JPH08338589A - Nozzle plug - Google Patents

Abstract

PURPOSE: To surely close a nozzle in a nozzle plug which closes a nozzle in a pipe line when the pipe line is replaced with another one or is repaired, by providing a tapered pressing member adapted to be driven by a piston so that a plurality of frictional pieces are projected radially outward and therefore are made into press contact with the inner surface of the nozzle. CONSTITUTION: In such a case that an existing pipe line which is connected to a nuclear reactor pressure container through a nozzle 7, is withdrawn, at first, a plug body 9 connected to a high pressure pump control device through high pressure joints 22, 24 provided in a housing lid 20 of a cylinder 10, is inserted in the nozzle 7. Then high pressure fluid is fed into a housing 12 on the piston rod 14 side of a piston 13 through a passage 23 so that the piston 13 is moved toward the housing lid 20, and accordingly, a tapered pressing member 30 is pulled by means of the piston rod 14 in order to outward project frictional pieces 33 radially arranged, toward a guide sleeve, resulting in that linings 34 provided at the distal ends of the frictional pieces 33 are made into press contact with the inner surface of the nozzle 7 so that the plug body 9 is fixed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a nozzle plug capable of closing a nozzle of a pipe connected to a container when the pipe is replaced or repaired.

[0002]

2. Description of the Related Art FIG. 4 shows an example of a reactor pressure vessel. This reactor pressure vessel comprises a hollow body 1 and a hollow pressure vessel body 3 having a lower mirror 2 at its lower end. And a pressure vessel head 4 that abuts on the upper end of the body portion 1 and closes the upper opening of the pressure vessel body 3, and is supported by a pedestal 6 standing inside the reactor containment vessel body 5. ing.

A nozzle 7 which communicates the outside and the inside of the body 1 is provided at a required position of the body 1, and the nozzle 7 is provided from the outside to the inside of the reactor pressure vessel. A pipe 8 such as a water supply pipe for supplying cooling water or a steam pipe for guiding the steam generated inside the reactor pressure vessel to the outside is connected.

In recent years, it has been considered to replace the above-mentioned pipe 8 with a material having further excellent corrosion resistance to further improve the reliability of the nuclear reactor.

[0005]

The reactor water (coolant) stored inside the reactor pressure vessel plays the role of a moderator that suppresses the emission of radiation from the inside of the reactor pressure vessel to the outside. In addition, the radiation dose of the reactor water itself is high.

Therefore, when removing the existing pipe 8, it is necessary to close the nozzle 7 to prevent the reactor water from flowing out of the reactor pressure vessel as much as possible.

The present invention has been made in view of the above-mentioned circumstances, and an object thereof is to provide a nozzle plug capable of reliably closing the nozzle.

[0008]

In order to achieve the above object, in a nozzle plug of the present invention, a cylinder having a housing that can be inserted into the nozzle and a circumferential direction along the outer peripheral surface of the housing. A seal member provided and capable of making close contact with the inner peripheral surface of the nozzle; and a taper push-out member formed in a truncated cone shape and fixed to the piston rod of the cylinder so that the large diameter portion is located on the side opposite to the housing. A guide sleeve having a hollow structure having a plurality of guide holes penetrating in the radial direction and capable of being inserted into a nozzle provided at one end of the housing so as to surround the tapered push-out member in the circumferential direction; A friction piece that is slidably inserted into the guide sleeve and an end surface located on the inner side of the guide sleeve is in contact with the outer peripheral surface of the tapered push-out member. .

In addition to the above-mentioned structure, the sealing member has a tube shape that can be expanded by the internal pressure.

In addition to the above-mentioned structure, a member having a high friction coefficient is provided on the end surface of the friction piece located on the outer side of the guide sleeve.

Further, in addition to the above-mentioned structure, the inclination angle of the outer peripheral surface of the tapered push-out member is set within the range of 5 to 10 ° with respect to the axis of the piston rod.

[0012]

In the nozzle plug of the present invention, when the guide sleeve and the cylinder are inserted into the nozzle, the seal member is brought into close contact with the inner peripheral surface of the nozzle to close the nozzle.

Further, fluid pressure is applied to the piston rod side fluid chamber of the cylinder to move the taper extruding member to the housing side, and each friction piece is brought into contact with the inner peripheral surface of the nozzle by the taper extruding member and Constrain the displacement of the nozzle plug.

