JP2021124138A - On-off valve mechanism of lever float type steam trap - Google Patents

Abstract

To provide an on-off valve mechanism of a lever float type steam trap which can realize smooth valve closing operation.SOLUTION: An on-off valve mechanism VM of a lever float type steam trap of the invention includes: a lever 8 which is connected to a float 1 and swings around a supporting point P1; a valve seat member 34 forming a valve seat 32 on which a valve body 10 is seated; a valve guard 50 which holds the valve body 10 and may move in a vertical direction; and a connection member 52 which connects the valve guard 50 with the lever 8. The connection member 52 moves the valve guard 50 in the vertical direction by swinging of the lever 8 to cause the valve body 10 to open or close. The connection member 52 is connected to the valve guard 50 in a tiltable manner.SELECTED DRAWING: Figure 3

Description

The present invention relates to an on-off valve mechanism of a lever float type steam trap in which a float is provided at one end of a lever and a valve body is provided at the other end, and the valve body is opened and closed by the buoyancy of the float.

In the lever float type steam trap, the float and the on-off valve mechanism are connected by a lever, and the buoyancy of the float acts as a force in the valve opening direction to open and close the valve (for example, Patent Document 1). In a valve mechanism as in Patent Document 1, a valve body seated in a valve hole and a valve shaft are inseparably formed integrally. Therefore, if the valve shaft is tilted when the valve is closed, the valve body cannot be seated smoothly in the valve hole, and there is a concern that the valve closing may be defective. If such a valve closing failure occurs, it may lead to steam leakage. In particular, in a high-pressure environment, the velocity of the fluid passing through the valve hole becomes high, so that if steam leakage occurs due to poor valve closing, erosion of the valve body and the valve hole by the fluid may be accelerated.

Japanese Unexamined Patent Publication No. 2010-2429223

Further, in the valve closing state, the force with which the valve body is pressed against the valve hole by the internal pressure acts as the valve closing force. In the integrated design of the valve body and the valve shaft, there is a concern that a large load will be applied to the valve shaft due to the impact when the valve is closed.

An object of the present invention is to provide an on-off valve mechanism for a lever float type steam trap that can realize a smooth valve closing operation.

In order to achieve the above object, the on-off valve mechanism of the lever float type steam trap of the present invention is a valve seat member that forms a lever that is connected to the float and swings around a fulcrum and a valve seat on which the valve body is seated. A valve guard that holds the valve body and can move in the vertical direction, and the valve guard and the lever are connected to each other, and the valve guard is moved in the vertical direction by swinging the lever to open and close by the valve body. It is equipped with a connecting member that allows the operation to be performed. The connecting member is tiltably connected to the valve guard.

According to this configuration, the connecting member constituting the valve shaft and the valve body are separately configured, and the connecting member is tiltably connected to the valve guard holding the valve body. That is, the inclination of the connecting member is absorbed by the inclination of the valve guard, and the valve body itself operates only in the vertical direction (vertical direction). As a result, the valve body is not seated in an inclined state. Therefore, a smooth valve closing operation can be realized, and the occurrence of valve closing failure can be prevented.

In the present invention, a holder that supports the valve guard so as to be movable in the vertical direction and supports the valve seat member so as to be relatively immovable may be provided. According to this configuration, it is possible to realize an on-off valve mechanism in which the valve closing operation is smooth with a simple structure.

In the present invention, the valve body may be provided with a stopper that engages with the valve guard and regulates the lower limit position of the valve body with respect to the valve guard. According to this configuration, it is possible to prevent the valve body from moving excessively downward, so that the load acting on the valve body is reduced.

In this case, a ring fitted to the outer periphery of the upper portion of the valve body may be further provided, and a compression spring may be inserted between the ring and the stopper. According to this configuration, the load received by the valve body at the time of sitting and in the seated state is absorbed by the compression spring, so that the load on the valve body and the valve shaft can be reduced.

In the present invention, the valve guard and the connecting member may be connected by a pin penetrating the connecting member. According to this configuration, the inclination of the connecting member can be absorbed by the rotation of the connecting pin. As a result, a smooth valve closing operation can be realized with a simple structure.

According to the on-off valve mechanism of the lever float type steam trap of the present invention, it is possible to prevent the valve body from being seated in an inclined state and to realize a smooth valve closing operation.

