Patent Description:
In an example valve device, a float is disposed in a valve chamber. A float moves upward and downward in accordance with the amount of drain in the valve chamber to thereby open and close a valve hole. When the float closes the valve hole, the float is seated not only on a valve seat but also on a float seat. Accordingly, the state where the float closes the valve hole is maintained with stability, see <CIT>. <CIT> discloses also a valve device comprising a casing including a valve chamber. Furthermore, a valve seat including a valve hole is disposed in the valve chamber. A float is disposed in the valve chamber and movable in accordance with an amount of drain in the valve chamber to thereby open and close the valve hole. A support is provided supporting the float in a state of being seated on the valve seat and closing the valve hole.

Similar valve devices are also disclosed in <CIT> and <CIT>.

As described above, the float seat has a significant function for seating the float on the valve seat with stability. Thus, when position accuracy of the float seat decreases, stability in seating the float on the valve seat might decrease.

It is therefore an object of the technique disclosed here to enhance stability in seating a float on a valve seat.

A valve device disclosed here includes: a casing including a valve chamber; a valve seat disposed in the valve chamber and including a valve hole: a float disposed in the valve chamber and movable in accordance with an amount of drain in the valve chamber to thereby open and close the valve hole; and a support supporting the float in a state of being seated on the valve seat and closing the valve hole, wherein the support includes a base including an opening through which space above the base and space below the base communicate with each other in the valve chamber and having a closed frame shape which surrounds the opening and two float seats disposed in the base, and the float in the state of being seated on the valve seat and closing the valve hole being seated on the two float seats.

The valve device can enhance stability in seating the float on the valve seat.

Further advantages, features and potential applications of the present invention may be gathered from the description which follows, in conjunction with the embodiments illustrated in the drawings.

Throughout the description, the claims and the drawings, those terms and associated reference signs will be used as are notable from the enclosed list of reference signs. In the drawings is shown:.

An exemplary embodiment will be described in detail hereinafter with reference to the drawings. <FIG> is a cross-sectional view illustrating a schematic configuration of a valve device <NUM>.

The valve device <NUM> is a float-type valve device. The valve device <NUM> includes: a casing <NUM> including a valve chamber <NUM>; a valve seat <NUM> disposed in the valve chamber <NUM> and including a valve hole <NUM>; a float <NUM> disposed in the valve chamber <NUM> and movable in accordance with the amount of drain in the valve chamber <NUM> to thereby open and close the valve hole <NUM>; and a support <NUM> supporting the float <NUM> in the state of being seated on the valve seat <NUM> and closing the valve hole <NUM>. In this example, the valve device <NUM> is a drain trap (also referred to as a steam trap or a gas trap).

A fluid that flows into the valve device <NUM> is drain (condensate) and steam. The valve device <NUM> allows passage of drain and blocks passage of steam. That is, the float <NUM> opens the valve hole <NUM> while drain is flowing into the casing <NUM> and closes the valve hole <NUM> when stream flows into the casing <NUM>.

Specifically, the casing <NUM> has a divided structure including a first part <NUM> and a second part <NUM>. The first part <NUM> and the second part <NUM> are fastened with bolts and define a closed container. The valve chamber <NUM> is disposed in the casing <NUM>. That is, the first part <NUM> and the second part <NUM> define the valve chamber <NUM>.

The first part <NUM> has an opening 11a that opens the valve chamber <NUM> sideways. The second part <NUM> is attached to the first part <NUM> to close the opening 11a.

Specifically, the casing <NUM> includes a ceiling wall <NUM>, a bottom wall <NUM>, and a peripheral wall <NUM> coupling the ceiling wall and the bottom wall <NUM>. The ceiling wall <NUM>, the bottom wall <NUM>, and the peripheral wall <NUM> define the valve chamber <NUM>. The first part <NUM> includes the ceiling wall <NUM>, the bottom wall <NUM>, and a portion of the peripheral wall <NUM>. The second part <NUM> includes the other portion of the peripheral wall <NUM>. The portion of the peripheral wall <NUM> included in the first part <NUM> includes the opening 11a. The opening 11a is open sideways.

