JP3393291B2 - safety valve - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a safety valve used for pressure vessels and the like.

[0002]

2. Description of the Related Art A conventional safety valve is provided with a valve seat of a main body which communicates with a pressure container, a valve body which separates from and contacts the valve seat, and a spring which presses the valve body against the valve seat.

When the gas pressure in the pressure container starts to blow, a slight amount of gas begins to leak from between the valve and the valve seat, and when the blow pressure is further increased, the valve body separates from the valve seat and opens the valve. Then, the gas in the pressure vessel is discharged into the atmosphere through the discharge port.

Here, the blowing start pressure is the pressure at which the safety valve actually starts blowing, and is the pressure at the inlet side when a slight outflow of gas is detected at the outlet side.

The blowout pressure is the pressure at the inlet side when the safety valve operates and the fluid blows out, and has a measurable lift or a pressure at which a continuous discharge state can be recognized.

[0006]

In the safety valve of the conventional example, when the gas pressure in the pressure vessel, which had been an abnormally high pressure, becomes normal, the valve is pressed by the spring and rapidly descends to be seated. Therefore, the valve and the valve seat may be damaged due to a strong impact.

Therefore, in order to solve this problem, the following safety valve has been developed. A valve seat surrounding the outlet is provided in the main body, a spring case is connected to the main body, the valve is slidably inserted in a guide portion of the spring case, and the valve is crimped to the valve seat by a spring. A safety valve having a pressure regulating chamber provided on the outer peripheral portion of a valve seat; a safety valve having a fluid resistance adjusting passage provided between the pressure regulating chamber and the discharge port.

However, this safety valve has the following problems. (1) When the valve is opened, the pressure fluid discharged from the fluid outlet collides with the valve and is discharged into the atmosphere from the discharge port while pressing the valve. However, there are several outlets,
Further, since the spring is opened in the lateral direction of the spring case, the pressure fluid exerts not only a force in the longitudinal direction, that is, the central axis direction but also a force in the lateral direction, that is, the radial direction on the valve.
Therefore, the valve cannot tilt and slide smoothly, which makes it difficult to open the valve quickly. (2) In addition, a chattering phenomenon may occur due to the pressure change of the fluid pressure in the pressure chamber, and the valve may be damaged.

The present invention has been made in view of the above circumstances and has an object to allow a valve to operate smoothly. Another purpose is to prevent chattering.

[0010]

According to the present invention, a valve seat is provided at an outlet of a fluid passage hole of a main body, a spring case having a discharge port is connected to the main body, and a valve slides on a guide portion of the spring case. A safety valve in which the valve is freely inserted and attached to the valve seat by a spring and a pressure adjusting chamber is provided outside the valve seat; and a discharge port is formed in a main body insertion portion of the spring case. A safety valve characterized in that a throttle member is provided on the main body to form a throttle channel, and the pressure regulating chamber and the discharge port are communicated with each other via the throttle channel.

According to the present invention, a valve seat is provided at an outlet of a fluid passage hole of a main body, a spring case is connected to the main body, and a valve is slidably attached to a guide portion of the spring case. Is a safety valve in which a pressure regulating chamber is provided outside the valve seat while being pressed against the valve seat by; and a fluid gap is formed between a guide portion of the spring case and the valve, and a straight cylindrical portion of the spring case. A safety valve characterized in that a discharge port communicating with the fluid gap is formed in
Is.

According to the present invention, a valve seat is provided at the outlet of the fluid passage hole of the main body, a spring case is connected to the main body, and the valve is slidably inserted in the guide portion of the spring case. A pressure regulating chamber which is pressure-contacted to the valve seat by means of a pressure regulating chamber on the outside of the valve seat; a discharge port is formed in the main body insertion portion of the spring case, and a throttle member is provided in the main body. A passage is formed, the pressure regulating chamber and the discharge port are communicated with each other through the throttle passage, a fluid gap is formed between the guide portion of the spring case and the valve, and the straight tube portion of the spring case is provided with the fluid passage. A safety valve characterized in that a discharge port communicating with a fluid gap is formed.

[0013]

When the pressure starts to blow, the pressure gas begins to leak from between the valve seat and the valve and flows into the pressure adjusting chamber. When the gas pressure in the pressure vessel further rises to the blowout pressure, the valve is pushed up by the pressure gas to separate from the valve seat, and opens.
At this time, the pressure fluid is temporarily retained in the pressure regulating chamber, and on the one hand, the pressure fluid flows from the pressure regulating chamber through the throttle channel into the discharge chamber and is discharged into the atmosphere through the discharge port. It is released into the atmosphere. At this time, the gas passing through the fluid gap serves as a fluid bearing for the spring case guide portion and the valve, and the contact and friction become zero, so that the valve moves smoothly.

