valve

Abstract

To provide a valve for liquid hydrogen that prevents operator difficulty due to leakage from the gland. [Solution] In a valve 1 in which a valve body 3 provided at one end of a stem 5 abuts against a valve seat 2f formed on a valve body 2, the stem 5 passes through a bonnet 6 provided above the valve body 2 and has a handle 4 at the other end. A gland packing 7 is provided between the outer circumferential surface of the stem 5 and the inner circumferential surface of the bonnet 6 near the open end of the bonnet 6, and a protective member 8 is provided so as to fit onto the stem 5 and cover the open end surface of the gland packing 7.

Description

Technical Field

[0001] The present invention relates to a valve for controlling the flow of a fluid, and is suitable as a valve for controlling a cryogenic fluid.

Background Art

[0002] The on-off valve, which is a fluid controller disclosed in Patent Document 1, is suitable as a valve for controlling a cryogenic fluid. In Patent Document 1, a valve body 10 provided at one end of a valve rod 9 is provided so as to be able to contact and separate from a valve seat 2d formed in a valve box 2, and by operating a handle wheel 11 provided at the other end of the valve rod 9, the valve rod 9 moves up and down to open and close. The valve rod 9 is provided so as to penetrate a lid 4 provided above the valve box 11, and by pressing a seal packing 13a provided on the lid 4 with a packing presser ring 13b, leakage to the outside is prevented. For such a valve for a cryogenic fluid, by making the valve rod 9 sufficiently long, the influence of the cryogenic fluid on the operation part can be reduced.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] A valve for a cryogenic fluid as disclosed in Patent Document 1 is also used for liquefied gases such as liquid nitrogen, liquid oxygen, liquid hydrogen, liquefied natural gas, etc. However, when flowing a liquefied gas, high-pressure gas may accumulate between the lid and the valve rod due to vaporization and leak from the seal packing. In such a leak, since the cryogenic high-pressure gas jets out against the operation member, it causes difficulty in operation in a manual valve where an operator directly performs the operation.

[0005] The present invention has been made in view of the above, and aims to provide a valve for liquefied gas that prevents operator difficulties due to leakage from the gland section. [Means for solving the problem]

[0006] The valve designed to solve the above problem is A valve body having an inlet, an outlet, a flow path connecting the two, and a valve chamber, A stem is provided with a valve body at one end that contacts and separates from a valve seat formed at the valve chamber side opening end of the inflow passage, and a handle at the other end. A through hole is formed for inserting the stem, and the bonnet is fixed to the valve body, A gland packing is interposed between the outer circumferential surface of the stem and the inner circumferential surface of the through hole near the open end of the bonnet, The gland packing is provided between the handle and a protective member that is fitted onto the stem and covers the open end surface of the gland packing.

[0007] The valve of the present invention prevents low-temperature gas ejected from the gland packing from directly contacting the handle by fitting a protective member to the stem so as to cover the open end surface of the gland packing, thus not affecting the operator's operation.

[0008] The valves developed to solve the above problems are further The protective member is characterized in that, in a plan view, it is a plate-shaped member that is larger than the handle.

[0009] By designing the protective component in this way, it is possible to prevent the ejected low-temperature gas from affecting workers. [Effects of the Invention]

[0010] The valve of the present invention provides a valve that prevents operator difficulties due to leaks from the gland packing. [Brief explanation of the drawing]

[0011] [Figure 1] This is a front cross-sectional view showing a valve according to the first embodiment of the present invention. [Figure 2] This is a front cross-sectional view showing a valve according to a second embodiment of the present invention. [Modes for carrying out the invention]

[0012] Hereinafter, preferred embodiments of the valve according to the present invention will be described with reference to the drawings. Unless otherwise specifically stated, the shapes of the components described in this embodiment, their relative arrangement, etc., are not intended to limit the scope of this invention, but are merely illustrative examples. Furthermore, for convenience, the directions of members, etc., may be referred to as up, down, left, and right according to the directions in the drawings, but these do not limit the scope of the present invention.

[0013] Figure 1 shows Embodiment 1 of the present invention. Figure 1 is a front cross-sectional view of the valve of the present invention. The valve 1 of the present invention comprises a valve body 2 having an inlet 2a, an outlet 2b, an inflow passage 2c, an outflow passage 2d, and a valve chamber 2e, with a valve seat 2f formed at the valve chamber side opening end of the inflow passage 2c; a stem 5 having a valve element 3 that abuts against and separates from the valve seat 2f at one end and a handle 4 at the other end; a bonnet 6 having a through hole 6a through which the stem 5 is inserted and fixed to the valve body 2; a gland packing 7 interposed near the open end of the bonnet 6 between the inner circumferential surface of the through hole 6a of the bonnet 6 and the outer circumferential surface of the stem; and a protective member 8 fitted to the stem 5 between the gland packing 7 and the handle 4 so as to cover the open end surface of the gland packing.