The first part <NUM> has an inlet <NUM> through which a fluid flows from outside of the casing <NUM> into the valve chamber <NUM>. The inlet <NUM> penetrates the ceiling wall <NUM> in the top-bottom direction.

The second part <NUM> and the bottom wall <NUM> of the first part <NUM> have an outflow channel <NUM> and an outlet <NUM> through which a fluid flows from the valve chamber <NUM> to the outside of the casing <NUM>. That is, the outflow channel <NUM> is continuous from the second part <NUM> to the bottom wall <NUM>. The upstream end of the outflow channel <NUM> is located in the second part <NUM> and is open in a lower portion of the valve chamber <NUM>. The downstream end of the outflow channel <NUM> is the outlet <NUM>. The outlet <NUM> is open downward in the bottom wall <NUM>. The axis of the inlet <NUM> and the axis of the outlet <NUM> substantially coaxially extend in the top-bottom direction.

In the casing <NUM>, a fluid channel is defined by the inlet <NUM>, the valve chamber <NUM>, the outflow channel <NUM>, and the outlet <NUM>. A fluid flows from the inlet <NUM> into the valve chamber <NUM>, passes through the valve chamber <NUM>, and flows out from the outlet <NUM> through the outflow channel <NUM>.

The valve seat <NUM> is disposed in the second part <NUM>. The valve seat <NUM> is disposed at the upstream end of the outflow channel <NUM> in the valve chamber <NUM>. That is, the valve seat <NUM> is disposed in a lower portion of the valve chamber <NUM>. The valve seat <NUM> is screwed to the upstream end of the outflow channel <NUM>. The valve seat <NUM> has a valve hole <NUM> allowing the valve chamber <NUM> and the outflow channel <NUM> to communicate with each other.

The float <NUM> serves as a valve member that opens and closes the valve hole <NUM>. The float <NUM> has a hollow substantially spherical shape. The float <NUM> is movably housed in the valve chamber <NUM>. The float <NUM> is suspended in the valve chamber <NUM>. Thus, the float <NUM> moves upward and downward in accordance with the amount of drain in the valve chamber <NUM>.

The support <NUM> includes a base <NUM> including an opening <NUM> and having a frame shape and two float seats <NUM> disposed on the base <NUM>, and the float <NUM> in the state of being seated on the valve seat <NUM> and closing the valve hole <NUM> is seated on the two float seats <NUM>. The valve seat <NUM> and the two float seats <NUM> support the float <NUM> in the state of closing the valve hole <NUM> at three points.

The base <NUM> is disposed in the second part <NUM> in a cantilever manner. That is, one end of the base <NUM> is coupled to the second part <NUM>, and the other end of the base <NUM> is a free end. Specifically, the base <NUM> extends inward of the valve chamber <NUM> from a portion of the second part <NUM> below the valve seat <NUM>. More specifically, the base <NUM> and the second part <NUM> are made of a single member. For example, the second part <NUM> and the base <NUM> are integrally formed by casting.

The base <NUM> is opposed to the bottom wall <NUM> and a gap is present between the base <NUM> and the bottom wall <NUM>. The base <NUM> is disposed below the float <NUM> in the valve chamber <NUM>.

The two float seats <NUM> are disposed at the tip of the base <NUM>. The two float seats <NUM> are disposed on a surface of the base <NUM> facing the float <NUM>. The valve seat <NUM> and the two float seats <NUM> are disposed to form a triangle in order to achieve three-point support of the float <NUM>.

The casing <NUM> may include a screen <NUM> that removes foreign substance from a fluid flowing into the valve chamber <NUM>, and a bimetal <NUM> that forcibly opens the float <NUM> at start of the valve device <NUM>.

The screen <NUM> is disposed in the first part <NUM>. The screen <NUM> is located near the inlet <NUM> in the valve chamber <NUM>. The screen <NUM> is a mesh-shaped member such that a fluid such as drain and steam can pass through the screen <NUM>.

