., a valve opening speed and a speed of valve closing as will be described in detail later.

When the control pipe is closed again by restoration of the self-resettable detector head, manually actuatable valve, etc., the pressure within the accumulator chamber 4 is increased by the fluid flowing thereinto through the communicating aperture 1 2 until it becomes as high as the fluid pressure within the valve chamber 3. At this time, the clapper 11 is urged to rotate clockwise by the turning moment due to its own weight (Fig.

6C). As a result, the flow path is blocked and the valve is put into its closed position. A spring 1 3 may preferably be provided as illustrated in Fig. 7A, to positively urge the clapper 11 clockwise.

Fig. 7A to Fig. 7C illustrate a modified form of the first embodiment, wherein the communicating aperture 1 2 constituting the fluid inlet means is provided on the clapper 11 in such a manner that the primary pipe connection 5 may be allowed to communicate with the accumulator chamber 4 when the valve is in the closed position and the valve chamber 3 may be allowed to communicate with the accumulator chamber 4 when the valve is in the open position. More specifically, in the modified embodiment as illustrated in Figs.

7A to 7C, the primary pipe connection 5 is disposed on the left as viewed in the drawing and the secondary pipe connection 6 is disposed on the right, and the communicating aperture 1 2 is formed on the clapper 11 at a suitable position adapted for such a pipe connecting formation. The spring 1 3 is provided for urging the clapper 11 to rotate clockwise as described above.

In this modified embodiment, the accumulator chamber 4 is pressurized when the detector head etc. is closed as in the foregoing embodiment, so that the valve is kept closed by the clapper 11, i.e., the clapper 11 is kept at the closed position (Fig. 7A). When the detector head, etc. is released to open, the pressure of the fluid within the accumulator chamber 4 is reduced so that the counterclockwise turning moment given to the clapper 1 by the pressdrized fluid within the valve chamber 3 prevails over the clockwise turning moment given by the weight of the clapper 11 and the action of the spring 1 3. As a result, the clapper 11 is formed to rotate to open the valve and to form the flow path (Fig.

7B). When the manually actuatable valve etc.

is restored to its closed position, the accumulator chamber 4 is pressurized again to reach a pressure as high as that of the valve chamber 3. Then, the clapper 11 is urged by the clockwise turning moment imparted by the weight of the clapper 11 and the action of the spring 1 3 (Fig. 7C) to resume the closed position.

Fig. 8 illustrates a second embodiment of the present invention. The valve as illustrated in Fig. 8 has the valve chamber 3 and the accumulator chamber 4 therein and further has the valve body 1 which includes the primary pipe connection 5, the secondary pipe connection 6, the control pipe connection 7, and the clapper 11 formed in a sectorial shape in section and rotatably connected to the valve body 1 by the shaft 8. In addition, the valve further has the communicating aperture 1 2 formed in the valve body 1 for forming a fluid inlet means communicating with the valve chamber 3 and the accumulator chamber 4.The communicating aperture 1 2 is provided at a position where the aperture 1 2 can communicate with the valve chamber 3 and the accumulator chamber 4, irrrespective of the rotational position of the clapper 11.

This embodiment has substantially the same formation as that of the first embodiment as described above except for the position of the communicating aperture, and the reference numbers used in Fig. 8 correspond to the numbers used in Figs. 1 to 7C, respectively.

The operation of the embodiment illustrated in Fig. 8 is substantially the same as that of the first embodiment as illustrated in Figs. 6A to 6C. The clapper 11 may also have the spring 1 3 as illustrated in Fig. 9 to ensure rotational urging of the clapper 11 for closing the valve.

Fig. 9 illustrates a modification of the second embodiment, wherein a fluid inlet means is formed by the communicating aperture 12 provided on the valve body 1 so as to communicate with the primary pipe connection 5 and the accumulator chamber 4. More specifically, in the embodiment illustrated in Fig. 9, the primary pipe connection 5 is provided on the left side as viewed in the figure and the secondary pipe connection 6 is provided on the right side as viewed in the figure. To adapt for this pipe connecting formation, the communicating aperture 1 2 is formed on the valve body 1 at a leftward position thereof.