It is a vertical cross-sectional view which shows the lever float type steam trap provided with the on-off valve mechanism which concerns on 1st Embodiment of this invention. It is a top view which shows the main part of the lever float type steam trap. It is a vertical cross-sectional view which shows the drain valve of the lever float type steam trap enlarged. It is a perspective view which shows the spacer of the lever float type steam trap.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. In the following description, "upstream" and "downstream" mean "upstream" and "downstream" in the fluid flow direction.

FIG. 1 is a configuration diagram showing a lever float type steam trap provided with an on-off valve mechanism VM according to the first embodiment of the present invention. The lever float type steam trap opens and closes the drain valve 2 by the buoyancy of the float 1 to drain the condensate (drain) D. The case 6 forming the float chamber 4 for accommodating the float 1 and the front end portion ( A lever 8 to which a float 1 is connected is provided at one end). The lever 8 is connected to the float 1 at the front end portion 8a and swings around the fulcrum P1. That is, the lever 8 is swingably supported by the case 6 around the fulcrum P1 by a known structure. A valve body 10 of the drain valve 2 is attached in the vicinity of the fulcrum P1 between the front end portion 8a of the lever 8 and the fulcrum P1.

As shown in FIG. 2, in the present embodiment, the lever 8 has a pair of left and right lever pieces 9, 9. Specifically, the lever 8 has a U-shape in a plan view in which the front ends of the pair of lever pieces 9 and 9 are connected by the connecting piece 11. That is, the connecting piece 11 of the lever 8 constitutes the front end portion 8a connected to the float 1.

When the liquid level of the drain D in the float chamber 4 shown in FIG. 1 rises, the float 1 rises, and the lever 8 swings around the fulcrum P1 in the direction of the arrow A1. As a result, the valve body 10 of the drain valve 2 rises to open the valve, and the drain D is discharged. When the liquid level of the drain D in the float chamber 4 drops, the float 1 drops, and the lever 8 swings around the fulcrum P1 in the direction of arrow A2. As a result, the valve body 10 of the drain valve 2 is lowered to close the valve. Details of the drain valve 2 will be described later.

In the case 6 constituting the exterior body, the cover body 16 is connected to the flange portion 14 of the case body 12 having one end portion (left end portion in the drawing) opened by a fastening member 18 such as a bolt. The float chamber 4 is formed by an area surrounded by the case body 12 and the cover body 16. Steam is trapped in the float chamber 4. An inlet 100 for introducing a primary fluid containing steam and drain D into the float chamber 4 is formed in the upper part of the case body 12.

The cover body 16 is a member having a shape that closes an opening at one end (left end) of the case 6, and an outflow path 20 having a circular cross section for draining the drain D is formed inside the cover body 16. There is. An outflow passage downstream portion 20a communicating with an outlet (not shown) to the outside is connected to the upper side of the outflow passage 20. Further, a communication passage 22 for communicating the float chamber 4 and the outflow passage 20 is provided in the vicinity of the lower end portion of the outflow passage 20 in the cover body 16.

The communication passage 22 is formed by a spacer 24 interposed between the drain valve 2 and the cover body 16. The spacer 24 is a tubular member extending in the left-right direction in FIG. 1, and one end side in the longitudinal direction opens to the float chamber 4 and the other end side opens to the outflow passage 20. A flange-shaped first flange 26 is formed at one end (float chamber 4 side) in the longitudinal direction of the cylindrical portion 27 of the spacer 24, and a flange-shaped second flange 28 is formed at an intermediate portion in the longitudinal direction. A plurality of bolt insertion holes 28a are formed in the second flange 28, and the spacer 24 is coupled to the cover body 16 by the bolts 30 inserted through the bolt insertion holes 28a.

The drain valve 2 is arranged on the upstream side (float chamber 4 side) of the spacer 24 in the float chamber 4. The drain valve 2 drains the drain D that has flowed into the float chamber 4 and has accumulated. A plurality of female threads 26a (FIG. 4) for connecting the drain valve 2 are formed on the first flange 26 of the spacer 24.

