FLUID ON / OFF VALVE AND AIR CONDITIONING UNIT FOR USE THEREOF

Abstract

A fluid on / off valve comprising a brass alloy with a lead content of 1000 ppm or less, which contains tin (Sn) in an amount of 1.05%, copper (Cu) in an amount of 61.720%, bismuth (Bi) in an amount of 1.890%, iron (Fe) in an amount of 0.070%, aluminum (Al) in an amount of 0.0012%, phosphorus (P) in an amount of 0.059%, antimony (Sb) in an amount of 0.004% and zinc (Zn) as the remainder of the alloy.

Description

TECHNICAL FIELD

[0001] The present invention relates to a fluid on / off valve such as a two-way valve or a three-way valve arranged between or in refrigerant lines of a refrigeration cycle, and more particularly to a fluid on / off valve capable of reducing environmental pollution and an air conditioner using the fluid on / off valve. TECHNICAL BACKGROUND

[0002] Generally, a device using a refrigeration cycle, such as an air conditioner, is designed such that refrigerant piping connects an indoor unit and an outdoor unit, and includes a three-way valve with a service port in the refrigerant piping so that venting and refrigerant sealing can be performed after the piping connection is completed (see Patent Literature 1).

[0003] Fig.Figure 7 illustrates the air conditioner described in Patent Literature 1. The air conditioner is configured such that the refrigerant pipes 103a, 103b connect the outdoor unit 100 and the indoor unit 101, and the two-way valve 104 and the three-way valve 105 are respectively disposed between the refrigerant pipes 103a, 103b and the connecting portions of the refrigerant pipes 103a, 103b. After the pipes are connected, venting and refrigerant sealing are performed by opening / closing the service port 106 of the three-way valve 105.

[0004] Patent Literature 2 describes Sn-containing Bi-based, Sn-containing Bi- and Sb-based, and Sn-containing Bi-, Se- and Sb-based lead-free brass alloys.

[0005] Patent Literature 3 describes a pressure-resistant and corrosion-resistant copper alloy containing 73.0 mass% to 79.5 mass% of Cu and 2.5 mass% to 4.0 mass% of Si with a balance of Zn and unavoidable impurities, wherein the content of Cu and the content of Si are in a certain relationship. List of cited documentsPatent literature PTL 1: Japanese Unexamined Patent Publication No. 2009-250274 PTL 2: US Patent Application No. 2009 / 0297390 A1 PTL 3: European patent application 2 634 275 A1 SUMMARY OF THE INVENTION

[0006] A conventional air conditioner has an advantage that the use of the three-way valve 105 enables venting without refrigerant leakage and installation while avoiding environmental pollution due to refrigerant leakage.

[0007] However, since the two-way valve 104 and the three-way valve 105 have complex shapes and require high manufacturing precision, these valves are designed from a material with good processability. Therefore, under current conditions, these valves are molded or manufactured from a lead-containing brass alloy. Since the brass alloy has excellent characteristics such as corrosion resistance, machinability, and mechanical properties, this material is suitable for the complex, high-precision fluid on / off valve. However, the brass alloy contains lead, which poses a problem in that it makes a fluid on / off valve a component with a high environmental impact.

[0008] Thus, with a view to eliminating environmental pollution, the fluid on / off valve can be modified to a fluid on / off valve made of a brass alloy with a lead content of 1000 ppm or less and can thus be described as essentially lead-free.

[0009] However, if the fluid on / off valve is a lead-free fluid on / off valve, a brass alloy constituting the fluid on / off valve reacts with ammonia contained in an atmosphere and leads to stress corrosion cracking.

[0010] In particular, the fluid on / off valve, such as a two-way valve or a three-way valve, which is arranged between refrigerant pipes in use, is prone to stress corrosion cracking because the fluid on / off valve is usually arranged in an outdoor unit and is thus always exposed to an atmosphere, and the atmosphere often comes into contact with ammonia resulting from the excrement of small animals such as a dog or a cat.

