JPH033836B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a bellows joint for piping that is an improvement on gimbal-type and hinge-type bellows joints in piping systems of nuclear power plants.

[Conventional technology]

Piping systems used in nuclear power plants, such as those used in the primary cooling system of fast breeder reactors (hereinafter referred to as FBRs), transport sodium at temperatures as high as approximately 500°C, so the piping systems are The material used is stainless steel, nickel alloy steel, etc., which have high high-temperature strength. Furthermore, since the outer surface is coated with a heat insulating material to reduce the amount of heat dissipated, the material temperature of the piping reaches approximately 500°C. Therefore, thermal expansion of the piping causes an increase in thermal stress, and the allowable stress value of the material also decreases, creating a risk of damage to the piping system. In order to alleviate the thermal stress, we had to run complicated piping.
As a result, plant construction costs have increased.

In order to alleviate this increase in plant construction costs, expansion-contraction joints are provided at predetermined positions in the piping system to absorb thermal expansion and make the piping system more compact. However, in nuclear power plants such as FBR, it is necessary to form a boundary to prevent internal fluid leakage, so expansion-contraction joints are generally considered to be bellows joints that can completely seal. Gimbal type bellows joints, which are rotary angle displacement type bellows joints in which the load displacement angle is uniquely determined by balance, are mainly considered.

As shown in Fig. 8, a gimbal type bellows joint rotatably connects one shell 1 and a fixing ring 2 by a pair of opposing pins 3 provided so that the axis of the pin passes through the center of the bellows joint. , the other shell 1' and the fixing ring 2 are rotatably connected by another pair of opposing pins 3' at a position rotated 90 degrees with respect to the axes of the two pins 3. In the figure, 4 is a boundary bellows, 5 is a back-up bellows arranged concentrically outside the boundary bellows 4, and both ends of the boundary bellows 4 and 5 are connected to shells 1 and 1' via skirts 6 and 6'. It is connected and fixed to an integral pressure-resistant boundary 7, 7'. Reference numerals 8 and 8' denote sleeves that reduce pressure loss and smooth the flow of fluid.

The gimbal type bellows joint with such a configuration is installed at a predetermined position in the piping system, and external force generated due to thermal expansion of the piping system during operation is caused by the angular displacement rotating around the axis of the pin 3 and the axis of the pin 3. Since the rotation is a combination of the center and the angular displacement that rotates around the axis of pin 3', which is rotated 90 degrees, angular displacement occurs 360 degrees in all directions around the center point of the bellows joint. However, it can absorb external forces generated by thermal expansion of piping.

[Problem that the invention seeks to solve]

By the way, since the above-mentioned gimbal type bellows joint is integrated with the shells 1 and 1', which are the link mechanism parts, and the pressure-resistant boundaries 7, 7', the Y-junction part 9 of the hardware is used for starting, stopping, and controlling the nuclear power plant. Large thermal stress is generated due to the difference in temperature followability between the pressure boundary and the link mechanism shell caused by thermal transient events. Also Y
Since the junction portion 9 is made thick for strength, it cannot sufficiently absorb the thermal expansion displacement of the pressure boundaries 7, 7' in the pipe radial direction.

Therefore, the present invention can alleviate the thermal stress generated in the Y-junction part of the hardware of the gimbal-type bellows joint, can sufficiently absorb the thermal expansion displacement of the pressure-resistant boundary, and is also easy to manufacture and assemble. The purpose of this invention is to provide a bellows joint for piping with improved durability and repairability.

[Means for solving problems]

In order to solve the above problems, the bellows joint for piping of the present invention separates the pressure boundary and the link mechanism shell in gimbal type and hinge type bellows joints, and separates the outer periphery of the pressure boundary and the link mechanism shell. It is characterized in that the stump is slidably locked and connected in the axial and radial directions of the pressure-resistant boundary, and is fitted in a concave-convex manner in the circumferential direction.

