US3851906A - Head closure system - Google Patents

Head closure system Download PDF

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Publication number
US3851906A
US3851906A US00179703A US17970371A US3851906A US 3851906 A US3851906 A US 3851906A US 00179703 A US00179703 A US 00179703A US 17970371 A US17970371 A US 17970371A US 3851906 A US3851906 A US 3851906A
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US
United States
Prior art keywords
stud
threads
head
sections
tensioning means
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US00179703A
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English (en)
Inventor
E Frisch
H Andrews
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
CBS Corp
Original Assignee
Westinghouse Electric Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority to BE788682D priority Critical patent/BE788682A/fr
Application filed by Westinghouse Electric Corp filed Critical Westinghouse Electric Corp
Priority to US00179703A priority patent/US3851906A/en
Priority to CA145,010A priority patent/CA960379A/en
Priority to GB3466172A priority patent/GB1354193A/en
Priority to NL7211400A priority patent/NL7211400A/xx
Priority to DE2242534A priority patent/DE2242534A1/de
Priority to CH1311972A priority patent/CH552266A/xx
Priority to ES406599A priority patent/ES406599A1/es
Priority to FR7232245A priority patent/FR2152873B1/fr
Priority to SE7211822A priority patent/SE378699B/xx
Priority to IT29134/72A priority patent/IT967410B/it
Priority to JP47091307A priority patent/JPS5135678B2/ja
Priority to AT785072A priority patent/AT314676B/de
Application granted granted Critical
Publication of US3851906A publication Critical patent/US3851906A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • G—PHYSICS
    • G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
    • G21C—NUCLEAR REACTORS
    • G21C13/00—Pressure vessels; Containment vessels; Containment in general
    • G21C13/02—Details
    • G21C13/06—Sealing-plugs
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23P—METAL-WORKING NOT OTHERWISE PROVIDED FOR; COMBINED OPERATIONS; UNIVERSAL MACHINE TOOLS
    • B23P19/00—Machines for simply fitting together or separating metal parts or objects, or metal and non-metal parts, whether or not involving some deformation; Tools or devices therefor so far as not provided for in other classes
    • B23P19/04—Machines for simply fitting together or separating metal parts or objects, or metal and non-metal parts, whether or not involving some deformation; Tools or devices therefor so far as not provided for in other classes for assembling or disassembling parts
    • B23P19/06—Screw or nut setting or loosening machines
    • B23P19/067—Bolt tensioners
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
    • B25B—TOOLS OR BENCH DEVICES NOT OTHERWISE PROVIDED FOR, FOR FASTENING, CONNECTING, DISENGAGING OR HOLDING
    • B25B29/00—Accessories
    • B25B29/02—Bolt tensioners
    • G—PHYSICS
    • G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
    • G21C—NUCLEAR REACTORS
    • G21C13/00—Pressure vessels; Containment vessels; Containment in general
    • G21C13/02—Details
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E30/00—Energy generation of nuclear origin
    • Y02E30/30—Nuclear fission reactors
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T292/00—Closure fasteners
    • Y10T292/08—Bolts
    • Y10T292/1099—Screw
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T292/00—Closure fasteners
    • Y10T292/20—Clamps
    • Y10T292/221—Screw and nut

