JPS58198741A - Seal structure of aperture part of gas chamber - Google Patents

Abstract

PURPOSE:To test the airtightness of the aperture part of a gas chamber easily, by supplying a testing gas to the part between two O rings attached to a contacting face 3 of a cover body 2 on concentric circles. CONSTITUTION:In the test for the airtightness of the cover body 2 which is pressed and fastened to an aperture part 1 of a gas chamber, one end of a testing gas induction tube 7 is connected to a connector 18 of a hole 6 for test, and the other end is connected to a bomb 16 through a valve 15. A hatch 8 is opened to press and fasten the cover body 2 to the lower face of the aperture part 1 of the gas chamber. The valve 15 is opened to supply a pressure air to the part between O rings 4 and 5, and a pressure indicater 14 is watched to set the pressure of gaseous nitrogen between O rings 4 and 5 to a prescribed value. At this time, the pressure air supplied from the bomb 16 is filled up only in a small space surrounded with O rings 4 and 5, a lining 17, and the contacting face 3 of the cover body 2. Next, the valve 15 is closed to confirm that the needle of the pressure indicater 14 does not fall.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a structure for sealing an opening of a gas chamber filled with an inert gas or the like.

For example, various equipment used for molten sodium, which is a fast breeder reactor coolant, are placed in a gas chamber filled with an inert gas such as nitrogen. And in this gas chamber, there is a
As shown in the figure, a plurality of gas chamber openings 1 are formed. This gas chamber opening l will be formed in the floor 9 of the upper chamber 19 of the gas chamber 10, and the opening l will be Hetsuchi 8
As an example, this hem 8 into which is fitted has a thickness of In
, a diameter of about 2 m is used, and the hook 8 is opened and closed by lifting a hook (not shown) attached to the top surface of the hook 8 using a crane or the like. Then, the lid 2'i, which is crimped and fastened to the lower surface of the gas chamber opening 1, is removed downward, and equipment is carried into or out of the gas chamber IO through the opening 1. Here, the gas chamber 1G□ and the upper chamber 19 located above the gas chamber IO have a conventional lid structure, but an annular groove 13 is cut in the contact surface 3 of the lid 2 as shown in FIG. Then, a sealing O-ring 4 having a diameter larger than the depth of the annular groove 13 is fitted. The sealing O-ring 4 is press-fitted to the lower surface of the opening 1 via a flat and smooth lining 17 attached to the lower surface of the opening of the gas chamber 1O.

That is, by screwing the lid 2 to the anchor nut 2 with bolts 11, the lid 2 and the lower surface of the opening 1 are hermetically sealed by the O-ring 4. The sealing structure using the O-ring 4 is then appropriately inspected by an airtight test. Conventional methods were used to perform such airtightness tests. First, the hatch 8 is released, and the lid 2 is pressed and fastened to the lower surface of the gas chamber opening. While the air in the gas chamber 10 is replaced with nitrogen gas, the gas chamber 10 is
Increase the pressure of nitrogen gas inside to the specified pressure. The presence or absence of gas leakage was then inspected at the gas chamber opening l using a nitrogen gas detection means. However, the airtightness test of a seal structure using such a conventional method requires an extremely large amount of nitrogen gas for testing, about the amount equivalent to one tank lorry. At the same time, the airtightness test required a lot of time because the entire gas chamber was filled with nitrogen gas for testing.

Therefore, the present invention has been made in view of the above circumstances, and provides a sealing structure that allows the airtightness test of the gas chamber opening to be performed extremely easily. An inner O-ring 4 for sealing is attached to the contact surface 3 of the lid body 2 to be press-fastened, and an outer O-ring 5 for sealing is attached approximately concentrically with the O-ring 4 and on the outside of the O-ring 4. Then, an airtight test hole 6 is opened in the contact surface 3 of the lid body 2 at an intermediate position between both O-rings 4 and 5. A feature is that a test gas guide pipe 7 can be communicated with the test hole 6.

Embodiments of the seal structure of the present invention will be described below based on the drawings.

FIG. 2 is a longitudinal sectional elevational view of the seal structure of the present invention. As is clear from the figure □, in this structure, two concentric annular grooves 13 are cut in the contact surface 3 of the lid 2. Then, an inner O-ring 4 and an outer O-ring 5 for sealing are provided in each annular groove 13.
and fit into place.