[Effect]

As mentioned above, the link mechanism shell is separated from the pressure-resistant boundary, and the separated end is locked and connected to the outer periphery of the pressure-resistant boundary so that it can slide in the axial and radial directions. Even if there is a difference in temperature followability between the pressure-resistant boundary and the link mechanism shell, no large thermal stress is generated at the locking connection portion between the pressure-resistant boundary and the link mechanism shell due to individual thermal expansion. Further, thermal expansion displacement of the pressure-resistant boundary is sufficiently absorbed by the slidable locking connection portion, and no excessive load is applied to each other. Further, in the above-mentioned slidable locking connection portion, the resistant boundary and the link mechanism shell restrain movement in the circumferential direction by fitting with the concave and convex portions, so rotation of both is restricted and torsional deformation is prevented.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a bellows joint for piping according to the present invention will be explained with reference to FIG. Since the same reference numerals in the figure as in FIG. 8 indicate the same parts, the explanation thereof will be omitted. The pressure boundaries 7, 7' and the link mechanism shells 1, 1' are separated as shown in the figure, and the divided ends of the pressure boundaries 7, 7' and the link mechanism shells 1, 1' are separated from the pressure boundaries 7, 7' and the link mechanism shells 1, 1'.
7' are slidably locked and connected in the axial and radial directions, and are fitted in the circumferential direction. That is, a thrust lip 10 is integrally provided on the outer periphery of the pressure-resistant boundaries 7, 7'(7' side is omitted) as shown in FIG. As shown in b, a plurality of keys 11, four in this example, are integrally provided in equiangular squares. On the other hand, four recesses 13 through which the keys 11 can pass are provided on the inner periphery of the divided end 12 of the link mechanism shell 1, (1'). Then, with this concave portion 13 fitted into the key 11, the divided ends 12 of the link mechanism shells 1, 1' are brought close to the thrust lip 10, and the key 1
Both ends of a presser ring 14 divided into four parts are removably fixed with bolts 15 to lock the divided end 12. In addition, a large number of spacers 16 made of materials such as ceramics can be attached and detached in the circumferential direction of the surface facing the divided end 12 of the link mechanism shell 1, (1') of the thrust lip 10, as shown in FIG. 2c. installed on,
Furthermore, a spacer 17 made of a material such as ceramics is removably attached to the side surface of the recess 13 of the divided end 12, as shown in FIG. 2d. In the piping bellows joint with this structure, the internal pressure thrust is a thrust lip of 10
and is held by the link mechanism shells 1 and 1',
The weight of the piping is measured by the spacer 17 attached to the key 11.
and is held by the link mechanism shells 1, 1'.
During operation of a nuclear power plant, the pressure boundaries 7, 7' and the link mechanism shells 1, 1' undergo thermal expansion individually, so that the locking connection between the two, that is, the link mechanism shells 1, 1', is separated. No significant thermal stress occurs in the end 12, thrust lip 10 and key 11. In addition, the thermal expansion displacement of the pressure-resistant boundaries 7, 7' and the link mechanism shells 1, 1' is sufficiently absorbed by the slidable locking connection parts, and no excessive load is applied to each other, thereby preventing damage. . Furthermore, in the slidable locking connection part, the recess 13 on the inner periphery of the divided end 12 of the link mechanism shells 1, 1' and the key 11 on the outer periphery of the pressure-resistant boundaries 7, 7' are engaged with each other to prevent movement in the circumferential direction. Since the rotation of both is restricted, torsional deformation is prevented. Further, since a large number of spacers 16 made of a material such as ceramics are attached in the circumferential direction of the contact surface receiving the internal pressure thrust, that is, the outer surface of the thrust lip 10, adhesion is prevented. Furthermore, since a spacer 17 made of a material such as ceramics is attached to the side surface of the recess 13, the link mechanism shells 1, 1' may be caused by twisting in the circumferential direction of the pressure-resistant boundaries 7, 7' or deviation in the direction perpendicular to the axis. Even if it comes into contact with the side surface of the recess 13 on the inner periphery of the divided end 12, adhesion can be prevented.