Definitions

  • the studs utilized for securing the head of the reactor pressure vessel are provided with modified breechblock threads at their, lower ends, and also at their upper ends. After being detensioned, the studs are rotated 60 for disengagement from corresponding threads in a flange at the top of the pressure vessel and are lifted out of the stud holes when the head is removed.
  • the stiids are tensioned and detensioned by a plurality of portable hydraulic stud tensioning devices or tensioners which are attached to the upper ends of the studs by the modified breechbloek threads at the upper ends of the studs.
  • the tensioners are carried by a separate hoist system mounted on the closure head for the vessel.
  • This invention relates, generally, to pressure vessels and, more particularly, to systems for securing and releasing the closure heads of nuclear reactor vessels.
  • the closure heads of large nuclear power reactors have been secured to the pressure vessel by a large number of studs which are threaded into the vessel flange and extend through corresponding holes in the head flange.
  • the necessary loading on the studs has been achieved by hand tightening of the upper nuts while the studs are being preloaded by a small number, usually three, of portable hydraulic tensioning devices which are applied to the studs in a prearranged sequence until all studs are equally loaded.
  • the studs In order to remove the closure head for refueling, the studs must be tensioned until the nuts become unloaded and can be backed off by hand. Following this, all studs are completely removed and stored before the closure head is lifted off and refueling operations can commence. On a typical reactor, the studs are seven inches in diameter and there are eight threads per inch covering nine inches of stud length. Therefore, approximately 140 complete revolutions of each stud are required for removal and subsequent replacement.
  • each of the portable tensioners is connected to a stud by means of a six-inch long nut, forming part of the tensioner actuator shaft, to an upper threaded extension of the stud. Accordingly, approximately 100 revolutions of the shaft are required for each application of the tensioner and two applications per stud are normally required to obtain the proper stud loading.
  • the necessary reduction in the time required to remove and to replace the closure head by an operating crew is achieved by replacing the prior studs with a smaller number, for example 36, of larger diameter studs and by utilizing a modified breechblock system for attaching the studs to the pressure vessel flange as well as for connecting them to portable hydraulic tensioners.
  • the tensioners are carried by a separate hoist system mounted on a shroud structure encircling the reactor control rod drive mechanisms.
  • the shroud structure is mounted on top of the closure head.
  • the engagement or disengagement of the studs to either the pressure vessel or to the tensioners is accomplished by a rotation of the studs or the tensioner shafts, requiring only a relatively short time on the part of the operating crew. After all studs have been detensioned or unloaded and rotated to the clear position, they are simultaneously lifted out of the stud holes when the closure head is removed. The studs remain in place on the closure head during the refueling operation, thereby saving the time previously required for separate removal and storage. Because of the relatively large clearances provided between adjoining modified breechblock threads when the studs are detensioned, there is a minimum possibility of galling of the threads.
  • FIG. 1 is a view, in elevation, of a head closure system embodying principal features of the invention
  • FIGS. 2a and 2b when joined end-to-end, constitute a sectional view through a portion of a reactor vessel and closure head and one of the holding studs and a portable tensioning device;
  • FIG. 3 is a view, in plan, of the structure shown in FIG. 2a..
  • FIG. 4 is a view, in section, taken along the line IVIV of FIG. 2b.
  • FIG. 5 is an enlarged view, in section, taken along the line V-V in FIG. 2b.
  • FIG. 6 is an enlarged detail view taken along the line VI-VI in FIG. 1, partly in section and partly in side elevation, of a hoist for one of the portable tensioning devices;
  • FIG. 7 is a view, in front elevation, of the hoist shown in FIG. 6;
  • FIG.8 is a view, in section, of a portion of a modified holding stud.
  • FIG. 9 is a view, in section, taken along the line IX-IX in FIG. 8.
  • the structure shown therein comprises a portion of a generally cylindrical reactor vessel 10 having an integral outwardly extending flange 11, and a closure head 12 having an integral outwardly extending flange 13 which mates with the flange-ll on the vessel 10.
  • the vessel 10 may be of a type, well known in the art, suitable for use in a nuclear power system.
  • the head 12 is retained on the vessel 10 by means o'fa plurality, for example 36, of holding studs 14.
  • the studs 14 are disposed in vertically aligned holes 16a and 16b in the head flange l3 and the vessel flange 11,
  • the hole 16a extends through the head 1 flange 13 and the hole 16 terminates in the vessel flange lll.
  • the reactor is in operating condition with all studs 14 in position on the flange 13 of the head 12 with tension applied.
  • the necessary tensioning of the studs is produced by a small number, for example three, of portable hydraulic tensioning devices 22 which are applied to the studs in a prearranged sequence.
  • the necessary reduction in operating time is achieved by utilizing a modificd breeehblock system for attaching the holding studs to'the pressure vessel flange as well as for connecting them to the hydraulic tensioning devices or tensioners. Engagement or disengagement of the studs to either the pressure vessel or to a tensioner is accomplished by a 60 rotation of the studs or the tensioner shaft.