When the sealing member has a tube shape, a fluid pressure is applied to the inside of the sealing member to bring the outer periphery of the sealing member into contact with the inner peripheral surface of the nozzle to close the nozzle.

Further, when a member having a high friction coefficient is provided on the outer end surface of the friction piece, the friction resistance between the friction piece and the inner peripheral surface of the nozzle is increased by the member, and the nozzle plug for the nozzle is increased. The force that restrains the displacement of is increased.

The inclination angle of the outer peripheral surface of the taper extruding member is set to 5
When set in the range of 10 °, the pushing action of the pushing member against the friction piece is effectively exhibited.

[0017]

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

1 to 3 show the outline of one embodiment of the nozzle plug of the present invention, 9 is a plug body, and the plug body 9 is connected to a cylinder 10 and one end of the cylinder 10. And the guide sleeve 11.

The cylinder 10 has a housing 12
And a piston 13 inserted into the housing 12 so as to be capable of reciprocating, and a piston rod 14 connected to the piston 13.

The housing 12 has a cylindrical shape with an outer diameter that can be inserted into the nozzle 7 and is closed on one side. The housing 12 has a through hole 15 penetrating along the axis in the substantially central portion of the closed end.
And a nozzle corner 7a of the nozzle 7 on the outer circumference of the opening on the other side.
A flange 16 having a shape conforming to the above, and a plurality of small wheels 17 arranged at equal intervals in the circumferential direction at a portion of the base of the flange 16 facing the nozzle corner 7a.

Further, a hanging metal fitting 18 for hoisting the plug body 9 is provided at a predetermined position on the outer circumference of the flange 16, and an O-ring 19 fitted in the opening of the housing 12 and fitted on the outer circumference. It has a housing lid 20 that closes the opening through the.

A through hole 21 that penetrates through the housing lid 20 and connects the outside and the internal space of the housing 12 is provided at a substantially central portion of the housing lid 20, and the through hole 21 is provided on the outer surface side of the housing lid 20. A high pressure joint 22 is provided.

In addition, at a predetermined position in the peripheral portion of the housing lid 20, there is provided a passage 23 penetrating the housing lid 20 and further penetrating the inside of the peripheral wall of the housing 12 to the internal space near the closed end of the housing 12. A high pressure joint 24 is provided on the outer surface side of the housing lid 20 of the flow path 23.

Each of the high pressure joints 22 and 24 can be connected to a high pressure pump pressure control device (not shown) through a high pressure pipe (not shown).

Further, two sealing grooves 25 extending in the circumferential direction at a predetermined interval in the longitudinal direction of the housing 12 are provided in a portion of the outer peripheral surface of the housing 12 near the end of the flow path 23, The sealing groove 25 communicates with the flow path 23 and the internal space of the housing 12.

The piston 13 has the above-mentioned housing lid 20.
It is provided so that it can be slid in the axial direction of the housing 12 while being in close contact with the inner peripheral surface of the housing 12 through an O-ring 35 that is inserted into the internal space of the housing 12 that is sealed by There is.

The piston rod 14 has a base portion connected to the substantially central portion of the piston 13 and penetrates the through hole 15 to project to the outside of the housing 12, and has a threaded portion 14a at the projecting tip portion.

A high pressure seal tube 26 is fitted on the sealing groove 25 provided on the outer periphery of the housing 12. As shown in FIG. 3, the high-pressure seal tube 26 has a fluid inlet / outlet 27 communicating with the end of the flow path 23, and the fluid inlet / outlet 27 is provided with a crimp joint 28.

The crimp joint 28 is crimped to the fluid inlet / outlet port 27 of the high-pressure seal tube 26 by the pressure applied by the high-pressure fluid supplied through the flow path 23, and the high-pressure fluid inside the high-pressure seal tube 26. It is formed so that it can lead to.

The high-pressure seal tube 26 has the above-described flow passage 2 when the plug body 9 is inserted into the nozzle 7.
When a high-pressure fluid is supplied via 3, it expands and comes into close contact with the inner peripheral surface of the nozzle 7.

The guide sleeve 11 has a hollow cylindrical shape having the same outer diameter as that of the cylinder 10 which can be inserted into the nozzle 7, and is formed so as to be connected to the closed end of the cylinder 10. Further, there are guide holes 29 arranged at equal intervals in the circumferential direction and penetrating in the radial direction at substantially central positions in the longitudinal direction, and further, at equal intervals in the circumferential direction on the outer circumference near both ends of the guide sleeve 11. It has a plurality of small wheels 17 placed side by side.

