JPS6244143B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for attaching finger pins to the flanges of pressure vessels in all fields, such as nuclear reactor pressure vessels, reactor containment vessels, general heat exchangers, and chemical plant pressure vessels. The present invention relates to a method for tightening a pressure vessel by applying an initial tightening force.

In order to maintain the sealing performance of a gasket attached to a flange of a pressure vessel, it has been conventional practice to apply a predetermined initial tightening force to the flange. That is, as shown in Fig. 1, the bolts b set on the body flange a of the pressure vessel are inserted through the holes in the upper cover flange c, the upper cover flange c is placed on the upper part of the body flange a, and the nuts d are tightened with a torque wrench. If the flange is turned or no torque is applied, an initial tightening force is applied to the flange using a tensioner.

In this method, bolt b is designed to withstand the internal pressure of the pressure vessel, so the diameter is large and the price is high. Also, it is difficult to control the bolt tightening force, which takes time, and the threaded part of bolt b may seize. There is a great risk of Furthermore, if a tensioner is used for initial tightening, the price will be high, and in the case of a nuclear reactor pressure vessel, etc., it will become even more expensive if remote control is taken into account.

On the other hand, the finger pin type flange has a small flange and is easy to open and close, but the sealing method is limited to a self-tightening gasket with a small initial tightening force. In the case of atmosphere, there are many cases where it cannot be used due to problems with the material of the gasket, and the reality is that the advantages of finger pins are not being utilized.

The purpose of the present invention is to reduce the size of the flange by using finger pins in the flange, and to facilitate manufacturing, opening/closing, and remote control.Also, even with the finger pin type, it is possible to eliminate the restriction caused by the internal fluid and to achieve high temperatures. This was developed with the aim of providing a method for tightening pressure vessels that enables use at high pressures.The upper cover flange is placed on the body flange, and the flange portion is tightened with a tightener to create a seal between the flanges. Apply an initial tightening force to the gasket provided on the surface, and use the initial tightening force to align the pin holes provided in each of the upper lid flange and the body flange parallel to the sealing surface, and insert the finger pin into the pin hole. It is characterized by this.

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

2 and 3 show an embodiment of the present invention, in which 1 is a body flange, 2 is an upper lid flange, 3 is a gasket made of metal such as Inconel or stainless steel,
4 is a finger pin, 5 is a bolt for initial tightening of the flange, 6 is the same nut, 7 and 8 are tightening jigs, and the jigs 7 and 8 are the protrusions of the flange, the shelves,
It is designed to be able to engage with lugs, etc. In addition to such bolts and nuts, a fluid pressure cylinder or the like may also be used as the tightener.

Next, I will explain how to perform initial tightening.
The gasket 3 is fitted into the groove of the upper lid flange 2, and the upper lid flange 2 is placed on the body flange 1. At this point, a gap x exists in the flange sealing surface as shown in FIG.

Next, a tightener is set on the outside of the flange, and in this embodiment, a predetermined initial tightening force is applied to the gasket 3 by rotating the nut 6 with a torque wrench. The gasket 3 is deformed by this initial tightening, and the flange sealing surfaces are brought into close contact as shown in FIG. 5, and the pin holes in the top cover flange 2 and the pin holes in the body flange 1 match.

When the pin holes match, insert the finger pin 4 into the pin hole, loosen the nut 6, and remove the tightener.
The internal pressure of the pressure vessel during operation is supported by the finger pins 4 during operation, such as pressurization and heating.

If the tightener is a bolt type, for example, in a nuclear reactor pressure vessel, a bolt with a diameter of about 50 mm is attached to the outer circumferential surface of the flange.
Approximately 100 pieces are required, but the conventional one requires about 150 pieces.
Since approximately 100 mm diameter bolts were required, the flange portion of the present invention is smaller. Furthermore, when the tightening device is a fluid pressure cylinder, it is possible to further reduce the size of the tightening device, and it is also possible to combine it with a simple remote control device.

The procedure for loosening the flange is the reverse of the above procedure.

FIG. 6 shows another embodiment of the present invention, in which the bolt 5 of the tightener is fixed to the body flange 1. Even with such a configuration, it is possible to perform tightening. In the figure, the same reference numerals as those shown in FIG. 2 indicate the same parts.

It should be noted that the present invention is not limited to the above-described embodiments, and it goes without saying that various changes can be made without departing from the gist of the present invention.

According to the pressure vessel tightening method of the present invention, () the internal pressure of the pressure vessel can be received by the finger pins, and the tightening device does not need to support the internal pressure of the pressure vessel by merely applying an initial tightening force; Therefore, since the flange portion is small, it is easy to manufacture, inexpensive, and easy to handle.

() Easy to open and close because the flange is small.

() Since the internal pressure can be received by the finger pin, it will not become unusable depending on the type of internal fluid, and it can also be used at high temperatures and high pressures.

It can produce excellent effects such as

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram of the conventional pressure vessel tightening method;
FIG. 2 is an explanatory diagram of an embodiment of the pressure vessel tightening method of the present invention, FIG. 3 is a view taken in the - direction arrow of FIG. 2,
Figure 4 is from Figure 2 and is an explanatory diagram of the state of the gasket when the top cover flange is placed on it. Figure 5 is an explanatory diagram of the state of the gasket when the same initial tightening force is applied. FIG. 6 is an explanatory diagram of another embodiment of the pressure vessel tightening method of the invention. In the figure, 1 is the body flange, 2 is the top cover flange, 3 is the gasket, 4 is the finger pin, 5 is the bolt,
6 indicates a nut, and 7 and 8 indicate jigs.

Claims (1)

[Claims] 1 Place the top cover flange on the body flange, tighten the flange part with a tightener, apply initial tightening force to the gasket provided on the sealing surface between the flanges, and use the initial tightening force to tighten the top cover flange and the body flange, respectively. A method for tightening a pressure vessel, comprising aligning a pin hole provided in parallel with the sealing surface and inserting a finger pin into the pin hole.