Furthermore, an airtightness test hole 6 (-) is bored through the lid body 2 at an intermediate position between both O-rings 4 and 5. Then, the test hole 6
A connector 18 is attached to the.

Next, a method for detecting leakage using the pressure drop method in the structure of the present invention will be described.

An airtight test of the lid 2 press-fastened to the gas chamber opening 1 is performed as follows. First, one end of the test gas guide tube 7 is connected to the connector 18 attached to the first airtightness test hole 6. The other end of the guide tube 7 is connected via a valve 15 to a cylinder 16 filled with gas such as pressurized air. At the same time, a pressure gauge 14 is communicated with the intermediate portion of the test gas guide pipe 7 between the valve 15 and the connector 18. Then, the hatch 8 is opened, and the lid 2 is pressed and fastened to the lower surface of the gas chamber opening l. , then open the valve 15 and open the two O
Supply pressurized air between rings 4.5. Then, while watching the pressure gauge 14, the nitrogen gas pressure between both O-rings 4.5 is set to a predetermined value. At this time, the pressurized air supplied from the cylinder 16 fills only the small space surrounded by the two O-rings 4.5, the lining 17, and the contact surface 3 of the lid 2. Next, close the valve 15 and confirm that the pointer of the pressure gauge 14 does not fall in this state. At this time, if there is a defect in the seal structure, pressurized air will leak from the seal structure and the pointer of the pressure gauge 14 will drop. Another test method for this structure is to supply helium gas (or halogen gas or even carbon dioxide gas) into the seal structure.

In this state, if the sensor of the helium gas or halogen gas leak detector is brought close to the gas chamber opening 1, the airtightness test of the lid 2 can be performed. In addition, the gas chamber lO
In normal use, the test gas guide tube 7 and the cylinder 16 are removed, and the inner Q+) ring 4 maintains airtightness between the lid 2 and the gas chamber opening 1. Alternatively, the tip of the connector 18 attached to the airtight test hole 6 is closed, and the space between the lid body 2 and the lower surface of the gas chamber opening l is sealed by the two O-rings 4 and 5.

The seal structure of the present invention has the above configuration and has the following effects.

In the sealing structure of the present invention, two O-rings 4 and 5 are mounted substantially concentrically on the contact surface 3 of the lid body 2, and the test gas guide pipe 7 can be communicated between the two O-rings 4 and 5. Therefore, in order to perform an airtightness test on the lid 2, it is sufficient to supply a small amount of test gas between the two rings 4 and 5. Therefore, it is not necessary to fill the entire gas chamber with the test gas as in the case of the conventional structure, so the amount of test gas supplied becomes extremely small. At the same time, the time required for the airtightness test is minimized.Although the gas chamber normally has a plurality of openings, the seal structure of the present invention allows each opening to be airtightly sealed separately. Tests can be conducted. Therefore, 0 for sealing
The airtightness test 2 is performed again only on the lid body in which the ring 4.5 has been replaced, and the sealing effect can be confirmed.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of a conventional opening sealing structure, and FIG. 2 is a longitudinal sectional view of an opening sealing structure of the present invention. l...Gas≧H mouth part, 2...lid body, 3-...contact surface, 4.5...0 ring, 6...hole for airtightness test, 7...
...Test gas guide pipe, 8...Hetsuchi, 9...Floor, 1
G... Gas chamber, 11... Bolt, 12... Anchor nut, 13... Howling groove, 14... Pressure gauge, 15
...Valve S16...Cylinder, 17...Lining,
18...Connector, 19...Upper chamber. Agent Valve 3tL-Kubo 1) Taku Mi 1 Figure 2 9 87 ,, 213 3 It 9 7 4 \

Claims (1)

[Claims] On the abutment surface ■ of the lid body 2) that is press-fastened to the gas chamber opening (1), an inner O-ring for sealing (to) and the O-ring (
(a) Attach an outer O-ring 0 for sealing approximately concentrically to the outside of the O-ring (4); one O-ring (4);
A hole for airtightness test is opened in the abutment surface @) of the lid body □ at the intermediate position of (5), and a test gas guide tube can be communicated with the test hole (6). Gas chamber opening seal structure 0