When the gas pressure in the pressure vessel returns to normal, the valve is pressed by the biasing means and seated. The valve is gradually lowered and seated while receiving the resistance of the pressure gas remaining in the pressure chamber.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described with reference to FIGS. The rear end of the main body 1 is connected to a pressure vessel (not shown), and the front end is screwed to the spring case 3.

The spring case 3 comprises a straight cylinder portion 3a, a guide cylinder portion 3b, and a main body insertion portion 3C. This straight tube portion 3a
A discharge port 7 that communicates with the atmosphere is formed therein. A plurality of the discharge ports 7 are formed in the radial direction, but the number, the size of the diameter, and the like are appropriately selected as needed.

The valve 10 is inserted from the upper end of the spring case 3, and the valve 10 is slidably inserted into the guide tube portion 3b. A fluid gap 6 is formed between the valve 10 and the guide tube portion 3b, and the width w of the gap 6 is appropriately selected as needed. A packing 11 that abuts the valve seat 5 is provided on the lower surface of the valve 10.

The spindle 15 is inserted from the upper end of the spring case 3, and the tip 15a of the spindle 15 is inserted into the valve 10.
It is fitted into the receiving hole 16 of the. A spring 20 sandwiched between upper and lower spring receivers 17 and 18 is fitted on the spindle 15.

An adjusting screw 21 is screwed onto the inner surface of the upper end of the spring case 3. The adjusting screw 21 includes a large-diameter portion 21a that presses the spring receiver 18, a small-diameter portion 21b that is continuous with the large-diameter portion 21a, and a storage hole 21c that passes through the centers of the two portions 21a and 21b.

When the adjusting screw 21 is rotated in a predetermined direction to press the spring receiver 18, the tip portion 15a of the spindle 15 presses the valve 10 toward the valve seat 5 to close the valve. The pressing force of the valve 10 is adjusted to an appropriate value by the adjusting screw 21.

The nut 2 is attached to the small diameter portion 21b of the adjusting screw 21.
2. The cap 23 is screwed in order and the nut 22 is brought into contact with the straight cylindrical portion 3a. The stopper 24 is screwed onto the cap 23, and the tip 24a of the stopper 24 is inserted into the accommodation hole 21c of the adjusting screw 21. At this time, the distance L between the front end 24a of the stopper and the rear end 15b of the spindle 15 is appropriately selected as needed.

The tip portion 1A of the body 1 is screwed into the body insertion portion 3c of the spring case 3. The main body 1 is connected to a pressure vessel (not shown), and a fluid passage hole 4 is formed at the center of the main body 1. A valve seat 5 is formed on the front end surface of the main body 1, and a taper portion 1t and a screw portion 1s are formed on the outer peripheral surface of the front end portion 1a.

A variable diaphragm member 40 is screwed onto the screw portion 1s. The variable throttle unit 40 includes a truncated cone-shaped throttle unit 40a and a gear-shaped rotary locking unit 40b.

The body insertion portion 3c is provided with a stopper hole 3s and a discharge port 45. The stopper 12 that engages with the rotation locking portion 40b is screwed into the stopper hole 3s. A plurality of discharge ports 45 are provided in the discharge chamber 49, and the number, diameter, etc. are appropriately selected as necessary.

The discharge chamber 49 communicates with the pressure adjusting chamber 48 via the throttle channel 46. The throttle passage 46 is a flow path formed between the frustoconical inner surface 3t of the main body insertion portion 3c and the frustoconical throttling portion 40a of the variable throttle member, and flows by rotating the variable throttle member 40. The path width 46w changes and the flow rate changes.

The pressure adjusting chamber 48 includes the valve 10 and the guide portion 3b.
In the room formed between the inner surface 3n of the and the tapered portion 1t,
The volume changes as the valve 10 slides. This pressure regulation chamber 4
No. 8 has a trapezoidal cross section, but its shape is not particularly limited.
You may form a character-shaped notch part and may form a pressure regulation chamber of square cross section or a rectangular shape.

As is clear from the above description, in the present safety valve, after the spring case 3 is screwed to the main body, the valve 10 and the spindle 1 are sequentially installed from the upper end of the spring case.
5, the adjusting screw 21 and the like can be attached, so that the assembling work can be easily performed.

The operation of the first embodiment will be described.
When the gas pressure in the pressure container rises, the gas pressure A10 in the fluid through hole 4 of the main body 1 rises to a so-called blowing start pressure. Then, the gas pressure A10 applied to the valve 10
However, the pressure becomes slightly larger than the pressing force of the spring 20, and a very small amount of the pressure gas A10 starts to leak from between the packing 11 and the valve seat 5.

Further, when the gas pressure in the pressure vessel rises and becomes a blowout pressure, a larger pressing force is applied to the valve 10, so that the valve 10 rises against the spring force as shown in FIG. Move away from the valve seat 5.