The bimetal <NUM> is disposed in the second part <NUM>. One end of the bimetal <NUM> is fixed to the second part <NUM>, and the other end of the bimetal <NUM> is a free end. The bimetal <NUM> is curved as a whole. The bimetal <NUM> is deformed in accordance with the temperature of the bimetal <NUM>.

When the bimetal <NUM> is at a low temperature, the free end of the bimetal <NUM> is located near the valve seat <NUM> and slightly away from the valve seat <NUM>. The free end of the bimetal <NUM> at this position causes the float <NUM> to be separated from the valve seat <NUM>. When the bimetal <NUM> is at a high temperature, the free end of the bimetal <NUM> is located close to the valve seat <NUM>. The free end of the bimetal <NUM> at this position does not hinder sitting of the float <NUM> on the valve seat <NUM>.

With reference to <FIG> and <FIG>, the support <NUM> will be described in further detail. <FIG> is a perspective view of the second part <NUM>. <FIG> illustrates the base <NUM> when seen in an axial direction of the valve hole <NUM> of the valve seat <NUM>.

The base <NUM> has a substantially sector shape and is curved to be recessed toward the bottom wall <NUM>. Specifically, the base <NUM> includes two arms <NUM> extending from the second part <NUM>, and a plate <NUM> coupling the two arms <NUM> to each other. The float seats <NUM> are disposed at the tips of the arms <NUM>. The substantially circular opening <NUM> penetrates the plate <NUM>.

The two arms <NUM>, that is, the two float seats <NUM>, are spaced apart from each other in a circumferential direction about the axis of the valve hole <NUM>. Each of the arms <NUM> extends inward of the valve chamber <NUM> from the second part <NUM>. That is, one end of each arm <NUM> in an extension direction thereof is coupled to the second part <NUM>, and the other end of each arm <NUM> in the extension direction is a free end on the inner side of the valve chamber <NUM>. Each arm <NUM> is curved to be recessed toward the bottom wall <NUM>. Each arm <NUM> is thicker than the plate <NUM>.

The float seats <NUM> are disposed on surfaces of the tips of the arms <NUM> facing the float <NUM>.

The plate <NUM> is coupled to the entire area of each arm <NUM> from one end to the other end in the extension direction. The plate <NUM> is recessed toward the bottom wall <NUM>.

The arms <NUM> and the plate <NUM> are curved not to contact the float <NUM> seated on the valve seat <NUM> and the two float seats <NUM>.

Basic operation of the valve device <NUM> will be described. <FIG> is a cross-sectional view illustrating a closed state of the valve device <NUM>. <FIG> is a cross-sectional view illustrating an open state of the valve device <NUM>.

The valve device <NUM> is disposed in, for example, a pipe of a steam system. Steam and drain distributed in the pipe flow into the valve device <NUM>. At start of the valve device <NUM>, the bimetal <NUM> is at a relatively low temperature, and the free end of the bimetal <NUM> is located away from the valve seat <NUM>, as illustrated in <FIG>. Seating of the float <NUM> on the valve seat <NUM> is hindered by the bimetal <NUM>, and the float <NUM> is forcibly opened. In this state, when air in the pipe (i.e., initial air) or low-temperature drain flows into the valve chamber <NUM> of the valve device <NUM>, initial air or low-temperature drain flows out of the valve device <NUM> through the valve hole <NUM> and the outflow channel <NUM>. In this manner, initial air or low temperature drain that has flowed into the valve device <NUM> is quickly discharged from the valve device <NUM>. A fluid such as initial air or low temperature drain that has flowed from the inlet <NUM> first passes through the screen <NUM>. At this time, foreign substance is removed from the fluid by the screen <NUM>.