Reference numeral 30 denotes a taper extruding member, which has a large-diameter portion 31 adapted to the inner diameter of the guide sleeve 11 and is 5 ° to 10 ° with respect to the axis.
It has a frustoconical shape having a side peripheral surface formed with an inclination of °, and is screwed into the threaded portion 14a of the piston rod 14 of the cylinder 10 so that the large diameter portion 31 is located on the side opposite to the housing 12, It is fastened by a nut 32, and is configured to reciprocate inside the guide sleeve 11 in the axial direction of the guide sleeve 11 as the piston 13 operates.

Reference numeral 33 is a friction piece, and the friction piece 33 is slidably inserted into the guide hole 29 of the guide sleeve 11 and has an end face located on the inner side of the guide sleeve 11 and the taper pushing member 30. Is formed so as to contact the outer peripheral surface of the guide sleeve 11 of the friction piece 33.
A lining 34 having a high friction coefficient is attached to the end surface located on the outer side.

The operation of this embodiment will be described below.

When removing the existing pipe 8 such as the water supply pipe and the steam pipe connected to the reactor pressure vessel through the nozzle 7, the high pressure joints 22 and 24 provided on the housing lid 20 of the cylinder 10 are used. The plug main body 9 connected to a high pressure pump control device (not shown) is lifted through the hanging metal fitting 18 and is hung inside the pressure vessel main body 3 and inserted into the nozzle 7 to be removed.

The plug body 9 inserted into the nozzle 7 is guided by the small wheels 17 provided on the outer circumference of the guide sleeve 11 to proceed into the nozzle 7, and is provided near the flange 16 of the housing 12. Small wheels 17
Stops when the nozzle comes into contact with the nozzle corner 7a.

Then, by operating the high-pressure pump control device, the high-pressure fluid is passed through the high-pressure joint 24 and the flow path 23 to the inside of the housing 12 on the piston rod 14 side of the piston 13 of the cylinder 10 and the high-pressure seal tube 2.
6 and a through hole 21 provided in the housing lid 20.
The fluid is removed from the inside of the housing 12 on the housing lid 20 side of the piston 13 of the cylinder 10 via the high pressure joint 22.

The high pressure fluid supplied to the inside of the housing 12 on the piston rod 14 side of the piston 13 is
Fluid pressure is applied to 3 to move the piston 13 to the housing lid 20 side, and the tapered push-out member 30 connected to the piston 13 via the piston rod 14 is moved to the housing 12 side.

When the taper push-out member 30 moves toward the housing 12, the friction pieces 33 in contact with the outer peripheral surface of the taper push-out member 30 are pushed outward of the guide sleeve 11 to guide the friction pieces 33. As a result of the lining 34 provided on the outer end surface of the sleeve 11 being strongly pressed against the inner surface of the nozzle 7, the plug body 9 is fixed to the nozzle 7 by the frictional force of the lining 34.

On the other hand, the high-pressure fluid supplied to the high-pressure seal tube 26 pressurizes the crimp joint 28 to crimp the fluid inlet / outlet port 27 of the high-pressure seal tube 26 and flows into the high-pressure seal tube 26 to enter the high-pressure seal tube 2.
A fluid pressure is applied to the inside of the high pressure seal tube 26.
By expanding the outer peripheral surface of the high-pressure seal tube 26 on the outer periphery of the housing 12.
And the inner surface of the nozzle 7 are pressure-bonded to prevent the fluid such as water stored inside the pressure vessel main body 3 from flowing out from the nozzle 7.

When the removal and renewal of the pipe 8 is completed, the high pressure pump controller is operated again to
The high pressure fluid is supplied to the inside of the housing 12 on the housing lid 20 side of the piston 13 of the cylinder 10 via the high pressure joint 22 and the through hole 21 provided in the housing lid 20, and the cylinder 1 via the flow path 23 and the high pressure joint 24.
The high pressure fluid inside the housing 12 on the piston rod 14 side of the zero piston 13 and in the high pressure seal tube 26 is eliminated.

The high-pressure fluid supplied into the housing 12 on the housing lid 20 side of the piston 13 is
A fluid pressure is applied to the piston 13 to move the piston 13 to the guide sleeve 11 side, and the tapered push-out member 30 connected to the piston 13 via the piston rod 14 is moved to the opposite housing 12 side.