  • each stud 14 has a plurality of separate parallel horizontally extending interrupted threads 17a at its lower portion and similar threads 17b at its upper portion.
  • Each hole in the vessel flange has threads 18a therein corresponding to the threads at the lower portion of the stud.
  • threads 18b corresponding to the threads 17b in the upper portion of the stud, are provided in a generally cylindrical extension 19 on an actuator shaft 21 of the hydraulic tensioner 22 which will be described more fully hereinafter.
  • interrupted threads 17a and 17b at the lower end and the upper end, respectivcly, of the stud actually are generated by cutting separate parallel grooves in the stud rather than a continuous helical groove, which is the case with standard breechblock threads. This modification is utilized to prevent any contact with the corresponding threads when rotating the stud or the tensioner actuator shaft to the lock" position.
  • the threads 18a are cut in a separate bushing 23 which, in turn, is attached to the flange 11 by standard or Acme threads 24 which may be machined in the flange without difficulty.
  • the completely finished bushing 23 is threaded into the flange to the proper depth and is locked in place by a pin 25 so that the interrupted portions of the threads assume the same position on all bushings relative to the vessel centerline.
  • the threads 18b may be machined directly in the ex-' tension 19 which is threaded onto the lower end of the actuator shaft 21 and secured thereto by a pin 26.
  • the use of the bushings 23 hasthe additional advantage of permitting selection of a material better suited for the application than the vessel material.
  • the bushings may also, if desired, be plated with a corrosion resistant material, such as nickel or zinc, to reduce the corrosive effect of water when the vessel is submerged during the refueling period. It also makes it possible to replace a bushing in case of accidental damage to the main threads.
  • the threads on the stud and in the vessel flange or bushing are aligned in vertical sections with gaps between sections having a greater angular extent than the angular extent of the thread sections.
  • the threads are arranged in three vertical sections.
  • each stud 14 may be rotated by means of a straight cylindrical handle 27 projecting radially from the stud and attached thereto by threading into the stud.
  • a hinged locking bar 29 prevents accidental movement of the studfrom either position.
  • a support 31 for the locking bar 29 is attached to the flange 13 by screws 32. In order to avoid interference with normal rotation of the stud, the locking bar 29 may be swung out of the way to a position indicated by dot-dash lines in FIG. 2B.
  • a thrust ball bearing 33 is attached to the lower end of each stud.
  • the bearing 33 shown more clearly in FIG. 8, is attached to the stud by means of a clamp plate 34 and a bolt 35.
  • a circular plate 36 having a large central hole serves as a seat for the thrust bearing when the stud is in the inserted position.
  • the plate 36 is attached to the bushing 23 by means of several bolts 37.
  • the vertical distance from the seat 38 of the support plate to the bushing threads is so selected as to obtain maximum axial clearance between stud and bushing threads in this position.
  • the stud is centered in the bushing by a taper 39 in the support plate hole.
  • the necessary tensioning of the studs is achieved by utilizing a small number, for example three, of the portable hydraulic tensioning devices 22 which are applied to the studs in a prearranged sequence.
  • the tensioner 22 When in position for service, as illustrated in FIG. 2A, the tensioner 22 rests on the flat upper surface of the head flange l3 and is rotationally aligned with the stud by an alignment pin 41.
  • the tensioner 22 comprises two pistons 42 disposed in two cylinders 43 supported between a base plate 44 and a top plate 45 which are held together by four tie rods 46 as shown in FIG. 3.
  • the pistons are mounted in tandem to obtain the required stud loading without exceeding a hydraulic pressure of 10,000 psi.
  • a heavy cylindrical bushing 47 is attached to the base plate 44, as by welding, and serves as the support for the tensioner when it rests on the head flange 13.
  • the bushing 47 encloses the upper portion of the stud 14.
  • the tensioner actuator shaft 21 is surrounded by the pistons 42.
  • the cylindrical extension 19 is fixed on the lower end of the shaft 21.
  • the extension 19 contains the threads 18b corresponding to the threads 17b on the upper portion of the stud 14. Sufficient clearances are provided between the horizontal surfaces of the threads 17b and 18b to prevent interference during subsequent rotation of the extension 19 to the engaged or lock position.
  • a thrust ball bearing 48 similar to the bearing 33, is attached to the lower end of the actuator shaft 21. When the tensioner is positioned, the outer bearing race 49 rests on the upper flat surface of the stud l4 and the entire weight of the actuator shaft assembly is carried by the bearing. The bearing location is selected to obtain maximum axial clearance between threads 17b and 18b.
  • the bearing also reduces the effort required to rotate the actuator shaft to the engaged or lock" position bymeans of a hand wheel 51.
  • the correct amount of rotation in either direction is insured by a pointer 52, fixed on the actuator shaft, and two stop pins 53 located on the top plate 45.
  • the tensioner is gradually pressurized by supplying hydraulic fluid underneath the pistons 4-2 through openings 54 in the cylinders 13.
  • the developed upward thrust is transmitted through a spherical washer 55 and a fixed member or nut 56 on the actuator shaft assembly which moves freely upwardly until contact is established between threads 17b and 18b.
  • the nut 56 is threaded on the upper portion of the shaft 21 and is fixed by a set screw 57.