The spring 1 3 is provided to the clapper 11 for urging the clapper 11 to rotate clockwise.

In this embodiment, the clapper 11 is opened or closed according to a change of the pressure within the accumulator chamber 4 in a manner similar to those in the foregoing embodiments. The operation is substantially the same as that illustrated in Fig. 7A to 7C.

In Fig. 10, there is illustrated another modification of the second embodiment wherein a flow control device 14 is provided in the communicating aperture 1 2. By this flow control device 14, the ratio of the diameter of the control pipe connection 7 and that of the communicating aperture 1 2 can be changed so as to freely vary the opening/closing rotation speed of the clapper 11.

Fig. 11 illustrates a third embodiment of the present invention. The valve illustrated in Fig. 11 has, in place of the communicating aperture 12 of the second embodiment, a bypass 1 5 branched from a pipe leading to the primary pipe connection 5 and connected to a suitable position of the accumulator chamber side. The remaining arrangement is similar to that of the second embodiment.

Although the bypass 1 5 is connected to the accumulator chamber 4 in Fig. 11, the bypass 1 5 may alternatively be connected to the control pipe connection 7 or a pipe (not shown) coupled to the control pipe connection 7, so long as the bypass 1 5 may communicate with the accumulator chamber 4. Where the flow control device 14 is provided in the bypass 15, the opening/closing speed of the clapper 11 can be controlled freely as in the embodiment of Fig. 10.

Figs. 1 2 and 1 3 illustrate a fourth embodiment of the present invention. The valve illustrated in Figs. 1 2 and 1 3 has the valve chamber 3 and the accumulator chamber 4 therein and further has the valve body 1 provided with the primary pipe connection 5, the secondary pipe connection 6, the control pipe connection 7 and the clapper 11 formed in a sectorial shape in section and rotatably connected to the valve body 1 near the secondary pipe connection 6 by the shaft 8. As a fluid inlet means a gap 1 6 is formed between the valve body 1 and the clapper 11.

The gap 1 6 has an opening area sufficient to allow the fluid introduced into the valve body 1 to pass therethrough from the valve chamber 3 to the accumulator chamber 4. In the embodiment as illustrated, the gap 1 6 is formed by skiving the valve body 1. Alternatively, it is possible to reduce the size of the clapper 11 to form the gap 1 6 between the clapper 11 and the valve body 1. The opening/closing speed of the clapper 11 is varied depending upon the opening area of the gap 1 6. Therefore, the opening/closing speed of the clapper 11 can be varied by changing the size of the gasket 2.

This embodiment has substantially the same construction as those of the first and the second embodiments except that the gap 1 6 is provided instead of the communicating aperture 12, and the reference numbers used in Figs. 1 2 and 1 3 correspond to the numbers used for the first and the second embodiments, respectively. The operation of this embodiment is similar to that illustrated in Figs.

6A to 6C. The spring 1 3 may be provided on the clapper 11 in this embodiment, too, to ensure rotational urging of the clapper 11 for closing the valve.

Although the clapper 11 is formed hollow in the foregoing embodiments, the clapper 11 may be solid. In this case, the communicating aperture may be formed in the clapper 11.

Further embodiments wherein the valve body 1 and the clapper 11 have structures somewhat different from those of the foregoing embodiments will now be described. The valves of these embodiments have a clapper which is provided rotatably in the valve body and essentially comprised of a valve portion and a partition portion. The opening and closing of the clapper is effected utilizing the pressure of the fluid introduced into the valve body.