The means for slidably locking and connecting the outer periphery of the pressure-resistant boundaries 7, 7' and the divided end of the link mechanism shell in the axial and radial directions of the pressure-resistant boundaries, and engaging the concave-convex portion in the circumferential direction is limited to the above embodiment. There are various types, as shown in a and b in FIGS. 3 to 7.

To explain the means shown in FIGS. 3a and 3b,
A thrust lip 10 is integrally provided on the outer periphery of the pressure-resistant boundaries 7, 7'(7' side is omitted), and a plurality of key insertion holes 18 are provided in the circumferential direction of the outer surface of this thrust lip 10.
A self-weight lip 19 is integrally provided on the outer periphery of the pressure-resistant boundary 7 (7') facing the outer surface of the thrust lip 10, and a key is inserted into a position opposite to the key insertion hole 18 in the circumferential direction of this self-weight lip 19. A groove 20 is provided. On the other hand, link mechanism shell 1, 1'
A recess 13 is provided at the same position as the key insertion hole 18 on the inner periphery of the divided end 12 (the 1' side is not shown). Then, the part of the divided end 12 of the link mechanism shell 1, (1') other than the recess 13 is passed through the key insertion groove 20 of the self-weight lip 19, and the divided end 12 is inserted into the annular groove 20 between the thrust lips 10 and 19. After being located at
Slightly rotate the link mechanism shell 1 (1') to align the recess 13 of the split end 12 with the key insertion hole 18, and then insert the key insertion groove 20 of the self-weight lip 19 into the recess 1.
3. Insert the key 22 into the key insertion hole 18, and removably fix the arms 23 protruding from the upper surface of the base end of the key 22 on both sides to the self-weight lip 19 with bolts 24 to lock the divided end 12. Moreover, the movement of the link mechanism portion shells 1, (1') in the circumferential direction is restrained by the key 22.

In this structure, the internal pressure thrust is held by the thrust lip 10 and the link mechanism shells 1, 1', and the weight of the piping is held by the key 22 and the link mechanism shells 1, 1'.

To explain the means shown in Fig. 4 a and b,
A thrust lip 10 is integrally provided on the outer periphery of the pressure-resistant boundaries 7, 7'(7' side is omitted), and a plurality of bolt holes 25 are provided in the circumferential direction of the outer surface of this thrust lip 10, while the link mechanism shell 1, An oblong hole 26 is provided at the same position as the bolt hole 25 in the circumferential direction of the divided end 12 of (1'). And the oblong hole 2 of the divided end 12
A spacer 28 having a circular bolt insertion hole 27 thicker than the plate thickness of the split end 12 is inserted into the spacer 6 so that the split end 12 faces the thrust lip 10, and a bolt insertion hole 29 is provided outside the split end 12. The presser ring 30 is secured by tightening the upper bolt 31 that matches the bolt insertion hole 29 of the presser ring 30, the bolt insertion hole 27 of the spacer 28, and the bolt hole 25 of the thrust lip 10. The split end 12 is fixed, and the circumferential movement of the link mechanism shells 1, (1') is restrained by the spacer 28.

In this structure, the internal pressure thrust is held by the thrust lip 10 and the link mechanism shells 1, 1', and the weight of the piping is transferred via the bolt 31 to the link mechanism shells 1, 1'.
1'.

To explain the means shown in Fig. 5 a and b,
A thrust lip 10' is integrally provided on the outer periphery of the pressure-resistant boundaries 7, 7'(7' side is not shown), and a plurality of recesses 32 are provided on the outer peripheral surface of this thrust lip 10'.
On the other hand, the divided end 12 of the link mechanism shell 1, (1')
A cylindrical body 33 is integrally provided on the outer surface of the cylindrical body 33.
A plurality of protrusions 34 are integrally provided on the inner circumferential side of the recess 32, and the protrusions 34 are fitted into the recess 32. The cylinder body 3
A plurality of bolt holes 35 are provided in the circumferential direction of the end surface of 3. Then, a presser ring 37 having a plurality of bolt insertion holes 36 in the circumferential direction is applied to the end surface of the cylinder body 33,
The bolt insertion hole 36 is aligned with the bolt hole 35, and the bolt 38 is tightened thereto to fix the presser ring 37, so that the divided end 12 is locked to the thrust lip 10', and the thrust lip is The movement of the link mechanism shell 1, (1') in the circumferential direction is restrained by a recess 32 on the outer circumferential surface of the link mechanism shell 10'.