[0011] In addition, the fluid on / off valve, such as a two-way valve or three-way valve arranged between refrigerant pipes in use, is subjected to special and harsh operating conditions because a temperature of the valve may even reach 60 °C due to the refrigerant flowing inside the valve, which is considerably higher than the surrounding atmospheric temperature, so that the sensitivity of the valve to react with ammonia increases and stress corrosion cracking is easily caused.

[0012] In view of these points, therefore, the present invention aims to use a lead-free fluid on / off valve and provides a substantially lead-free fluid on / off valve that prevents stress corrosion cracking at a practical level, and an air conditioner using the lead-free fluid on / off valve.

[0013] The present invention relates to a fluid on / off valve formed of a brass alloy having a lead content of 1000 ppm or less and containing tin (Sn) in an amount of 0.8% or more.

[0014] When the fluid on / off valve is arranged for use between refrigerant pipes, the stress corrosion cracking of the valve can be prevented even in the environment where the valve is exposed to an atmosphere containing high ammonia and heated to a temperature higher than the atmospheric temperature, so that a reaction with the ammonia can easily proceed.

[0015] As described above, the present invention makes it possible to prevent stress corrosion cracking of the fluid on / off valve while reducing environmental pollution, and also to improve the reliability of the fluid on / off valve and the air conditioner using the fluid on / off valve. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a refrigerant cycle diagram of an air conditioner according to a first exemplary embodiment of the present invention. Fig. 2A is a front view illustrating an appearance of an outdoor unit of the air conditioner according to the first exemplary embodiment of the present invention. Fig. 2B is a side view illustrating a partially broken duct cover of the outdoor unit of the air conditioner according to the first exemplary embodiment of the present invention. Fig. 3 is a sectional view illustrating a three-way valve of the air conditioner according to the first exemplary embodiment of the present invention. Fig. 4 is an exploded sectional view illustrating the three-way valve of the air conditioner according to the first exemplary embodiment of the present invention. Fig. 5 is a perspective view illustrating a test state of a test piece according to the present invention. Fig. 6 is a sectional view illustrating a two-way valve of an air conditioner according to a second exemplary embodiment of the present invention. Fig. Figure 7 is a refrigerant cycle diagram of a conventional air conditioner. DESCRIPTION OF THE EMBODIMENTS

[0016] Exemplary embodiments of the present invention will be described below with reference to the drawings. It should be noted that the present invention is not limited to the exemplary embodiments. FIRST EXEMPLARY EMBODIMENT

[0017] Fig. 1 is a refrigerant cycle diagram of an air conditioner according to a first exemplary embodiment of the present invention. Fig. 2A is a front view illustrating an appearance of an outdoor unit of the air conditioner according to the first exemplary embodiment of the present invention. Fig. 2B is a side view illustrating a partially broken duct cover of the outdoor unit of the air conditioner according to the first exemplary embodiment of the present invention. Fig.3 is a sectional view illustrating a three-way valve of the air conditioner according to the first exemplary embodiment of the present invention. Fig. 4 is an exploded sectional view illustrating the three-way valve of the air conditioner according to the first exemplary embodiment of the present invention.

[0018] In Fig.1, the air conditioner according to the present exemplary embodiment includes an outdoor unit 5. The outdoor unit 5 has a compressor 1 for compressing a refrigerant, a four-way valve 2 for switching a refrigerant circuit during cooling and heating operations, an outdoor heat exchanger 3 for heat exchange between a refrigerant and the outside air, and a pressure reducer 4 for depressurizing a refrigerant. The air conditioner further includes an indoor unit 7 with an indoor heat exchanger 6 for heat exchange between a refrigerant and the indoor air. Furthermore, the air conditioner includes liquid connection lines 8 and gas connection lines 9, each of which connects the indoor unit 7 and the outdoor unit 5.Furthermore, the first fluid on / off valve 10 is arranged in a line between a connection opening to the gas connection line 9 and the four-way valve 2 in the outdoor unit 5 and a second fluid on / off valve 11 is arranged in a line between a second connection opening to the liquid connection line 8 and the pressure reducer 4 in the outdoor unit 5.

