JPH0833160B2 - Clamp device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a clamp device for sealing an instrumentation port or an instrumentation pipe connection port related to a nuclear reactor system, and more particularly to a penetrator of a reactor vessel lid and a thermoelectric A high quality clamping device for maintaining a proper seal at the interface between a pair of instrumentation columns.

Due to various hazards associated with the operation of nuclear power plants, design and quality standards for reactor equipment are very high and stringent. Therefore, even a problem that can be solved directly in a non-nuclear environment is a difficult problem in relation to nuclear reactor equipment and requires attention. For example, in many industrial environments it is generally necessary to measure and monitor pressure, temperature and other parameters of various work equipment. In a nuclear power plant environment, such monitoring can be very dangerous due to the potential leakage of radioactive material. Therefore, in the environment of a nuclear power plant, it is essential that the instrumentation used to make the above measurements be precisely designed to prevent the aforementioned leaks.

The potential for leakage of radioactive material from a nuclear power plant is reduced as much as possible by the containment building surrounding the nuclear steam supply system, but the working conditions inside this containment building are potentially dangerous during normal reactor operation. is there. This is especially true during reactor refueling, as high background radioactivity and high airborne particulate radioactivity are present in the containment building. The maximum dose limits that workers can enter at these locations during reactor operation and refueling are set by safety standards. Many of these similar locations are dangerous during refueling due to high ambient temperatures. Also, in most situations, these locations are not easily accessible and no security platform is available. Therefore, it is desirable to provide a clamping device that can be quickly and easily assembled to minimize exposure of workers to such hazardous working conditions. Also, repairing or replacing the instrument port clamp device quickly and efficiently reduces the downtime of the nuclear power plant and reduces the cost of supplying replacement power, which is economically feasible. Very desirable from.

For a clearer understanding of the invention, one of the typical interfaces of the instrumentation port is shown in FIG. As shown in the figure, the lower object, namely the conduit or flange 10
Is attached or otherwise attached to a container (not shown) having the parameter to be measured, while the upper object, i.e. the conduit or flange 11, is attached to a device (not shown) for measuring the parameter or otherwise. Is fitted in a manner. For special applications such as nuclear power plants, flanges
The lower part of 10 is screwed onto the penetrating body of the lid and welded to the penetrating body. Flange 10 and 11 are generally tubular in shape,
Each has an upper surface and a lower surface designed to engage one another in a sealing relationship with respect to the gasket 12. gasket
In order to effectively compress 12 and seal or seal the interface between flanges 10, 11, the clamping device must
It is desirable to apply axial pressure to 10 and 11. Regarding the boundary surface of the instrumentation port shown in FIG.
The pressure exerted on each flange must be directed to the border edge of that flange. That is, the clamping device needs to apply a certain upward axial force to the flange 10 while applying substantially the same downward axial force to the flange 11.

Sealing between the flanges 10 and 11 is an important safety issue when designing a nuclear reactor for a nuclear power plant. As will be appreciated by those skilled in the art, such flange interfaces are typically located in nuclear power plants in areas having high radiation levels and high process temperatures.
Because of these special circumstances, a high quality clamping device capable of sealing the interface between the flanges 10, 11 is not only desirable but also needed. In some applications it is desirable to form such clamping devices from high strength materials.
Also, the quick and easy installation and removal of the clamping device used to seal such interfaces is very important to the safety of the operator.

A conventional clamping device which has been used up to now is shown generally at 20 in FIG. This clamping device 20
Consists of three essentially identical body parts 13A, 13B and 13C, the span of each body part being approximately 110 ° in angle.
There is a gap 15 of about 10 ° between the body parts. Body part 13
A flange portion is provided at each end of A, 13B, and 13C, and the main body portions are attached to each other by using the flange portion. That is,
A cap screw 14 or other holding means as shown is passed through the flange portion to hold the body portion in a generally ring shape and the clamp device is assembled to the flanges 10 and 11.

