JPH0434287Y2 - - Google Patents

Description

[Detailed description of the invention] <Purpose of the invention><Field of industrial application> The present invention relates to a safety valve that is installed in a passageway for various fluids and is responsible for controlling the pressure of the fluid.
The present invention relates to a novel safety valve construction suitable for construction from a plastic material that is particularly resistant to corrosion against chemicals and the like.

<Background of the invention> Chemicals are handled in chemical plants, etc., so the pipelines, etc. must be chemically resistant, and the safety valves, gate valves, etc. that make up part of them are also required to have similar performance. accurate operation is required.

By the way, if accurate operation is simply required, almost the desired performance can be obtained by constructing a complex-shaped valve body from a metal material and incorporating this valve body to construct a safety valve. However, when using a plastic material as the main component of a safety valve, which has excellent corrosion resistance against chemicals, it was impossible to have a complicated valve body structure. For this reason, there are relatively few safety valves that have excellent chemical resistance and accurate operation, and few react instantaneously when the desired pressure setting is reached, and many leak even before the set pressure is reached. Most of the cases started. From a structural point of view, in the past, the pressure receiving body itself, which receives fluid pressure, was integrated with the valve body that controlled fluid leakage, and pulsations or pressure increases in fluid pressure immediately caused the valve to open or close. It was because it would get involved.

<Technical issues attempted to be solved> Here, the present invention proposes a safety valve with a novel structure that can be expected to operate accurately even when a material such as plastic with excellent chemical resistance is used as the main component of the safety valve. This is an attempt at development.

<<Structure of the invention>><Means for achieving the object> In other words, the safety valve of the present invention has a pressure accumulation chamber to which fluid pressure is applied, a relief hole through which the fluid in the pressure accumulation chamber escapes when this pressure exceeds a certain value, and the relief valve. A valve element is provided which closes the opening of the hole on the pressure accumulator side by biasing a valve spring until the pressure of the fluid reaches a constant value, and the valve element has a diaphragm-like pressure receiving valve element. The valve body has a small diameter and is crimped onto a valve seat that communicates with the relief hole side which is attached in a floating state while being biased by a fine movement spring in the direction of projection from the valve body, and the valve body is , has a cylindrical shape with a small diameter on the tip side, while the valve seat has a tapered opening with a small diameter on the relief hole side, and the valve body and valve seat are continuous in an annular shape in the circumferential direction. The valve body is characterized in that the valve body contacts each other at the closing part, and the valve body is provided at two or more locations offset in the axial direction of the valve body, thereby achieving the above object. .

<Example> The present invention will be specifically described below based on the illustrated example. Reference numeral 1 denotes a safety valve, which is connected, for example, to the tip of a pilot pipe 2 branched from a conduit, and from which a relief pipe 3 is further extended and connected. Of course, depending on its configuration, the safety valve 1 may not be attached to the pilot pipe 2, but may be provided in the middle of the fluid supply pipe line. The safety valve 1 will be described in detail below. Reference numeral 5 denotes a valve box constituting the safety valve 1, in which a valve body 6 and a valve spring 7 are assembled. The valve box 5 is roughly divided into four parts. First, reference numeral 10 is a body made of a plastic material with excellent corrosion resistance, and 11 is a valve holder made of a plastic material that is assembled above the body 10. Further, the plate 12 is an upper press plate made of stainless steel or the like provided above the valve press plate 11, and the reference numeral 13 is a bottom press plate made of stainless steel or the like provided at the bottom of the body 10.
First, a pressure accumulation chamber 15 is formed in the center of the body 10 of the valve box 5, and an introduction hole 16 for connecting the pilot pipe 2 from the outside is communicated with the pressure accumulation chamber 15. A relief hole 17 communicating with the relief pipe 3 is bored.
The area near the boundary between the relief hole 17 and the pressure accumulation chamber 15 is tapered with a smaller diameter on the side of the relief pipe 3, and serves as the valve seat 18 against which the valve body 6 comes into contact. Further, the valve holding plate 11 provided above the body portion 10 has a guide hole 20 for the valve body 6 bored in the center thereof. Further, the upper holding plate 12 of the valve case 5 has a valve spring storage portion 22 near its center, into which an adjustment bolt 23 for adjusting the pressure strength of the valve spring 7 is screwed. Furthermore, code 2
3' is a lock nut for the adjustment bolt 23, which is made of plastic material, for example. Furthermore, a piping hole 24 for receiving the relief pipe 3 is formed in the bottom holding plate 13. These body portion 10, valve holding plate 1
1. The upper holding plate 12 and the bottom holding plate 13 are tightened and integrated by, for example, four bolts 25 passing through their peripheries, and constitute the valve box 5. Next, the valve body 6 housed in the pressure accumulation chamber 15 in the valve box 5 will be explained. This valve body 27 is composed of a pressure receiving valve body 27 and a valve body 28. The pressure receiving valve body 27 has a diaphragm shape, and a valve holding plate 11 is provided on the upper surface of the pressure receiving valve body 27.
The valve spring 7 is fitted into the guide hole 20 of
The receiving core 30 is formed to protrude. The valve body 6 is attached so that the diaphragm-shaped outer peripheral portion of the pressure receiving valve body 27 is sandwiched between the body portion 10 and the valve holding plate 11 when the valve body 5 is assembled together. Incidentally, this sandwiching portion may be provided with packing or the like to maintain airtightness, if necessary. On the other hand, the pressure receiving valve body 27
On the relief hole side (lower in the figure) is a short circular rod-shaped valve body 2.
8 is attached in a floating state so that it can freely protrude downward, and specifically, the holder 3 is attached to the attachment part 31.
2 are screwed together, and the valve body 28 is fitted into the holder 32 so as to protrude from below, and the flange portion 29 abuts against the middle flange portion 32' of the holder 32 to prevent it from slipping out. It is something to do. A fine movement spring 33 is compressed between the valve body 28 and the center of the mounting portion 31, so that the valve body 28 always has a tendency to protrude. Furthermore, this valve body 28 is constructed so that its distal end side has a small diameter,
A specific example of this structure is to form a slight step at the tip and taper off from there, with the step serving as the shoulder portion 35 and the tip side forming the tapered portion 36. Of course, as a configuration in which the tip end side has a small diameter, there may be no taper portion, and there may be a configuration in which multiple steps are formed. The valve body 28 having the shoulder portion 35 and the tapered portion 36 comes into contact with the tapered valve seat 18 at a closing portion 40 that is connected to the tapered valve seat 18 in an annular manner in the circumferential direction. As shown in FIGS. 3 to 5, the shoulder portion 35 is offset in the axial direction of the valve body 28.
Codes 40A and 40B are provided at two locations: and the tapered portion 36.
It is formed as shown in . Of course, this shoulder part 3
The number of abutting points between the valve seat 18 and the valve body 28 can be set to two or more, or an appropriate number, by adding additional valves 5 as appropriate.

