Technical background : In case a rupture occurs on a conduit for such fluid as natural gas, oil, and water, and causes fires, explosions, or floods, a safety valve is installed in order to shut off the flow.

Among the most common types of such valves are those which are activated by the vibrations of an earthquake, those which work when the leakage of fluid lower the pressure in the lines, and those which are tripped when even a minute leak of gas is detected. Most of these valves use a rivet to block the flow, but each of them works in only one of the three cases above. Therefore, in an earthquake prone area, all of the three types of valves have to be installed.

Also, such valves are costly to manufacture owing to their complicated structures.

The detailed explanation of the invention: This device was invented to solve the problems aforementioned. Among other things, this valve, unlike others, could be triggered by any of the three causes: the excessive shaking from an earthquake, a drop in pressure in the pipeline resulting from a leak in a crack, and the detection of any minute gas leaks.

The purpose of this invention could be achieved by the concerted operations of the following parts. At the center of the valve, there is a vertical cylinder, or a passage for a blocking device, looking like an upturned rivet (rivet hereafter). The rivet is big enough to plug the outlet with a smaller caliber than the cylinder. The upper side of the cylinder is connected to the inlet pipe of the fluid supply. The rivet is hung against the cap of the cylinder by the force of attraction from a magnet in a magnet holder, which is placed on the other side of the cap, directly above the rivet.

When the magnet holder wobbles in the slot on the upper side of the cap, it moves with the magnet inside making the distance between the magnet and the rivet farther apart and thus weakens the attraction. Therefore, the rivet would be detached from the other side of the cap to stop the flow. There is also a reset valve that can slide the rivet back to its normal position from the blocking state. Finally, there is a solenoid that is magnetized by a signal from a gas-leak detector, and thus pushes the magnet holder away from the rivet. Again, the added distance would have the rivet overcome the attraction and in doing so close the outlet.

The inlet and outlet of the housing are linked at a right angle to each other on the cylinder through which the rivet moves down to plug the outlet, if need be. The outlet line is narrow enough that the rivet could clog it. The magnet holder, holding the magnet at its bottom, has a thick, round disk at the top, which can be moved up or down to adjust its responsiveness. The reset valve consists of two parts; a lever and a tunneled-out ball (or tunneled ball hereafter). The lever is linked to the ball within from the outside. Therefore, when the lever is pulled clockwise or counterclockwise, the tunneled-out ball revolves either to open or to close the passage by having the tunnel lined up with the cylinder and outlet pipeline or doing otherwise. In the mean time, when the ball is revolved to close the passage, the round belly pushes the rivet up to the original slot ; i. e. resetting the rivet.

In addition, the valve has, on the outer wall of the housing, a plummet of beads that helps the properly leveled installation. Moreover, the convex surface of the rivet head guarantees the secure sealing of the outlet.

Brief explanations of the figure 1-5 Fig. 1 : the sectional drawing of the housing.

Fig. 2 : the sectional drawing of the housing from the direction of A-A in figure 1.

Fig. 3 : the sectional clinographic projection of the magnet holder.

Fig. 4 : the sectional clinographic projection of the blocking rivet".

Fig. 5 : the clinographic projection of the reset valve.

The desirable combination for the best operation : This section presents the detailed explanations of each part of the valve along with the pictorial aids attached.

Figure 1 to 5 is the sectional drawing or the sectional clinographic projection of the valves housing, the housing (from the direction of A-A in fig. 1), magnet holder, blocking rivet, and reset valve, respectively.

As can be seen in the figures, the valve is equipped with a blocking rivet (12) in the cylinder of the housing (11). Above the rivet (12), there is a magnet holder (15), holding the rivet (12) in place.

Inlet and Outlet: The housing has an inlet (111) on its side and outlet (112) at its bottom, with the cylindrical hollow (114) in between, through which the rivet moves vertically. The inlet is the one through which gas or other fluid is fed in. The outlet line, with a smaller caliber than the cylinder (114), has gas users and appliances connected.

As featured in fig. 1 and 2, between the cylinder and the outlet, there is a ridge lining the wall, on which the rivet head fits to block the passage.

The inlet line, that allows fluid like gas to enter into the abovementioned housing (11), is connected to the upper or middle part of the cylinder (114), also forenamed.

At the top of the cylinder, there is a removable cap (18) attached. Each of the upper and under sides of the cap has a slot (18b, 18a) on it, into which the magnet holder (15) and the stem of the rivet (12a) fit, respectively.

Sealants or other alternatives are used to secure the airtight fitting of the cap into the cylinder top.

Rivet: The cylinder houses an upside-down rivet (12).