Then, steam or high temperature drain flows into the valve device <NUM>. The drain is stored in a lower portion of the valve chamber <NUM>, and the steam remains in an upper portion of the valve chamber <NUM>. While the float <NUM> is in the open state, the drain flows out from the valve chamber <NUM> through the valve hole <NUM>. Thereafter, when the temperature of the bimetal <NUM> increases, the bimetal <NUM> is deformed, and as illustrated in <FIG>, the free end of the bimetal <NUM> moves to a position at which seating of the float <NUM> on the valve seat <NUM> is not hindered. Accordingly, the float <NUM> can be seated on the valve seat <NUM>, and can close the valve hole <NUM>. If the amount of drain in the valve chamber <NUM> is not significantly large, the float <NUM> is seated on the valve seat <NUM> and closes the valve hole <NUM>. At this time, the float <NUM> is also seated on the two float seats <NUM>. That is, the float <NUM> is supported at three points by the valve seat <NUM> and the two float seats <NUM>.

When the amount of drain in the valve chamber <NUM> increases, the float <NUM> is caused to float by the drain, as illustrated in <FIG>. Accordingly, the float <NUM> rises and is released from the valve seat <NUM> to thereby open the valve hole <NUM>. The drain flows out from the valve chamber <NUM> into the outflow channel <NUM> through the valve hole <NUM>. The drain that has flowed from the valve hole <NUM> passes through the outflow channel <NUM>, and flows out from the valve device <NUM> through the outlet <NUM>. At this time, since steam in the valve chamber <NUM> remains in space above the drain in the valve chamber <NUM>, the steam does not flow out from the valve device <NUM> through the valve hole <NUM>.

When the amount of drain in the valve chamber <NUM> decreases, the float <NUM> descends with the decrease of the drain amount, and is seated on the valve seat <NUM> and closes the valve hole <NUM>, as illustrated in <FIG>. In this manner, outflow of drain from the valve device <NUM> stops. At this time, the float <NUM> is also seated on the float seats <NUM> as well as the valve seat <NUM>. In the state where the valve hole <NUM> is closed, the float <NUM> is supported at three points by the valve seat <NUM> and the two float seats <NUM>. In this state, even when steam flows into the valve chamber <NUM>, since the valve hole <NUM> is immersed in drain and the valve hole <NUM> is closed by the float <NUM>, the steam does not flow out from the valve device <NUM> through the valve hole <NUM>.

When the amount of drain in the valve chamber <NUM> increases, the float <NUM> is caused to rise again by drain. The float <NUM> is released from the valve seat <NUM> and opens the valve hole <NUM>.

In the manner described above, in the valve device <NUM>, the float <NUM> moves upward and downward in accordance with the amount of drain in the valve chamber <NUM>, and the valve hole <NUM> is opened and closed. Accordingly, drain intermittently passes in the valve device <NUM>. On the other hand, in the cases of both opening and closing the valve, passage of steam through the valve device <NUM> is inhibited.

The support <NUM> will now be further described.

The two float seats <NUM> of the support <NUM> support the float <NUM> in the state of being seated on the valve seat <NUM> and closing the valve hole <NUM>, at three points together with the valve seat <NUM>. Accordingly, the state where the float <NUM> closes the valve hole <NUM> is maintained with stability.

The two float seats <NUM> are disposed on the frame-shaped base <NUM>. Since the base <NUM> has the frame shape, the base <NUM> has relatively high rigidity. Thus, deformation of the base <NUM> is reduced so that the positions of the two float seats <NUM> can be maintained with high accuracy. For example, suppose a case where an external shock is applied to the valve device <NUM> in transporting the valve device <NUM>. Even in such a case, since the base <NUM> has high rigidity, the base <NUM> is not easily deformed. Thus, in incorporating the valve device <NUM> in a pipe or other part of the steam system, a work such as a work of deforming the base <NUM> to adjust the positions of the two float seats <NUM> becomes unnecessary.