Next, a case where the clamp device 20 is used for the boundary surface of the instrumentation port of the reactor vessel as shown in FIG. 1 will be described. Due to its shape and weight, the clamping device 20 of FIG. 2 is brought to the interface of the instrumentation port in a disassembled form. Next, at least two workers are generally required to assemble the clamping device 20 in place around the outer portion of the interface between the flanges 10 and 11. Since the cooling shroud and other equipment are fixedly installed above the reactor vessel lid, the flanges 10 and 11 are only accessible to the operator from the radial outside of the reactor vessel lid. The particular working procedure of the clamping device that has been used thus far requires the use of an axial loading device that seats on the gasket before using the clamping device. Such axial loading devices are generally heavy and cumbersome, and their installation is very difficult. Also, the need for this axial loading device limits the available work space, thus complicating the assembly of the clamping device 20. Once the axial load is properly positioned, flanges 10 and 11
In order to obtain a substantially uniform contact and pressure against and to minimize bending of the cap screw stalk, each gap 15 between the body portions must be carefully adjusted to be substantially equal. About 66 m / Kg (10
It is normal to apply torque up to 0ft / lb). To apply torque to this extent would require a fairly long torque device. It should be noted that in many cases over-torque on the cap screw 14 will result in over-compression of the gasket 12. For gaskets, overcompression has an undesired and significant effect on its sealing capacity. Prior art clamping devices were commonly used as a means of limiting the clearance between the flanges to prevent over compression of the gasket as described above. As will be apparent from the above description, the procedures and equipment required to assemble the clamping device 20 were time consuming and had the great potential for improper installation. Such a drawback is that the clamping device must be installed in an inconvenient and dangerous position, so that the worker is moored with ropes or other safety devices, the worker is in a mask, heavy gloves, or radiation-resistant clothing with a gas-proof surface. If you think that you must wear disturbing equipment such as
It becomes more remarkable.

Although it is known to use articulated clamps to overcome some of the above mentioned drawbacks, conventional articulated clamps present problems and problems associated with using such clamps in a nuclear power plant environment. It was not possible to completely solve the drawbacks. For example, the articulated clamping devices used to date have not solved the serious problem of gasket compression potential, resulting in the use of clearance limiting means. While such clearance control measures may have been adequate for their intended purpose, in many nuclear power plant systems, due to existing space limitations and existing instrumentation. The shape of the port flange has hindered the use of gap limiting means.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a clamping device and clamping device for use in the environment of a nuclear power plant that is quick, safe and easy to install.

Another object of the invention is to provide a clamping device which produces a uniform clamping pressure in the circumferential direction without the aid of an axial loading device.

Yet another object of the present invention is to provide a clamping device which prevents over compression of the sealing gasket without the need for gap limiting means.

Yet another object of the present invention is to provide a clamping device that reduces the exposure of workers to hazardous work environments and the number of workers so exposed as much as possible.

Still another object of the present invention is to provide a clamp device that can be attached / detached by applying a relatively small torque without using a special tool.

A clamping device for achieving the above-mentioned objects and other objects is a clamping device for sealing an interface between a substantially tubular first conduit and a substantially tubular second conduit,
At least two arcuate intermediate body members, each of the arcuate intermediate body members having first and second flangeless ends, the chord arc distance of each of the intermediate body members being no greater than about 90 degrees. The intermediate body member, a first link plate that pivotally connects the first end of the intermediate body member, and two arc-shaped end body members, each of the end body members having An end body member having a flange end and no flange, wherein the arcuate distance of each of the arcuate end body members is not greater than about 90 degrees; and the second end of the intermediate body member is the end body member. Second and third link plates pivotally connected to the non-flange end of the, and holding means for releasably holding the intimate contact between the reference surfaces, each of the end body members. The flanged end has a reference surface and the clamping device is a flanged end of the clamping device. From an open position that allows passage around the conduit to a preloaded position where the datum surface is in intimate contact, whereby the datum when the clamping device is assembled around the conduit. The intimate contact of the surfaces creates a suitable axial pressure at the interface and prevents overcompression of the interface.

DETAILED DESCRIPTION Referring to FIGS. 3 and 4, one embodiment of the clamping device of the present invention is shown in plan and cross-sectional views, respectively. The clamping device, indicated generally by the numeral 30, is composed of two end body members 31. Each end body member 31
Has a first end or non-flange end 31U and a second end or flange end 31F. In the closed state, that is, in the assembled state, these flanged ends are held together by a cap screw (holding means) 35. In the preferred embodiment, one of the flanged ends 31F has a non-threaded cap screw hole and the other flanged end 31F has a threaded cap screw hole. The non-flange ends 31U of the end body members 31 are joined together in such a manner that the radial spacing existing between the flanged ends 31F can be adjusted.
Thus, the present invention provides an integral clamping device having an adjustable end adapted to open in a jaw-like manner. During the assembly operation, this jaw-like structure allows the fully assembled clamping device to be changed to the open position, except that the cap screws have not yet been inserted. The clamping device in the open position is easily placed in position over the flanges 10 and 11.