[0019] Further, in the air conditioner according to the present exemplary embodiment, the compressor 1, the four-way valve 2, the outdoor heat exchanger 3, the pressure reducer 4, the second fluid on / off valve 11, the liquid communication pipe 8, the indoor heat exchanger 6, the gas communication pipe 9, and the first fluid on / off valve 10 are combined into an annular whole through a pipe to configure a refrigerant cycle.

[0020] The first fluid on / off valve 10 is a three-way valve through which venting and refrigerant confinement occur after the lines are connected, and the second fluid on / off valve 11 is a two-way valve. The first fluid on / off valve 10 and the second fluid on / off valve 11 are each arranged such that they are accessible from a side surface of the outdoor unit 5, as shown in Fig. 2. The first fluid on / off valve 10 and the second fluid on / off valve 11 are both covered by a conduit cover 5a and are often located in an environment such that both valves are exposed to the atmosphere in a position close to the ground or the like. The first fluid on / off valve 10 and the second fluid on / off valve 11 are each formed by molding a brass alloy.

[0021] Furthermore, as the refrigerant used for the refrigerant cycle constituting the air conditioner according to the present exemplary embodiment, tetrafluoropropene or trifluoropropene is used as a base component. A hydrofluoroolefin refrigerant with low environmental impact is used. Such a hydrofluoroolefin refrigerant is formed by blending two or three components of difluoromethane, pentafluoroethane, and tetrafluoroethane together so that a global warming potential (GWP) is 5 to 750 inclusive, preferably 350 or less, and more preferably 150 or less.Specifically, a single refrigerant made up of hydrofluorocarbon-based (HFC-based) refrigerants such as R32, or hydrogen fluoride-based refrigerants with a carbon-carbon double bond such as 2,3,3,3-tetrafluoropropene (HFO-1234yf) is used, or a refrigerant mixture containing these refrigerants as main components is used.

[0022] In cooling operation, the four-way valve 2 is connected so that a discharge side of the compressor 1 communicates with the outdoor heat exchanger 3. Consequently, a refrigerant compressed by the compressor 1 becomes a high-temperature, high-pressure refrigerant and, as such, is supplied to the outdoor heat exchanger 3 through the four-way valve 2. Then, the refrigerant undergoes heat exchange with the outside air for heat dissipation in the outdoor heat exchanger 3, thereby becoming a high-pressure liquid refrigerant, and, as such, is supplied to the pressure reducer 4. The high-pressure liquid refrigerant is depressurized in the pressure reducer 4, thereby becoming a low-temperature, low-pressure two-phase refrigerant, and is supplied to the indoor unit 7 through the second fluid on / off valve 11 and the fluid connection line 8.In the indoor unit 7, the refrigerant enters the indoor heat exchanger 6, undergoes heat exchange with the indoor air to absorb heat, and is evaporated into a low-temperature gas refrigerant. This cools the indoor temperature to cool the interior of a room. The refrigerant then flows through the gas connection line 9, is returned to the outdoor unit 5, and is re-supplied to the compressor 1 through the first fluid on / off valve 10 and the four-way valve 2.

[0023] In heating mode, the four-way valve 2 is connected so that the discharge side of the compressor 1 communicates with the first fluid on / off valve 10. Consequently, the refrigerant compressed by the compressor 1 becomes a high-temperature, high-pressure refrigerant and, as such, is delivered to the indoor unit 7 through the four-way valve 2, the first fluid on / off valve 10, and the gas connection line 9. The high-temperature, high-pressure refrigerant enters the indoor heat exchanger 6, undergoes heat exchange with the indoor air in the indoor heat exchanger 6 to dissipate the heat to be cooled, and thereby becomes a high-pressure liquid refrigerant. This raises the indoor temperature to warm the interior of a room.Thereafter, the refrigerant is supplied through the fluid communication line 8 to the second fluid on / off valve 11 and to the pressure reducer 4, is depressurized in the pressure reducer 4 to a low-temperature low-pressure two-phase refrigerant, is supplied to the outdoor heat exchanger 3 to undergo heat exchange with the outside air and be evaporated, and is returned to the compressor 1 through the four-way valve 2.

