JPH06257682A - Swing check valve with plurality of valve plates - Google Patents

Abstract

PURPOSE:To avoid the irregular open and close motion of a valve plate for maintaining the predetermined opening thereof, and prevent the occurrence of a noise or a vibration, even upon the occurrence of the variation of flow state in upstream piping, by providing such an opening adjustment mechanism as corresponding at least to one of a plurality of valve plates. CONSTITUTION:In a swing check valve with a plurality of valve plates, two valve plates 1A and 1B are fixed to valve stems 3A and 3B journalled to both support sections of a valve box 2 in such state as freely rotatable and liquidtight or airtight. Also, the valve seat sections 5 of the plates 1A and 1B contact and part from valve box seat sections 4 for open and close operation, as a result of turning motion in an open direction due to a forward flow fluid P1 in the valve box 2, and turning motion in a close direction due to a reverse flow fluid P2 and own weight. In addition, a valve opening adjustment mechanism 7 is provided, so as to correspond to one valve plate 1A of the two. According to this construction, when the protrusion amount of the adjusting screw B of the mechanism 7 into the valve box 2 is made large and the opening of the valve plate 1A is restricted to be small, the irregular open and close motion of the other valve plate 1B can be avoided and the opening thereof can be maintained at the preset level, even upon the occurrence of the variation of a flow in upper stream piping 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a swing type check valve having a plurality of valve bodies.

[0002]

2. Description of the Related Art For example, as shown in FIG. 6, two valve bodies 1A and 1B are fixed to valve rods 3A and 3B which are rotatably supported by both side shafts of a valve box 2 and are liquid-tightly or airtightly supported. Rotation in the valve opening direction due to the forward fluid P1 in the valve box 2 and rotation in the valve closing direction due to the reverse fluid P2 and its own weight cause the valve box seal to move.
In the swing-type check valve having a plurality of valve bodies configured to open and close by contacting and separating the valve body sheet portion 5 from the valve portion 4, the rectified fluid flows from the upstream pipe 6 into the valve box 2. In this case, the pressure distribution of the forward fluid P1 on the two valve bodies 1A and 1B becomes substantially equal, and the valve bodies 1A and 1B open at a predetermined opening. However, when the flow condition on the upstream pipe 6 side changes and the rectified fluid does not flow in, the flow balance in the valve box 2 is impaired, and the forward fluid P1 for the two valve bodies 1A, 1B is lost. Becomes uneven, and, for example, one valve body 1A is opened at a predetermined opening, but the other valve body 1B irregularly repeats opening and closing movements, or both valve bodies 1A are opened. , 1B becomes an unstable state in which the opening and closing movements are alternately repeated, and noise and vibration are generated.

Therefore, even if the flow condition of the upstream pipe 6 fluctuates, the unstable state as described above does not occur, and a swing type reverse valve having a plurality of valve elements capable of reliably preventing the generation of noise and vibration. Development of a stop valve is required. Therefore, as a result of earnest research, the inventor of the present invention, when the flow condition of the upstream pipe 6 fluctuates, if the opening degree of one valve body 1A is adjusted in accordance with the fluctuating flow condition, It was confirmed that even if the flow balance in Fig. 2 is impaired, the other valve body 1B or both valve bodies 1A and 1B can be held at a predetermined opening while avoiding the irregular opening and closing movements, and the present invention has been completed. It was

[0004]

The problem to be solved is that, when the flow condition of the upstream piping fluctuates, the balance of the flow in the valve box is impaired, and the pressure distribution of the forward fluid to the plurality of valve elements is distributed. Is uneven, and an unstable state in which opening and closing movements are repeated irregularly is generated, which causes noise and vibration.

[0005]

SUMMARY OF THE INVENTION According to the present invention, a plurality of valve elements are fixed to a valve rod which is rotatable and liquid-tightly or airtightly supported on both side shaft support portions of a valve box, and a forward fluid in the valve box is provided. A plurality of valve bodies configured to open and close by the valve body seat portion coming into contact with and separating from the valve box seat portion by the rotation in the valve opening direction by the pressure and the rotation in the valve closing direction by the reverse fluid pressure. In the swing type check valve having the above-mentioned, an opening degree adjusting mechanism is provided corresponding to at least one valve element of the plurality of valve elements, and the valve element is provided even if the flow condition of the upstream pipe fluctuates. We achieved the purpose of reliably preventing the generation of noise and vibration by avoiding the irregular opening and closing movement of the above and maintaining it at a predetermined opening.