In particular, the configuration of the support <NUM> described above is effective for a configuration in which the valve seat <NUM> and the support <NUM> are disposed in the second part <NUM> attached to the first part <NUM> from a side to close the valve chamber <NUM> that is open sideways. For example, in a configuration in which the valve seat <NUM> is disposed in the second part <NUM> and float seats are disposed in the first part <NUM>, the positional relationship between the valve seat <NUM> and the float seats is greatly affected by attachment accuracy of the first part <NUM> and the second part <NUM>. On the other hand, in the configuration in which the valve seat <NUM> and the support <NUM> are disposed in the second part <NUM>, the positional relationship between the valve seat <NUM> and the two float seats <NUM> is not affected by the attachment accuracy of the first part <NUM> and the second part <NUM>. If the valve seat <NUM> and the two float seats <NUM> have high position accuracy before the second part <NUM> is attached to the first part <NUM>, the valve seat <NUM> and the two float seats <NUM> maintain high position accuracy after the second part <NUM> is attached to the first part <NUM>. In addition, since the second part <NUM> and the support <NUM> are made of a single member in this example, the positional relationship between the valve seat <NUM> and the two float seats <NUM> is maintained with high accuracy.

To achieve three-point support of the float <NUM> by the valve seat <NUM> and the two float seats <NUM> in the configuration in which the second part <NUM> includes both the valve seat <NUM> and the support <NUM>, the two float seats <NUM> need to be located at some distance from the valve seat <NUM> (specifically, at a position at which a triangle that can support the float <NUM> with stability is formed by the valve seat <NUM> and the two float seats <NUM>). Since the base <NUM> is disposed in the second part <NUM> in a cantilever manner, a distance can be easily obtained between the valve seat <NUM> and the two float seats <NUM>. In this case, in a conceivable configuration, the float seat is disposed in each of two beams extending from the second part <NUM> in a cantilever manner. Cantilever members tend to be less rigid. On the other hand, in the valve device <NUM>, the base <NUM> extending from the second part <NUM> in a cantilever manner has the frame shape, and the two float seats <NUM> are disposed in the base <NUM>. Since the base <NUM> has the frame shape, the base <NUM> has higher rigidity than those of simple beams. Accordingly, even in the configuration in which the base <NUM> is disposed in the second part <NUM> in a cantilever manner, the positions of the float seats <NUM> can be maintained with high accuracy.

In addition, the base <NUM> include the two arms <NUM> extending from the second part <NUM>, and the plate <NUM> coupling the two arms <NUM>. The float seats <NUM> are disposed in each of the two arms <NUM>, and the arms <NUM> are thicker than the plate <NUM>. Accordingly, rigidity of a portion of the base <NUM> where the float seats <NUM> are disposed (i.e., the arms <NUM>) can be increased, and the positions of the float seats <NUM> can be maintained with higher accuracy. Furthermore, the plate <NUM> is coupled to the entire area of each of the arms <NUM> in the extension direction. Accordingly, rigidity of the entire base <NUM> is increased, and the positions of the float seats <NUM> can be maintained with higher accuracy.

In addition, in the configuration in which the cantilever member extends from the second part <NUM>, the base <NUM> includes the opening <NUM> so that the float <NUM> can be seated on the valve seat <NUM> and the two float seats <NUM> with stability.

Specifically, to cause the float <NUM> to descend and be seated on the valve seat <NUM> and further the float seats <NUM> with stability, waves of drain occurring when the amount of drain in the valve chamber <NUM> decreases are preferably small. Since the base <NUM> including the opening <NUM> extends from the second part <NUM> into the valve chamber <NUM>, waves of drain can be reduced. That is, since the base <NUM> includes the opening <NUM>, drain can pass through the opening <NUM> around the base <NUM>. The base <NUM> serves as a larger distribution resistance in the valve chamber <NUM>, and can moderate a flow of drain around the base <NUM>. Accordingly, waves of drain are reduced. As a result, swing of the float <NUM> is reduced when the float <NUM> approaches the valve seat <NUM> and the two float seats <NUM> so that the float <NUM> can be thereby seated on the valve seat <NUM> and the two float seats <NUM> with stability.

In addition, since the float seats <NUM> are disposed in the base <NUM>, the base <NUM> is disposed below the float <NUM>. Thus, when the float <NUM> approaches the valve seat <NUM> and the two float seats <NUM>, the liquid level of drain also approaches the base <NUM>. The effect of reducing waves of drain by the base <NUM> serving as a distribution resistance increases as the base <NUM> approaches the liquid level of drain. The necessity for reducing drain waves also increases when the drain amount decreases and the float <NUM> approaches the valve seat <NUM> and the two float seats <NUM>. That is, the base <NUM> can reduce drain waves more effectively when necessary. As a result, the float <NUM> can be seated on the valve seat <NUM> and the two float seats <NUM> with stability.

