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                                                                    Exhibit 3.21

                              AMENDED AND RESTATED
                          CERTIFICATE OF INCORPORATION
                                       OF

                              TWECO PRODUCTS, INC.


     TWECO PRODUCTS, INC., a corporation organized and existing under the laws
of the State of Delaware (the "CORPORATION"), hereby certifies as follows:

     A.   The original Certificate of Incorporation of the Corporation was filed
with the Secretary of State of the State of Delaware on March 13, 1981 under the
Corporation's former name "PALCOSUB, INC."

     B.   This Amended and Restated Certificate of Incorporation has been duly
adopted in accordance with Sections 242, 245 and 303 of the General Corporation
Law of the State of Delaware (the "DGCL") to put into effect and carry out the
First Amended and Restated Joint Plan of Reorganization under Chapter 11 of the
Bankruptcy Code for Thermadyne Holdings Corporation, Thermadyne Mfg. LLC,
Thermadyne Capital Corp., Thermadyne Industries, Inc., Victor Equipment Company,
Thermadyne International Corp., Thermadyne Cylinder Co., Thermal Dynamics
Corporation, C&G Systems Holding, Inc., MECO Holding Company, Tweco Products,
Inc., Tag Realty, Inc., Victor-Coyne International, Inc., Victor Gas Systems,
Inc., Stoody Company, Thermal Arc, Inc., C & G Systems, Inc., Marison Cylinder
Company, Wichita Warehouse Corporation, Coyne Natural Gas Systems, Inc., and
Modern Engineering Company, Inc., as confirmed on April 3, 2003 by order of the
United States Bankruptcy Court for the Eastern District of Missouri, Eastern
Division.

     C.   The text of the Certificate of Incorporation is hereby amended and
restated to read in its entirety as follows:

     FIRST: The name of the Corporation is TWECO PRODUCTS, INC.

     SECOND: The registered office of the Corporation in the State of Delaware
is located at Corporation Trust Center, 1209 Orange Street, in the City of
Wilmington, County of New Castle. The name of the registered agent of the
Corporation at such address is The Corporation Trust Company.

     THIRD: The purpose for which the Corporation is organized is to engage in
any and all lawful acts and activity for which corporations may be organized
under the DGCL. The Corporation will have perpetual existence.

     FOURTH: The total number of shares of stock that the Corporation shall have
authority to issue is 1,000 shares of common stock, par value $.01 per share.
Notwithstanding any other provision contained herein to the contrary, the
Corporation shall not issue nonvoting equity securities. This prohibition on
issuance of nonvoting equity securities is included in this Amended and Restated
Certificate of Incorporation in

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compliance with Section 1123 of the Bankruptcy Code, and shall have no force and
effect except to the extent and for so long as such Section 1123 is applicable
to the Corporation.

     FIFTH: Directors of the Corporation need not be elected by written ballot
unless the bylaws of the Corporation otherwise provide.

     SIXTH: The directors of the Corporation shall have the power to adopt,
amend, and repeal the bylaws of the Corporation.

     SEVENTH: No contract or transaction between the Corporation and one or more
of its directors, officers, or stockholders or between the Corporation and any
person (as used herein "PERSON" means other corporation, partnership,
association, firm, trust, joint venture, political subdivision, or
instrumentality) or other organization in which one or more of its directors,
officers, or stockholders are directors, officers, or stockholders, or have a
financial interest, shall be void or voidable solely for this reason, or solely
because the director or officer is present at or participates in the meeting of
the board or committee that authorizes the contract or transaction, or solely
because his, her, or their votes are counted for such purpose, if: (i) the
material facts as to his or her relationship or interest and as to the contract
or transaction are disclosed or are known to the board of directors or the
committee, and the board of directors or committee in good faith authorizes the
contract or transaction by the affirmative votes of a majority of the
disinterested directors, even though the disinterested directors be less than a
quorum; or (ii) the material facts as to his or her relationship or interest and
as to the contract or transaction are disclosed or are known to the stockholders
entitled to vote thereon, and the contract or transaction is specifically
approved in good faith by vote of the stockholders; or (iii) the contract or
transaction is fair as to the Corporation as of the time it is authorized,
approved, or ratified by the board of directors, a committee thereof, or the
stockholders. Common or interested directors may be counted in determining the
presence of a quorum at a meeting of the board of directors or of a committee
which authorizes the contract or transaction.