  • Continued movement causes lifting of the main stud 14 until stud threads 17a contact bushing threads 18a. Further application of pressure results in tensioning of the stud until the desired loading is obtained.
  • the pressure is maintained at a constant value while an adjustable member or main nut 58, which is threaded on the stud 14, is tightened by hand until firm contact is established with a spherical washer 59 and the head flange 13.
  • the stud load is transferred to the adjustable member 58 and the tensioner pistons are returned to the lower position by application of hydraulic pressure above the upper piston through an opening 61 in the upper cylinder 43.
  • the rotation of the adjustable member or main nut 58 is accomplished in this example by a hand wheel 62 which drives a gear 63.
  • the gear 63 causes rotation of a thin-walled tube 64 which is constructed to permit a small vertical movement.
  • Teeth 65 provided in a thickened portion at the lower end of the tube 64, are slidably disposed in slots 66 provided in the upper outer surface of the main nut 58 to rotate the nut.
  • the actual value of the stud loading may be estimated by a micrometer 67 on top of the actuator shaft which indirectly measures the elongation or strain of the stressed part of the stud by comparing its length with that of an unstressed rod 68 of the same material located in a central hole in the stud. Since this method is well known in the art, no further explanation of its operation will be furnished herein.
  • the hand wheel 51 is rotated to the clear position to disengage the threads 17b and 18b.
  • the tensioner 22 may now be lifted straight up by means of lifting lug 69 and hoist hook 70 and transferred to another stud.
  • the tensioners 22 are again positioned on all studs in a prearranged sequence and the following procedures executed to unload the studs.
  • the hand wheel 51 is moved to the lock position and hydraulic pressure is applied-under the pistons thereby stretching the stud 14 until the main nut 58 is completely unloaded.
  • the nut is backed off a short distance, the piston pressure is removed, and the pistons are returned to the lower position.
  • the actuator shaft may be rotated to the clear position and the tensioner removed. After all studs have been unloaded in this manner. they are rotated to the clear" position by means of the handles 27 to disengage the stud threads, and the headmay be lifted with all studs in place in the head.
  • FIG. 1 The upper, external part of a reactor with the herein described Head Closure System is shown in FIG. 1. As illustrated, the reactor is in operating condition with all studs 14 in position on the flange 13 ofthe head 12 with tension applied.
  • Control rod drive mechanisms 71 extending from the top of the head to a missile shield 72 are encircled by a generally circular shroud structure 73 which may be made of angle irons 74 and steel plates 75. For convenience, the shroud structure may be made in three sections and it is secured to the head 12.
  • the missile shield 72 is attached directly to the head 12 by several heavy rods 76. Ventilating holes 77 are provided near the bottom of the shroud for a natural circulation cooling of the mechanism coils.
  • the wiring for the control rod mechanisms and also for nuclear instrumentation is brought through multi-conductor cables 78 to a cable tray 79 which .is attached by hinge joints to the shroud structure 73.
  • the cable tray which is at least 7 feet wide in a typical structure, makes it impossible to service six or more of the head closure studs, directly below the tray, by 1 any overhead crane. For this reason, and for convenience, a separate hoist system is provided below the cable tray 79.
  • a hoist mechanism 81 is provided for each of the portable stud tensioners 22.
  • the hoist mechanisms travel on a circular track 82 which is supported on brackets 83 attached to the angle irons 74 of the shroud structure.
  • the track diameter is such that the hoist hooks are directly on the stud circle.
  • the stud tensioners may be easily and rapidly lowered into position on any of the closure studs by means of the hoist mechanisms 81.
  • the tensioner In order to avoid interference between the interrupted threads at the upper part of the studs and on the tensioner actuator shaft extension, the tensioner must be accurately aligned rotationally during the lowering operation. This is achieved by providing alignment guides 84 which are attached to the shroud structure 73. An alignment guide 84 is provided for each stud 14. The guides 84 enter a slot 85, cut in the tensioner base plate 44, as indicated in FIG. 3. If desired, the tensioners may be removed from the reactor during normal operation by moving the hoists with the withdrawn tensioners to a position on the track 82 accessible to an overhead crane sling 86. This permits removal of hoist and tensioner as a unit without requiring any transfer of load. The removal of a stud may be accomplished in the same manner.
  • Each hoist mechanism comprises a trolley carriage 87 having two heavily flanged trolley wheels 88 which ride on top of the circular track 82.
  • the track 82 includes an I-beam. 89 having a rail 91 secured to the top flange of the beam.
  • the I-beam 89 is attached to the brackets 83 by gusset plates 93.
  • Motive power is provided by an electric gear motor 92 connected to one of the trolley wheels 88.
  • a safety latch 94 is provided to limit any upward movement to a safe value.
  • the safety latch 94 includes a shaft 95 rotatably mounted on the trolley carriage 87 and a roller 96 rotatably mounted on a pin attached to the end of a lever arm 97, secured to the shaft 95. In the latched position, the roller is brought in close proximity to the bottom flange of the I-beam I 89.
