Valve

Abstract

The purpose of the present invention is to provide a valve that uses a hollow stem and reduces the stress caused by an internal / external pressure difference at the stem so as not to be readily damaged by the stress caused by the internal / external pressure difference at the stem.　This valve comprises a valve body 10 that comprises a valve chamber 16 and an inlet-side passage 11 and an outlet-side passage 12 that communicate with the valve chamber, a valve element 17 that moves into contact with and separates from a valve seat 13 that is formed at the valve chamber at an opening of the inlet-side passage, an actuator 20 that operates the valve element, a bonnet 32 that rises from the valve body, connects the valve body and the actuator, and has an internal accommodation space 33, and a stem 30 that is accommodated in the accommodation space, connects the actuator and the valve element, and transmits the operation of the actuator to the valve element.　The stem has an internal space 34 and a communication hole 39 that allows the internal space and the accommodation space to communicate.

Description

valve

[0001] The present invention relates to a valve.

[0002] In recent years, there has been a demand for control valves for adjusting flow rates and shut-off valves that can be used in high-pressure, cryogenic environments, such as those found in hydrogen station supply infrastructure and in manufacturing infrastructure using reactive gases. For example, in the case of a valve that controls the flow rate of liquid hydrogen, the liquid-contacting portion reaches approximately -253°C, so the stem connecting the valve body and the actuator is made long to reduce the effect of the cryogenic temperature on the gland seal. In addition, by adopting a hollow, cylindrical stem, the weight of the stem is reduced, thereby reducing the weight of the valve and suppressing the effect of heat conduction from the stem.

[0003] The cryogenic valve described in Patent Document 1 has a structure shown in Figure 4, in which connecting pipes 122 and 121 are attached to a valve body 102, and a valve seat 123 is formed. When a handle 104 is turned, the valve stem 103 moves up and down, and the valve stem connecting hardware 109 also moves up and down. The stem 101 includes an intermediate pipe 108, a valve stem connecting hardware 109, and a disc packing mounting portion 107, to which a disc packing 105 is attached. The disc packing 105 and the valve seat 123 come into contact with and separate from each other, thereby controlling the flow of fluid. The valve disc 101 and valve body 102 are covered with a jacket 106.

[0004] The valve body 101 has a structure including an intermediate pipe 108, a valve stem connecting hardware 109, and a disk packing mounting portion 107, and has an internal space that is lightweight and reduces the thermal effects of cryogenic liquid hydrogen.

[0005] Publicly-Published Utility Model No. 18637-1980

[0006] The valve described in Patent Document 1 flows liquid hydrogen, an extremely low-temperature liquid, and the temperature of the liquid-contacting parts reaches approximately 253°C. If the intermediate pipe 108 and the valve stem connecting hardware 109, and the intermediate pipe 108 and the disc packing mounting part 107 are sealed to isolate the internal space of the stem 101 from the external space, the external space will become high-pressure (up to approximately 10 MPa) due to the vaporized hydrogen, and a load will be applied to the stem due to the pressure difference between the internal space and the external space. This will cause deformation of the stem and the load on the stem, which will cause stress concentration at the joints of the valve, such as welded parts, and may lead to valve failure.

[0007] The present invention has been made in consideration of the above points, and its purpose is to provide a valve that reduces the stress caused by the pressure difference between the inside and outside of the stem in a valve that uses a hollow stem, thereby making it less likely to fail due to stress caused by the pressure difference between the inside and outside of the stem.

[0008] The present invention (1) is a valve comprising: a valve body having a valve chamber and an inlet-side flow path and an outlet-side flow path communicating with the valve chamber; a valve disc that moves toward and away from a valve seat formed at an opening of the inlet-side flow path of the valve chamber; an actuator that operates the valve disc; a bonnet that stands upright from the valve body, connects the valve body to the actuator, and has an internal storage space; and a stem that is housed in the storage space, connects the actuator to the valve disc, and transmits the operation of the actuator to the valve disc, wherein the stem has an internal space and a communication hole that connects the internal space with the storage space.