In this structure, the internal pressure thrust is applied to the presser ring 37 and the bolt 3.
8, and the weight of the piping is held by the thrust lip 10' and the link mechanism shells 1, 1'.

To explain the means shown in FIGS. 6a and b,
A thrust lip 10 and a self-weight lip 39 are integrally provided facing each other on the outer periphery of the pressure-resistant boundaries 7, 7'(7' side is omitted), and an annular groove 40 is formed between them. A plurality of convex portions 41 are provided in the circumferential direction of this annular groove 40.
will be established. On the other hand, the link mechanism shell 1, (1') is divided into two in the circumferential direction, and a flange 42 is provided on each divided edge, and bolt insertion holes 43 are provided at regular intervals in the longitudinal direction of the flange 42. Further, a recess 45 is provided on the inner periphery of the divided end 12 of the link mechanism shell 1, (1') to fit into the circumferential protrusion 41 of the annular groove 40. Then, the divided end 12 of the link mechanism shell 1, (1'), which is divided into two in the circumferential direction, is inserted into the annular groove 40 from the outside, and the divided end 12 is inserted into the convex part 41 in the annular groove 40. After fitting into the recess 45 on the inner circumference, the flanges 42 of the two-part link mechanism shell 1, (1') are butted together, the bolt 46 is inserted into the bolt insertion hole 43, and the nut 47 is tightened to complete the two-part link. Mechanism shells 1 and (1') are connected to each other. Note that the connection may be made by welding instead of the bolts 46 and nuts 47. In this way, the divided end 12 comes to be locked between the thrust lip 10 and the self-weight lip 39, and the protrusion 41 in the annular groove 40
At this point, the movement of the link mechanism shells 1, (1') in the circumferential direction is restricted.

In this structure, the internal pressure thrust is held by the thrust lip 10 and the link mechanism shells 1 and 1', and the dead weight of the piping is carried by the dead weight lip 39 and the link mechanism shells 1 and 1'.
1'.

To explain the means shown in Fig. 7a and b,
A thrust lip 10 and a self-weight lip 39 are integrally provided facing each other on the outer periphery of the pressure-resistant boundaries 7, 7' (the 7' side is not shown), and an annular groove 40 is formed between them. A plurality of convex portions 41 are provided in the circumferential direction of this annular groove 40.
will be established. On the other hand, the outer surface of the divided end 12 of the link mechanism shell 1, (1') has an annular recess 4 facing the circumferential surface.
form 8. And link mechanism shell 1,
1' is arranged on the outer periphery of the pressure-resistant boundary 7, (7'), the hook part 50 on the outer periphery side of the shell tooth 49 divided into two parts in the circumferential direction is fitted into the annular recess 48, and the inner periphery side is annular. After inserting into the groove 40 and fitting the plurality of recesses 51 provided on the inner circumferential side to the protrusion 41 in the annular groove 40, the two-piece shell insert 49 is formed.
Attach the link mechanism shell 1, (1') with the bolt 52.
The outer wall 53 of the annular recess 48 at the divided end 12 of
Fixed to. In addition, 54 is a two-part shell tooth 4
9 is a connection key, and 55 is a connection key holding plate.

In this way, the divided end 12 of the link mechanism shell 1, (1') receives the thrust lip 1 through the shell insert 49.
0 and its own weight lip 39,
In addition, the circumferential movement of the link mechanism shells 1, (1') is prevented by the convex portion 41 in the annular groove 40.
Becomes restrained through 9.