  • this is achieved by machining a centrally located axially extending hole 106 with varying diameters in steps in the lower portion of the stud 14a so that the remaining stud area is proportional to the load carried by any particular section of the stud. As shown, the diameters become smaller in steps until the upper stud thread is reached. For a six-thread stud the lower section. which carries only one-sixth of the total load, will have across-sectional area of one-sixth of the maximum stud area. The next section will have twosixths of the maximum area and so on until maximum area is reached at the top of the hole which is substantially coextensive with the threaded portion of the stud. Thus, the number of stud sections corresponds to the number of threads on the stud. I
  • the lower stud section will lengthen until the gap lY is closed. At this time, the load on the lower thread is one-sixth of the total load and will not increase beyond this value. Fur- .ther increase in the stud load will cause closing of gap 2Y and so forth until allgaps are closed when full stud loading is reached with all thread loadings being equal.
  • the stud hole 106 is covered at the lower end by a cap 107 attached to the stud by bolts 108.
  • the thrust ball bearing 33 is centered on a hub of the cap and is secured by the clamp 34 and bolt 35.
  • the central rod 68 which is used in the measurement of stud loading, now continues through the threaded section and rests on the upper surface of the cap. This is permissible since the elongation per inch of this section now is the same as that of the stud itself.
  • the plate 36 which serves as a seat for the thrust bearing when the stud is in the bottom position, is attached to the bushing 23 by bolts 37 as previously described.
  • the modified stud structure may also be used at the upper stud end for connection to the hydraulic tensioner.
  • the invention provides a head closure system which makes it possible to remove and to replace the closure head of a nuclear reactor pressure vessel in relatively short periods of time with a relatively small amount of equipment. Therefore, the reactor refueling time and the cost of the equipment are materially reduced by utilizing the present system in which provision is made for quickly attaching portable tensioners to holding studs and detaching the tensioners from the studs.
  • a head closure system for a generally cylindrical pressure vessel and a closure head having outwardly extending mating flanges with a plurality of vertically aligned holes therein comprising studs rotatably disposed in said holes to retain the head on the vessel, each stud having a plurality of separate parallel horizontally extending interrupted threads at its lower portion and also at its upper portion, each hole in the vessel flange having threads therein corresponding to the threads at the lower portion of each stud, said threads being aligned in vertical sections with gaps between sections having a greater angular extent than the angular extent of the thread sections, said stud being rotatable to align the thread sections on the studs with the thread sections in the vessel flange, portable tensioning means adapted for mounting on said closure head for applying tension on each stud to retain the head on the vessel, and said tensioning means having threads therein corresponding to the threads at the upper portion of the stud for attaching the tensioning means to the stud.
  • the rotatable member comprises a vertically disposed shaft, and including thrust bearing means at the lower end of the shaft supporting the shaft on the upper end of the stud.
  • a head closure system for a generally cylindrical pressure vessel and a closure head having outwardly extending mating flanges with a plurality of vertically aligned holes therein, in combination, holding studs disposed in said holes to retain the head on the vessel, each stud having a plurality of separate parallel horizontally extending interrupted threads at its upper portion, portable tensioning means for applying tension on each stud to retain the head on the vessel, said tensioning means having threads therein corresponding to the threads at the upper portion of the stud for attaching the tensioning means to the stud, said threads being aligned in vertical sections with gaps between sections having a greater angular extent than the angular extent of the thread sections, a rotatable member mounted in the tensioning means and containing the threads corresponding to the threads at the upper portion of the stud, means for rotating said member to align the thread sections in the member with the thread sections on the stud, a generally cylindrical shroud structure mounted on the head, a circular track supported by the shroud
  • the circular track includes an l-beam having a rail secured to its top flange
  • the hoist mechanism comprises a trolley carriage having a flanged roller riding on the rail
  • safety latch means disposed in close proximity to the bottom flange of the l-beam to prevent derailment of the trolley carriage.
  • latch means includes a shaft rotatably mounted on the trolley carriage and means operable by the shaft into close proximity to the bottom flange of the I-beam.
  • a tension load distribution system comprising a holding member having a hole therein for receiving a tension stud member, said stud member having a plurality of separate parallel horizontally extending interrupted threads thereon, said holding member having threads in the hole corresponding to the threads on the stud member, said threads being aligned in vertical sections with gaps between sections having a greater angular extent than the angular extent of the thread sections, one of said members being rotatable to align the thread sections on the stud member with the thread sections in the holding member, stud tensioning means mounted on said holding member for elongating the stud member when the stud member and holding member threads are in alignment, and said stud member having an axially extending hole therein with varying diameters which respectively correspond with said threads mounted on the stud member, thereby to permit the application of equal loading on all stud members threads when the stud member is elongated by said stud elongation means.