As shown in FIG. 3, the drain valve 2 has the valve body 10 and a valve seat member 34 forming a valve seat 32 on which the valve body 10 is seated. The valve seat member 34 has a valve hole 36 formed inside the valve seat member 34, and the upper end (upstream end) of the valve hole 36 communicates with the valve seat 32. That is, when the valve body 10 is seated on the valve seat 32, the valve hole 36 is closed and the drain D does not flow (closed state). When the valve body 10 is separated from the valve seat 32, the valve hole 36 is opened and the drain D flows (open state).

The lower end (downstream end) of the valve hole 36 is connected to the outflow passage 20 via the communication passage 22 of FIG. Specifically, the drain valve 2 includes a holder 38 that supports the valve body 10 so as to be movable in the vertical direction and supports the valve seat member 34 so as to be relatively immovable.

The holder 38 has an upstream passage 40 formed on the upper side inside the holder 38, and a downstream passage 42 formed on the lower side inside the holder 38. The upstream passage 40 communicates with the float chamber 4, and the downstream passage 42 communicates with the communication passage 22. Inside the holder 38 of FIG. 3, a valve seat member mounting hole 44 that communicates the upstream side passage 40 and the downstream side passage 42 is formed. Specifically, the valve seat member 34 is mounted in the valve seat member mounting hole 44, and the upstream side passage 40 and the downstream side passage 42 communicate with each other through the valve hole 36 of the valve seat member 34.

A valve body insertion hole 46 is formed in the upper part of the holder 38. The valve body insertion hole 46 communicates the float chamber 4 and the upstream passage 40 in the vertical direction. In the present embodiment, the valve body insertion hole 46 is formed by a bush 45 mounted on the holder 38. The valve body 10 passes through the hollow hole (valve body insertion hole) 46 of the tubular bush 45.

A screw insertion hole (not shown) is formed in the holder 38 of FIG. By screwing the bolt 25 into the female screw 26a (FIG. 4) of the first flange 26 of the spacer 24 through the screw insertion hole of the holder 38, the holder 38 having the valve seat 32 is attached to the cover body 6 via the spacer 24. Has been done. A gasket 48 is interposed between the spacer 24 and the holder 38.

Next, the valve body 10 will be described. As shown in FIG. 3, the drain valve 2 further includes a valve guard 50 and a connecting member 52. The valve guard 50 holds the valve body 10 and is movable in the vertical direction in the valve body insertion hole 46. The connecting member 52 connects the valve guard 50 and the lever 8, and the valve guard 50 is moved in the vertical direction by swinging the lever 8 to open and close the valve body 10. That is, the valve body 10 is connected to the lever 8 via the connecting member 52 and the valve guard 50.

The connecting member 52 is connected to the lever 8 by the first connecting pin 54. Specifically, as shown in FIG. 2, the connecting member 52 is arranged between the left and right lever pieces 9, 9, and the first connecting pin 54 penetrates the left and right lever pieces 9, 9 and the connecting member 52. ..

The connecting member 52 is tiltably connected to the valve guard 50. Specifically, the valve guard 50 and the connecting member 52 are connected by a second connecting pin 56 penetrating the connecting member 52. An insertion hole 50a that opens upward is formed in the upper part of the valve guard 50, and the connecting member 52 is inserted into the insertion hole 50a from above. In this state, the second connecting pin 56 penetrates the valve guard 50 and the connecting member 52. The diameter of the insertion hole 50a is formed to be larger than the outer diameter of the connecting member 52, and the connecting member 52 is configured to swing around the second connecting pin 56. On the other hand, the valve guard 50 moves substantially in the vertical direction in the valve body insertion hole 46.

A valve body insertion hole 58 extending in the vertical direction is formed in the lower portion of the valve guard 50. In the present embodiment, the valve body insertion hole 58 is a stepped through hole. That is, the valve body insertion hole 58 has a large diameter hole 62 on the upper side and a small diameter hole 64 on the lower side with the step portion 60 interposed therebetween. An annular locking groove 62a is formed on the upper portion of the peripheral wall of the large diameter hole 62. An annular receiving portion 66 projecting inward in the radial direction is formed at the lower end portion of the small diameter hole 64. That is, the receiving portion 66 is formed to have a smaller diameter than the small diameter hole 64.

The valve body 10 has a cylindrical shape that is long in the vertical direction, and the lower end portion 10a thereof is formed in a tapered shape in which the diameter is reduced downward. When the lower end portion 10a is seated on the valve seat 32, the valve hole 36 is closed. A flange-shaped flange portion 65 projecting outward in the radial direction is formed in the vertical intermediate portion of the valve body 10.

