JPS5831508B2 - liquid level control valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention +-3 relates to a liquid level control valve of a maximum liquid level adjustment type that restricts the flow of liquefied petroleum gas into a tank when filling the tank with liquefied petroleum gas.

In general, when storing liquids in tanks, it is often necessary to control the maximum amount of liquid in the tank.

For example, some state regulations in the United States prohibit filling a tank to more than 80% of its capacity with liquefied petroleum gas.

It is therefore necessary for tanks of this type to be equipped with a device that automatically prevents them from being filled with liquid beyond a predetermined level.

Various control devices have been proposed to control the flow rate of such liquid or gas.

Known examples include U.S. Pat. No. 1,492,272, 2
There are No. 499409, No. 2504638, No. 2569110, No. 24, No. 31721, etc.

Typically, these devices utilize a float and valve combination to slowly close a fluid inlet port.

In such a conventional valve mechanism, as the float rises, the liquid passage gradually narrows and the flow rate decreases, so it takes a long time to fill the tank with fluid.Furthermore, the float rises extremely slowly, so the valve Opening and closing were incomplete, resulting in overflow.

Also, taking the above US Pat. No. 2,504,638 as an example,
This control valve is equipped with a double cam mechanism.

The first cam gradually changes a valve in the control valve arrangement from a fully closed condition to a fully open condition in response to a drop in liquid level from a predetermined maximum level to a predetermined minimum level.

The second cam is configured to keep the valve fully open until the tank reaches a predetermined minimum level and is filled to a predetermined maximum level.

Therefore, in this type of device, if the liquid level in the tank drops only slightly, the valve will not open completely.

Attempting to refill the tank in this condition will encounter significant resistance from the fill port, and the force exerted by this resistance on the cam will result in the cam returning to the closed position before the fill stroke is complete.

On the other hand, U.S. Patent Nos. 2,854,022 and 37,562
The No. 69 device utilizes a linkage means to operatively connect the float to the valve so that the valve opens and closes in bursts rather than gradually as described above.

Although this device may alleviate some of the drawbacks mentioned above, the linking means of both patents are less reliable and more expensive than the simpler construction of the prior art devices.

Another type of liquid level control valve generally uses a spring member that is involved in opening and closing the valve.

Known US Pat. No. 2,881,790, 3338
There are issues such as No. 262.

This type of valve has a spring that is continuously in compression, so that the occurrence of spring fatigue and failure is a significant concern.

Damage to these valves used in tanks poses problems not only in repair costs but also in the loss of time for disassembly and reassembly.

The present invention was made in view of the problems of the conventional maximum liquid level control valve for liquefied petroleum gas tanks as described above, and has the following objects.

(1) It has a simple structure without using a double cam mechanism or a complicated link mechanism, and is reliable and effective without using springs that are subjected to continuous high loads that can lead to fatigue or breakage. To provide a liquid level control valve.

(2) To provide a liquid level control valve that can easily fill a tank with liquid regardless of the liquid level as long as it is below the highest liquid level.

(3) During the process of filling the tank with liquid, the valve is completely open, and as soon as the maximum liquid level is reached, the valve is completely closed, allowing for quick and reliable filling of liquid without overflow. To provide a liquid level control valve capable of accurately satisfying a predetermined maximum liquid level at the same time.

For the above purpose, the liquid level control valve according to the present invention includes a valve body having a valve seat and a liquid passage passage and which is attachable to the side wall of a tank, a float pivotally supported on the valve body, and a valve body having a valve seat and a liquid passage passage. It is positioned within the main body and is movable between a closed position where it is seated on the valve seat and an open position where it is away from the valve seat, and when it receives inflowing liquid pressure, it moves toward the closed position and opens the passageway. a sealing element adapted to close; and a sealing element mounted between the valve body and the sealing element to push the sealing element from the closed position toward the open position when there is no incoming liquid pressure. a spring configured to open the passageway when the sealing element is in the open position, and a spring configured to maintain a static state when the sealing element is in the open position; and a single cam means adapted to prevent movement of said sealing element towards said closed position when below the level.

This eliminates the need for a double cam mechanism or complicated link mechanism, resulting in a simple configuration, and the spring, which is used to return the sealing element, is normally static and carries almost no load, causing fatigue. There is little risk of damage.

In addition, since the sealing element is normally biased by a spring and held in the open position away from the valve seat by restraint from the cam means, it is very possible to fill the tank with liquid. Since it remains open during the filling process, liquid can be injected at a constant flow rate, thus making filling easier and faster.

Furthermore, when the liquid level reaches a predetermined maximum liquid level, the sealing element, which is no longer restrained from movement by a single cam, is immediately placed in the closed position where it seats on the valve seat under the action of liquid pressure, quickly and reliably. The passage is closed to prevent overflow and satisfy the required maximum liquid level.

