US3780204A

US3780204A - Electrical penetration assembly

Info

Publication number: US3780204A
Application number: US00256807A
Authority: US
Inventors: L Oliver; F Ingham; E Dubell
Original assignee: Deutsche ITT Industries GmbH
Current assignee: TDK Micronas GmbH; ITT Inc
Priority date: 1972-05-25
Filing date: 1972-05-25
Publication date: 1973-12-18
Anticipated expiration: 1990-12-18
Also published as: GB1428801A; JPS537031B2; JPS4943194A; CA985756A; IT988659B

Abstract

An electrical penetration assembly for installation in a containment wall formed of a nozzle extending through the wall and terminating in flanges at each end thereof. A canister assembly formed of a pipe member is positioned within the nozzle and extends through the containment wall. A glass-sealed hermetic header is positioned in the pipe member at the first end thereof and is secured to the pipe member at one end. A plurality of electrical conductors, terminating in electrical contacts, extend through the header and are sealed thereto, each of the conductors extending through the header to the other end of the pipe member. Means are provided for supporting the conductors in the pipe member. Electrical contact terminals terminate the electrical conductors at the other end of the header. In addition, means are provided for securing the electrical contact terminal means to the other end of the pipe member. The securing means at the other end of the pipe member may comprise a second glass-sealed hermetic header. Electrical connection to the electrical contact in the header is made by individual electrical contacts. The first end of the pipe member is positioned at the external side of the containment wall, and a flange member is secured to the pipe end and adapted to be fastened to one of the nozzle flanges. In addition, a channel is formed in the flange member, the channel providing means for pressurizing the interior of the pipe member. Means are provided for determining leakage in the assembly. A terminal housing is secured to the flange member, the terminal housing providing environmental and mechanical protection for the terminal area.

Description

United States Patent 91 Oliver et a1.

[ Dec. 18, 1973 1 1 ELECTRICAL PENETRATION ASSEMBLY [75] Inventors: Lehnd W. Oliver, Phoenix; Francis 11. lngham, Scottsdale; Edward G. Dubell, Phoenix, all of Ariz.

[7 3] Assignee: International Telephone and Telegraph Corporation, New York,

[22] Filed: my 25, 1972 [21] Appl. No.: 256,807

[56] met. Cited UNITED STATES PATENTS 3,520,989 7/1970 Funk et a1 174/151 3,601,526 8/1971 Boltne et a1 174/151 FORElGN PATENTS OR APPLICATIONS 1,490,332 1/1969 Germany 174/152 GM Primary Examiner-Laramie E. Askin V I Attorney-Cor nell Remsen, Jr. et a1.

[57] ABSTRACT An electrical penetration assembly for installation in a containment wall formed of a nozzle extending through the wall and terminating in flanges at each end thereof. A canister assembly formed of a pipe member is positioned within the nozzle and extends through the containment wall. A glass-sealed hermetic header is positioned in the pipe member at the first end thereof and is secured to the pipe member at one end. A plurality of electrical conductors, terminating in electrical contacts, extend through the header and are sealed thereto, each of the conductors extending through the header to the other end of the pipe member. Means are provided for supporting the conductors in the pipe member. Electrical contact terminals terminate the electrical conductors at the other end of the header. In addition, means are provided for securing the electrical contact terminal means to the other end of the pipe member. The securing means at the other end of the pipe member may comprise a second glass-sealed hermetic header. Electrical connection to the electrical contact in the header is made by individual electrical contacts. The first end of the pipe member is positioned at the external side of the containment wall, and a flange member is secured to the pipe end and adapted to be fastened to one of the nozzle flanges. In addition, a channel is formed in the flange member, the channel providing means for pressurizing the interior of the pipe member. Means are provided for determining leakage in the assembly. A terminal housing is secured to the flange member, the terminal housing providing environmental and mechanical protection for the terminal area.

9 Claims, 3 Drawing Figures PAIENTEU mu: 1 8 ms smnurz' ELECTRICAL PENETRATION ASSEMBLY The invention relates in general to electrical penetration assembliesand, more particularly, to a containment electrical penetrator for conducting electrical current from points outside thick reactor containment walls to points within the containment wall without allowing leakage of gas or fluids through the containment wall.

