JPH08326957A - Dew condensation preventive butterfly valve - Google Patents

Abstract

PURPOSE: To provide a dew condensation preventive butterfly valve which is free of starting condensation even if no cold insulation is made up to an operating device, and is excellent in economy wherein its thermal insulation works are facilitated in the butterfly valve mainly used for the cold water pipeline of air conditioning equipment. CONSTITUTION: A ring shaped metallic disc 4a is connected to the outer circumferential surface of the outer cylinder section 3c of an extended bonnet 3 containing a hollow extended shaft 2, a metallic cylindrical member 5 is connected to the outer circumferential periphery of the disc 4a, and the extended shaft 2 is made of stainless steel. Furthermore, each non-metallic member 6 and 7 is interposed between a flange 3b connecting the extended bonnet 3 with a body 15 and a flange 15a, and among a bolt 8, a washer 9 and the flange 15a respectively so as to allow heat to be insulated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dew condensation preventing butterfly valve used for cold water piping for cold insulation of air conditioning equipment.

[0002]

2. Description of the Related Art Conventionally, in a butterfly valve used for cold water piping of an air conditioner, in order to prevent the surrounding environment from being contaminated by water droplets generated by dew condensation, it is necessary to heat-insulate the entire valve together with the piping to keep it cool. In general, the operating device may be covered with cold insulation as much as possible, and even the indicator showing the opening of the valve may be covered, and the opening may be difficult to understand. In addition, the work for keeping these cold is troublesome and difficult, which also causes an increase in piping cost.

[0003] In order to avoid cold-insulating the operating device as described above, the valve may have an extended bonnet structure so that the operating device is located as far as possible from the flow passage in the body through which the cold water flows. Therefore, it is not possible to completely prevent the operating device from becoming cold and causing dew condensation. In particular, in a high humidity environment or season, problems due to condensation may occur.

[0004]

The present invention was developed in order to solve the above-mentioned problems, and the problem to be solved by the present invention is to operate mainly in a butterfly valve used for cold water piping of air conditioning equipment. An object of the present invention is to provide a dew condensation-preventing butterfly valve that is economically advantageous in that there is no risk of dew condensation even if the device is not covered with cold insulation, and that heat insulation work is easy.

[0005]

In order to achieve the above object, in the dew condensation prevention butterfly valve of the present invention, an extension shaft connected to a valve stem is formed in a hollow structure, and the extension shaft is built in an extension bonnet. At the same time, heat radiation fins were provided on the outer peripheral surface of the extension bonnet.

In this case, it is preferable that the above-mentioned radiation fin has a structure in which a ring-shaped metal disc is connected to the outer peripheral surface of the outer cylinder of the extension bonnet, and a metal cylindrical member is connected to the outer peripheral edge of the disc. . Further, the lower end of the tubular member is brought into contact with the heat insulating coating applied to the valve body.

It is preferable to mount non-metallic members between the flanges connecting the extension bonnet and the body and between the bolts and nuts connecting the flanges and one or both of these flanges. The extension shaft and the outer cylinder are made of stainless steel having a low thermal conductivity.

[0008]

Most of the body of the butterfly valve is heat-insulated together with the piping, so that the air does not come into direct contact with the low-temperature body and no condensation occurs. The operating device mounting flange of the extension bonnet that is far from the flow passage in the body where cold water flows and the operating device become cold, causing condensation problems. The reason why the heat is easily taken away is that these parts are connected to the low temperature part by the metal material having high heat conductivity, and the connected metal member is the extension shaft of the stem. And the outer cylinder part of the extension bonnet.

Of these two members, since the stem extension shaft has a hollow structure, a large heat radiation area can be obtained.
Moreover, the cross-sectional area is small and the thermal conductivity is low, and the distance is long and the thermal gradient is small. Further, if the extension shaft is made of stainless steel, the thermal conductivity will be further reduced. Therefore, the operating device takes very little heat through the extension shaft.

Further, a heat radiation fin is provided on the outer peripheral surface of the outer cylinder of the extension bonnet. The heat radiation fin is connected to an annular metal disc, and a short metal tubular member is connected to the outer peripheral edge of the disc. Therefore, heat is applied to the tubular member and the disk by the surrounding atmosphere, and this heat is transmitted to the outer cylinder part of the extension bonnet, and the outer cylinder part of the extension bonnet supplements the heat taken to the low temperature part of the body. ing. The cylindrical member is for increasing the surface area in contact with the atmosphere so that the heat given from the atmosphere is larger than the heat taken by the low temperature portion. If the outer cylinder part is made of stainless steel, the thermal conductivity is lowered, and it is difficult for the outer cylinder part to have a low temperature.