The pressure gas A10 flows into the pressure regulation chamber 48 and is retained therein, while the pressure gas A10 in the pressure regulation chamber 48 enters the discharge chamber 49 through the throttle channel 46 and enters from the discharge port 45. It is discharged into the atmosphere and, on the other hand, is discharged into the atmosphere through the fluid gap 6 and the discharge port 7 into the atmosphere.

In this way, the pressure gas A10 in the pressure adjusting chamber 48 is
Since it enters the discharge chamber 49 while being throttled by the throttle channel 46, it is possible to mitigate a drastic pressure fluctuation in the pressure adjusting chamber 48. Therefore, the occurrence of the chattering phenomenon of the valve 10 is prevented. In addition, the pressure gas A10 in the pressure adjusting chamber 48
Since the gas passes through the fluid gap 6, this gas plays a role of a fluid bearing, so that the friction of the valve becomes zero and the sliding of the valve becomes smooth.

When the gas pressure in the pressure vessel further rises, the valve 10 further rises, and the rear end 1 of the spindle 15
Since 5b collides with the stopper 24a, the rise of the valve 10 is restricted. Therefore, by adjusting the position of the stopper 24, the most raised position of the valve 10, that is, the opening degree of the valve can be adjusted.

Next, when the gas pressure in the pressure vessel drops to normal pressure, the pressing force of the valve 10 becomes weaker than the spring force, so the valve 10 moves toward the valve seat 5.
Since the pressure adjusting chamber 48 communicates with the discharge port 45 via the throttle channel 46, the pressure gas A10 in the pressure adjusting chamber 48 does not disappear suddenly. Therefore, the pressure gas A10 remaining in the pressure adjusting chamber 48 serves as a drop resistance of the valve 10, so that the packing 11 of the valve 10 slowly contacts the valve seat 5.

A second embodiment of the present invention will be described with reference to FIG. 4. The difference between this embodiment and the first embodiment is that a fixed diaphragm member 50 is used instead of the variable diaphragm member. The fixed diaphragm member 50 is a diaphragm portion 50 having a rectangular cross section.
a. With this throttle portion 50a, the pressure adjusting chamber 48
A throttle channel 46 that connects the discharge chamber 49 with the discharge chamber 49 is formed.

[0035]

The present invention has the following remarkable effects. (1) Since the pressure adjusting chamber and the discharge port are made to communicate with each other through the throttle passage, the pressure liquid remaining in the pressure adjusting chamber flows out to the discharge port while the discharge flow rate is regulated by the throttle flow passage. Therefore, the chattering phenomenon can be prevented from occurring when the valve is opened.

(2) Since a fluid gap is formed between the valve and the guide portion of the spring case, and the fluid gap is communicated with the pressure adjusting chamber and the discharge port of the spring case, the valve and the guide portion are communicated with each other. Fluid is interposed between them. Since this fluid functions as a fluid bearing, the valve can be slid smoothly.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing a first embodiment of the present invention.

FIG. 2 is an enlarged view of a main part of FIG.

FIG. 3 is an enlarged view of an essential part showing a valve opened state.

FIG. 4 is a vertical sectional view showing a second embodiment of the present invention.

[Explanation of symbols]

1 body 3 spring case 5 seat 7 outlet 10 valves 40 Variable diaphragm member 45 outlet 46 Restricted flow path 47 Discharge chamber 48 Pressure regulation room 50 Fixed diaphragm member

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-9-49576 (JP, A) JP-A-8-200530 (JP, A) JP-A-9-72443 (JP, A) Actual development Sho-51- 69916 (JP, U) Actual development 56-101268 (JP, U) Actual development 56-62467 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) F16K 17/04 F16K 47 / 02 F17C 13/04 301

Claims (3)

(57) [Claims] 1. A valve seat is provided at an outlet of a fluid passage hole of a main body, a spring case is connected to the main body, and a valve is slidably inserted into a guide cylinder portion of the spring case. A safety valve, which is in pressure contact with the valve seat and is provided with a pressure adjusting chamber outside the valve seat; a discharge port is formed in a main body insertion portion of the spring case, and a throttle member is provided in the main body. The safety valve is characterized in that the pressure regulating chamber and the discharge port are communicated with each other through the throttle channel. 2. A valve seat is provided at an outlet of a fluid passage hole of a main body, a spring case is connected to the main body, and a valve is slidably inserted into a guide cylinder portion of the spring case. A safety valve, which is in pressure contact with the valve seat and is provided with a pressure adjusting chamber outside the valve seat; a discharge port is formed in a main body insertion portion of the spring case, and a throttle member is provided in the main body. To form a fluid gap between the guide portion of the spring case and the valve, and to connect the fluid to the straight tube portion of the spring case. A safety valve characterized by forming a discharge port that communicates with the gap. 3. The safety valve according to claim 1, wherein the throttle member is a slidable variable throttle member.