The rivet is composed of a stem (12a) and a head (12b). The stem would normally be fitted into and hung from the bottom slot of the cap due to the attraction of the magnet (16) on other side. The heads round, hemispheric surface guarantees the plugging of the passage, when dropped on the ridge.

One thing that should be noted well here is that for the convenient readjustment into the slot, the stem should not be completely removed from the slot in any case, even when the rivet is blocking the flow.

The bottom slot (18a) should be tight enough for the rivet not to swing from side to side, but loose enough for it to drop freely, if necessary.

Reset valve: This device is also equipped with a reset valve (13), which can return the rivet to the normal setting and, at the same time, block the outlet (112).

As described in fig. 5, the reset valve is comprised of two parts, a lever (113) and a tunneled ball (13), connected to the lever through the housing wall (11). The tunneled ball is placed below the rivet with its tunnel (13a) lined up with a cylinder and outlet in the normal setting.

However, when the rivet is blocking the outlet, the passage could be opened again by a 90 degree turn of the lever. With an counterclockwise 90 degree turn of the lever, the round belly of the ball would push the rivet up into the slot, but would still close the passage in itself.

So, with a clockwise 90 degree turn of the lever, the tunnel (13a) would be set in an open position. In other words, the counterclockwise 90 degree turn alone could stop the flow of fluid, regardless of the rivet position.

Solenoid: In addition, there is a solenoid (14) that works correspondingly with the leak detector for the fluid conveying system.

The solenoid is an electromagnet, which becomes magnetized at the signal from a leak detector. If magnetized, the solenoid pushes the magnet holder (15) together with the magnet (16), distancing them from the rivet, and thus the rivet drops. The solenoid is planted in the side wall of the housing next to the round disk of the magnet holder.

Magnet: As depicted in figures and aforementioned, the magnet (16) is confined at the bottom center of the magnet holder, which is placed in the slot (18b) on the upper side of the cap (18). The magnet is used to have the rivet (12) stuck on the other side of the cap with its attraction.

Magnet holder (15): As can be seen in the drawings, the magnet holder has the shape of an upturned wine glass, but with a much thicker base (15a), which was described as a disk before. The disk is placed far apart from the magnet to set the center of gravity of the holder higher.

That way, the holder becomes more sensitive to even a minor tilt of this safety valve so as to lean away from the rivet, resulting in blockage.

In short, the higher location of the disk (15a) lifts the gravity center of the magnet holder, and makes the holder subject to tilting. The pit (18b) on the upper side of the cap (18) has enough room for the holder to wobble.

However, since the disks position is vertically adjustable, the sensitivity of the magnet holder to tilting is also controllable.

The responsiveness of the valve also depends on the diameter of the rivet head (12b) and the pressure the rivet gets from the flow of fluid.

On the outer side of the housing wall, there is a chamber, in which a plummet of beads (17) are draped to help the valve level.

As depicted in fig. 1 and 2, the plummet should be draped through the hole (17b) below to level the safety valve.

Now, heres some simple, exemplary operations of the valve installed with a gas meter.

As a precondition for the examples, the gas meter is assumed to carry out nothing but conventional roles, sensing the flow of gas and displaying the volume of gas used.

In normal conditions, in which no vibration shakes the valve, and no break appears on the gas supply line, the rivet (12) is hung against the cap (18) and the tunneled ball is in the open position.

The first exemplary case is the one, in which a rupture occurred on the outlet pipeline, and so the flow of gas becomes faster. Because of the increased speed, the pressure on the rivet head (12b) becomes greater, and eventually tearing the rivet down toward the outlet (112) away from the attraction of the magnet (16). Hence, the rivet clogs the flow of gas.

With a simple 90 degree counterclockwise turn of the reset valve lever (113), the rivet could be replaced to the normal position, after the rupture has been mended. Thats because the round belly of the tunneled ball, to which the lever is attached, would push the rivet stem (12a) up to the slot at the bottom of the cap.

The second is in the case of an earthquake. When there is an earthquake, seismic vibrations rattle the magnet holder (15) in the valve. The more the magnet holder is shaken, the farther the distance between the magnet and the rivet stem (12a) would be, and thus the weaker attraction the rivet would get. So, if the shake is severe enough, the rivet would drop to block the passage. In the third case, a gas leak is sensed by a leak detector, which then sends a signal to the solenoid (14). Upon the signal, the solenoid is magnetized to push the magnet holder (15) away from the rivet (12). The added distance weakens the attraction of the magnet. Then the rivet drops to plug the outlet (112). In the second and third cases, the rivet (12) can be reset in the same way with that of the first case.

In addition to this, the reset valve (13) can be manually operated to open or close the passage, whether or not any of the three cases actually occur.