The outer diameter of the valve body 10 is formed to be smaller than the inner diameter of the receiving portion 66. The outer diameter of the flange portion 65 is formed to be larger than the inner diameter of the receiving portion 66 and smaller than the diameter of the small diameter hole 64. Therefore, when the valve body 10 is lowered, the lower surface of the flange portion 65 comes into contact with the upper surface of the receiving portion 66. That is, the flange portion 65 constitutes a stopper 65 that regulates the lower limit position of the valve body 10 with respect to the valve guard 50.

A ring 68 is fitted on the outer circumference of the upper portion of the valve body 10. In this embodiment, the ring 68 is made up of washers. The outer diameter of the ring 68 is formed to be slightly smaller than the diameter of the large diameter hole 62. The inner diameter of the ring 68 is formed to be slightly larger than the outer diameter of the valve body 10 and smaller than the diameter of the small diameter hole.

The C ring 69 is engaged with the locking groove 62a on the peripheral wall of the large diameter hole 62. The C ring 69 prevents the valve body 10 and the ring 68 from coming out upward. A compression spring 70 is inserted between the ring 68 and the stopper (flange portion) 65. As a result, the force acting on the valve body 10 is absorbed.

The lever 8 to which the float 1 is connected, the valve seat member 34 forming the valve seat 32, the valve guard 50 holding the valve body 10, the connecting member 52 connecting the lever 8 and the valve guard 50, and the compression spring 70 make the lever. The on-off valve mechanism VM of the float type steam trap is configured. However, the compression spring 70 may not be provided.

Next, the weight 72 that assists the opening operation of the valve body 10 will be described. As shown in FIG. 1, the weight 72 is provided behind the fulcrum P1 in the lever 8. The weight 72 is preferably a corrosion-resistant material, and is, for example, an austenitic stainless steel such as SUS304. However, the material of the weight 72 is not limited to this. The weight of the weight 72 varies greatly depending on the working pressure, for example, the valve structure, size, etc., and is appropriately set in consideration of these.

As shown in FIG. 2, the weight 72 has a pair of left and right weight parts 74, 74. The left and right weight parts 74 and 74 are attached to the outer surfaces of the left and right lever pieces 9 and 9, respectively. It is preferable that the left and right weight parts 74, 74 have the same shape and the same weight. In this embodiment, each weight component 74 has a stepped cylindrical shape. Specifically, each weight component 74 has a first cylindrical portion 76 that abuts on the lever piece 9, and a second cylindrical portion 78 having a diameter larger than that of the first cylindrical portion 76.

The second cylindrical portion 78 is provided on the opposite side of the first cylindrical portion 76 from the lever piece 9. The first cylindrical portion 76 and the second cylindrical portion 78 are connected by a truncated cone portion 80. The small diameter side end face of the truncated cone portion 80 is connected to the first cylindrical portion 76, and the large diameter side end face of the truncated cone portion 80 is connected to the second cylindrical portion 78. That is, the truncated cone portion 80 has a tapered shape in which the diameter gradually increases from the first cylindrical portion 76 toward the second cylindrical portion 78. In the present embodiment, the first cylindrical portion 76, the second cylindrical portion 78, and the truncated cone portion 80 are inseparably integrally formed. However, the structure and shape of the weight component 74 are not limited to this.

Further, an additional weight component 82 is provided between the pair of left and right lever pieces 9, 9. In this embodiment, the additional weight component 82 has a disk shape. However, the shape of the additional weight component 82 is not limited to this.

The left and right weight parts 74, 74 and the additional weight parts 82 are attached to the lever 8 by a third connecting pin 84. Specifically, the third connecting pin 84 extends through the left and right weight components 74,74, the left and right lever pieces 9,9, and the additional weight component 82. However, the support structure of the weight 72 is not limited to this.

The lever float type steam trap of FIG. 1 further includes a stopper member 85 that restricts the movement of the weight 72 on the lever 8. In the present embodiment, a part of the spacer 24 constitutes the stopper member 85. Specifically, the first flange 26 and the cylindrical portion 27 of the spacer 24 constitute the stopper member 85.