In this structure, the internal pressure thrust is held by the thrust lip 10 and the link mechanism shells 1, 1', and the dead weight of the piping is carried out by the dead weight lip 39 and the link mechanism shells 1, 1'.
is maintained by

Although not shown in each of the means shown in ab in FIGS. 3 to 7 above, the surface of the thrust lip that comes into contact with the split end side of the link mechanism shell and the recess on the split end side of the link mechanism shell make contact. As shown in FIGS. 2c and 2d, a spacer made of a material such as ceramics for preventing adhesion is removably attached to the upper surface of the convex portion in the annular groove on the pressure-resistant boundary side.

〔Effect of the invention〕

As detailed above, the piping bellows joint of the present invention divides the link mechanism shell from the pressure-resistant boundary, and engages the divided end so as to be slidable in the axial and radial directions directly or indirectly on the outer periphery of the pressure-resistant boundary. Since the locking connection is made, large thermal stresses are not generated in the locking connection portion during startup, shutdown, and thermal transient events of the nuclear power plant. Further, thermal expansion displacement of the pressure-resistant boundary is sufficiently absorbed by the slidable locking connection portion, and no excessive load is applied to the link mechanism shell, thereby preventing damage. Further, since the movement in the circumferential direction at the slidable locking connection portion between the pressure-resistant boundary and the link mechanism shell is restrained by the convex-concave fitting, the rotation of both is restricted and torsional deformation is prevented.

[Brief explanation of drawings]

Fig. 1 is a longitudinal sectional view showing one embodiment of the bellows joint for piping of the present invention, Fig. 2a is an enlarged view of part A in Fig. 1, Fig. 2b is a view taken in the direction of arrow B in Fig. Figure 2C is a diagram showing a spacer removably attached to the circumferential direction of the thrust lip, Figure 2d is a diagram showing a spacer removably attached to the side surface of the recess at the split end of the link mechanism shell, and Figure 3. 7 to 7 show various examples of means for slidably locking and connecting the outer periphery of the pressure-resistant boundary and the divided end of the link mechanism shell in the axial and radial directions of the pressure-resistant boundary, and engaging the concave and convex portions in the circumferential direction. Each figure (a) is a sectional view of a main part, each figure (b) is a view taken along arrow B in each figure (a), and FIG. 8 is a longitudinal sectional view showing a conventional gimbal type bellows joint. 1, 1'... Link mechanism shell, 7, 7'...
Pressure boundary, 10... Thrust lip, 11...
Key, 12... Divided end of link mechanism shell, 1
3... Recessed portion, 14... Presser ring, 18... Key insertion hole, 19... Weight lip, 20... Key insertion groove, 21... Annular groove, 22... Key, 25... Bolt hole, 26... ...Oval hole, 28...Spacer, 2
9... Bolt insertion hole, 30... Presser ring, 31...
Bolt, 32... recess, 33... cylinder, 34...
Recessed portion, 35... Bolt hole, 36... Bolt insertion hole, 37... Presser ring, 39... Weight lip, 40
... annular groove, 41 ... convex part, 42 ... flange,
43... Bolt insertion hole, 45... Recess, 48...
Annular recess, 49...Half-split shell tooth, 50
...Hook part, 51...Concave part.

Claims (1)