In this way a reliable and effective level control valve is obtained.

Preferred embodiments of the present invention will be described below with reference to the drawings.

In FIG. 1, the liquefied petroleum gas tank 10 is
It has a mounting flange 13 attached thereto and further welded to the wall of the tank 10 at the top.

An automatic valve 12 is mounted on the flange 13 with a fixture 18, and an inlet check valve 16 for preventing backflow is screwed into the automatic valve 12.

As this inlet check valve, any commercially available check valve, such as Model No. D113 manufactured by Fisher Controls, may be suitably used.

The end 11 of the check valve 16 is externally threaded to receive an injection hose leading from a pump or reservoir for filling the tank 10 with liquefied petroleum gas.

An outlet valve 19 of conventional type is mounted on tank 10 for the discharge of liquefied petroleum gas.

A pipe for delivering liquefied gas to many users is attached to the outlet valve 19.

FIG. 2 shows the automatic valve 1 removed from the mounting 7 flange 13.
A partially cutaway top view of automatic valve 12 is shown.
has a hollow valve body 23 and a mounting base 22 integrally formed with the valve body via a shoulder 24.

The base portion 22 is fixed to the mounting 7 flange 13 by a fixture 18, as shown in FIG.

The end 28 of the valve body 23 is U-shaped with a pair of arms 29 and 30, and is adapted to rotatably hold a cam 31 attached to one end of a float 34.

Float 34 and cam 31 are pivotally connected to arms 29, 30 by pins 35 which extend through cam 31 and arms 29, 30 for limited movement in a vertical plane relative to tank 10. Furthermore, its head is fixed and protrudes at both ends.

Washers 36 and 37 are mounted on each side of the cam 31 to act as spacers for the bearings.

Additionally, washers 36, 37 serve to keep cam 31 centered on arms 29, 300 as cam 31 pivots about pin 35.

A pin 40 is further attached on the valve body 23, and the pin 4
0 passes through the notch opening of the cam 31 and the float 34
and cam 31 act as a stopper that allows movement in the vertical plane within a limited range from approximately 400 degrees below horizontal to slightly above horizontal.

The cutout portion of the cam 31 and the restricted position of the pin 40 are shown in FIG. 3 by solid lines and broken lines.

The valve body 23 is provided with a pair of holes 41, 42 through which liquefied gas is introduced into the tank when the tank is filled.

A stem 43 extends longitudinally through the valve body 23 and is attached at one end to a sealing member or flap 46 by a screw 47.

The other end of the stem 43 has a rounded tip and projects outward from the valve body 23 toward the space between the arms 29 and 30.

Movement of the stem 43 into the valve body 23 is restricted by a retaining ring 49 .

Retaining ring 49 is mounted in a suitable groove within stem 43.

The spring 52 is a compression spring with a very small spring force arranged around the stem 43 and acts between the valve body 23 and the sealing flap 46.

The sealing flap 46 is positioned adjacent the valve seat 53 such that when it abuts the valve seat 53, liquefied gas from the inlet opening 54 cannot flow into the tank 10 through the hole 41.42. has been done.

Conversely, when the flap 46 is moved away from the valve seat 53 due to the cooperation of the cam 31 and the stem 43, liquefied gas is allowed to pass through the holes 41, 42 and fill the tank.

A small vent hole 57 is formed within the artificial opening 54 to vent any pressure created between the flap 46 and the inlet check valve 16.

Figure 3 shows the internal structure of the valve body 23 and the cam 3L stem 4.
3 and a spring 520; FIG.

A female threaded hole 56 is formed in the base portion 22 to receive the inlet check valve 16 (FIG. 1).

When the tank is filled, liquefied gas passing through valve 16 enters inlet opening 54, passes through one end of passage 55, and passes through hole 41.
, 43 into the tank 10.

The liquefied gas is discharged and consumed through the outlet valve 19.

When the liquid level in the tank falls, the float 34 pivots downward about the pin 35.

The end portion 48 of the stem 43 fixed to the sealing member 46 has a dimensional relationship that does not interfere with the bent surface 60 of the cam 31 when the sealing member 46 is held in the open position by the spring 52. Therefore, the pivoting movement of the float 34 is not hindered.

As mentioned above, in order to limit the pivoting range of the float 34, the pin 40 is fixed to the valve body 23 through the cutout opening 59 of the cam 31, so that when the liquid level falls below a predetermined value, The upper edge 58 of the notch opening 59 of the cam 31
0 and prevents the float 34 from pivoting downward any further.

In this position, the curved surface 60 of the cam 31 rotates upwardly into abutment with the end 48 of the stem 43.

As a result, the curved surface 60 of the cam 31 retains the stem 43 within the valve body 23, and the retaining ring 49 retains the stem 43 within the valve body 230 surface 60.
4, the sealing flap 46 is pressed against the valve seat 5
Separated from 3.

