US3910478A - Dual high explosive shape detonation - Google Patents

Dual high explosive shape detonation Download PDF

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Publication number
US3910478A
US3910478A US398941A US39894173A US3910478A US 3910478 A US3910478 A US 3910478A US 398941 A US398941 A US 398941A US 39894173 A US39894173 A US 39894173A US 3910478 A US3910478 A US 3910478A
Authority
US
United States
Prior art keywords
explosive
welding
initiating
detonation
detonators
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
US398941A
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English (en)
Inventor
William G Howell
Robert H Wittman
Theodore A Espinoza
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.)
ExxonMobil Technology and Engineering Co
Original Assignee
Exxon Research and Engineering Co
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
Application filed by Exxon Research and Engineering Co filed Critical Exxon Research and Engineering Co
Priority to US398941A priority Critical patent/US3910478A/en
Priority to CA188,020A priority patent/CA993232A/en
Priority to AU63727/73A priority patent/AU474973B2/en
Priority to GB5852473A priority patent/GB1460300A/en
Priority to NL7400174A priority patent/NL7400174A/xx
Priority to NO740183A priority patent/NO147741C/no
Priority to DE2403437A priority patent/DE2403437C2/de
Priority to JP49012290A priority patent/JPS49122459A/ja
Priority to FR7403633A priority patent/FR2221230B1/fr
Priority to IT49101/74A priority patent/IT1004356B/it
Application granted granted Critical
Publication of US3910478A publication Critical patent/US3910478A/en
Priority to JP1980033833U priority patent/JPS55134088U/ja
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K20/00—Non-electric welding by applying impact or other pressure, with or without the application of heat, e.g. cladding or plating
    • B23K20/06—Non-electric welding by applying impact or other pressure, with or without the application of heat, e.g. cladding or plating by means of high energy impulses, e.g. magnetic energy
    • B23K20/08—Explosive welding
    • B23K20/085—Explosive welding for tubes, e.g. plugging
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
    • F16L13/00—Non-disconnectible pipe-joints, e.g. soldered, adhesive or caulked joints