Figs. 1 4 to 1 7 illustrate a fifth embodiment of the present invention. In these figures, the valve has the valve chamber 3 and the accumulator chamber 4 formed within the valve body 1. The pipe connections 5 and 6 for the primary and the secondary side are provided on the valve chamber side of the valve body 1. The control pipe connection 7 is provided on the accumulator chamber side for reducing the pressure within the accumulator 4. The clapper 11 is rotatably mounted at a suitable position of the valve body 1 and the fluid inlet mechanism for introducing the fluid from the primary pipe connection 5 into the accumulator chamber 4.

The clapper 11 comprises a valve portion 11 a for opening or closing a primary inlet or a secondary outlet and a partition portion 11 b for partitioning between the valve chamber 3 and the accumulator chamber 4 as illustrated in Fig. 1 7. In this embodiment, the valve portion 11 a is adapted to open or close the secondary outlet, and the entire clapper 11 is pivotally mounted by the shaft 8 provided on the valve body 1 near the secondary pipe connection 6. The valve portion 11 a abuts against the valve packing or the annular seat ring 9 to block the flow path when the valve is closed as illustrated in Fig. 16.

A broken line in Fig. 1 6 shows the clapper 11 in its rotated position when the valve is opened.

The clapper 11 has the communicating aperture 1 2 formed at a suitable position of the partition portion 11 b. The communicating aperture 1 2 constitutes the fluid inlet means i.e., means for introducing the fluid from the primary pipe connection 5 into the accumulator chamber 4 and is provided at a position where the valve chamber can communicate with the accumulator, irrrespective of the position of the clapper 11. The opening/closing speed of the clapper 11 may be controlled by varying the opening diameter of the communicating aperture 1 2. In the figures, 10 is the seat ring pressing means. An inner wall 1 a of the valve body 1 is formed by a curved face corresponding to a rotation locus of a tip end portion 11 C of the partition portion 11 b.A packing 11 d is provided at the edge of the tip end portion 11 C so as to slidably contact the inner wall 1 a of the valve body 1.

The operation of the valve of the present embodiment will now be described referring to Figs. 1 8A to 18C. As in the first embodiment, it is assumed that the valve is used for a foam fire extinguishing system.

As illustrated in Fig. 18A, the valve is normally in the closed position so that the fluid from the primary pipe connection 5 is led to the valve chamber 3, the communicating aperture 1 2 of the partition portion 11 b, the accumulator chamber 4, the control pipe connection 7, the control pipe, and blocked by the self-resettable detector head (not shown), the manually actuatable valve (not shown), the electromagnetic valve (not shown), etc. to press them. The pressurized fluid within the valve chamber 3 and the accumulator chamber 4 imparts clockwise turning moment to the clapper 11 to press the clapper 11. Therefore, the flow path within the valve body 1 is blocked by the valve portion 11 a to keep the valve at the closed position.

When the manually actuatable valve etc. is released to open, the fluid pressure within the accumulator chamber 4 is reduced. Therefore, the clapper 11 is pressed by the pressurized fluid within the valve chamber 3 to rotate counterclockwise. This counterclockwise turning moment prevails over the clockwise turning moment exerted by the weight of the clapper 11, to rotate the clapper 11. As a result, the valve is put into the open position to let the fluid of the primary side flow into the secondary side (Fig. 18B).The rotating speed, i.e., the speed of valve opening and speed of valve closing as will be described in detail later may be controlled as desired, by suitably selecting the ratio of the diameter of the opening area of the control pipe connection to the opening area of the communicating aperture 1 2 which is smaller than that of the control pipe connection 7.

When the manually actuatable valve etc. is restored to its original position and the control pipe is closed again, the accumulator chamber 4 is gradually pressurized by the fluid introduced thereinto through the communicating aperture 1 2 to reach a pressure as high as the fluid pressure within the valve chamber 3. At this time, the clapper 11 is urged to rotate clockwise by a turning moment exerted by its own weight (Fig. 18cm. so that the flow path is blocked and the valve resumes the closed position. Where the spring 1 3 as illustrated in Fig. 1 9 is provided on the clapper 11, the clockwise urging is effected more positively.