The taper push-out member 30 is not the housing 12.
When the friction piece 3 is moved to the side, the action of pushing each friction piece 33, which is in contact with the outer peripheral surface of the taper pushing member 30, toward the outside of the guide sleeve 11 disappears, and as a result, the friction piece 3
The constraint generated between the lining 34 provided on the outer end surface of the guide sleeve 11 and the inner surface of the nozzle 7 is released.

On the other hand, the crimp joint 28 is pressurized to be crimped to the fluid inlet / outlet port 27 of the high pressure seal tube 26 and flown into the high pressure seal tube 26 to apply fluid pressure to the high pressure seal tube 26, and the high pressure seal is applied. As a result of the high-pressure fluid expanding the tube 26 being removed, the high-pressure seal tube 26 contracts and the high-pressure seal tube 26
The sealing action between the outer peripheral surface of the nozzle and the inner surface of the nozzle 7 disappears.

Therefore, the plug main body 9 is lifted up via the hanging metal fitting 18 and is detached from the nozzle 7 to which the pipe 8 is newly connected.

In this embodiment, when the plug body 9 is inserted into the nozzle 7, the high pressure fluid is supplied into the housing 12 to operate the piston 13 and the friction piece 33 to the nozzle 7 via the taper extruding member 30. To fix the plug body 9 by strongly abutting the inner surface of the nozzle, supply the high-pressure fluid into the high-pressure sealing tube 26 to expand the high-pressure sealing tube 26, and bring the outer peripheral surface thereof into contact with the inner surface of the nozzle 7. Since the nozzle 7 is formed so as to be sealed by the above, the sealing property and the fixing ability of the nozzle plug can be adjusted at the same time by increasing or decreasing the pressure of the high-pressure fluid, and the nozzle 7 can be surely closed. If the nozzle plug is applied to the work of closing the nozzle 7 of the reactor pressure vessel, the reactor water with a high radiation dose stored inside the reactor pressure vessel will be exposed to the outside. It can be prevented from flowing out.

The nozzle plug of the present invention is not limited to the above-mentioned embodiment, and it goes without saying that various modifications can be made without departing from the gist of the present invention.

[0048]

According to the nozzle plug of the present invention, various excellent effects as described below can be obtained.

(1) The nozzle plug can be fixed at a predetermined position inside the nozzle, and the nozzle can be reliably closed.

(2) When a tube-shaped sealing member is applied, it is possible to simultaneously adjust the fixing ability and sealing performance of the nozzle plug by increasing or decreasing the fluid pressure.

[Brief description of drawings]

FIG. 1 is a sectional view showing an outline of an embodiment of a nozzle plug of the present invention.

FIG. 2 is a view taken along the line II-II of FIG.

FIG. 3 is an enlarged cross-sectional view of the high pressure seal tube related to FIG. 1.

FIG. 4 is a sectional view showing an example of a reactor pressure vessel.

[Explanation of symbols]

 7 Nozzle 10 Cylinder 11 Guide Sleeve 12 Housing 13 Piston 14 Piston Rod 26 High Pressure Seal Tube (Seal Member) 29 Guide Hole 30 Taper Extruding Member 33 Friction Piece 34 Lining (Member)

Claims (4)

[Claims] 1. A cylinder having a housing that can be inserted into a nozzle, a seal member that is provided along an outer peripheral surface of the housing along a circumferential direction and can be in close contact with an inner peripheral surface of the nozzle, and a truncated cone. The taper extruding member formed in a shape and fixed to the piston rod of the cylinder so that the large diameter portion is located on the side opposite to the housing, and the taper extruding member having a plurality of guide holes penetrating in the radial direction. A guide sleeve having a hollow structure which can be inserted into a nozzle provided at one end of the housing so as to surround the sleeve in the circumferential direction, and an end face which is slidably inserted into the guide hole and located on the inner side of the guide sleeve. And a friction piece formed so as to come into contact with the outer peripheral surface of the tapered push-out member. 2. The nozzle plug according to claim 1, wherein the seal member has a tube shape that can be expanded by an internal pressure. 3. The nozzle plug according to claim 1, wherein a member having a high friction coefficient is provided on an end surface of the friction piece located on the outer side of the guide sleeve. 4. The nozzle plug according to claim 1, wherein the inclination angle of the outer peripheral surface of the tapered push-out member is set within a range of 5 to 10 ° with respect to the axis of the piston rod.