[0024] In Fig. 3 and Fig. Referring now to Fig. 4, a configuration of the first fluid on / off valve 10, which is one of the fluid on / off valves used for an air conditioner according to the present exemplary embodiment, will be described below.

[0025] The first fluid on / off valve 10 is a three-way valve and the valve body 21 of the three-way valve is equipped with the inwardly leading line connection 22, the outwardly leading line connection 23, the maintenance connection 24 and the valve rod holder 26 into which the valve rod 25 is screwed.

[0026] The gas connection line 9 connected to the indoor heat exchanger 6 is connected to the inward-leading line connection 22 via the union nut 27. The copper line 28 is soldered to the outward-leading line connection 23 using a flux, and the line 29 (see refrigerant circuit diagram from Fig. 1) is connected, coming from the outdoor heat exchanger 3, in a similar way to the copper pipe 28.

[0027] The valve insert 30 is inserted into the service port 24, and the service cap 31 is screwed over it. The service port 24 is normally tightly sealed, and a vacuum is released through the service port 24 when the air conditioner is installed.

[0028] The valve rod cap 32 is screwed into the valve rod receptacle 26 to prevent dust from entering the valve rod receptacle 26. The valve rod 25 in the valve rod receptacle 26 includes as a unit: an externally threaded portion 25a, a hexagonal opening 25b for a hexagonal wrench, and a groove portion 25d for inserting an O-ring 25c, as shown in Fig.4. The external thread portion 25a of the valve rod 25 is screwed into the internal thread portion 26a provided in the valve rod receptacle 26, and the valve rod 25 is moved forward or backward by inserting a hexagon wrench (not illustrated) into the hexagonal hole 25b for receiving the hexagon wrench and rotating the hexagon wrench, whereby the valve seat 23a of the outgoing pipe port can be opened / closed.

[0029] The valve body 21 of a three-way valve having the design described above is formed by molding a brass alloy used therefor, as described above, and a brass alloy with a lead content of 1000 ppm is used as the brass alloy.

[0030] In the above-mentioned lead-free brass alloy with a lead content of 1000 ppm or less, as described in the TECHNICAL BACKGROUND section, a brass alloy constituting the fluid on / off valve reacts with ammonia contained in an atmosphere and causes stress corrosion cracking.

[0031] Thus, in the present exemplary embodiment, the fluid on / off valve is formed from a lead-free brass alloy having a lead content of 1000 ppm or less, which contains Sn to an extent of more than 0.220% and which further contains bismuth (Bi) to an extent of more than 1.320%.

[0032] Table 1 shows the results of an ammonia stress corrosion cracking test conducted to evaluate the stress corrosion cracking of a three-way valve made of the lead-free brass alloy.

[0033] In the test, as in Fig.As illustrated in Figure 5, a ventilation plate was placed above ammonia water (14%) in a desiccator containing the ammonia water. A test specimen described below was placed on the ventilation plate and left to stand for 72 hours to expose it to an ammonia atmosphere. The test specimen was then removed, cleaned with a nitric acid solution, and subjected to visual inspection. As a result of this inspection, a test specimen without cracking is designated as "Good" and a test specimen with cracking is designated as "Poor" in an "Evaluation" box in Table 1. In addition, a distance t between a surface of the ammonia water and the ventilation plate was approximately 100 mm, and the test specimen was in a state of non-contact with the ammonia water.

[0034] Furthermore, the test specimen was a Fig.3, wherein the dimensions and tightening torques of the inwardly leading line connection 22, the service connection 24 and the valve rod holder 26 are each designed as described in Table 2. Table 1 Cu Sn Bi Fe Al P Si Ni Sb Zn Rating (union nut) Test specimen 1 59,500 0,220 2,120 0,100 - 0,004 - - 0,002 Rest of the alloy Bad Test specimen 2 61,720 1,050 1,890 0,070 0,0012 0,059 - - 0,004 Rest of the alloy Good Test specimen 3 58,300 0,610 1,320 0,160 - 0,800 - - - Rest of the alloy Bad Test specimen 4 58,900 0,700 - 0,007 - 0,021 - 0,009 - Rest of the alloy Bad Table 2 Size union nut Valve stem cap Maintenance connection cap Inward-leading cable connection ∅ 6.35 mm (1 / 4-inch) 18.0 N·m - - 7 / 16-20UNF Ø 9.53 mm (3 / 8 inch) 42.0 N·m - - 5 / 8-18UNF Valve rod holder Opposite side 22 mm - 17.0 N·m - Opposite side 19 mm - 17.0 N·m - Maintenance connection 1 / 2-20UNF - - 11.0 N·m