As shown in FIG. 4, the first flange 26 and the second flange 28 are formed in an oval shape when viewed from the axial direction. Specifically, the first flange 26 is formed by a curved surface in which the upper surface 26u and the lower surface 26d extend linearly when viewed from the axial direction, and the left and right side surfaces 26s and 26s bulge outward. Similarly, in the second flange 28, the upper surface 28u and the lower surface 28d extend linearly when viewed from the axial direction, and the left and right side surfaces 28s and 28s are formed of curved surfaces bulging outward. The second flange 28 is formed with an additional flange portion 29 that projects upward from the intermediate portion of the upper surface 28u in order to secure the support rigidity.

As shown in FIG. 1, in the present embodiment, the upper surfaces 26u and 26u of the first flange 26 and the upper surface of the cylindrical portion 27 constitute the stopper member 85. Specifically, the first cylindrical portion 76 of the weight component 74 abuts on the upper surfaces 26u and 26u of the first flange 26, and the lower surface of the additional weight component 82 abuts on the upper surface of the cylindrical portion 27.

As shown in FIG. 2, by adjusting the tapered shape of the truncated cone portion 80 and the curved surface shapes of the side surfaces 26s and 28s of the first and second flanges 26 and 28, the weight component 74 has the first and second flanges 26. , 28 can be avoided, and the weight 72 can be brought into contact with the stopper member 85 at a target lever angle while ensuring the weight of the weight 72. Further, since the spacer 24 also serves as the stopper member 85, an increase in the number of parts is suppressed and the structure is simplified.

Next, the operation of the lever float type steam trap of the present embodiment will be described. The primary side fluid containing high-temperature steam flows into the float chamber 4 of FIG. 1, and the drain D mixed in the primary side fluid collects in the float chamber 4. When the drain D is below the set water level, the float 1 is held at the lower limit position shown by the alternate long and short dash line in FIG. At this time, the drain valve 2 is in a closed state in which the valve hole 36 of FIG. 3 is closed by the valve body 10, and the high-temperature steam contained in the primary fluid is trapped in the float chamber 4.

When the drain D accumulated in the float chamber 4 exceeds the set water level, as shown by the solid line in FIG. 1, the lever 8 rotates around the fulcrum P1 in the direction of the arrow A1 in response to the buoyancy from the drain D and floats. The valve body 10 of FIG. 3, which moves upward integrally with 1, opens the valve hole 36. As a result, the drain valve 2 is opened, and the fluid containing the drain D passes through the valve hole 36, the downstream passage 42 inside the holder 38, the communication passage 22 inside the spacer 24 in FIG. 1, and the outflow passage 20. It is discharged to the outside of the steam trap from the downstream portion 20a of the outflow passage.

At this time, due to the weight of the weight 72, a force in the direction of arrow A3, that is, a force in the valve opening direction acts on the lever 8. Therefore, the opening operation of the valve body 10 becomes smooth even in a high temperature and high pressure environment.

When the drain D in the float chamber 4 is reduced by the discharge, the float 1 is lowered by its own weight, and the lever 8 is rotated around the fulcrum P1 in the direction of the arrow A2 to be in a fully closed state. At this time, since the connecting member 52 of FIG. 3 swings around the second connecting pin 56, the inclination of the connecting member 52 is absorbed and the valve body 10 operates in the vertical direction (vertical direction). As a result, the valve body 10 is not seated on the valve seat 32 in an inclined state, and a smooth valve closing operation is realized. Further, since the load received by the valve body 10 at the time of sitting and in the seated state is absorbed by the compression spring 70, the load on the valve body 10 is reduced.

In a high temperature and high pressure environment, the density of the drain D inside becomes small, so that the buoyancy becomes small. Further, the force acting on the valve body 10 in the closed state is a force that presses the valve body 10 against the valve hole 36 by the internal pressure, and a larger force is required to open the valve. Therefore, in a high temperature and high pressure environment, a large force is required to open the valve. According to the above configuration, as a force to assist the buoyancy of the float 1, a weight 72 acting in the valve opening direction is attached on the lever 8 connected to the float 1. Therefore, it is possible to secure the valve opening force in a high temperature and high pressure environment while suppressing an increase in the size of the float 1 and the length of the lever 8 from the fulcrum P1 to the float 1. Further, since the movement of the weight 72 is restricted by the stopper member 85, it is possible to prevent the weight 72 from moving excessively and interfering with other parts.