Definitions

  • ABSTRACT A high welding explosive mass in placed circumferentially on a metal sleeve having a substantially cylindrical outer surface and is formed of a circumferential body having a greater thickness at the center of the mass than at its ends such that on initiation maximum explosive impact is exerted inwardly toward said sleeve to weld it to the abutting ends of two encircled pipes, the welding explosive body being provided with.
  • the initiating explosive means having a detonation velocity substantially greater than the detonation velocity of the body, both the detonation velocities being above about 15,000 feet per second.
  • the present invention is directed to explosive welding of pipe. More particularly, the invention is concerned with a formed explosive for explosive welding of hollow cylinders such as pipe. In its more specific aspects, the invention is directed to an explosive massor body for explosive pipe welding in which a formed welding explosive mass of a particular shape is em ployed in explosive welding with an initiating explosive means arranged at the center of the mass or body.
  • the present invention may be briefly described and summarized as involving an explosive with a detonation explosive adapted to be arranged on a collar circumferentially embracing abutting ends of pipe at least adjacent to the center of the collar.
  • a mandrel is useful in explosive welding of pipe sections together.
  • a mandrel may be placed within abutting pipe sections under a metal collar.
  • the ends of the pipe may be buffedto clean metal.
  • the collar is preferably interiorally formed to have a tapered shape such that the ends thereof are of a lesser thickness than the cen ter.
  • the outer surface of the collar is substantially cylindrical and on it is placed a formed mass or body of high explosive used for welding which is adapted to cover the collar and which is layered, stepped, molded, or mounded, cast, or formed in any shape such that the thickness of the high welding explosive mass is greater at the center thereof than at its outer periphery.
  • a high explosive detonation means Arranged in explosive contact with the high welding explosive is a high explosive detonation means at the center of the body of high welding explosive.
  • the high welding explosive mass or body on the collar is contacted on its periphery by this high explosive detonation or initiating explosive means connected to at least two equidistant spaced apart detonators which in turn are connected to a source of electrical energy or source of energy such that on initiation of the welding explosive, the collar is substantially instantaneously driven at a sufiicient force against the abutting ends of the pipe sections to weld the inner surface of the collar thereto and weld the sections together; the mandrel may then .be moved in the pipe to the next section to be welded onto the ever-increasing length of pipe line being formed.
  • the main charge or welding explosive and the initiating charge or explosive wrapped about the welding explosive in the central plane.
  • the initiating explosive is in explosive contact with the welding explosive, so that upon detonation of be stepped, triangular, conical, truncated conical, or
  • the detonation velocity of the initiating explosive is substantially greater than that of the welding explosive in order that, as explained before, the detona tion wave front created upon initiation has a wedge or arrow shape and collision ofthe two fronts resembles that of two closely spaced initiation points of a homogeneous explosive.
  • the high welding explosive used in the. mass or body on the collar and in the initiating explosive means may be any one of a number of high explosives such as, but not limited to, Detasheet C. which is 63% by weight PETN, 7% by weight nitrocellulose and polymeric materials and has a specific gravity of 1.48, a detonation velocity of about 23,000 feet persecond, and is currently supplied on the market in rubbery sheet form, pentaerythritol tetranitate (PETN) with red lead and a binder composed of a mixture of butyl rubber and polymers of B pinene, TNT, cyclomethylene (RDX), Pen tolite which is a 50:50 mixture of TNT and PETN, amatol, a 50:50 mixture of ammonium nitrate and TNT, and other well-known high explosives and mixtures thereof which may be shaped, formed or case on the collar as will be described more fully hereinafter.
  • PETN pentaerythritol tetran
  • Explosives should be selected having detonation velocities within the range from about 15,000 to about 30,000 feet per second. Generally, explosives having detonation velocities within the range from about be from aboutl/I6 inch to about 1 inch in width, while the inner tapered surfaces may each be from about.
  • the high welding explosive shaped or formed or otherwise placedon the collar such as by casting or molding may have a thickness at least adjacent its center about 200% to about 100% of the thickness, of the sleeve or collar on which it is adapted to be placed at. least adjacent its center and a thickness adjacent its ends about 200% to about 100% of the collar at least adjacent the ends of the collar.
  • This high explosive may be shaped, formed, cast, molded, or layered and may mounded in cross-section.
  • the size of the pipe which maybe welded may vary from about 2 to about 48 inches in diameter with collars corresponding in size to weld the ends of the pipe together, but larger diameters of pipe may be used.
  • the amount of high welding explosive to be em- I ployed will vary, of course, with the size of the pipe collar and the detonation velocity of the explosive. How ever, the high explosive mass or body in the form of a ring on the'collar may have thickness at the center of the collar sufficient to have a from about 8 to about 16 grams per square inch down to a thickness of from,
  • the explo sive would have a thickness at the center of the collar of about 12 grams per square inch and at the ends or edges of the collar from about 4 to about 6 grams per square inch,
  • the initiating explosive means may be in the form of a strip of high explosive at the center of the welding explosive mass or body and may'comprise from about 1 to about 10% by weight of the body and may be arranged in an indentation in the mass or body which may extend inwardly to the outer surface of the collar or sleeve.
  • the indentation may be in the form of a notch and mayhave a V-shape;
  • the collar may have a thickness at the center sub-, stantially the same as or slightly larger than the wall thickness of thepipe sections tapering on' its inner surface to about one-half the pipe sections wall thickness.
  • the center inner surface of the collar or sleeve may 45% to about 48% of thelength of the collar.
  • a 12-inch pipe may require a collar about 4 inches in length while a 48-inch pipe may require a collar of about 4 to about 6 inches, length.
  • a nominal 2-inch pipe I may require a collar of about 2 inches length, whereas 22,000 to about 30,000 feet per second may be used in I the initiating explosive means and explosives having detonation velocities within the range from about 15,000 to 23,000 feet per second in thebody or mass of welding explosive.