[0035] In addition, the stress corrosion cracking was evaluated based on the results of the inward-facing pipe connection 22 and the union nut 27, since the inward-facing pipe connection 22 and the union nut 27, where the tightening torques were high, were exposed to the harshest loads.

[0036] From the test results, it is shown that when using a brass alloy containing Sn in an amount of 0.8% or more, which is greater than 0.7%, preferably in an amount of 1.050% or more, stress corrosion cracking can be prevented even when the lead-free brass alloy with a lead content adjusted to 1000 ppm or less is used.

[0037] This makes it possible to prevent stress corrosion cracking even in the fluid on / off valve, such as a two-way valve or three-way valve, which is arranged for use between refrigerant pipes, that is, the fluid on / off valve which is exposed to the atmosphere with high ammonia content and has a temperature higher than the atmospheric temperature so that it easily reacts with the ammonia.

[0038] Furthermore, as illustrated in the present exemplary embodiment, the air conditioner using a single refrigerant from among HFC-based refrigerants such as R32, or hydrogen fluoride-based refrigerants with a carbon-carbon double bond such as HFO-1234yf, or a refrigerant with a low global warming potential containing these refrigerants as main components, has a high refrigerant pressure compressed by the compressor. Therefore, even if the fluid on / off valve is subjected to a compression load higher than a compression load of a fluid on / off valve used in an air conditioner using a conventional refrigerant such as 410A, stress corrosion cracking can be prevented to a high extent.Accordingly, the environmental impact can be significantly reduced by using the above-mentioned refrigerant with a low heating potential and using the fluid on / off valve made of the lead-free brass alloy.

[0039] In addition, since an excessive Sn content leads to air holes in the casting and thus impairs machinability or ductility, the Sn content is 2.5% or less, and preferably 2.0% or less (Sn: more than 0.220% to 2.5%).

[0040] Furthermore, the Bi content is set to more than 1.320%, and is preferably 1.890% or more. Since Bi has the characteristic of improving machinability, the inclusion of Bi can suppress the deterioration in workability, such as cutting, that accompanies the use of a lead-free brass alloy. This property is preferable because it can bring about an increase in productivity in a fluid on / off valve having a plurality of ports and a screw thread formed on the inner / outer edges of the ports. Since an excessive Bi content impairs tensile strength and ductility, the Bi content is preferably 2.120% (Bi: more than 1.320% to less than 2.120%).

[0041] Furthermore, in the lead-free brass alloy used in the above test and illustrated in Table 1, the copper (Cu) content is 58.300%-61.720%, the Sn content is 0.220%-1.050%, the Bi content is more than 1.320% and less than 2.120%, and the remainder of the alloy consists of zinc (Zn) and impurities. However, from the standpoint of workability or the like, the Cu content is preferably more than 59.500%-66.00% (Cu: more than 59.500%-66.00%). SECOND EXEMPLARY EMBODIMENT

[0042] An exemplary embodiment of the present invention illustrates another example of a lead-free brass alloy fluid orifice valve in which stress corrosion cracking is suppressed by setting a lead content to 1000 ppm or less.

[0043] The lead-free brass alloy of the fluid on / off valve consists of a brass alloy with a lead content of 1000 ppm or less, which contains silicon (Si), preferably Si in an amount of 0.001% or more, particularly preferably Si in an amount of 3.060% or more.

[0044] Table 3 shows the results of an ammonia stress corrosion cracking test conducted to evaluate the stress corrosion cracking of a three-way valve made of the lead-free brass alloy.