[0006]

According to the present invention, when the flow condition of the upstream piping fluctuates, the flow balance in the valve box is impaired by adjusting the opening of one valve body, for example, according to the fluctuating flow condition. Even in this case, it is possible to avoid the irregular opening / closing movement of the other valve body and hold it at a predetermined opening degree.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. Note that the same or corresponding portions as those of the conventional example described in FIG. FIG. 1 is a vertical side view showing an embodiment of the present invention. In this figure, a swing check valve having a plurality of valve bodies has two valve bodies 1A, 1A.
B is fixed to the valve rods 3A and 3B which are rotatably supported on both side shafts of the valve box 2 and are liquid-tightly or air-tightly supported, and the rotation in the valve opening direction by the forward fluid P1 in the valve box 2 is reversed. Directional fluid P
2 and the valve body sheet portion 5 is brought into contact with and separated from the valve box sheet portion 4 by the rotation in the valve closing direction due to its own weight to open and close. An opening adjustment mechanism 7 is provided corresponding to the one valve body 1A. That is, the opening adjustment mechanism 7 includes the valve box 2
And a sleeve 7A with an internal thread, which is attached to the valve body 1A by being screwed into the sleeve 7A with an internal thread.
It is composed of an adjusting screw 7B extending in the direction and a positioning lock nut 7C screwed to the adjusting screw 7B.

With such a configuration, when the rectified forward fluid P1 having a predetermined pressure is flowing from the upstream pipe 6 into the valve box 2, the forward fluid P1 for the two valve bodies 1A and 1B is obtained. The pressure distribution of the
Is opened as indicated by a solid line, and the valve body seat 4 is rotated by the flow of the reverse direction fluid P2 and its own weight in the valve closing direction.
The valve portion 5 is in a closed state in which the contact portion 5 is in pressure contact. On the other hand, if the flow condition on the upstream pipe 6 side fluctuates and, for example, the flow velocity becomes extremely high and the rectified fluid does not flow into the valve box 2, the flow balance in the valve box 2 is impaired. The pressure distribution of the forward fluid P1 with respect to the two valve bodies 1A and 1B becomes uneven, and, for example, as shown in FIG.
Although A is opened at a predetermined opening, the other valve body 1B is in an unstable state in which opening and closing movements are repeated irregularly, and noise and vibration are generated. In this way, when the flow condition on the upstream pipe 6 side fluctuates and the flow velocity becomes extremely high or is predicted to increase, as shown in FIG. 3, the adjustment screw 7B in the opening adjustment mechanism 7 is adjusted. If the amount of protrusion in the valve box 2 is increased and the opening degree of the one valve body 1A is restricted to a small value, even if the flow balance in the valve box 2 is impaired due to fluctuations in the flow condition on the upstream pipe 6 side, The other valve body 1B can be held at a predetermined opening while avoiding an irregular opening / closing movement. Therefore, it becomes possible to reliably prevent the generation of noise and vibration.

As shown in FIG. 4, the opening adjusting mechanism 7 includes a cylinder 7D which is mounted through the valve box 2 and a piston rod which is inserted into the cylinder 7D and extends in the direction of one valve element 1A. 7E and the switching valve 7F, and by introducing the fluid of the upstream pipe 6 into the cylinder 7D by the switching operation of the switching valve 7F, the protrusion amount of the piston rod 7E is adjusted to adjust the opening degree of one valve body 1A. It may be configured to do so. In addition, as shown in FIG.
One end of A, 3B is made to project to the outside of the valve box 2 in a liquid-tight or air-tight manner, and an arm 7G is attached to each projecting part.
A nut 7I is fixed concentrically with the through hole 7H formed in the above, and the adjustment bolt 7J screwed into this nut 7I is made to correspond to a hit member provided outside the valve box 2 to open both valve bodies 1A and 1B. The adjustment may be performed.

[0010]

As described above, according to the present invention, when the flow condition of the upstream pipe fluctuates, if the opening degree of one valve body is adjusted in response to the fluctuating flow condition, the inside of the valve box can be adjusted. Even if the flow balance is impaired, it is possible to avoid the irregular opening and closing movements of other valve bodies and hold them at a predetermined opening degree, so it is possible to reliably prevent the generation of noise and vibration. .

[Brief description of drawings]

FIG. 1 is a vertical side view showing an embodiment of the present invention.

FIG. 2 is a vertical sectional side view showing an example of an operating state of a valve body.

FIG. 3 is a vertical cross-sectional side view showing an example when an opening degree adjustment mechanism is executed.

FIG. 4 is an enlarged side view showing a modified example of the opening adjustment mechanism.

FIG. 5 is a vertical sectional side view showing another embodiment of the present invention.

FIG. 6 is a vertical sectional side view of a conventional example.

[Explanation of symbols]

 1A Valve body 1B Valve body 2 Valve box 3 Valve rod 4 Valve box seat part 5 Valve body seat part 7 Opening adjustment mechanism P1 Forward fluid P2 Reverse fluid

Claims (1)

[Claims] 1. A plurality of valve elements are fixed to a valve rod which is rotatably supported on both side shafts of a valve box and is liquid-tightly or airtightly supported.
Rotation in the valve opening direction due to the forward fluid in the valve box and rotation in the valve closing direction due to the reverse fluid and its own weight causes the valve body sheet section to contact and separate from the valve box sheet section for opening and closing. In a swing-type check valve having a plurality of valve elements configured as described above, an opening degree adjusting mechanism is provided corresponding to at least one valve element of the plurality of valve elements. Swing type check valve.