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Mechanical Engineering (AREA)
  • Plasma & Fusion (AREA)
  • General Engineering & Computer Science (AREA)
  • High Energy & Nuclear Physics (AREA)
  • Pressure Vessels And Lids Thereof (AREA)
  • Carriers, Traveling Bodies, And Overhead Traveling Cranes (AREA)
US00179703A 1971-09-13 1971-09-13 Head closure system Expired - Lifetime US3851906A (en)

Priority Applications (13)

Application Number Priority Date Filing Date Title
BE788682D BE788682A (fr) 1971-09-13 Systeme de fixation et de liberation de couvercle superieur de cuve de reacteur
US00179703A US3851906A (en) 1971-09-13 1971-09-13 Head closure system
CA145,010A CA960379A (en) 1971-09-13 1972-06-19 Head closure system for nuclear reactor pressure vessel
GB3466172A GB1354193A (en) 1971-09-13 1972-07-25 Pressure vessel arrangement
NL7211400A NL7211400A (fr) 1971-09-13 1972-08-21
DE2242534A DE2242534A1 (de) 1971-09-13 1972-08-30 Kernreaktor
CH1311972A CH552266A (de) 1971-09-13 1972-09-06 Kernreaktor.
ES406599A ES406599A1 (es) 1971-09-13 1972-09-12 Una disposicion de cierre de cabeza para un recipiente de presion.
FR7232245A FR2152873B1 (fr) 1971-09-13 1972-09-12
SE7211822A SE378699B (sv) 1971-09-13 1972-09-13 Locktillslutningsanordning for trycktankar, serskilt kernreaktortrycktankar
IT29134/72A IT967410B (it) 1971-09-13 1972-09-13 Sistema per la chiusura di testate di reattori nucleari
JP47091307A JPS5135678B2 (fr) 1971-09-13 1972-09-13
AT785072A AT314676B (de) 1971-09-13 1972-09-13 Kernreaktor mit einem Reaktordruckbehälter

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US00179703A US3851906A (en) 1971-09-13 1971-09-13 Head closure system

Publications (1)

Publication Number Publication Date
US3851906A true US3851906A (en) 1974-12-03

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Family Applications (1)

Application Number Title Priority Date Filing Date
US00179703A Expired - Lifetime US3851906A (en) 1971-09-13 1971-09-13 Head closure system

Country Status (10)

Country Link
US (1) US3851906A (fr)
JP (1) JPS5135678B2 (fr)
BE (1) BE788682A (fr)
CA (1) CA960379A (fr)
ES (1) ES406599A1 (fr)
FR (1) FR2152873B1 (fr)
GB (1) GB1354193A (fr)
IT (1) IT967410B (fr)
NL (1) NL7211400A (fr)
SE (1) SE378699B (fr)