The safety valve of the present invention has the specific mechanism described above, and operates as follows. First, normally, when the safety valve 1 is not in operation, the valve body 28 is in contact with the valve seat 18, and in this case, the valve body 28 is located slightly above the lowest position. be. That is, the flange portion 29 of the valve body 28 does not come into contact with the inner flange portion 32' of the holder 32 (it is floating). On the other hand, the entire valve body 6 including the valve body 28 is pressed downward by the valve spring 7. In this state, the fluid from the pilot pipe 2 fills the pressure accumulator 15, and when the pressure reaches the regulation value, pressure is applied to the valve body 6, causing the diaphragm-shaped pressure receiving valve body 27 to close to the valve spring. It acts in such a way that it resists the force 7 and pushes it upward in the figure. By the way, at this time, even if the pressure receives a pulsating wave and causes the pressure receiving valve body 27 to move slightly, the valve body 28 is attached to the pressure receiving valve body 27 in a movable state. The valve body 28 , which essentially cuts off communication between the pressure accumulation chamber 15 and the relief hole 17 , is constantly biased downward under the pressure of the fine movement spring 33 , thereby causing the valve seat 18 and the valve body 28 to be biased downward. The state of pressure contact with the material is always maintained. When a pressure higher than the required value is applied, the valve body 6 is pushed up sufficiently, and together with the valve body 28, the pressure-receiving valve body 27 is biased upward, releasing the fluid to the relief hole 17 side, and the desired pressure is increased. That is.

<<Effects of the invention>> The present invention has the above-mentioned configuration and operation, and since the valve body 6 has a double structure of the diaphragm-shaped pressure receiving valve body 27 and the valve body 28, first of all, The area of the pressure-receiving part is wide, and settings can be adjusted at low pressures.

In addition, regarding fluid relief (leakage) when the specified pressure is reached, the valve body 6 has a double structure, so there is no leakage before the set value, and the valve body is not affected by pressure fluctuations in the pressure accumulation chamber. Therefore, leaks due to pressure fluctuations and pulsations do not occur.

Furthermore, since there is no so-called gland seal part structurally, there is no leakage from the gland.

Furthermore, since it is relatively simple in structure and can be constructed from plastic materials with excellent corrosion resistance, it can be constructed more appropriately as a safety valve for piping routes that handle chemicals, etc. It is something. Of course, since the present invention can be constructed from plastic materials which are relatively difficult to process precisely, it is of course possible to construct it from metal materials.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway perspective view of the safety valve of the present invention. Fig. 2 is an exploded perspective view of the same as above, Fig. 3 is a longitudinal sectional side view of the same as above, Fig. 4 is an enlarged sectional view of the valve body portion, and Fig. 5 is the operation of the same as above. It is a longitudinal side view showing a state. 1... Safety valve, 2... Pilot pipe, 3... Relief pipe, 5... Valve box, 6... Valve body, 7... Valve spring, 10... Body, 11... Valve holding plate,
12...Top press plate, 13...Bottom press plate,
15...Pressure accumulation chamber, 16...Introduction hole, 17...Relief hole, 18...Valve seat, 20...Guide hole, 22...Valve spring storage section, 23...Adjustment bolt, 2
3'...Lock nut, 24...Piping hole, 25...
... Bolt, 27 ... Pressure receiving valve body, 28 ... Valve body,
29...Flange part, 30...Core holder, 31...Mounting part, 32...Holder, 32'...Flange part,
33...Fine movement spring, 35...Shoulder, 36...
...Tapered part, 40, 40A, 40B... Closed part.

Claims (1)

[Scope of utility model registration request] A pressure accumulation chamber to which fluid pressure is applied, a relief hole that releases the fluid in the pressure accumulation chamber when the pressure exceeds a certain value, and a valve spring that connects the opening of the relief hole on the pressure accumulation chamber side until the fluid pressure reaches a certain value. The valve body is comprised of a diaphragm-shaped pressure-receiving valve element and a valve element having a diameter smaller than that of the pressure-receiving valve element, and which is attached by a fine movement spring in a direction that constantly protrudes from the pressure-receiving valve element. The valve body has a cylindrical shape with a smaller diameter on the tip side, and a valve body that is attached in a floating state while being biased and is crimped onto a valve seat that is always in communication with the relief hole side. The seat has a tapered opening with a smaller diameter on the relief hole side, and the valve body and the valve seat contact each other at a continuous annular closing part in the circumferential direction, and this closing part is offset in the axial direction of the valve body. A safety valve characterized by being provided in two or more locations.