In addition, since the base <NUM> is opposed to the bottom wall <NUM> and forms a gap between the base <NUM> and the bottom wall <NUM>, space above the base <NUM> and space below the base <NUM> communicate with each other through the opening <NUM>. Thus, the amount of drain distributed between the base <NUM> and the bottom wall <NUM> increases. The base <NUM> and the bottom wall <NUM> serve as distribution resistance of drain distributed between the base <NUM> and the bottom wall <NUM>. That is, when the amount of drain distributed between the base <NUM> and the bottom wall <NUM> increases, a flow of drain becomes gentler, and waves of drain are further reduced.

As described above, the valve device <NUM> includes: the casing <NUM> including the valve chamber <NUM>; the valve seat <NUM> disposed in the valve chamber <NUM> and including the valve hole <NUM>; the float <NUM> disposed in the valve chamber <NUM> and movable in accordance with an amount of drain in the valve chamber <NUM> to thereby open and close the valve hole <NUM>; and the support <NUM> supporting the float <NUM> in a state of being seated on the valve seat <NUM> and closing the valve hole <NUM>, the support <NUM> includes the base <NUM> including the opening <NUM> and having a frame shape and the two float seats <NUM> disposed in the base <NUM>, and the float <NUM> in a state of being seated on the valve seat <NUM> and closing the valve hole <NUM> is seated on the two float seats <NUM>.

With this configuration, the float <NUM> in the state of closing the valve hole <NUM> is supported at three points by the valve seat <NUM> and the two float seats <NUM>. Since the base <NUM> on which the two float seats <NUM> are disposed has the frame shape, the base <NUM> has high rigidity. Thus, the positions of the two float seats <NUM> are maintained with high accuracy. As a result, the positional relationship between the valve seat <NUM> and the two float seats <NUM> is also maintained with high accuracy, and stability in seating the float <NUM> on the valve seat <NUM> can be enhanced. In addition, since the base <NUM> includes the opening <NUM>, drain can be distributed through the opening <NUM> so that the function of the base <NUM> as a distribution resistance increases. Accordingly, the base <NUM> can reduce waves of drain, and swing of the float <NUM> occurring when the float <NUM> is seated on the valve seat <NUM> and the two float seats <NUM> is reduced. As a result, stability in seating the float <NUM> on the valve seat <NUM> can be further enhanced.

The casing <NUM> has the divided structure including the first part <NUM> and the second part <NUM>, the first part <NUM> and the second part <NUM> define the valve chamber <NUM>, the valve seat <NUM> is disposed in the second part <NUM>, and the base <NUM> is disposed in the second part <NUM> in a cantilever manner.

With this configuration, since both the valve seat <NUM> and the base <NUM> are disposed in the second part <NUM>, the positional relationship between the valve seat <NUM> and the two float seats <NUM> is maintained with high accuracy without an influence of accuracy in attaching the first part <NUM> and the second part <NUM>. In addition, since the base <NUM> is disposed in the second part <NUM> in a cantilever manner, a distance can be easily obtained between the valve seat <NUM> and the two float seats <NUM>. Even in the configuration in which the base <NUM> is disposed in the second part <NUM> in a cantilever manner, since the base <NUM> has the frame shape, position accuracy of the two float seats <NUM> can be obtained.

In addition, the first part <NUM> includes the opening 14a in which the valve chamber <NUM> is open sideways, and the second part <NUM> is attached to the first part <NUM> to close the opening 14a.

In this configuration, the configuration in which the base <NUM> is disposed in the second part <NUM> in a cantilever manner is especially effective. By employing the configuration in which the base <NUM> is disposed in the second part <NUM> in a cantilever manner, the configuration in which the two float seats <NUM> are disposed in the valve chamber <NUM> can be easily obtained.