Cited By (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3963565A (en) * 1973-02-13 1976-06-15 Siempelkamp Giesserei Kg Holddown arrangement for removable cover of a pressurized nuclear-reactor core and method of using same
US4071402A (en) * 1975-01-10 1978-01-31 Westinghouse Electric Corporation Nuclear reactor apparatus
US4138321A (en) * 1976-04-30 1979-02-06 Kraftwerk Union Aktiengesellschaft Lifting device
US4312708A (en) * 1979-03-05 1982-01-26 Thaxton, Inc. Reactor stud hole plug unit
US4452753A (en) * 1982-02-26 1984-06-05 Combustion Engineering, Inc. Apparatus for cleaning and inspecting closure studs of a nuclear reactor vessel
US4666658A (en) * 1983-11-16 1987-05-19 Westinghouse Electric Corp. Refueling of nuclear reactors
US4785520A (en) * 1985-10-29 1988-11-22 Framatome Process for locating the ideal screwing position of bolts of large dimensions
US4830814A (en) * 1987-06-29 1989-05-16 Westinghouse Electric Corp. Integrated head package for a nuclear reactor
US4961899A (en) * 1984-08-23 1990-10-09 Westinghouse Electric Corp. Multiple-cable connecting device for a nuclear reactor
US5069862A (en) * 1988-09-27 1991-12-03 Framatome Apparatus for handling a machine for the tensioning of screwed connecting elements
US5309626A (en) * 1992-10-30 1994-05-10 Westinghouse Electric Corp. Reactor vessel head O-ring installation tool
US5664502A (en) * 1994-07-27 1997-09-09 Westinghouse Electric Corporation Wheel assembly capable of maintaining engagement with a rail having an uneven portion therein
US5730421A (en) * 1995-08-21 1998-03-24 Westinghouse Electric Corporation Apparatus for servicing a reactor such as tensioning reactor vessel head studs
US5784426A (en) * 1995-11-20 1998-07-21 General Electric Company Bottom open sled system
EP1006283A1 (fr) * 1998-12-02 2000-06-07 Siemens Aktiengesellschaft Dispositif pour étanchéir un tube, en particulier une colonne d'instrumentation
US6167764B1 (en) 1998-07-28 2001-01-02 Westinghouse Electric Company Llc Stud tensioning method
US6763570B2 (en) 2001-11-30 2004-07-20 Westinghouse Electric Company Llc Method of closing a pressure vessel
US20050084057A1 (en) * 2003-09-24 2005-04-21 Harkness Alexander W. Head assembly
KR100963524B1 (ko) 2008-05-08 2010-06-15 주식회사 무진기연 분리 및 합체 장치를 갖춘 원자로 스터드 드라이버
US20130185932A1 (en) * 2011-02-01 2013-07-25 Mitsubishi Heavy Industries, Ltd. Fastening and loosening device

Families Citing this family (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5430296U (fr) * 1977-08-02 1979-02-27
FR2414978A1 (fr) 1978-01-23 1979-08-17 Skf Cie Applic Mecanique Dispositif automatique de vissage et de manutention de goujons
JPS55123133A (en) * 1979-03-16 1980-09-22 Agency Of Ind Science & Technol Manufacture of semiconductor device
JPS5731144A (en) * 1980-07-31 1982-02-19 Fujitsu Ltd Mamufacture of semiconductor device
JPS5740938A (en) * 1980-08-26 1982-03-06 Nec Corp Manufacture of semiconductor device
US4530813A (en) * 1980-11-10 1985-07-23 Jacobson Earl Bruce Modular reactor head shielding system
US4797247A (en) * 1983-07-05 1989-01-10 Westinghouse Electric Corp. Thermal insulation of nuclear reactor
WO1987001364A1 (fr) * 1985-08-28 1987-03-12 The Hokkaido Electric Power Co., Inc. Appareil de transport du type suspendu pour machine d'extraction de goujons, et appareil permettant de commander le positionnement de celui-ci
CN114714078B (zh) * 2022-04-07 2023-01-13 内蒙古工业大学 固体火箭发动机药柱与封头自动装配一体化装置

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US947975A (en) * 1908-05-22 1910-02-01 Jennings Scott Mccomb Extensible post or pillar for loose-leaf binders.
US2632354A (en) * 1949-04-25 1953-03-24 John B Black Blind bolt
US2888292A (en) * 1955-07-15 1959-05-26 Babcock & Wilcox Co Closure for a pressure vessel
US3554868A (en) * 1967-10-09 1971-01-12 Westinghouse Electric Corp Reactor internals lower radial support system
US3707107A (en) * 1970-01-26 1972-12-26 Hans Bieri Screw connection for high loading