Flap 46 is held in an open position for filling tank 10 by spring 52.

In this open position, the spring 52 is configured so that it is hardly compressed.

As the liquefied gas passes through the valve 16 and into the tank 100 entry opening 54, liquefied gas pressure is applied to the fluff 46 tending to move the flap 46 toward the valve seat 53.

However, the stem is fixed by the curved surface 60 of the cam 31 abutting on the end 48 of the stem 43 and such movement is prevented.

As more liquefied gas is continuously added to tank 10, the liquid level within tank 10 rises and comes into contact with the float.

As it continues to fill, the float 34 pivots upwardly around the pin 35 due to buoyancy within the liquefied gas.

When the float 34 reaches the horizontal position, the end 48 of the stem
comes to separate from the bent surface 60 of the cam 31, which was rotating clockwise.

This movement of the cam causes the single-shaped portion 61 of the cam 31 to pivot into a position adjacent the end 48 of the stem 43.

The gap in the single-shaped portion 61 forces the end 48 of the stem 43 towards the surface 65 of the cam 31 under the pressure of the liquefied gas acting on the sealing flap 46 .

As stem 43 moves toward cam 31, the force of spring 52 is gradually overcome and compressed, forcing sealing flap 46 into sealing contact with valve seat 53.

As a result, the holes 41 and 42 are blocked from the inlet opening 54,
Liquefied gas no longer flows into the tank 10.

The inlet check valve 16 has an injection hose connected to an end 17 (first
This prevents liquefied gas from escaping from the tank 10 when it is removed from the tank 10.

When the pressure developed between fluff 46 and check valve 16 is released through discharge hole 57 , spring 52 acts on flap 46 and pulls flap 46 away from valve seat 53 .

At this time, the end 48 of the stem 43 is removed from the 1-shaped section 61, allowing the cam 31 to rotate counterclockwise around the pin 35 without obstruction, and the float 34 is removed from the tank 10. It pivots downward in response to the drop in the liquid level.

Thus, the bent surface 60 of the cam 31 is connected to the end 48 of the stem 43.
, and the filling cycle of tank 10 is repeated again in the same manner as described above.

Mounting 7 The flange 13 and the automatic valve 12 can be mounted at any height on the side wall of the tank 10 depending on the construction of the automatic valve 12, the shape of the tank 10 or the maximum liquid level that the tank 10 is to be filled. Can be done.

Regulations in some states in the U.S. require 80% of tank capacity.
Since it is prohibited to fill the tank capacity by more than 80%, a desirable maximum liquid level can be set at 80% of the tank capacity.

The flange 13 and valve 12 are thus positioned to suit this value and automatically prevent the tank 10 from filling beyond this predetermined value.

Although the present invention has been described in detail with reference to the embodiments shown in the accompanying drawings, the accompanying drawings merely illustrate one preferred embodiment of the invention, and changes and modifications that can be readily thought of by those skilled in the art are within the scope of the present invention. Please understand that this is included in

[Brief explanation of the drawing]

FIG. 1 is a front view of a tank equipped with a control valve of the present invention, FIG. 2 is a partially cutaway top view of the control valve, and FIG. 3 is a partially cutaway front view of the control valve. 10...Tank, 23...Valve body, 3
1...Cam, 34...Float, 41,
42...-TL43...Stem, 46
...Flap, 52...Spring,
53... Valve seat, 54, 55... Opening.

Claims (1)

[Scope of Claims] 1. A liquid level control valve that restricts the flow of fluid into a tank, the valve body having a valve seat and a passage for fluid passage and that can be attached to a side wall of the tank, and the valve body. a float pivotally supported on the main body, the float being positioned within the valve main body and movable between a closed position in which it seats on the valve seat and an open position away from the valve seat when receiving incoming liquid pressure; a sealing element adapted to move toward a closed position to close said passageway; and a sealing element mounted between said valve body and said sealing element adapted to move said sealing element into said passage when there is no incoming liquid pressure. a spring configured to press from a closed position toward the open position to open the passage; and a spring actuated by the float to cause the sealing element to move toward the closed position when the float is below a maximum liquid level. cam means adapted to prevent movement of the liquid level control valve. 2 the sealing element includes a movable stem extending through the valve body and having a first end and a second end, and further includes a sealing member that engages the valve seat; 2. A liquid level control valve according to claim 1, wherein said first end is attached to said sealing member, and said second end projects and is engageable with said cam means. 3. The spring is a compression spring with a very small spring force and is pressed down when subjected to incoming liquid pressure, further pressing the sealing element against the valve seat. A liquid level control valve according to claim 1. 4. the cam means having a recess positioned adjacent the first end, the stem being moved into the recess when the tank is filled, and the sealing member displacing the valve seat; Claim 2 which is adapted to engage with
Liquid level control valve as described in section.