[0045] In the test, similar to the first exemplary embodiment, a vent plate was placed in a desiccator containing 14% ammonia water, and a test specimen described below was placed on the vent plate and left to stand for 72 hours to expose it to an ammonia atmosphere. The test specimen was then removed, cleaned with a nitric acid solution, and subjected to visual inspection. As a result of this inspection, in an "Evaluation" box in Table 3, a test specimen without cracking is designated as "Good" and a test specimen with cracking is designated as "Poor." In addition, a distance t between a surface of the ammonia water and the vent plate was approximately 100 mm, and the test specimen was in a state of non-contact with the ammonia water.

[0046] Furthermore, the test specimen was a Fig.3, wherein the dimensions and tightening torques of the inward pipe port 22, the service port 24, and the valve rod retainer 26 are each as shown in Table 2 described in the “First Exemplary Embodiment.” Table 3 Cu Si Bi Fe Al P Sn Ni Sb Zn Rating (union nut) Test specimen 5 59,060 0,001 1,116 0,009 0,018 0,001 0,005 0,001 0,007 Rest of the alloy Bad Test specimen 6 75,170 3,060 - 0,017 - 0,093 0,025 0,006 - Rest of the alloy Good

[0047] In addition, the stress corrosion cracking evaluation was also carried out in this exemplary embodiment based on the results of the inwardly leading pipe connection 22 and the union nut 27, since the inwardly leading pipe connection 22 and the union nut 27, where the tightening torques were each high, were exposed to the harshest load.

[0048] The test results show that when using a brass alloy containing Si in an amount of 0.001% or more, particularly preferably 3.060% or more, the Si improves stress corrosion cracking resistance, and thus, stress corrosion cracking can be prevented even when using a lead-free brass alloy with a lead content controlled at 1000 ppm or less. The above-mentioned Si improves stress corrosion cracking resistance and also improves machinability. However, when the Si content is 4.0% or more, the effect of improving machinability proportional to the Si content is no longer achieved, so the Si content is preferably less than 4.0% (Si: from 0.001% to less than 4.0%).

[0049] Accordingly, similarly to the first exemplary embodiment, stress corrosion cracking can be prevented even in the fluid on / off valve disposed for use between refrigerant pipes, that is, the fluid on / off valve exposed to the atmosphere with high ammonia content and having a temperature higher than the atmospheric temperature so as to easily react with the ammonia.

[0050] For the lead-free brass alloy used in the above test, as shown in Table 3, the Cu content is 59.060% to 75.170%, the Si content is 0.001% or more (in other words, containing at least Si) to 3.060% or more, and the remainder of the alloy consists of Zn and impurities. If the Si content is 3.060% or more, the Cu content is up to 79%, and preferably up to 75.170% (Cu: more than 59.060% to 79%). THIRD EXEMPLARY EMBODIMENT

[0051] Fig. Figure 6 illustrates a fluid on / off valve according to a third exemplary embodiment of the present invention, wherein the fluid on / off valve is a two-way valve. The two-way valve includes an inwardly leading conduit port 42, an outwardly leading conduit port 43, and a valve stem receptacle 46 into which a valve stem 45 is screwed.

[0052] The liquid connection line 8 connected to the indoor heat exchanger 6 is connected to the inward-leading line connection 42 via a union nut 47. A copper line (not shown) is soldered to the outward-leading line connection 43 via a flux, and the line 29a (see refrigerant circuit diagram from Fig. 1) is connected, coming from the outdoor heat exchanger 3, in a similar way to the copper pipe.

[0053] The two-way valve is also formed from the lead-free brass alloy described in the first exemplary embodiment, or from the lead-free brass alloy described in the second exemplary embodiment.

[0054] Accordingly, the fluid on / off valve according to the third exemplary embodiment corresponds in operation and effect to the first exemplary embodiment or the second exemplary embodiment.