In one embodiment of the invention, the link coupling means for linking both end body members so as to adjust the spacing between the flanged ends of the clamping device includes an intermediate body member. Means such as link plates 33 are provided to pivot the intermediate body members 32 together and to the flangeless ends 31U of the end body members 31. Intermediate body member 3
Bosses 34 extend from each end of 2 and the non-flange end 31U of the end body member 31, and each boss 34 extends in a known manner into a hole in the link plate 33. In the preferred embodiment, each boss 34 has a retaining means, such as a split pin, for retaining the link plate on the boss 34. The body members as shown in FIG. 4 are preferably joined by a pair of link plates 33.

Those skilled in the art will readily appreciate that means other than those detailed above can be used to link the flangeless ends of the end body members together. For example, in some cases it may be preferable to provide more than one intermediate body member. In other cases, it may be desirable to widen the arcuate span of the end body member and link the flangeless ends 31U directly to each other by a link plate.

The operation of the clamping device according to the present invention can be effectively explained by describing the use of the clamping device of FIGS. 3 and 4 in connection with the instrumentation port interface shown in FIG. Let's do it.

Due in part to the articulated structure of the clamping device of the present invention, the clamping device could be installed with little effort around the instrumentation port interface shown in FIG. When the cap screw 35 is removed from the clamp device 30, the flanged end 31F of the clamp device is easily separated in a jaw-like manner. In particular, because of the provision of at least two pivotally connected end body members 31, the flanged ends 31F are easily separated from one another by a distance sufficient for the clamping device 30 to pass around the flanges 10 and 11. To separate. These flanged ends 31F are then easily rejoined by the cap screws 35.

As shown in FIGS. 3 and 4, the clamp device 30 according to one embodiment of the present invention is substantially ring-shaped when in the assembled form, and the ring-shaped clamp device 30 is shown.
The inner portion or inner surface of the is adapted to engage the outer portion or outer surface of the flanges 10 and 11. As mentioned above, it is desirable for the clamping device of the present invention to apply a suitable seating force to the flange interface. As best shown in FIGS. 1 and 4, such seating force application is substantially non-perpendicular to the inwardly facing portions of the clamping device 30 with respect to the axes 38 of the flanges 10 and 11. This is accomplished by providing flat surfaces 36 and 37. In the assembled configuration, the surfaces 36 and 37 of the clamping device 30 are substantially parallel to the surfaces 39 and 40 of the flanges 10 and 11, respectively. When the clamp device 30 is assembled, the inner diameter of the clamp device 30 tends to become smaller until the cap screw 35 pulls the flanged end 31F together to fit them together. Due to the decrease in the inner diameter of the clamping device 30, the surface 36 engages the surface 39 and the surface 37 engages the surface 40 so that opposing axial pressure is exerted on the flanges 10 and 11. For the most accurate axial pressure application, the inwardly facing portions of the clamping device 30 should be machined, cast or forged to precisely engage the surfaces 39 and 40 of the flanges 11 and 10. Is preferred. In particular, the spatial relationship between the surfaces 36, 37 and the surfaces 39, 40 of the clamping device 30 is
It is controlled so that an appropriate axial pressure acts when the flanged end 31F comes into contact.

As mentioned above, it is important for an instrumentation port interface clamping device of the type disclosed herein to achieve and maintain proper uniform contact and pressure against the interface. Such uniform contact and pressure will ensure proper seating of gasket 12 and prevent over-compression against gasket 12. Also, this uniform contact and pressure helps maintain a proper seal during emergency situations. Part of these purposes is the flanged end of the end body member.
This is achieved by forming a reference surface on 31F. In accordance with the present invention, the clamping device 30 is, for example, machined, cast or forged according to aspects known in the art such that the flanges 10 and 1 when the reference surface 31D is in contact.
It is designed to provide proper contact and pressure to the interface between the ones. By "preloading" the clamping device of the present invention in this manner, the time required to position and assemble the clamping device on the instrumentation port interface is reduced and the need for clearance limiting means is eliminated. .
That is, once the clamping device is arranged around the flange by the method described above, when sufficient torque is applied to the cap screw to cause a close contact between the reference surfaces of the flange end,
Appropriate dimensional relationships of the clamping device are realized. This properly seats and compresses the gasket. Further torque on the cap screw does not overcompress the gasket, and further torque will cause the gasket to remain seated as the pressure in the flange increases, so It is preferred as a means of preloading the flange. In particular, the clamping device of the present invention has about 60
It achieves the above objectives when a torque of only ft / lb (39.6m / Kg) is applied to the cap screws. In the preferred embodiment of the invention, the reference surface is simply the flat surface 31D of the flanged end 31F. However, it will be apparent to those skilled in the art that the use of any particular shaped or contoured reference surface is within the scope of the present invention. For example, it may be desirable to provide the reference surface with an engagement that provides axial alignment of the flanged ends 31F.