BACKGROUND OF THE INVENTION The rapidly expanding demand for increased electrical energy in a pollution-free atmosphere has required an increase in the construction of nuclear power generating plants. These plants are designed and constructed to anticipate the most severe of natures adversities. The nuclear power generating plant is built with a thick reactor containment wall, typically five feet thick, such that it is necessary to provide electrical connections from points outside the wall to points within the wall without allowing leakage of gas or fluids through the containment wall. These electrical connections are for instrumentation, control, and power functions and also include rod position, radiation monitoring, and temperature instrumentation and control as well as power for fuel transfer cooling pumps, valves, and recirculating fans. Normally, penetration is made by means of a fivefoot-long nozzle built through the wall which is flanged at either end. Typically, assemblies must be installed from both the outboard and inboard side of the wall and require electrical connections to be completed within the nozzle. Installation becomes difficult because of insufficient slack in the wires for terminating to the rear of the flanged assemblies. Such a design also requires terminations to be made within the nozzle as well as at either end of the nozzle. In addition, leakage in the connectors has been caused by overheating of the seals during individual factory welding of glasssealed connectors into the flanges as well as during flange field welding during installation.

Conventional-type connectors have been found to be not ideally suited to termination because of the need for familiarity with such connectors. With such a construction, crossed circuits and damaged contacts, as well as damage to the conductors, have resulted. In addition, it has been found that field installation required for potting or encapsulating connectors has resulted in long delay times as well as the need for expensive labor costs and equipment. To terminate the nozzles at each end of the wall, attempts have been made .to utilize large size terminal boxes. However, these terminal boxes have been considered a disadvantage because of the space required and because of the possible effects of seismic disturbances on overhanging structures. In addition, the terminal time required for changing electrical contacts where conventional terminal lock nuts are utilized has been found to be extremely lengthy, since the terminal nut must be completely removed and replaced after each terminal is installed.

In order to overcome the attendant disadvantages of prior art connectors utilized to penetrate containment walls, the present convention utilizes an assembly which is inserted from one side only, and all electrical terminations between the outboard and inboard ends of the assembly are completed at the factory prior to installation. All manufacturing welds are located at a maximum distance away from glass seals to prevent overheating. Because O-ring sealing is used for installation, there is no field welding required; and therefore, the possibility for damaging the seals during installation is eliminated. Instead of utilizing relatively small individual military-speciflcation-type connectors, contact spacing is provided which is very liberal. In addition, all connections are grommet-sealed, and no potting or encapsulation is required during the installation. Moreover, a terminal housing cover is utilized which is a fraction of the size of a corresponding terminal box.

SUMMARY OF THE INVENTION The invention comprises an electrical penetration assembly for installation in a containment wall formed of a nozzle extending through the wall and terminating in flanges at each end thereof. A canister assembly formed of a pipe member is positioned within the nozzle and extends through the containment wall. A glasssealed hermetic header is positioned in the pipe member at the first end thereof and is secured to the pipe member at one end. A plurality of electrical conductors, terminating in electrical contacts, extend through the header and are sealed thereto, each of the conductors extending through the header to the other end of the pipe member. Means are provided for supporting the conductors in the pipe member. Electrical contact terminals terminate the electrical conductors at the other end of the header. In addition, means are provided for securing the electrical contact terminal means to the other end of the pipe member. The securing means at the other end of the pipe member may comprise a second glass-sealed hermetic header. Electrical connection to the electrical contact in the header is made by individual electrical contacts. The first end of the pipe member is positioned at the external side of r the containment wall, and a flange member is secured to the pipe end and adapted to be fastened to one of the nozzle flanges. In addition, a channel is formed in the flange member, the channel providing means for pressurizing the interior of the pipe member. Means are provided for determining leakage in the assembly. A terminal housing is secured to the flange member, the terminal housing providing environmental and mechanical protection for the terminal area.

The advantages of the invention, both as to its construction and mode of operation, will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings in which like-referenced numerals designate like parts throughout the figures. Y

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view, partly in section, of an electrical penetration assembly;

FIG. 2 is an end view of the electrical penetration assembly of FIG. 1; and

FIG. 3 is an enlarged sectional view of the termination area of the assembly.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to FIG. 1, there is shown an electrical penetration assembly for installation in a containment wall having a nozzle 12 extending permanently through the wall. The nozzle is secured to a flange section 14 at one end thereof and a flange section 16 at the other end thereof. The penetration assembly is formed of a pipe member 18 which is inserted from the interior of the containment wall shown on the right in the drawing at the flange 16. The exterior end 22 of the pipe 18 is secured to an end flange member 24 whose interior surface abuts the flange 14 of the nozzle and is sealed thereto by means of O-

rings

26 and 28, typically formed of silicone. The flange 24 is sealed at the end of the pipe member 22 at an enlarged diameter inner bore section 32, typically by welding.