  • the initiating explosive means should have a detonation velocity substantially greater than the detonation velocity of the welding explosive body or mass.
  • a detonation velocity of the ini. tiating explosive should be about 25% to about 35% greater than the detonation velocity of the welding expipe of nominal 20 inches diameter may require a nominal 4 inches length collar.
  • FIG. 5 is a partial sectional view of stepped, molded or cast high welding explosive similar to FIG. 4;
  • FIG. 6 is a partial sectional view similar to FIGS. 1-3
  • numerals 11 and 12 designate sections of pipe which are to be joined by explosive welding by means of a collar or sleeve 13 on which is arranged circumferentially a mass. or body 14 of mounded high welding explosive which is provided with a slit, indentation, or notch 15 which is filled with an explosive detonation or initiating explosive means 16 and which may protrude above the body 14.
  • Arranged on the means 16 spaced apart equidistantly are at least two detonators 17 connected by electrical leads 18 to a source of electrical energy not shown.
  • the initiating explosive means 16 is used toset off and explode the welding explosive 14 simultaneously. More than two equally spaced apart detonators may be used when t a large pipe is to be welded but in this particular case they are 180 apart since the pipe may be nominally 12 inches in diameter.
  • a collar or sleeve 13 on pipe sections 11 and 12 has layers 20 of high welding explosive circumferentially arranged thereon with a layer or strip of the initiating explosive means 21 also circumferentially arranged provided with at least two detonators 22 (although only one is shown) to which they are connected by electrical leads 3 to a source of electrical energy (not shown).
  • FIG. 5 is somewhat similar to FIG. 4 but in this case the welding explosive 30 is cast into steps 31 in cross section and has arranged on it at the center thereof an initiating explosive strip 32 with electrical leads'33 connected to detonators 34.
  • FIG. 6 which is somewhat like FIGS. 1-3, a V- shaped notch or indentation 40 is formed in welding explosive body 41 and is filled with initiating explosive means 42 on which are arranged detonators 43 connected by electrical leads to a source of electrical energy not shown.
  • V-shaped notch extends to the outer surface of the collar or sleeve 13.
  • wedge-shaped detonation wave fronts 44 as shown in FIG. 7 are set up.
  • a means for overcoming this problem in accordance with the present invention comprises employment of at least a dual explosive system, with the initiating explosive arranged in contact with, the main welding explosive body, the crux of the present invention.
  • the main welding explosive charge has a detonation velocity about 25% slower than that of the initiating explosive and theinitiating explosive is wrapped centrally around the sleeve.
  • the detonation wave travels more rapidly around the center of the sleeve than toward the edges of the sleeve. This results in a wedge-shaped detonation front as illustrated in FIG. 7.
  • angles between the detonation waves as they sweep toward the edge of the sleeve at the detonation wave intersection approach an angle approximately the same asthe average angles at detonation wave intersections as desired.
  • This intersection configuration turns the direction of the jet (toward being parallel with the.
  • angles are all important.
  • a suitable angle is about to about
  • the detonation velocity of initiating explosive means may be about 27,500 feet per second.
  • the use of the selected angle between the tapered bottomsurface of the collar and the adjacent pipe surface is necessary and important because of the necessity to establish necessary impact conditions in the shortest time and therefore the shortest distance possible from the collar to the abutted pipe ends.
  • parallel geometry for the collar and pipe take a longer time and require a greater distance from the collar to the pipe which the present invention avoids.
  • Tapering the collar or sleeve also requires a lesser amount of explosive to propel the collar or sleeve. This allows reduction of the explosive layer or mass (ring) thickness. The total amount of explosive is reduced with numerous benefits both from an economic and safety standpoint.
  • the ends of pipe sections 11 and 12, respectively, may be buffed to clean metal for about 2 inches from each of the ends and the ends butted.
  • a mandrel may then be centrally located thereunder. When it is deter mined that the pipe sections are accurately alignedand the ends thereof in full abutment, the mandrel may then be expanded against the interior of the pipe sec-,
  • space or notch formed by tapered pipe ends between the pipe ends may result in a smooth welded collar and may avoid the formation of an outward slight bulge to I the welded collar. This slight bulge, if any, has no effect on the strength or integrity of the welded pipe and may be hardly noticeable.
  • Pipe sections may be welded together with a minimum expenditure of equipment, effort and time. Pipe sections 12-44 inches in diameter and of greater or lesser diameter are easily welded together.
  • the invention is, therefore, new, useful and unobvioussince heretofore manpower and/ormachines were necessary ing of abutting cylindrical members which comprises: a welding explosive mass circumferentially located, on a metallic substantially cylindrical sleeve surrounding the abutting members; said welding explosive mass comprising a circumferential body of high explosive and having a greater thickness at its centerv than at its endstransversely disposed of said center such that upon initiation the. maximum explosive impact is exerted inwardly toward said sleeve,
  • initiating explosive means arranged on said body at least at its center and extending circumferentially. therearound in explosive contact with said body;
  • At least two equidistantly spaced apart detonators in operable contact with said initiating explosive means and adapted to be connected to a source of energy, said detonators being arranged for causing a symmetrical blast load to be applied to said mernbers upon energization thereof; and said initiating explosive means having a detonation velocity substantially greaterthan that of said welding explosive mass such that upon detonation of said initiating explosive and said welding explosive by the simultaneous energization of said detonators there emanates from each of said detonatorsat said spaced apart locations at least a pair of opposed wedge-shaped wave fronts which travel in opposite directions about said sleeve and impact at about 1 halfway between said detonators with a corresponding one of the wave fronts emanating from the other of said detonators and wherein the apex of each of said wave fronts is caused by said initiat ing explosive and the remaining portion of each of said wave fronts which flanks the apex thereof is caused by said