The gasket 12 is properly seated by the clamping device of the present invention without the need for the axial loading device previously used. This advantage is achieved in part by providing body members 31 and 32 with arcuate spans that are substantially smaller than the arcuate spans of body portions 13A, 13B and 13C due to the clamping devices previously used. Is derived. Preferably, the body member according to the present invention does not span an arc greater than about 90 °. The inventor of the present application has found that the reduction of the arcuate span and the reduction of the inner diameter of the clamp device increase the contact area between the clamp device 30 and the flanges 10 and 11. This increased contact area helps seat the gasket 12 when assembling the clamping device 30. Also,
Increasing the number of body members having a reduced arcuate span also aids seating of the gasket 12 when assembling the clamping device 30. The use of the clamping device according to the invention obviates the need for an axial loading device, thus simplifying its assembly procedure and reducing the time an operator is exposed to potentially dangerous conditions.

Referring to FIG. 5, another embodiment of a clamping device according to the present invention is shown in cross-section in connection with a representative instrumentation port interface. In this form of embodiment, the conduits, tubular objects or flanges 41, 42 cooperate in a telescopic manner to seal the instrumentation port interface therebetween. In the context of a reactor vessel, the flange 41 comprises the upper portion of the flange 10 (Fig. 1) and the flange 42 is a cylindrical conduit that carries a thermocouple extending into the interior of the flange 41. Like the conventional interface, the gasket 12 is provided to ensure proper sealing between the flanges 41 and 42. In contrast to the interface shown in FIG.
Proper seating of the gasket 12 in the figure requires that each flange be subjected to axial pressure directed away from its boundary edge. That is, the clamping device must apply axially upward pressure with respect to the flange 41 to the flange or cylindrical conduit 42. A conventional clamping device used to achieve this purpose is disclosed in
No. 63-117294. According to another embodiment of the invention, this object is achieved by the cooperation of the positioning clamp device 50 and the wedge clamp device 60. The clamping devices 50 and 60 may have any planar structure,
It is preferable to use a multi-joint structure as shown in FIG. However, as shown in FIG. 5, the clamping devices 50, 60
The sectional structures of the flanges 41 and 42 are substantially different from the sectional structures of the clamp device 30 and the flanges 10 and 11 shown in FIGS. 1 and 4. In particular, the flange 42 includes an annular groove (clamp receiving portion) 43 on the outer surface for receiving the positioning clamp device 50. The positioning clamp device 50 has an inwardly extending flange 51, and at least a part of the flange 51 engages with the annular groove 43. Further, the lower surface 52 of the positioning clamp device 50 has the flanges 41, 42.
Is not perpendicular to the central axis 44 of. In this way,
The axial distance between any part of the lower surface 52 and the ends of the flanges 41, 42 is functionally related to the radial distance of said part from the central axis 44. In particular, the distance between the surface or lower surface 52 and the end of the flange 42 is the surface radius,
That is, it decreases with decreasing radius at some location on the surface. The upper end of the flange 41 has a substantially flat surface 45, which is also not substantially perpendicular to the central axis 44. Also, the distance between the surface 45 and the boundary edge of the flange 41 also decreases with decreasing surface radius. The term flange end, as used herein, refers to the most axially separated portion of the flange, for example, flange 41
The edge of is the innermost radius of surface 45.

The front surface 45 and the lower surface 52 cooperate to define a wedge-shaped opening (clamp receiving portion) 70 for the clamping device 60. The inner surface of the clamping device 60 is an engagement means adapted to cooperatively engage the wedge-shaped opening 70. Especially the clamping device
60 has an upper surface 61 and a lower surface 62, both of which are arranged at non-perpendicular angles with respect to central axis 44. As shown in FIG. 5, lower surface 62 engages surface 45 and surface 45
Preferably, the upper surface 61 engages the lower surface 52 and is parallel to the lower surface 52. These surfaces 61 and 62 are inclined to approach the axial center of the opening 70 as the radial distance from the central axis 44 decreases. Due in part to the articulated structure of the clamping device 60 (see Figure 3), the inner diameter of the clamping device 60 decreases when the flanged ends 31F are pulled together.
Also, this reduction in the inner diameter of the clamping device 60 is due to the relationship between the axial and radial distances of the surface described above,
An attempt is made to exert an axially upward pressure on the flange 41 with respect to the flange 41.