A non-metal member mounted between the flanges connecting the extension bonnet and the body, and a non-metal member mounted between one or both of the bolts and nuts connecting the flanges and the flanges. Since the metal contact between the extended bonnet and the body is cut off by the heat insulation, the bonnet loses very little heat to the body.

As described above, the operating device mounting flange portion of the extension bonnet and the operating device take very little heat through the stem shaft and the outer cylinder portion of the extension bonnet. Therefore, these mounting flanges and operating devices receive more heat from the surrounding atmosphere than heat that is taken away, do not become cold, and do not condense in a humid environment or season, and do not condense with water droplets. Does not pollute the surrounding environment.

[0013]

1 is a partial sectional view showing an embodiment of a dew condensation preventing butterfly valve according to the present invention, and FIG. 2 is an exploded perspective view of a portion of the dew condensation preventing butterfly valve shown in FIG. 1 and 2, reference numeral 1 denotes a valve body of a dew condensation prevention butterfly valve. This valve body 1 is provided with a disc-shaped disc which is openable and closable inside a cylindrical body (not shown). It is operated by the stem 14. 2 is an extension shaft, 3 is an extension bonnet, 4 is a radiation fin, 4a is a metal disc, 5 is a metal tubular member, 6 is a non-metal disc, 7 is a non-metal bush, 8 is a bolt, 9
Is a washer, 10 is a nut, 11 is a holding disc, 12a and 1
2b is a split ring and 13 is an O-ring. Reference numeral 14 is a valve stem, 15 is a body, and 15a is an extended bonnet mounting flange for the body.

The extension shaft 2 has a hollow structure in which an upper connecting member 2a and a lower connecting member 2b are connected by a pipe member 2c, and the lower connecting member 2b is attached to the tip of a stem 14. The extension shaft 2 is made of stainless steel. The extension bonnet 3 has an operating device mounting flange 3a.
And a flange 3b connected to the body 15 are connected to an intermediate outer cylindrical portion 3c, and a heat radiating fin 4 is provided on an outer peripheral surface of the outer cylindrical portion 3c. The heat radiating fin 4 has an annular shape on the outer cylindrical portion 3c. It is constituted by a metal tubular member 5 which is connected to the metal disc 4a and is connected to the outer peripheral edge of the disc 4a. 5a
Is a small hole for draining water.

The flange 3b is an extension bonnet mounting flange 15a of the body 15 which is sandwiched between the non-metallic disc 6 and
It is connected using a bolt 8, a washer 9 and a nut 10. A non-metal bush 7 is mounted between the mounting flange 15a and the bolt 8 and washer 9.

Further, the O-ring 13 is mounted in the O-ring groove 14a of the stem shaft 14, and the body 15 and the stem shaft 14 are
And the split rings 12a and 12b are mounted in the split ring groove 14b of the stem shaft 14 and sandwiched between the presser disc 11 and the body 15 as shown in FIG. The stem 14 is being positioned.

What is indicated by a chain double-dashed line in FIG. 1 is a heat-insulating coating applied to the valve body 1, which is a tubular member 5.
The lower end 5a of the is directly in contact with this thermal insulation coating.

Next, the operation of the above embodiment will be described. The operating device mounting flange 3a of the extension bonnet 3 and the extension shaft 2
The upper connection member 2a and the operating device (not shown) attached to them are low in temperature and cause the problem of dew condensation.
This is because these parts are deprived of heat by the body 15 and the stem shaft 14, which are at a low temperature due to the influence of the low temperature fluid flowing inside the valve 1, and become a low temperature.

Since the extension shaft 2 of the stem has a hollow structure by the pipe member 2c, a large heat radiation area can be obtained.
Moreover, the cross-sectional area is small and the thermal conductivity is low, and the distance is long and the thermal gradient is small. Furthermore, since the extension shaft 2 is made of stainless steel, the thermal conductivity is further reduced. Therefore, the operating device takes very little heat through the extension shaft 2.