[0014] The inlet 2a and outlet 2b of the valve body 2 are configured to be connected to piping. Fluid flows in from the inlet 2a, passes through the inlet passage 2c, valve chamber 2e, and outlet passage 2d, and flows out from the outlet 2b. The inlet passage 2c opens to the bottom surface of the valve chamber 2e, and a valve seat 2f is formed so that the valve body 3 can abut against the opening to close off the fluid. The valve body 3 is configured to move perpendicularly to the valve seat 2f, and the contact portion with the valve seat 2f is tapered and is fixed to the stem 5 in a suspension structure. The bonnet 6 is screwed into the valve body 2 to cover the upper opening of the valve chamber 2f. The through hole 6a of the bonnet 6 extends vertically and has a female threaded portion in the middle, which screws into a male threaded portion formed in the middle of the stem 5, allowing the stem 5 to move vertically by rotating the handle 4. Near the open end of the through hole 6a, the diameter of the through hole is enlarged to accommodate a gland packing 7. The gland packing 7 is an annular member formed from a material such as graphite, PTFE, or PFA, and is pressed from above by the gland packing retainer 7a. The gland packing retainer 7a is pressed by a gland nut 7b which is screwed into the bonnet 6, and can be tightened further by screwing in the gland nut 7b as needed. The protective member 8 is provided to cover the open end surface of the gland packing, preventing gas ejected from the gland packing 7 from directly contacting the handle 4. The protective member 8 is a plate-shaped member larger than the handle 4, taking into consideration that the gas will flow around the protective member 8.

[0015] When liquefied gas flows through the valve 1 of the present invention, the inside of the valve is filled with a two-phase state of liquid and gas. In particular, the bonnet 6 is easily affected by the outside air temperature, and the gap between the through-hole 6a of the bonnet 6 and the stem 5 causes the vaporized gas to become high pressure, and high-pressure gas may jet out from the gland packing 7. In particular, conventionally, during valve operation, due to the influence of the sliding of the gland packing 7, gas jetting occurs, and low-temperature gas is applied to the handle 4, which may cause difficulty in handle operation and endanger the operator. The protective member 8 of the valve 1 of the present invention is for preventing this. By providing the protective member 8, the jetted gas does not directly act on the handle 4, and the influence of the jetted gas can be minimized.

[0016] Figure 2 shows Embodiment 2 of the present invention. In the description, the configurations described in Embodiment 1 are omitted. In Figure 2, a yoke 9 is attached to the bonnet 6, and a male screw portion formed on the stem 5 and a female screw portion formed on the yoke 9 are screwed together above the bonnet 6. By rotating the handle 4, the stem 5 can move up and down. The gland packing 7 is pressed from above by a gland packing retainer 7a, and the gland packing retainer 7a is pressed by a flange 7c fixed to the bonnet 6 with bolts. The protective member 8 is provided to fit on the stem 5 between the yoke 9 and the handle 4 and cover the open end face of the gland packing.

Industrial Applicability

[0017] The valve according to the present invention can prevent difficulties in operation due to leakage from the gland packing, and thus can be widely used as a manual valve for low-temperature fluids such as valves for liquefied gas.

Explanation of Reference Numerals

[0018] 1 Valve 2 Valve Body 2a Inlet 2b Outlet 2c Inlet Flow Path 2d Outlet Flow Path 2e Valve Chamber 2 - valve seat 3 - valve body 4 - handle 5 - stem 6 - bonnet 6a - through - hole 7 - gland packing 7a - gland packing retainer 7b - gland nut 7c - flange 8 - protection member 9 - yoke

Claims

1. A valve body having an inlet, an outlet, a flow path connecting the two, and a valve chamber, A stem is provided with a valve body at one end that contacts and separates from a valve seat formed at the valve chamber side opening end of the inflow passage, and a handle at the other end. A through hole is formed for inserting the stem, and the bonnet is fixed to the valve body, A gland packing is interposed between the outer circumferential surface of the stem and the inner circumferential surface of the through hole near the open end of the bonnet, A valve comprising a protective member provided between the gland packing and the handle, fitted onto the stem, and covering the open end surface of the gland packing.

2. The valve according to claim 1, characterized in that the protective member is a plate-shaped member that is larger than the handle in a plan view.

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