The casing <NUM> includes the ceiling wall <NUM>, the bottom wall <NUM>, and the peripheral wall <NUM> coupling the ceiling wall <NUM> and the bottom wall <NUM> to each other. The first part <NUM> includes the ceiling wall <NUM>, the bottom wall <NUM>, and a portion of the peripheral wall <NUM>. The ceiling wall <NUM>, the bottom wall <NUM>, and the peripheral wall <NUM> define the valve chamber <NUM>. The second part <NUM> includes a remaining portion of the peripheral wall <NUM>. The portion of the peripheral wall <NUM> included in the first part <NUM> includes the opening 14a. The base <NUM> is opposed to the bottom wall <NUM> and forms a gap between the base <NUM> and the bottom wall <NUM>.

With this configuration, the base <NUM> disposed in the second part <NUM> in a cantilever manner is opposed to the bottom wall <NUM> included in the first part <NUM>. A gap is present between the base <NUM> and the bottom wall <NUM>. Since the base <NUM> includes the opening <NUM>, drain is distributed through the opening <NUM> between the space above the base <NUM> and the gap between the base <NUM> and the bottom wall <NUM>. In the gap between the base <NUM> and the bottom wall <NUM>, the base <NUM> and the bottom wall <NUM> serve as distribution resistance. Thus, a flow of drain around the base <NUM> becomes gentler, and waves of drain are further reduced. As a result, swing of the float <NUM> is further reduced so that stability in seating the float <NUM> on the valve seat <NUM> can be thereby further enhanced.

In the foregoing description, the embodiments have been described as an example of the technique disclosed in the present application. The technique disclosed here, however, is not limited to these embodiments, and is applicable to other embodiments obtained by changes, replacements, additions, and/or omissions as necessary. Components described in the above embodiments may be combined as a new exemplary embodiment. Components included in the accompanying drawings and the detailed description can include components unnecessary for solving problems as well as components necessary for solving problems in order to exemplify the technique. Therefore, it should not be concluded that such unnecessary components are necessary only because these unnecessary components are included in the accompanying drawings or the detailed description.

For example, the valve device <NUM> is not limited to the drain trap. It is sufficient that the valve device <NUM> is a float-type valve device including a float.

Although the valve device <NUM> is connected to the vertical pipe such that the inlet <NUM> and the outlet <NUM> of the casing <NUM> are open in the top-bottom direction in the embodiment described above, the technique disclosure here is not limited to this embodiment. The valve device <NUM> may be connected to a horizontal pipe with the inlet <NUM> and the outlet <NUM> being open laterally.

Although the base <NUM> includes the two arms <NUM> and the plate <NUM> in the embodiment described above, the technique disclosure here is not limited to this embodiment. The base <NUM> may be made of a frame body having a uniform thickness. Alternatively, in the base <NUM>, the two arms <NUM> do not need to be entirely coupled to each other by the plate <NUM>, the tips of the two arms <NUM>, for example, may be coupled to each other by a beam-like member.

Claim 1:
A valve device (<NUM>) comprising:
a casing (<NUM>) including a valve chamber (<NUM>);
a valve seat (<NUM>) disposed in the valve chamber (<NUM>) and including a valve hole (<NUM>):
a float (<NUM>) disposed in the valve chamber (<NUM>) and movable in accordance with an amount of drain in the valve chamber (<NUM>) to thereby open and close the valve hole (<NUM>); and
a support (<NUM>) supporting the float (<NUM>) in a state of being seated on the valve seat (<NUM>) and closing the valve hole (<NUM>), wherein
the support (<NUM>) includes a base (<NUM>) including an opening (<NUM>) through which space above the base (<NUM>) and space below the base (<NUM>) communicate with each other in the valve chamber (<NUM>) and two float seats (<NUM>) disposed in the base (<NUM>), the float (<NUM>) in the state of being seated on the valve seat (<NUM>) and closing the valve hole (<NUM>) being seated on the two float seats (<NUM>), characterized in that the support (<NUM>) has a closed frame shape which surrounds the opening (<NUM>).