Fig. 1 9 illustrates a modification of the fifth embodiment, wherein the partition portion 11 b is made slightly smaller than that of the fifth embodiment to form, as the fluid inlet means the gap 1 6 having a distance a between the partition portion 11 b and the valve body 1 and the spring 1 3 is provided to urge the clapper 11 clockwise. In this embodiment, the opening/closing operation of the clapper 11 is carried out in response to a change in the pressure within the accumulator chamber 4, as in the foregoing embodiments. The opening area of the gap 1 6 may be varied by changing the distance a to control the rotation speed of the clapper 11.

In further embodiments as illustrated in Figs. 20 and 21, the primary pipe connection 5 is provided on the left side as viewed in the figures and the valve portion 11 a is positioned so as to open and close the primary inlet. To adapt for this formation, in case of Fig. 20, the communicating aperture 12 is formed so as to extend from the valve portion 11 a to the partition portion 11 b, and, in case of Fig. 21, the communicating aperture 12 is formed in the valve body 1. The embodiment of Fig. 21 further has the flow control device 14 provided in the communicating aperture 1 2. By this device, the opening diameter ratio of the control pipe connection 7 to the communicating aperture 1 2 can be varied to freely control the closing/opening speed of the clapper 11.As illustrated in Fig. 22, the bypass 1 5 may alternatively be provided to effect similar flow control. More specifically, the bypass 1 5 is branched from the pipe leading to the primary pipe connection 5 and connected to a pipe extending from the control pipe connection 7.

In a still further embodiment as illustrated in Fig. 23, the seat ring 9 at the secondary pipe connection 6 is slightly projected into the valve chamber 3 to increase the ratio, in area, of the accumulator chamber 4 to the valve chamber 3 as compared with the foregoing embodiments, e.g., the embodiment of Fig.

1 6. The packing 11 d is provided not only at the tip end portion 11 c.of the partition portion 11 b but on the clapper 11 at a position near the shaft 8. With this arrangement, the pressure control within the accumulator chamber 4 can be achieved more effectively.

Fig. 24 illustrates a still further modification which is applicable to each of the first to fifth embodiments. In the valve of this modification, the shaft 8 is fixed to the clapper 11, for example, by a pin. A needle pointer 1 7 is interlocked to the shaft 8 and graduation marks from fully open position to fully closed position are provided on an outer sidewall of the valve body 1. With this arrangement, the rotational position of the clapper 11, i.e., the opening degree of the valve can easily be seen from the outside. As illustrated by a phantom line, a handle 1 9 may be interlocked to the shaft 8 to enable manual rotation of the clapper 11. A means for amplifying a force may preferably be employed when a large force is required to rotate the handle 1 9.

As described above, the valve structure is simplified and the manufacturing, maintenance, inspection can be facilitated by integrally forming the valve chamber and the accumulator chamber in the valve body and rotatably mounting the clapper of the specified shape within the valve body. Further, since the valves of the embodiments are formed that the valve chamber may connect the primary side and the secondary side linearly, the flow path of the fluid can be simplified and a pressure loss of the fluid when the valve is in the full open position can be reduced very much. As a result, troubles can be reduced, the life is prolonged, and the burden of the fluid pressurizing source can be reduced. In addition, since the fluid inlet means is provided by a simple structure, the manufacturing cost can be reduced.

A valve of the present invention may be applied to various equipments as well as a foam fire extinguishing system.

Claims (16)

1. A valve which comprises: a valve body; a valve chamber and an accumulator chamber formed within said valve body; pipe connections for a primary side and a secondary side, respectively, which are provided on a valve chamber side of the valve body; a control pipe connection provided on an accumulator chamber side for reducing a pressure within said accumulator chamber; a clapper having a sectorial shape in section and rotatably mounted on said valve body with a center of the arc of the sectorial shape as a fulcrum for partitioning between said valve chamber and said accumulator chamber; and fluid inlet means for introducing fluid from the primary pipe connection into said accumulator chamber.