As will be apparent to those skilled in the art, it is possible, and may be desirable, to modify the clamping device shown in FIG. 5 in various configurations. For example, in some applications, a two-piece split ring may be used in place of the position clamp device 50. Also, in other applications it may be desirable to eliminate the positioning clamp device 50 altogether and simply form the flange 42 to have the proper profile. However, in most situations, especially in nuclear power plants, it is impractical to replace or redesign the flange 42, so it is desirable to provide a clamp such as the clamp device 50 in such situations. Further, the positioning clamp device 50 and the wedge type clamp device 60 may be combined to form one clamp, in which case the clamps are the positioning clamp device 50 and the wedge type clamp device.
It shall have an inner surface corresponding to 60 combinations.
Also, as will be apparent to one of ordinary skill in the art, the clamping device shown in FIG. 5 has sloped surfaces 45, 52, 61 and 62.
However, it is sufficient to provide only one of these surfaces to achieve the purpose of the clamping device disclosed herein. For example, the surface 45 in an array perpendicular to the central axis 44,
It is possible to provide 52 and 61 to keep the surface 62 in an inclined shape. By providing one inclined surface in this manner, the assembly of the clamping device 60 between the surfaces 52 and 45 will exert an axially upward pressure on the flange 42.

As made clear by the above description, the clamping and clamping devices of the present invention provide a quick and effective seal for the instrumentation port interface, thus providing a high degree of leakage protection for nuclear power plants. Reduces worker exposure to hazards. In particular, the clamping device provided by the present invention is for a relatively large instrumentation port, but can be easily handled by one operator. Also,
The clamp device can be quickly applied to the instrument port interface because only one cap screw needs to be assembled to the instrument port interface.

As will be apparent to one of ordinary skill in the art, the embodiments of the invention described above are provided by way of illustration only. For example, a clamping device has been described for use on tubular conduits associated with instrumentation port interfaces. However, the clamping device of the present invention is also applicable to conduits of other shapes such as square, rectangular and triangular. The clamping device of the present invention may also be used in other applications, such as transport containers and / or storage containers. Shape, without departing from the scope and spirit of the invention described in the claims,
It should be pointed out that various other changes can be made regarding the size and the like.

[Brief description of drawings]

FIG. 1 is a sectional view showing a typical instrumentation port boundary surface, and FIG.
FIG. 4 is a plan view showing a prior art clamping device, FIG. 3 is a plan view showing a clamping device according to an embodiment of the present invention, and FIG.
FIG. 4 is a sectional view taken along line 4-4 of FIG. 3, and FIG. 5 is a sectional view of another embodiment of the present invention. 10, 11, 41, 42 …… Flange, conduit or object 30 …… Clamping device 31 …… End body member 31D …… Reference surface 31F …… With flange end or second end 31U …… No flange end or first End 32 …… Intermediate body member (link coupling means) 33 …… Link plate (intermediate link, end link) 35 …… Pressing screw (holding means) 36,37 …… Surface (inner surface of body member) 39, 40 …… Surface (outer surface of conduit) 50, 60 …… Clamping device for clamping device 43 …… Annular groove (clamp receiving part) 70 …… Opening (clamp receiving part)

Claims (1)

[Claims] 1. A clamping device for sealing the interface between a substantially tubular first conduit and a substantially tubular second conduit, said first and second conduits of a reactor vessel. A part of the instrumentation port, the outer surface of the boundary end of the conduit adapted to receive the clamping device; (a) at least two arc-shaped intermediate body members, An intermediate body member each having first and second non-flange ends, wherein the chordal arc distance of each of the intermediate body members is not greater than about 90 degrees; and (b) the first end of the intermediate body member. A first link plate pivotally connected to each other; and (c) two arc-shaped end body members, each of which has a flanged end and a non-flanged end. The chordal arc distance of each of the end body members is not greater than about 90 degrees; Second and third link plates that pivotally connect the second end of the intermediate body member to the non-flange end of the end body member, and (e) each flanged end of the end body member is a reference. A surface, the clamping device being movable from an open position in which the flanged end of the clamping device can pass around the conduit to a preload position in which the reference surface is in intimate contact, This ensures that when the clamping device is assembled around the conduit, the intimate contact of the reference surface creates an appropriate axial pressure at the interface and prevents overcompression of the interface, (f) the reference. Holding means for releasably holding intimate contact between the surfaces.