Further, a ring-shaped metal disc 4a is connected to the outer peripheral surface of the outer cylinder portion 3c of the extension bonnet 3, and a short metal cylinder member 5 is connected to the outer peripheral edge of the disc 4a. Heat is applied to the shaped member 5 and the disk 4a by the surrounding atmosphere, and the heat is transmitted to the outer cylinder portion 3c of the extension bonnet 3 to supplement the heat taken by the body 15 from the outer cylinder portion 3c of the extension bonnet 3. The tubular member 5 has a large surface area which is in contact with the atmosphere and receives heat so that the heat given from the atmosphere can be applied to the body 15
It is for making more heat than is taken away by. In addition,
If the outer cylinder portion 3c is made of stainless steel, the thermal conductivity is lowered, the heat is not easily taken by the body 15, and the temperature does not easily become low.

A non-metal member (disk) 6 mounted between the flanges 3b and 15a connecting the extension bonnet 3 and the body 15, and a bolt 8 and a washer 9 connecting these flanges 3b and 15a. The non-metallic member (bush) 7 mounted between the flange 15a and the non-metallic member (bush) 7 is made of a synthetic resin having low thermal conductivity, and the extension bonnet 3 and the body 15 are cut off from metal contact with each other.
The heat of the extended bonnet 3 taken by the body 15 is extremely small.

In this way, the operating device mounting flange 3a of the extension bonnet 3 and the upper connecting member 2a of the extension shaft 2 are provided.
Also, the heat that is removed from the operating device mounted on these through the outer cylinder portion 3c of the extension shaft 2 and the extension bonnet 3 is extremely small. For this reason, the mounting flange 3a and the operating device receive more heat from the surrounding atmosphere than heat that is taken away, the temperature does not become low, and no condensation occurs even in a high humidity environment and season, and there is no water droplet. Does not pollute the surrounding environment.

Due to the effects as described above, the valve body 1 is, as shown by the two-dot chain line in FIG.
If the heat insulating coating is applied to a height at which the lower end portion 5a of the metal tubular member 5 directly contacts, the problem of dew condensation does not occur. The following results were obtained in the performance test of the butterfly valve having the structure according to the present example at the cold water temperature of 5 ° C. Cast iron, caliber 250A, butterfly valve: relative humidity of 85% at ambient temperature of 30 ° C, relative humidity of condensation at ambient temperature of 36 ° C, 82% Cast iron, diameter of 500A, butterfly valve: relative humidity of condensation at ambient temperature of 30 ° C Humidity is 82%. Dew formation relative temperature is 80% at ambient temperature of 36 ° C.

[0024]

As described above, the butterfly valve of the present invention is used in the cold water pipe of an air conditioner and does not cause the problem of dew condensation even if the operating device is not covered with cold insulation. Therefore, the surrounding environment is not polluted by the water droplets generated by dew condensation, and the cold insulation work and the heat insulation work are easy and simple, and the piping cost can be reduced.

[Brief description of drawings]

FIG. 1 is a partial sectional view showing an embodiment of a dew condensation preventing butterfly valve of the present invention.

FIG. 2 is an exploded perspective view of a portion of the dew condensation prevention butterfly valve shown in FIG.

[Explanation of symbols]

 1 Valve body 2 Extension shaft 3 Extension bonnet 3a Operating device mounting flange 3b Flange connecting to body 3c Outer cylinder part 4 Radiating fin 4a (Metal) disk 5 (Metal) cylindrical member 5a Lower end 6 Non-metallic member (Disc) 7 Non-metallic member (Bush) 8 Bolt 10 Nut 15 Body

Claims (4)

[Claims] 1. An anti-condensation structure characterized in that an extension shaft connected to a valve stem is formed in a hollow structure, the extension shaft is built into an extension bonnet, and a radiation fin is provided on an outer peripheral surface of the extension bonnet. Butterfly valve. 2. The radiating fin as described above, wherein an annular metal disc is connected to the outer peripheral surface of the outer cylinder of the extension bonnet, and a metal tubular member is connected to the outer peripheral edge of the disc. Dew condensation prevention butterfly valve. 3. The dew condensation preventing butterfly valve according to claim 2, wherein the lower end portion of the tubular member is configured to come into contact with a heat insulating coating applied to the valve body. 4. A non-metallic member is mounted between the flanges that connect the extension bonnet and the body, and between one or both of the bolts and nuts that connect these flanges and the flanges for heat insulation. The dew condensation prevention butterfly valve according to claim 1.