[0055] Although the fluid on / off valve and the air conditioner for use in the present invention have been described with reference to the above-mentioned exemplary embodiments, the present invention is not limited to the exemplary embodiments. That is, the exemplary embodiments disclosed herein are intended as examples and are not to be construed as limiting the invention. That is, the scope of the invention is defined by the appended claims rather than the descriptions given above, and all modifications and variations that fall within the scope of the claims or are equivalent to the scope of the claims are therefore intended to be included within the scope of the invention.

[0056] It should be noted that the above-mentioned air conditioner refers to a unit equipped with a refrigeration cycle, and it goes without saying that the air conditioner includes a conventional air conditioner and units such as a dehumidifier and a heat pump heater.

[0057] As described above, according to the present invention, the fluid on / off valve is formed of a brass alloy having a lead content of 1000 ppm or less and containing Sn in an amount of 0.8% or more.

[0058] Therefore, when the fluid on / off valve is arranged for use between refrigerant pipes, the stress corrosion cracking of the valve can be prevented even in the environment where the valve is exposed to the atmosphere containing high ammonia and heated to a temperature higher than the atmospheric temperature so that it can easily react with the ammonia.

[0059] Furthermore, according to the present invention, the fluid on / off valve may be formed of the brass alloy further containing Bi in an amount of 1.6% or more.

[0060] Consequently, good processability can be maintained even when using a lead-free brass alloy.

[0061] Furthermore, according to the present invention, the fluid on / off valve may be formed of a brass alloy having a lead content of 1000 ppm or less and containing Si in an amount of more than 0.001%.

[0062] Therefore, when the fluid on / off valve is arranged for use between refrigerant pipes, the stress corrosion cracking of the valve can be prevented even in the environment where the valve is exposed to the atmosphere containing high ammonia and heated to a temperature higher than the atmospheric temperature so that it can easily react with the ammonia.

[0063] Furthermore, the present invention may be an air conditioning device equipped with any of the fluid on / off valves mentioned above.

[0064] Consequently, stress corrosion cracking of the fluid on / off valve can be prevented and environmental pollution can be reduced without reducing the reliability of the fluid on / off valve and the air conditioner. INDUSTRIAL APPLICABILITY

[0065] The present invention can provide a fluid on / off valve that does not cause stress corrosion cracking despite being made of a lead-free brass alloy, as well as an air conditioner using the fluid on / off valve. Therefore, the present invention can reduce environmental pollution without compromising the reliability of a device such as the fluid on / off valve and the air conditioner equipped with a refrigeration cycle, and can be applied to various units, including refrigerant piping. REFERENCE SYMBOLS IN THE DRAWINGS 1 compressor 2 four-way valve 3 outdoor heat exchangers 4 pressure reducers 5, 100 outdoor unit 6 indoor heat exchangers 7, 101 indoor unit 8 Liquid connection line 9 Gas connection line 10 first fluid on / off valve (fluid on / off valve) 11 second fluid on / off valve (fluid on / off valve) 21 Valve body 22, 42 inward-facing cable connection 23, 43 external cable connection 24, 106 Maintenance connection 25, 45 valve rod 26, 46 valve rod holder 27, 47 union nut 28 copper cables 29, 29a lines 30 valve insert 31 Maintenance connection cap 32, 52 valve rod cap

Claims

A fluid on / off valve comprising a brass alloy with a lead content of 1000 ppm or less, which contains tin (Sn) in an amount of 1.05%, copper (Cu) in an amount of 61.720%, bismuth (Bi) in an amount of 1.890%, iron (Fe) in an amount of 0.070%, aluminum (Al) in an amount of 0.0012%, phosphorus (P) in an amount of 0.059%, antimony (Sb) in an amount of 0.004% and zinc (Zn) as the remainder of the alloy. Fluid on / off valve comprising a brass alloy with a lead content of 1000 ppm or less, which contains 3.06% silicon (Si), 75.170% copper (Cu), 0.017% iron (Fe), 0.093% phosphorus (P), 0.025% tin (Sn), 0.006% nickel (Ni) and zinc (Zn) as the balance of the alloy. An air conditioner comprising:a refrigerant circuit; andthe fluid on / off valve according to claim 1 or 2, wherein the fluid on / off valve is provided in a refrigerant circuit.

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