The flange 24 further contains a reduced diameter outer bore section 34 which is sealed to a hermetic stainless steel header 36. The header 36 contains an annular section 38 having a diameter slightly less than the inner diameter of the pipe 18 and has a forwardly extending collar 42 whose outer surface is secured to the bore section 34 of the flange 24. In addition, a protruding annular ring portion 44 abuts a shoulder 45 formed at the termination of the bore section 32.

A plurality of openings 46 are formed in the annular section 38 of the header 36. Positioned in each of the openings is an electrical conductor member 48 which is sealed by means of a glass to metal seal 52 in the openings. The conductors 48 extend on either side of the annular members 38. Positioned on the interior side surface of the annular member 38 is a molded rubber member 54 having a plurality of bores 55 therethrough. Positioned in the ,bores are a plurality of socket contacts 56, one end of which is secured to the conductors 48 and the other end of which may be crimped to electrical conductors 58.

Mounted on the other side of the annular member 38 and within the collar 42 is an end flange insulator member 62. The insulator has a pair of annular grooves 64 and 66 formed on its outer surface into which O-

rings

68 and 72, typically made of silicone, are inserted in order to form a seal between the outer surface of the insulator 62 and the inner surface of the member 42. In addition, a plurality of bores 74 extend through the insulator 62. Positioned in each of the bores are grommets 76, typically made of rubber or silicone. Electrical contacts 78 may be inserted into a bore 82 in the grommets so as to form an electrical connection with the other side of the conductors 48 at the socket end of the contact 78. The other end of the contact normally has a conductor 84 soldered or crimped thereto which extends externally from the front end of the pipe member 18. In addition, a retaining ring 86 may be inserted into an annular groove 88 formed in the inner surface of the member 42 so as to form a retaining ring for the insulator 62.

A gasket member 102 is secured to the outer surface of the flange 24 and a terminal housing 104 secured thereto by means of an end flange 106. Secured to the terminal housing is a cover member 108. Formed in the bottom of the terminal housing 104 and as part of the cover member 108 is a clamping device 112 through which conductors secured to the electrical connector may pass.

The internal end of the connector is of similar construction but contains a pipe section 122 having an enlarged diameter forward bore portion 124 and a reduced diameter rear bore portion 126. After the pipe 18 has been inserted into the nozzle 12, typically the member 122 is positioned so that the enlarged bore portion 124 is welded to the pipe. Then a flange member 127 is utilized to secure the flange 16 at the internal end of the nozzle together by means of a nut-and-bolt arrangement.

Centrally positioned within the pipe member 18 is a wire support disc 132 having a plurality of openings 134 through which the conductors interconnecting the input and output ends of the device may pass. In addition, certain of the conductors may have a shrink sleeve 136 surrounding them so as to enable the disc to provide proper spacing.

To check pressurization of the system as well as to provide a test port, a coupling device 142 is provided at the external end of the penetrator. The coupling device communicates with an opening 144 formed in the flange 24 with the opening 144 providing passage way internally of the penetrator.

While the device has been depicted as being used primarily as an electrical connector to provide electrical connections between the inner and outer surfaces of a containment wall, it should be understood, of course, that other uses of the assembly are possible such as in combination with fluid conductors.

In addition, a thermocouple assembly 152 has been illustrated in FIG. 1 which is connected to the interior of the assembly through a conductor 154 which in turn is threadably sealed to the header 36 by means of a threaded connector 156. A probe member 158 in turn passes through the member 54 thus communicating with the interior of the assembly. The probe member 158 may be utilized to detect a desired condition such as temperature with the assembly.

It should be further understood that the foregoing disclosure relates only to preferred embodiments of the invention, and it is intended to cover all changes and modifications of the examples of the invention herein chosen for the purpose of the disclosure which do not constitute departures from the spirit and scope of the invention.

What is claimed is:

1. An electrical penetration assembly for installation in a containment wall having a nozzle extending therethrough and terminating in flanges at each end thereof comprising:

a canister assembly formed of a pipe member adapted to be positioned within said nozzle;

a metal header secured to said pipe member at a first end thereof;

a plurality of electrical conductors extending from said header to the other end of said pipe member;

said header having a plurality of openings therethrough aligned with said electrical conductors;

a conductive element in each of said openings extending beyond the opposite sides of said header to provide free ends, glass filling each said opening to provide a glass-to-metal seal between said element and said header;

an electrical contact engaged with the free end of each said element on one side of said header facing said other end of said pipe member, said electrical conductors being connected to said contacts;

an insulator secured to the other side of said header, said insulator having passages therethrough in alignment with said elements, an electrical contact in each passage engaged with the free end of said element on said other side of said header, a conductor extending through each said passage and connected to said contact, and a grommet in each said passage sealing said contact to said insulator;

electrical contact terminal means terminating said electricaL conductors at the other end of said pipe member; and

means securing said electrical contact terminal means to the other end of said pipe member.