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US947975A (en) * 1908-05-22 1910-02-01 Jennings Scott Mccomb Extensible post or pillar for loose-leaf binders.
US2632354A (en) * 1949-04-25 1953-03-24 John B Black Blind bolt
US2888292A (en) * 1955-07-15 1959-05-26 Babcock & Wilcox Co Closure for a pressure vessel
US3554868A (en) * 1967-10-09 1971-01-12 Westinghouse Electric Corp Reactor internals lower radial support system
US3707107A (en) * 1970-01-26 1972-12-26 Hans Bieri Screw connection for high loading

Cited By (22)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3963565A (en) * 1973-02-13 1976-06-15 Siempelkamp Giesserei Kg Holddown arrangement for removable cover of a pressurized nuclear-reactor core and method of using same
US4071402A (en) * 1975-01-10 1978-01-31 Westinghouse Electric Corporation Nuclear reactor apparatus
US4138321A (en) * 1976-04-30 1979-02-06 Kraftwerk Union Aktiengesellschaft Lifting device
US4312708A (en) * 1979-03-05 1982-01-26 Thaxton, Inc. Reactor stud hole plug unit
US4452753A (en) * 1982-02-26 1984-06-05 Combustion Engineering, Inc. Apparatus for cleaning and inspecting closure studs of a nuclear reactor vessel
US4666658A (en) * 1983-11-16 1987-05-19 Westinghouse Electric Corp. Refueling of nuclear reactors
US4961899A (en) * 1984-08-23 1990-10-09 Westinghouse Electric Corp. Multiple-cable connecting device for a nuclear reactor
US4785520A (en) * 1985-10-29 1988-11-22 Framatome Process for locating the ideal screwing position of bolts of large dimensions
US4830814A (en) * 1987-06-29 1989-05-16 Westinghouse Electric Corp. Integrated head package for a nuclear reactor
US5069862A (en) * 1988-09-27 1991-12-03 Framatome Apparatus for handling a machine for the tensioning of screwed connecting elements
US5309626A (en) * 1992-10-30 1994-05-10 Westinghouse Electric Corp. Reactor vessel head O-ring installation tool
US5664502A (en) * 1994-07-27 1997-09-09 Westinghouse Electric Corporation Wheel assembly capable of maintaining engagement with a rail having an uneven portion therein
US5730421A (en) * 1995-08-21 1998-03-24 Westinghouse Electric Corporation Apparatus for servicing a reactor such as tensioning reactor vessel head studs
US5784426A (en) * 1995-11-20 1998-07-21 General Electric Company Bottom open sled system
US6167764B1 (en) 1998-07-28 2001-01-02 Westinghouse Electric Company Llc Stud tensioning method
EP1006283A1 (fr) * 1998-12-02 2000-06-07 Siemens Aktiengesellschaft Dispositif pour étanchéir un tube, en particulier une colonne d'instrumentation
US6763570B2 (en) 2001-11-30 2004-07-20 Westinghouse Electric Company Llc Method of closing a pressure vessel
US20050084057A1 (en) * 2003-09-24 2005-04-21 Harkness Alexander W. Head assembly
US7158605B2 (en) * 2003-09-24 2007-01-02 Westinghouse Electric Co Llc Head assembly
KR100963524B1 (ko) 2008-05-08 2010-06-15 주식회사 무진기연 분리 및 합체 장치를 갖춘 원자로 스터드 드라이버
US20130185932A1 (en) * 2011-02-01 2013-07-25 Mitsubishi Heavy Industries, Ltd. Fastening and loosening device
US9457439B2 (en) * 2011-02-01 2016-10-04 Mitsubishi Heavy Industries, Ltd. Fastening and loosening device

Also Published As

Publication number Publication date
FR2152873A1 (fr) 1973-04-27
CA960379A (en) 1974-12-31
GB1354193A (en) 1974-06-05
ES406599A1 (es) 1975-09-16
NL7211400A (fr) 1973-03-15
IT967410B (it) 1974-02-28
FR2152873B1 (fr) 1977-07-29
SE378699B (sv) 1975-09-08
JPS5135678B2 (fr) 1976-10-04
JPS4836599A (fr) 1973-05-30
BE788682A (fr) 1973-03-12

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