[0009] The valve of present invention (1) comprises a valve chest, valve body, actuator, bonnet, and stem. The bonnet has a storage space for the stem, and the pressure in the internal space of the stem and the storage space of the bonnet are equalized through the communicating hole. This prevents stress from being applied to the stem due to a pressure difference, and prevents failure due to stress caused by the pressure difference between the inside and outside of the stem.

[0010] The present invention (2) is the valve of the present invention (1), wherein the communication hole is formed at the end of the stem on the actuator side.

[0011] In the valve of present invention (2), the communication hole is formed at the actuator-side end of the stem, which is preferable as there is no risk of liquid hydrogen or hydrogen gas getting in. Furthermore, if the communication hole is formed on the side, there is a risk that it will have an adverse effect on the strength of the stem, so by forming the communication hole at the actuator-side end, the effect on strength is reduced, which is preferable.

[0012] The present invention (3) is a valve according to the present invention (2), wherein the end is a closure that closes the open end of a cylindrical stem having an open end that is open at least on the actuator side, and the communicating hole is formed in the closure.

[0013] In the present invention (3), the end is a closure that closes the open end of a cylindrical stem having an open end at least on the actuator side, and the communicating hole is formed in the closure, so that the structure of the stem can be simplified and costs can be reduced.

[0014] According to the present invention, it is possible to provide a valve that uses a hollow stem, in which the stress caused by the pressure difference between the inside and outside of the stem is reduced, and which does not malfunction due to the stress caused by the pressure difference between the inside and outside of the stem.

[0015] Fig. 1 is a partial cross-sectional view of the entire valve of the present invention. Fig. 2 is a partial cross-sectional view of the upper part of the stem of the valve of the present invention. Fig. 3 is a partial cross-sectional view of the lower part of the stem of the valve of the present invention. Fig. 4 is a partial cross-sectional view of the entire valve described in Patent Document 1.

[0016] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that the following embodiments are essentially preferred examples and are not intended to limit the scope of the present invention, its applications, or its uses.

[0017] 1 is a partial cross-sectional view of the entire valve of the present invention, and the valve 1 is mainly composed of a valve body 10, an actuator 20, and a stem 30. An inlet-side connecting pipe 14 and an outlet-side connecting pipe 15 are connected to the valve body 10, and are connected to an inlet-side flow path 11 and an outlet-side flow path 12 inside the valve body 10, respectively. A valve seat 13 is formed at the opening of the inlet-side flow path 16 in a valve chamber 16.

[0018] A drive shaft 22 is attached to a handle 21 of the actuator 20, and as the handle 21 rotates, the drive shaft 22 also rotates, and an internal thread (no reference number) engraved inside the support 24 engages with an external thread (no reference number) formed on the lower part of the drive shaft 22, causing the drive shaft lower locking part 23 to move up and down while rotating. As the valve stem upper locking part 26, which engages with the drive shaft lower locking part 23, moves up and down, the valve stem 25 also moves up and down.

[0019] A valve stem lower locking portion 29 is formed at the lower end of the valve stem 25. The valve stem 25 passes through the sealing male thread 27, which is screwed in and applies pressure to the gland packing 28 from above, preventing fluid and vaporized gas from leaking out of the valve along the valve stem 25. The anti-rotation stop 31 is intended to prevent the sealing male thread 27 from loosening due to vibration.

[0020] A bonnet 32 ​​extends from the top surface of the valve body 10, and its interior forms an accommodation space 33 capable of accommodating the stem 30. The interior of the stem 30 forms a hollow internal space 34, making it less susceptible to thermal effects from cryogenic fluid. An actuator-side closure 35 is disposed at the upper end of the stem 30, and a communication hole 39 is formed in the actuator-side closure 35. The presence of this communication hole 39 equalizes the pressure in the internal space 34 of the stem 30 and the space outside the stem 30, making it less likely that stress that could cause distortion will occur in the stem 30.