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  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Pressure Welding/Diffusion-Bonding (AREA)
  • Arc Welding In General (AREA)
US398941A 1973-03-12 1973-09-20 Dual high explosive shape detonation Expired - Lifetime US3910478A (en)

Priority Applications (11)

Application Number Priority Date Filing Date Title
US398941A US3910478A (en) 1973-03-12 1973-09-20 Dual high explosive shape detonation
CA188,020A CA993232A (en) 1973-03-12 1973-12-12 Dual high explosive shape detonation
AU63727/73A AU474973B2 (en) 1973-03-12 1973-12-18 Dual high explosive shape detonation
GB5852473A GB1460300A (en) 1973-03-12 1973-12-18 Explosive welding of cylinderical metallic members such as pipes
NL7400174A NL7400174A (de) 1973-03-12 1974-01-07
NO740183A NO147741C (no) 1973-03-12 1974-01-21 Fremgangsmaate og innretning for eksplosjonssveising av sylindriske metalliske deler
DE2403437A DE2403437C2 (de) 1973-03-12 1974-01-24 Verfahren und Vorrichtung zum Explosionsschweißen von zylindrischen metallischen Werkstücken.
JP49012290A JPS49122459A (de) 1973-03-12 1974-01-31
FR7403633A FR2221230B1 (de) 1973-03-12 1974-02-04
IT49101/74A IT1004356B (it) 1973-03-12 1974-03-07 Metodo e complesso a doppia carica sagomata di alto esplosivo per la saldatura di tubi
JP1980033833U JPS55134088U (de) 1973-03-12 1980-03-17

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US34013273A 1973-03-12 1973-03-12
US398941A US3910478A (en) 1973-03-12 1973-09-20 Dual high explosive shape detonation

Publications (1)

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US3910478A true US3910478A (en) 1975-10-07

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US398941A Expired - Lifetime US3910478A (en) 1973-03-12 1973-09-20 Dual high explosive shape detonation

Country Status (10)

Country Link
US (1) US3910478A (de)
JP (2) JPS49122459A (de)
AU (1) AU474973B2 (de)
CA (1) CA993232A (de)
DE (1) DE2403437C2 (de)
FR (1) FR2221230B1 (de)
GB (1) GB1460300A (de)
IT (1) IT1004356B (de)
NL (1) NL7400174A (de)
NO (1) NO147741C (de)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4228941A (en) * 1977-11-24 1980-10-21 Nitro Nobel Ab Method of joining an inner metal pipe with an outer surrounding metal pipe
US4231506A (en) * 1979-05-21 1980-11-04 Canadian Industries Limited Method of welding metal pipe sections with explosives
US4248373A (en) * 1979-05-21 1981-02-03 Canadian Industries Limited Explosive charge for explosive welding of large diameter metal pipe
US4635840A (en) * 1980-07-07 1987-01-13 Matija Cenanovic Forming method using an electromagnetically exploded filament
US4669649A (en) * 1982-12-03 1987-06-02 Nitro Nobel Ab Joint between two preferably metallic pipes and method of producing said joint
US4708280A (en) * 1985-10-23 1987-11-24 The United States Of America As Represented By The Administrator, National Aeronautics & Space Administration Tool and process for miniature explosive joining of tubes
US6843509B2 (en) 2002-12-02 2005-01-18 Colmac Coil Manufacturing, Inc. Coupler for use with metal conduits
US20080202738A1 (en) * 2007-02-28 2008-08-28 Colmac Coil Manufacturing, Inc. Heat exchanger system

