JPH0533826Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention is used, for example, for emergency disconnection of fluid handling equipment used when unloading LNG (liquefied natural gas) from tankers or loading tankers. It relates to on-off valves used in devices, etc.

[Conventional technology] For example, from a tanker docked at a sea berth,
In fluid handling equipment used for unloading LNG or loading it onto tankers,
If the movement of the tanker increases due to strong winds or waves, the transport pipe will be destroyed if left as it is, causing major damage such as leaking LNG and causing a fire. An emergency disconnection device is provided.

As shown in FIG. 3, on-off valves (ball valves in this example) 2, 2, which are closed in an emergency, are provided at each end of the connected pipe bodies 1, 1. The two valve bodies 2b, 2b are connected to the valve stem 2.
A link mechanism 3 is provided to interlock the valve bodies 2c, 2c of the on-off valves 2, 2, and flanges 4, 4 are provided on the joint surfaces of the valve bodies 2c, 2c of the on-off valves 2, 2, and the joined flanges 4,
4 is clamped by a clamp 6, and in an emergency, the link mechanism 3 is operated by a hydraulic cylinder 7 to close the valve bodies 2b, and then the clamp 6 is removed by a hydraulic cylinder (not shown) to remove the pipe. body 1,
1 (Japanese Unexamined Patent Publication No. 135199/1983).

[The problem that the idea attempts to solve]

In the conventional on-off valve 2 of the emergency disconnection device, the valve body 2b is brought into contact with one sealing member provided on the valve seat member to prevent liquid leakage when the valve is closed, but the sealing performance is poor. However, there is a problem that the liquid tends to leak easily.

This idea not only has good sealing properties and is resistant to liquid leakage, but also allows the sealing properties of the sealing member to be inspected.
An object of the present invention is to provide an on-off valve used in an emergency disconnection device of a fluid cargo handling device, etc., which can prevent abnormal pressure increase due to vaporization of liquids, etc., and various problems caused by this.

[Means to solve the problem]

In order to achieve the above object, this invention provides a valve body rotatably in a valve box equipped with a valve seat member,
Two sealing members that are placed in parallel with each other at a distance from each other are placed on the valve seat member so that the valve element comes into contact with the valve element when the valve is closed. A passage is provided in communication with the space defined by the valve element, the seal member, and the valve seat member when the valve element is closed, and a pressure relief passage is provided in the valve seat member from the inspection passage. A branch is provided in the pressure relief passage, and when the pressure of the fluid sealed in the space increases above a certain level when the valve is closed, the pressure of this fluid opens the pressure relief passage and the fluid flows out into the valve box. The structure is equipped with a check valve.

[Effect]

The two seal members independently prevent liquid leakage. Therefore, the sealing performance is good.

Since the inspection passage is provided between the two seal members, the sealing properties of the two seal members can be individually inspected.

In addition, when the check valve is closed and comes into close contact with the two sealing members of the valve seat member, the check valve
The fluid is sealed in the space partitioned by the two seal members and the valve seat member to maintain an airtight state, and in this state, the fluid absorbs heat from the atmosphere and begins to vaporize, increasing the pressure. When the pressure reaches a certain level, the pressure of this fluid opens the space, causing the fluid in the space to flow out from behind the sealing member into the inside of the valve box closed by the valve body, thereby preventing abnormal pressure rise between the sealing members.

For this reason, fluid may leak to the outside (into the atmosphere) or
The seal member will not be damaged.

Since the check valve is provided in the pressure relief passage branched from the test passage, the structure is simpler than in the case where the two passages are formed separately.

〔Example〕

Figures 1 and 2 show an embodiment of an on-off valve for a fluid cargo handling device, etc. according to this invention. In these figures, the same elements as those shown in Figure 3 are designated by the same reference numerals. The detailed explanation will be omitted.

A support flange (valve seat member) 9 is provided on the inner circumference of the flange 4, and an O-ring 10 and a seal 1
1 through bolts 12..., and retainer rings (valve seat members) 13, 14 are attached to the inner end surface of this support flange 9.
It is attached with bolts 15 so that a slight gap is formed between the inner peripheral portion and the closed valve body 2b. On the inner circumference of the retainer ring 13 is a rigid O-ring (sealing member) 16 made of steel or the like that closes the inside and outside of the valve body 2c, and on the inner circumference of the retainer ring 14 is a flexible O-ring (sealing member) 16 that functions similarly. C-shaped seals (sealing members) 17 are respectively attached so as to come into pressure contact with the closed valve bodies 2b.

Further, a test passage 18 is formed inside the retainer ring 14 and the support flange 9 and extends from between the O-ring 16 and the C-shaped seal 17. The root end (the left end in FIGS. 1 and 2) is inserted into the through hole, and the distal end can be opened to the outside via a tube 19 that can be opened and closed.
The test passage 18 and tube 19 are connected to the O-ring 1
6 and C-type seal 17 sealing performance (liquid leakage)
It is provided for the purpose of testing, as will be described later.

The retainer ring 14 attached to the inner end surface of the support flange 9 has a pressure release passage 30 extending upward from the bent portion of the test passage 18, and a check valve connected in communication with the upper end of this passage 30. A mounting portion 32 into which the holder 31 is inserted is formed. This attachment part 32 is formed into a conical surface 33 whose lower end part gradually decreases in diameter as it goes downward, and has a female screw part 34 formed at its upper end part. The retainer ring 14 is opened on the outer periphery of the retainer ring 14 and communicated with the inside of the valve box 2c.