[0021] The actuator side closure body 35 is formed with an actuator side closure body engaging portion 36 which engages with the valve stem lower engaging portion 29, and the up and down movement of the actuator 20 is transmitted to the stem 30, which moves up and down in conjunction with it.

[0022] A valve body side closure body 37 is arranged at the bottom of the stem 30, and a valve body side closure body locking portion 38 is formed below the valve body side closure body 37 to engage with the valve body 17.The valve body 17 moves up and down with the movement of the actuator 20, coming into contact with and separating from the valve seat 13, thereby opening and closing the valve.

[0023] Figure 2 is a partial cross-sectional view of the upper portion of the stem 30 of the valve 1 of the present invention shown in Figure 1. Some of the details already explained in Figure 1 will be omitted. A centering ring 42 is provided to prevent the stem 30 from shifting from its axis.

[0024] 2, welds 40 and 41 are provided to maintain airtightness, but without the communication hole 39, the pressure difference between the inside and outside of the stem 30 would be excessive, and excessive stress would be applied to the weld 40, which is a stress concentration point, which could cause deformation or fracture of the stem 30. The presence of the communication hole 39 minimizes the pressure difference between the inside and outside of the stem 30, preventing excessive stress from being applied to the weld 40.

[0025] Figure 3 is a partial cross-sectional view of the lower portion of the stem 30 of the valve 1 of the present invention shown in Figure 1. Some of the parts already explained in Figure 1 will not be explained again. A centering ring 45 is provided to prevent the stem 30 from shifting from its axis. A spring 46 is also provided between the valve body-side closure element 37 and the valve element 17.

[0026] 3, welds 47, 48, 49, and 50 are provided to maintain airtightness, but without communication hole 39, the pressure difference between the inside and outside of stem 30 would be excessive, and excessive stress would be applied to weld 47, which is a stress concentration point, causing deformation or fracture of stem 30. The presence of communication hole 39 minimizes the pressure difference between the inside and outside of stem 30, preventing excessive stress from being applied to weld 47.

[0027] As described above, the present valve can provide a valve that is less likely to malfunction in hydrogen stations and the like that flow fluids such as cryogenic liquid hydrogen.

[0028] REFERENCE SIGNS LIST 1 Valve 10 Valve body 11 Inlet side flow path 12 Outlet side flow path 13 Valve seat 14 Inlet side connecting pipe 15 Outlet side connecting pipe 16 Valve chamber 17 Valve element 20 Actuator 21 Handle 22 Drive shaft 23 Drive shaft lower locking portion 24 Support 25 Valve stem 26 Valve stem upper locking portion 27 Sealing male thread 28 Gland packing 29 Valve stem lower locking portion 30 Stem 31 Rotation stopper 32 Bonnet 33 Storage space 34 Internal space 35 Actuator side closing body 36 Actuator side closing body locking portion 37 Valve body side closing body 38 Valve body side closing body locking portion 39 Communication hole 40, 41, 47, 48, 49, 50 Welded portion 42, 45 Centering ring 46 Spring

Claims

1. A valve comprising a valve chamber, an inlet-side flow path and an outlet-side flow path communicating with the valve chamber, a valve body that abuts and separates from a valve seat formed at an opening of the inlet-side flow path of the valve chamber, an actuator that operates the valve body, a bonnet that stands upright from the valve body, connects the valve body and the actuator, and has an accommodation space inside, and a stem that is accommodated in the accommodation space, connects the actuator and the valve body, and transmits the operation of the actuator to the valve body, wherein the stem has an internal space and a communication hole that communicates the internal space with the accommodation part.

2. The valve according to claim 1, wherein the communication hole is formed at an end of the stem on the actuator side.

3. The valve according to claim 2, wherein the end is a closing body that closes an opening end of a cylindrical stem having at least an opening end on the actuator side opened, and the communication hole is formed in the closing body.