JPH029187Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention relates to a piping flange structure for low-temperature liquefied gas, and in particular to a structure that allows liquefied gas leaking from a piping flange to be guided to one location without being scattered around. related to things.

[Prior Art] Fig. 3 shows a semi-underground tank for storing low-temperature liquefied gas such as LNG or LPG. There is. A blind flange 4 is provided at the top of the pipe 3 so that a pump 5 inserted at the bottom for supplying or discharging liquefied gas can be taken out from the pipe 3 during maintenance.

Incidentally, the blind flange 4 is bolted to its mating surface via a gasket, but when cooled by low-temperature liquefied gas, the gasket shrinks or deteriorates, causing the joint to open and liquefied gas to scatter.・There is a risk of leakage. Once the leaked liquefied gas ignites, it is difficult to extinguish it, and since the stored amount is large, destroying the tank would cause great damage, so it is necessary to prevent this from happening.

Therefore, conventionally, a scattering prevention cover 6 was attached to cover the entire blind flange 4, and the liquefied gas leaking from the cover 6 was guided to one place to ensure safety.

[Problems to be Solved by the Invention] However, since the conventional scattering prevention cover 6 is designed to cover the entire blind flange 4, it has the disadvantage that it is large-scale and considerably heavy.

[Purpose of the invention] The purpose of the invention is to solve the problems of the conventional technology described above, such as simplification of assembly and reduction of costs due to the increase in the size of the shatterproof cover. The above disadvantages can be removed by partially covering the area and storing the leaked liquefied gas.
To obtain a piping flange structure for low-temperature liquefied gas that eliminates the need for a large scattering prevention cover, ensures safety, is small and lightweight, is easy to assemble, and is low-cost.

[Summary of the invention] The present invention, which meets the above objectives, covers the opening of the inter-flange gap formed radially outward of the gasket with an annular cover, and stores the liquefied gas leaking from the flange mating surface into the annular cover. The liquefied gas stored in the tank is configured to be guided to the outside through a hole provided in the annular cover. This allows leaked liquefied gas to be collected and guided to a single location outside without providing a cover over the entire flange, thereby preventing the equipment from becoming large or heavy. . Also, since the above cover is supported and fixed with bolts,
The cover can be easily attached.

[Embodiment of the invention] An embodiment of the invention will be described below based on FIG. Note that the flange of this embodiment is not limited to a blind flange.

As shown in FIG. 1, a flange mating surface end 11 of a piping flange 10 to which a flange mating surface 8 with a gasket 7 is fastened with bolts 9 is provided with a circumferential wall in order to bend the flange mating surface 8 and tighten the flange mating surface 8. A gap 12 is provided which is open at the end. Peripheral end 13 of piping flange 10 provided with this gap 12
An annular cover 14 is provided to cover this and store the liquefied gas leaking from the flange mating surface 8 through the opening of the gap 12 at the bottom. This annular cover 14 has a substantially C-shaped cross section, and the diameter connecting the tip of the upper plate of the C-shaped annular cover 14 and the tip of the rising part connected to the lower plate on the opposite side is as follows. The size is set to be slightly smaller than the diameter of the piping flange 10 so that the annular cover 14 can cover the peripheral end 13 of the piping flange 10. Further, the annular cover 14 is fixed to the piping flange 10 by tightening the upper plate of the annular cover 14 onto the bolts 9 and nuts 15. The lower plate of the annular cover 14 is provided with a hole 16 for guiding the liquefied gas accumulated inside the annular cover 14 to the outside, and the liquefied gas is led out to a predetermined location through a conduit 17 connected to the hole 16. It's becoming like that.

Now, in order to assemble the piping flange structure as described above, after joining the piping flange 10 by tightening the bolts 9 on the flange mating surface 8, the annular cover 14 is placed over the peripheral end 13 of the piping flange 10, and the cover is Attach the plate by tightening the nuts 15 times. and,
Assembly is completed by connecting the conduit 17 to the hole 16 in the lower plate.

Therefore, in this embodiment, it is not necessary to provide a large-scale cover around the entire periphery of the flange, and it is sufficient to cover only the peripheral end portion 13 of the flange slightly.Moreover, the annular cover 14 can be attached to the peripheral end portion 13 by tightening the annular cover 14 with a nut. Since it only needs to be tightened, it is small and easy to assemble.

In addition, to describe the operation of the above configuration example, when the gasket 7 that comes into direct contact with the low-temperature liquefied gas flowing through the piping begins to shrink or gradually deteriorate, a small gap is created in the flange mating surface 8 and the liquefied gas leaks out from the opening of the cavity 12. However, since the annular cover 14 is provided on the flange peripheral end 13, the liquefied gas is stored in this annular cover 14 without leaking to the outside.
It is then guided to a location via hole 16 and conduit 17. In addition, even if it does not ooze out but suddenly spews out, the opening of the air gap 12, which serves as the spout, is completely covered by the annular cover 14 with a predetermined capacity, so it does not scatter to the surroundings and all of the water is contained within the annular cover 14. The liquefied gas ejected is stored.

As described above, according to this embodiment, scattering and leakage of liquefied gas to the outside can be effectively prevented.
Major disasters such as fires caused by this can be reliably prevented.

FIG. 2 shows a modification of the embodiment shown in FIG. 1, and the difference from the embodiment shown in FIG. 1 is that the annular cover 14
The tip of the rising part connected to the lower plate is bent inward to make the whole section roughly G-shaped, and the bent part is attached to the piping flange 10 with bolts 9 through a sealing material 18.
By tightening it, not only the upper plate but also the lower plate was fixed. This has the advantage that the annular cover 14 can be attached more reliably, and that even if the amount of liquefied gas accumulated at the bottom increases, it can be prevented from flowing out.

[Effects of the invention] In summary, the present invention provides the following excellent effects.

(1) Since it is only necessary to provide a cover that covers only the peripheral end of the flange, and there is no need to provide a cover that covers the entire flange, the device can be made small and lightweight, and can be assembled easily and at low cost.

(2) Since it can be made smaller and lighter, the burden on the supports that support the piping can be reduced. Especially when it comes to underground tank piping that supplies or discharges liquefied gas,
There is no need to reinforce the roof that supports this, and the tank structure can be simplified.

[Brief explanation of drawings]

FIG. 1 is an enlarged sectional view of a main part of a piping flange structure for low-temperature liquefied gas showing a preferred embodiment of the present invention;
FIG. 2 is an enlarged sectional view of a main part showing a modification, and FIG. 3 is an explanatory diagram showing a conventional piping flange structure in an underground tank. In the figure, 7 is the gasket, 8 is the flange mating surface,
9 is a bolt, 10 is a piping flange, 13 is a peripheral end, 14 is an annular cover, and 16 is a hole.

Claims (1)

[Scope of utility model registration request] In a piping flange structure in which a gasket is interposed on the flange mating surface and bolts are tightened radially outward of the gasket, leakage from the mating surface covers the opening of the inter-flange gap formed radially outward of the gasket. The low-temperature liquefied gas is characterized by forming an annular cover for storing liquefied gas, supporting and fixing the cover with the bolts, and connecting a conduit to the cover for guiding the liquefied gas stored in the cover to the outside. Piping flange structure.