Check valve 31 inserted into mounting part 32
is a cylindrical body 35 screwed into the female threaded portion 34;
and a sphere 36 that is in contact with the conical surface 33, and a sphere 36 that is inserted between this sphere 36 and the cylindrical body 35.
6 and a coil sprung 37 that urges the conical surface 33 with a constant force.

The check valve 31 configured as described above is
Now, the O containing the test passage 18 and the tube 19
The LNG sealed between the ring 16 and the C-type seal 17 (the space defined by the valve body 2b, the O-ring 16, the C-type seal 17, and the retainer ring 14) is vaporized and the pressure exceeds a certain level. When this happens, the sphere 36 is pushed upward by this pressure, and a gap is created between the sphere 36 and the conical surface 33.
The vaporized LNG escapes from this gap and the cylindrical body 3
It flows out into the inside of the valve body 2c through the center hole 35a of the valve body 2c.

Next, the operation of the on-off valve of the fluid cargo handling device or the like configured as described above will be explained.

As already mentioned, in case of an emergency, close the valve body 2b, remove the clamp 6 (Fig. 3), and open/close the valve 2,
Separate 2. When the valve body 2b is in the closed state, the O-ring 16 and the C-shaped seal 17 are in close contact with the valve body 2b, respectively, to prevent fluid leakage. In this way, the O-ring 16 and the C-shaped seal 17 double prevent liquid leakage, resulting in extremely good sealing performance.

In the above, LNG is sealed in the space defined by the valve body 2b, the O-ring 16, the C-type seal 17, and the retainer ring 14 to maintain an airtight state, and in this state, LNG is removed from the atmosphere. When it absorbs heat and vaporizes, and the pressure rises to a certain level or higher, the check valve 31 operates and vaporizes.
LNG is caused to flow into the inside of the valve box 2c. Therefore, abnormal pressure increase does not occur between the O-ring 16 and the C-type seal 17, and fluid leakage from the C-type seal 17 to the outside (atmosphere) due to abnormal pressure increase, and the C-type Accidents such as damage to the seal 17 are prevented.

When two seal members are double sealed, it is not possible to inspect the sealing performance of the two seal members individually in a general seal test, but in this invention, the O-ring 16 and the C-type Since a testing passage 18 is provided between the seal 17 and the seal 17, the sealing properties of the O-ring 16 and the C-shaped seal 17 are individually tested using this passage.

That is, the sealing performance of the O-ring 16 is determined by increasing the internal pressure of the valve box 2c in the closed state and observing the pressure change in the pipe 19. In addition, regarding the C-type seal 17, the support flange 9 and the valve body 2
A liquid such as alcohol is injected into the gap below the seal 17 in FIG.

[Effect of idea]

As explained above, in the on-off valve of the fluid cargo handling device or the like of this invention, a valve body is rotatably provided in a valve box provided with a valve seat member, and the valve body is provided with a rotatable valve body. Two sealing members that bring the valve body into contact when the valve is closed are arranged in parallel with a distance from each other, and an openable and closable inspection passage for testing the sealing performance of the sealing member is provided when the valve body is closed. At times, the valve body is provided in communication with a space defined by the seal member and the valve seat member, and the valve seat member is provided with a pressure relief passage branching from the inspection passage. The pressure relief passage is provided with a check valve that opens the pressure relief passage due to the pressure of the fluid and causes the fluid to flow out into the valve box when the pressure of the fluid sealed in the space increases above a certain level when the valve is closed. The structure is designed to ensure good sealing performance, and even if the fluid is sealed in the space partitioned by the valve body and two seal members when the valve is closed, abnormal pressure rise will occur. Never. Therefore, it is possible to prevent accidents such as leakage of fluid from the seal member to the outside (into the atmosphere) and damage to the seal member, which are caused by abnormal pressure increase, as in the prior art.

In addition, since the sealing performance of the two sealing members can be accurately determined individually and independently, liquid leakage can be prevented more accurately. Moreover, since the check valve is provided in the pressure relief passage branching off from the test passage, there is an advantage that the structure is simpler than when the two passages are formed separately from each other.

[Brief explanation of the drawing]

1 and 2 show an embodiment of an on-off valve for a fluid cargo handling device, etc. according to this invention, and FIG. 1 is a cross-sectional view of the main part corresponding to the Y section in FIG.
FIG. 2 is an enlarged view of the X-circle portion in FIG. 1.
FIG. 3 is a sectional view of a conventional emergency disconnection device such as a liquid cargo handling device. 2b...Valve body, 2c...Valve box, 9...Support flange (valve seat member), 13, 14...Retainer ring (valve seat member), 16...O ring (sealing member), 17...C Mold seal (sealing member), 18
...Test passage, 30...Pressure relief passage, 31...
Check valve.

Claims (1)

[Scope of utility model registration request] A valve body 2b is rotatably provided in a valve box 2c provided with valve seat members 9, 13, and 14. Two seal members 1 that bring the body 2b into contact with each other
6 and 17 are arranged in parallel with each other at intervals, and a testing passage 18 that can be opened and closed for testing the sealing properties of the sealing members 16 and 17 is connected to the valve body 2b.
When the valve is closed, the valve body 2b and the seal member 16,1
7 and the valve seat member 14, and the valve seat members 9, 13, 1
4 is provided with a pressure relief passage 30 branching from the inspection passage 18, and in the pressure relief passage 30, when the pressure of the fluid sealed in the space increases above a certain level when the valve is closed, the pressure of this fluid is increased. An on-off valve for a fluid cargo handling device, etc., characterized in that it is provided with a check valve 31 that opens the pressure relief passage 30 under pressure and causes the fluid to flow out into the valve box 2c.