[Claims] 1 In gimbal type and hinge type bellows joints, the pressure boundary and the link mechanism shell are separated, and the outer periphery of the pressure boundary and the divided end of the link mechanism shell are aligned in the axial direction of the pressure boundary and the separated end of the link mechanism shell. A bellows joint for piping characterized by a locking connection that is slidable in the radial direction and a concave-convex fit in the circumferential direction. 2. Means for slidably locking and connecting the outer periphery of the pressure-resistant boundary and the divided end of the link mechanism shell in the axial and radial directions of the pressure-resistant boundary, and that engages concave and convex in the circumferential direction, is integrally provided on the outer periphery of the pressure-resistant boundary. a plurality of keys integrally provided at equal angular intervals in the circumferential direction on the piping connection side of the pressure-resistant boundary, and a plurality of recesses provided on the inner periphery of the divided end of the link mechanism shell and allowing the keys to pass through. 2. The bellows joint for piping according to claim 1, comprising: a split retaining ring having both ends removably fixed to the plurality of keys and locking a divided end of the link mechanism shell. 3 Thrust force provided on the outer periphery of the pressure-resistant boundary is provided by a means for slidably locking and connecting the outer periphery of the pressure-resistant boundary and the divided end of the link mechanism shell in the axial and radial directions of the pressure-resistant boundary, and engaging the grooves and recesses in the circumferential direction. a lip, a key insertion hole provided in the circumferential direction of the outer surface of the thrust lip, and a self-weight lip provided on the outer periphery of the pressure-resistant boundary facing the outer surface of the thrust lip and having a key insertion groove opposite to the key insertion hole. , a recess provided at the same position as the key insertion hole on the inner periphery of the divided end of the link mechanism shell, the key insertion groove, and the key inserted into the key insertion hole through the recess, and the proximal end is attached to and detached from the self-weight lip. 2. The bellows joint for piping according to claim 1, comprising an insertion key for locking the inner periphery of the divided end of the link mechanism shell which can be fixed. 4. A means is provided on the outer periphery of the pressure-tight boundary and a means for slidably locking and connecting the outer periphery of the pressure-tight boundary and the divided end of the link mechanism shell in the axial and radial directions of the pressure-tight boundary, and engages in a concave-convex manner in the circumferential direction. A thrust lip having a bolt hole in the direction, an oblong hole provided at the same position as the bolt hole on the inner periphery of the divided end of the link mechanism shell, and a bolt insertion hole inserted into the oblong hole. a circular spacer having
The bellows joint for piping according to claim 1, comprising a retaining ring that is removably fixed to the thrust lip via the spacer with a bolt and that locks the inner periphery of the divided end of the link mechanism shell. . 5. A means is provided on the outer periphery of the pressure-resistant boundary to slidably engage and connect the outer periphery of the pressure-resistant boundary and the divided end of the link mechanism shell in the axial and radial directions of the pressure-resistant boundary, and engages the concave and convex portions in the circumferential direction. a thrust lip having a plurality of concave grooves in a direction; a cylindrical body having a convex portion integrally provided on the outer surface of the divided end of the link mechanism shell and inserted into the concave portion of the thrust lip on the inner peripheral side; The bellows joint for piping according to claim 1, comprising a retainer ring which is detachably fixed to the body and locks the thrust lip. 6. Means for slidably locking and connecting the outer periphery of the pressure-resistant boundary and the divided end of the link mechanism shell in the axial direction and radial direction of the pressure-resistant boundary, and that engages in a concave-convex manner in the circumferential direction, is arranged opposite to the outer periphery of the pressure-resistant boundary. a thrust lip and a self-weight lip provided as a thrust lip, an annular groove formed between the thrust lip and the self-weight lip and having a convex portion in the circumferential direction, and the convex portion on the inner circumferential side of the divided end inserted into the annular groove. The bellows joint for piping according to claim 1, comprising a link mechanism shell that is divided into two in the circumferential direction and has a recess that fits into the shell. 7. Means for slidably locking and connecting the outer periphery of the pressure-resistant boundary and the divided end of the link mechanism shell in the axial and radial directions of the pressure-resistant boundary, and that engages in a concave-convex manner in the circumferential direction, is arranged opposite to the outer periphery of the pressure-resistant boundary. a thrust lip and a self-weight lip provided as a lip, an annular groove formed between the thrust lip and the self-weight lip and having a convex portion in the circumferential direction, and an annular groove formed on the outer surface of the divided end of the link mechanism shell. A recessed portion, and a shell insert tooth divided into two parts in the circumferential direction, the outer circumferential side of which is fitted into the annular recessed portion, the inner circumferential side of which is inserted into the annular groove, and which has a recessed portion on the inner circumferential side that fits into the convex portion. Bellows fitting for piping according to scope 1.