     EIGHTH: The Corporation shall indemnify any person who was, is, or is
threatened to be made a party to a proceeding (as hereinafter defined) by reason
of the fact that he or she (i) is or was a director or officer of the
Corporation or (ii) while a director or officer of the Corporation, is or was
serving at the request of the Corporation as a director, officer, partner,
venturer, proprietor, trustee, employee, agent, or similar functionary of
another foreign or domestic corporation, partnership, joint venture, sole
proprietorship, trust, employee benefit plan, or other enterprise, to the
fullest extent permitted under the DGCL, as the same exists or may hereafter be
amended. Such right shall be a contract right and as such shall run to the
benefit of any director or officer who is elected and accepts the position of
director or officer of the Corporation or elects to continue to serve as a
director or officer of the Corporation while this Article Eighth is in effect.
Any repeal or amendment of this Article Eighth shall be prospective only and
shall not limit the rights of any such director or officer or the obligations of
the Corporation with respect to any claim arising from or related to the
services of such director or officer in any of the foregoing capacities prior to
any such repeal or amendment to this Article Eighth. Such right shall include
the right to be paid by the

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Corporation expenses incurred in defending any such proceeding in advance of its
final disposition to the maximum extent permitted under the DGCL, as the same
exists or may hereafter be amended. If a claim for indemnification or
advancement of expenses hereunder is not paid in full by the Corporation within
sixty (60) days after a written claim has been received by the Corporation, the
claimant may at any time thereafter bring suit against the Corporation to
recover the unpaid amount of the claim, and if successful in whole or in part,
the claimant shall also be entitled to be paid the expenses of prosecuting such
claim. It shall be a defense to any such action that such indemnification or
advancement of costs of defense are not permitted under the DGCL, but the burden
of proving such defense shall be on the Corporation. Neither the failure of the
Corporation (including its board of directors or any committee thereof,
independent legal counsel, or stockholders) to have made its determination prior
to the commencement of such action that indemnification of, or advancement of
costs of defense to, the claimant is permissible in the circumstances nor an
actual determination by the Corporation (including its board of directors or any
committee thereof, independent legal counsel, or stockholders) that such
indemnification or advancement is not permissible shall be a defense to the
action or create a presumption that such indemnification or advancement is not
permissible. In the event of the death of any person having a right of
indemnification under the foregoing provisions, such right shall inure to the
benefit of his or her heirs, executors, administrators, and personal
representatives. The rights conferred above shall not be exclusive of any other
right which any person may have or hereafter acquire under any statute, by-law,
resolution of stockholders or directors, agreement, or otherwise.

     The Corporation may additionally indemnify any employee or agent of the
Corporation to the fullest extent permitted by law.

     As used herein, the term "PROCEEDING" means any threatened, pending, or
completed action, suit, or proceeding, whether civil, criminal, administrative,
arbitrative, or investigative, any appeal in such an action, suit, or
proceeding, and any inquiry or investigation that could lead to such an action,
suit, or proceeding.

     NINTH: A director of the Corporation shall not be personally liable to the
Corporation or its stockholders for monetary damages for breach of fiduciary
duty as a director, except for liability (i) for any breach of the director's
duty of loyalty to the Corporation or its stockholders, (ii) for acts or
omissions not in good faith or which involve intentional misconduct or knowing
violation of law, (iii) under Section 174 of the DGCL, or (iv) for any
transaction from which the director derived an improper personal benefit. Any
repeal or amendment of this Article Ninth by the stockholders of the Corporation
shall be prospective only, and shall not adversely affect any limitation on the
personal liability of a director of the Corporation arising from an act or
omission occurring prior to the time of such repeal or amendment. In addition to
the circumstances in which a director of the Corporation is not personally
liable as set forth in the foregoing provisions of this Article Ninth, a
director shall not be liable to the Corporation or its stockholders to such
further extent as permitted by any law hereafter enacted, including without
limitation any subsequent amendment to the DGCL.

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     TENTH: The Corporation expressly elects not to be governed by Section 203
of the DGCL.

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     In witness whereof, the Corporation has caused this Amended and Restated
Certificate of Incorporation to be executed by the undersigned, duly authorized
officer of the Corporation as of this 19th day of May, 2003.


                                      TWECO PRODUCTS, INC.


                                      By:    /s/ Patricia S. Williams
                                             -----------------------------------
                                      Name:  Patricia S. Williams
                                      Title: Vice President, General Counsel and
                                             Secretary