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
SE434019B (sv) * 1981-10-07 1984-07-02 Volvo Ab Sett att medelst en sprengladdning sammanfoga ror samt anordning for genomforande av settet
SE463085B (sv) * 1987-09-28 1990-10-08 Exploweld Ab Laddningssystem foer explosionssvetsning
RU2468276C2 (ru) * 2010-10-04 2012-11-27 Василий Алексеевич Новаев Способ монтажа трубопровода
JP6305777B2 (ja) * 2014-01-28 2018-04-04 三菱日立パワーシステムズ株式会社 タービンロータディスクの補修方法及びタービンロータ

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2367206A (en) * 1942-03-11 1945-01-16 Du Pont Method of joining objects
US3222144A (en) * 1963-02-25 1965-12-07 Donald E Davenport Polycellular tubular grid structures and method of manufacture
US3263323A (en) * 1965-10-21 1966-08-02 United Aircraft Corp Fabrication of a continuous peripheral joint
US3455017A (en) * 1967-01-27 1969-07-15 Horst H Lemet Chromium Van Der Method for welding together tubular construction parts and tubular construction parts so welded
US3535767A (en) * 1965-08-19 1970-10-27 Aerojet General Co Method for joining metallic tubes by explosive bonding
US3542276A (en) * 1967-11-13 1970-11-24 Ideal Ind Open type explosion connector and method
US3563713A (en) * 1968-02-29 1971-02-16 Amf Inc Explosive welding
US3780927A (en) * 1973-01-24 1973-12-25 B Surnin Envelope for explosive connection of metal pipes

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS4860056U (de) * 1971-11-12 1973-07-31
JPS4860056A (de) * 1971-11-30 1973-08-23

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2367206A (en) * 1942-03-11 1945-01-16 Du Pont Method of joining objects
US3222144A (en) * 1963-02-25 1965-12-07 Donald E Davenport Polycellular tubular grid structures and method of manufacture
US3535767A (en) * 1965-08-19 1970-10-27 Aerojet General Co Method for joining metallic tubes by explosive bonding
US3263323A (en) * 1965-10-21 1966-08-02 United Aircraft Corp Fabrication of a continuous peripheral joint
US3455017A (en) * 1967-01-27 1969-07-15 Horst H Lemet Chromium Van Der Method for welding together tubular construction parts and tubular construction parts so welded
US3542276A (en) * 1967-11-13 1970-11-24 Ideal Ind Open type explosion connector and method
US3563713A (en) * 1968-02-29 1971-02-16 Amf Inc Explosive welding
US3780927A (en) * 1973-01-24 1973-12-25 B Surnin Envelope for explosive connection of metal pipes

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4228941A (en) * 1977-11-24 1980-10-21 Nitro Nobel Ab Method of joining an inner metal pipe with an outer surrounding metal pipe
US4231506A (en) * 1979-05-21 1980-11-04 Canadian Industries Limited Method of welding metal pipe sections with explosives
US4248373A (en) * 1979-05-21 1981-02-03 Canadian Industries Limited Explosive charge for explosive welding of large diameter metal pipe
US4635840A (en) * 1980-07-07 1987-01-13 Matija Cenanovic Forming method using an electromagnetically exploded filament
US4669649A (en) * 1982-12-03 1987-06-02 Nitro Nobel Ab Joint between two preferably metallic pipes and method of producing said joint
US4708280A (en) * 1985-10-23 1987-11-24 The United States Of America As Represented By The Administrator, National Aeronautics & Space Administration Tool and process for miniature explosive joining of tubes
US6843509B2 (en) 2002-12-02 2005-01-18 Colmac Coil Manufacturing, Inc. Coupler for use with metal conduits
US20080202738A1 (en) * 2007-02-28 2008-08-28 Colmac Coil Manufacturing, Inc. Heat exchanger system
US7597137B2 (en) 2007-02-28 2009-10-06 Colmac Coil Manufacturing, Inc. Heat exchanger system

Also Published As

Publication number Publication date
JPS49122459A (de) 1974-11-22
AU474973B2 (en) 1976-08-05
AU6372773A (en) 1975-06-19
DE2403437A1 (de) 1974-09-26
NO147741C (no) 1983-06-08
NO740183L (no) 1974-09-13
NO147741B (no) 1983-02-28
NL7400174A (de) 1974-09-16
CA993232A (en) 1976-07-20
FR2221230B1 (de) 1980-06-20
IT1004356B (it) 1976-07-10
GB1460300A (en) 1976-12-31
JPS55134088U (de) 1980-09-24
FR2221230A1 (de) 1974-10-11
DE2403437C2 (de) 1982-04-22

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