As shown in FIG. 2, since the weight 72 has a pair of left and right weight parts 74, the size of one weight part 74 is reduced, so that the size (weight) of the weight 72 can be easily adjusted. .. Further, since the lever 8 has a pair of left and right lever pieces 9 and 9, it is easy to arrange the left and right weight parts 74 in a well-balanced manner. Further, since the additional weight component 82 is provided between the pair of left and right lever pieces 9, 9, the weight of the weight 72 can be adjusted more easily.

A spacer 24 is attached to the case 6, and a holder 38 is attached to the spacer 24 via a gasket 48. The spacer 24 constitutes the stopper member 85. As a result, a lever float type steam trap with a weight can be realized with a simple configuration.

As shown in FIG. 3, the connecting member 52 and the valve body 10 constituting the valve shaft are separately formed, and the connecting member 52 is tiltably connected to the valve guard 50 holding the valve body 10. That is, the inclination of the connecting member 52 is absorbed by the inclination with respect to the valve guard 50, and the valve body 10 itself operates only in the vertical direction (vertical direction). As a result, the valve body 10 is not seated on the valve seat 32 in an inclined state. Therefore, a smooth valve closing operation can be realized, and the occurrence of valve closing failure can be prevented.

Further, the holder 38 supports the valve guard 50 so as to be movable in the vertical direction, and supports the valve seat member 34 so as to be relatively immovable. As a result, it is possible to realize an on-off valve mechanism VM with a simple structure and a smooth valve closing operation.

The valve body 10 is provided with a stopper 65 that engages with the valve guard 50 and regulates the lower limit position of the valve body 10 with respect to the valve guard 50. As a result, it is possible to prevent the valve body 10 from moving excessively downward, so that the load acting on the valve body 10 is reduced.

Further, a ring 68 is fitted on the outer periphery of the upper portion of the valve body 10, and a compression spring 70 is inserted between the ring 68 and the stopper 65. Therefore, since the load received by the valve body 10 when seated and in the seated state is absorbed by the compression spring 70, the load on the valve body 10 and the connecting member 52 can be reduced.

The valve guard 50 and the connecting member 52 are connected by a second connecting pin 56 that penetrates the connecting member 52. As a result, the inclination of the connecting member 52 can be absorbed by the rotation of the second connecting pin 56, so that a smooth valve closing operation can be realized with a simple structure.

The present invention is not limited to the above embodiments, and various additions, changes, or deletions can be made without departing from the gist of the present invention. For example, the weight 72 may be omitted. In this case, the spacer 24 is also omitted, and the holder 38 is connected to the case 6. Therefore, such things are also included within the scope of the present invention.

1 Float 8 Lever 10 Valve body 32 Valve seat 34 Valve seat member 38 Holder 50 Valve guard 52 Connecting member 56 Second connecting pin (pin)
65 Flange part (stopper)
68 Ring 70 Compression spring P1 fulcrum VM on-off valve mechanism

Claims (5)

A lever that is connected to the float and swings around the fulcrum,
A valve seat member that forms a valve seat on which the valve body is seated,
A valve guard that holds the valve body and can move up and down,
A connecting member that connects the valve guard and the lever and moves the valve guard in the vertical direction by swinging the lever to perform an opening / closing operation by the valve body is provided.
The connecting member is an on-off valve mechanism for a lever float type steam trap that is tiltably connected to the valve guard. The lever float type steam trap on-off valve mechanism according to claim 1, further comprising a holder that supports the valve guard so as to be movable in the vertical direction and supports the valve seat member so as to be relatively immovable. On-off valve mechanism of steam trap. In the on-off valve mechanism of the lever float type steam trap according to claim 1 or 2, the valve body is provided with a stopper that engages with the valve guard and regulates the lower limit position of the valve body with respect to the valve guard. Lever float type steam trap on-off valve mechanism. The on-off valve mechanism of the lever float type steam trap according to claim 3 further includes a ring fitted to the outer periphery of the upper portion of the valve body.
An on-off valve mechanism for a lever float type steam trap in which a compression spring is inserted between the ring and the stopper. In the on-off valve mechanism of the lever float type steam trap according to any one of claims 1 to 4, the valve guard and the connecting member are connected by a pin penetrating the connecting member. On-off valve mechanism.

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