2. An electrical penetration assembly in accordance with claim 1 wherein said securing means at the other end of the pipe member comprises a second one of said headers.v

3. An electrical penetrator in accordance with claim 1 wherein said first end of said pipe member is adapted to be positioned at the external side of said nozzle and wherein a flange member is secured to said pipe member end and is adapted to be fastened to one of said nozzle flanges.

4. An electrical penetration assembly in accordance with claim 3 wherein a channel is formed in said flange member, said channel providing means for pressurizing the interior of said pipe member.

5. An electrical penetrator assembly in accordance with claim 4 and further wherein means communicating with said channel are provided for determining leakage in said assembly.

6. An electrical penetrator assembly in accordance with claim 3 and further comprising a terminal housing secured to said flange member, said terminal housing providing environmental and mechanical protection for said terminal area.

7. An electrical penetration assembly in accordance with claim 1 including a resilient body on said one side of said header, said contacts on said one side being im' bedded in said body.

8. An electrical penetration assembly in accordance with claim 1 including:

a recess formed in said header on said other side thereof;

said insulator being slidably mounted in said recess;

sealing means between said insulator and said header; and

retaining means securing said insulator in said recess.

9. An electrical penetration assembly for installation in a containment wall having a nozzle extending therethrough terminating in flanges at each end thereof comprising:

a cannister assembly formed of a pipe member adapted to be positioned within said nozzle from one end thereof;

a ring adapted to be fixed to said flange at the other end of said nozzle, said ring having an annular groove formed in its inner periphery, a sealing member positioned in said groove;

one end of said pipe member being slidably mounted in said ring and engaging said sealing member in sealing relationship therewith;

an annular plate fixed to the other end of said pipe member and adapted to abut the other one of said flanges, sealing means in the face of said plate adapted to engage said other flange;

a glass-sealed hermetic header secured to said pipe member adjacent each end thereof; and

a plurality of electrical conductors extending through said headers and sealed thereto, said conductors terminating in electrical contacts on the sides of said headers opposite the facing sides thereof. l=

Claims

1. An electrical penetration assembly for installation in a containment wall having a nozzle extending therethrough and terminating in flanges at each end thereof comprising: a canister assembly formed of a pipe member adapted to be positioned within said nozzle; a metal header secured to said pipe member at a first end thereof; a plurality of electrical conductors extending from said header to the other end of said pipe member; said header having a plurality of openings therethrough aligned with said electrical conductors; a conductive element in each of said openings extending beyond the opposite sides of said header to provide free ends, glass filling each said opening to provide a glass-to-metal seal between said element and said header; an electrical contact engaged with the free end of each said element on one side of said header facing said other end of said pipe member, said electrical conductors being connected to said contacts; an insulator secured to the other side of said header, said insulator having passages therethrough in alignment with said elements, an electrical contact in each passage engaged with the free end of said element on said other side of said header, a conductor extending through each said passage and connected to said contact, and a grommet in each said passage sealing said contact to said insulator; electrical contact terminal means terminating said electricaL conductors at the other end of said pipe member; and means securing said electrical contact terminal means to the other end of said pipe member.

2. An electrical penetration assembly in accordance with claim 1 wherein said securing means at the other end of the pipe member comprises a second one of sAid headers.

7. An electrical penetration assembly in accordance with claim 1 including a resilient body on said one side of said header, said contacts on said one side being imbedded in said body.

8. An electrical penetration assembly in accordance with claim 1 including: a recess formed in said header on said other side thereof; said insulator being slidably mounted in said recess; sealing means between said insulator and said header; and retaining means securing said insulator in said recess.

9. An electrical penetration assembly for installation in a containment wall having a nozzle extending therethrough terminating in flanges at each end thereof comprising: a cannister assembly formed of a pipe member adapted to be positioned within said nozzle from one end thereof; a ring adapted to be fixed to said flange at the other end of said nozzle, said ring having an annular groove formed in its inner periphery, a sealing member positioned in said groove; one end of said pipe member being slidably mounted in said ring and engaging said sealing member in sealing relationship therewith; an annular plate fixed to the other end of said pipe member and adapted to abut the other one of said flanges, sealing means in the face of said plate adapted to engage said other flange; a glass-sealed hermetic header secured to said pipe member adjacent each end thereof; and a plurality of electrical conductors extending through said headers and sealed thereto, said conductors terminating in electrical contacts on the sides of said headers opposite the facing sides thereof.