2. A valve according to claim 1, wherein said fluid inlet means is formed of a communicating aperture provided in said clapper for communicating said valve chamber with said accumulator chamber therethrough.

3. A valve according to claim 1, wherein said fluid inlet means is formed of a communicating aperture provided in said clapper for communicating the primary pipe connection with said accumulator chamber therethrough when the valve is closed and communicating said valve chamber with said accumulator chamber therethrough when the valve is opened.

4. A valve according to claim 1, wherein said fluid inlet means is formed of a communicating aperture provided on said clapper for communicating said valve chamber or the primary pipe connection with said accumulator therethrough.

5. A valve according to claim 4, which further comprises a flow control device provided in said communicating aperture for controlling an opening/closing speed of said clapper.

6. A valve according to claim 1, wherein said fluid inlet means is formed of a bypass branched from a pipe leading to the primary pipe connection and connected to the accumulator side.

7. A valve according to claim 6, which further comprises a flow control device provided in said bypass for controlling an opening/closing speed of said clapper.

8. A valve according to claim 1, wherein said clapper is rotatably mounted on said valve body at a position near the secondary pipe connection and said fluid inlet means is formed by a gap provided between said valve body and said clapper to allow fluid intro diced into said valve body to pass there ,through.

9. A valve according to claim 1, 2, 3, 4, 7 or 8, which further comprises a spring provided on said clapper for urging said clapper to rotate to a closed position thereof.

10. A valve according to claim 1, 2, 3, 4, 5, 6, 7, or 8, which further comprises a shaft provided to the clapper and rotatable conjoint!y 'with said clapper, a needle pointer interlocked to said shaft and graduation marks provided on the outer surface of said valve bsdy, thereby to show an opening degree of the valve from the. outside.

11. A valve according to claim 1, 2, 3, 4, 5, C, 7 or 8, which further comprises a shaft piDJd ied tO tile clapper and rotatable conjo- irti'; with said clapper and a handle interlocked to said shaft thereby to enable manual rotation of the clapper.

12. A valve according to claim 1, 2, 3, 4, 5, 6, 7, or 8, wherein the primary pipe connection is connected to a fire extinguishing solution source, the secondary pipe connection is connected to a bubble head and the control pipe connection is connected to a selfressetable detector head, thereby to allow the valve to be used as a valve for a foam fire extinguishing system.

1 3. A valve which comprises: a valve body'; a valve chamber and an accumulator chamber formed within said valve body; a primary pipe connection and a secondary pipe connection provided on a valve chamber side of said valve body; a control pipe connection provided on an accumulator chamber side for reducing a pressure within said accumulator chamber; a clapper rotatably mounted on said valve body; and a fluid inlet mechanism for introducing fluid from the primary pipe connection into said accumulator chamber, said clapper comprising a valve portion for opening and closing a primary inlet or a secondary outlet and a partition portion for partitioning between said valve chamber and said accumulator chamber and said valve body having an inner wall curved so as to correspond to a rotation locus of a tip end portion of said partition portion.

14. A valve according to claim 13, wherein said fluid inlet means is formed of a communicating aperture provided on the clapper for communicating the primary pipe connection or the valve chamber with the accumulator chamber therethrough.

1 5. A valve according to claim 13, wherein said fluid inlet means is formed by a gap provided between the valve body and the clapper.

16. A valve according to claim 13, wherein said fluid inlet means is formed of a communicating aperture provided on said clapper for communicating said valve chamber or the primary pipe connection with said accumulator therethrough.

1 7. A valve, substantially in accordance with any embodiment herein described with reference to Figs. 1 to 24 of the accompanying drawings.