<PAGE>
                                                                   EXHIBIT 10.37

                                                                     CCR&W DRAFT
                                                                  3 January 2002


                                 FIRST AMENDMENT
                 Dated as of January ___, 2002 (the "Amendment")

         FIRST AMENDMENT TO THE REVOLVING CREDIT AND GUARANTY AGREEMENT, dated
as of November 26, 2001 (the "Credit Agreement"), among THERMADYNE MFG. LLC, a
Delaware limited liability company (the "Borrower"), a debtor and
debtor-in-possession in a case pending under Chapter 11 of the Bankruptcy Code,
THERMADYNE HOLDINGS CORPORATION, a Delaware corporation and the parent company
of the Borrower (the "Parent"), THERMADYNE CAPITAL CORP., a Delaware
corporation, THERMADYNE INDUSTRIES, INC., a Delaware corporation, VICTOR
EQUIPMENT COMPANY, a Delaware corporation, THERMADYNE INTERNATIONAL CORP., a
Delaware corporation, THERMADYNE CYLINDER CO., a California corporation, THERMAL
DYNAMICS CORPORATION, a Delaware corporation, C&G SYSTEMS HOLDING, INC., a
Delaware corporation, MECO HOLDING COMPANY, a Delaware corporation, TWECO
PRODUCTS, INC., a Delaware corporation, TAG REALTY, INC., a Texas corporation,
VICTOR-COYNE INTERNATIONAL, INC., a Delaware corporation, VICTOR GAS SYSTEMS,
INC., a Delaware corporation, STOODY COMPANY, a Delaware corporation, THERMAL
ARC, INC., a Delaware corporation, C&G SYSTEMS, INC., an Illinois corporation,
MARISON CYLINDER COMPANY, a Delaware corporation, WICHITA WAREHOUSE CORPORATION,
a Kansas corporation, COYNE NATURAL GAS SYSTEMS, INC., a Missouri corporation,
and MODERN ENGINEERING COMPANY, INC., a Missouri corporation (each, a "U.S.
Guarantor" and collectively, the "U.S. Guarantors" and together with the
Borrower, the "Debtors"), each of which is a debtor and debtor-in-possession in
a case pending in the Bankruptcy Court (as hereinafter defined) under Chapter 11
of the Bankruptcy Code (the cases of the Borrower and the U.S. Guarantors, each
a "Case" and collectively, the "Cases"), each of the other financial
institutions from time to time party hereto (the "Lenders") and ABN AMRO BANK
N.V. ("ABN AMRO"), as administrative agent and collateral agent (in such
capacity, the "Agent") for the Lenders. Capitalized terms used but not defined
herein shall have the respective meanings given to such terms in the Credit
Agreement.

         WHEREAS, the Borrower has requested, and the Lenders, the Agent and the
U.S. Guarantors have agreed, on terms and conditions set forth herein, to
certain modifications of the Credit Agreement; and

         WHEREAS, from and after the Effective Date (as hereinafter defined) of
this First Amendment, the Credit Agreement shall be amended, subject to and upon
the terms and conditions set forth herein;

         NOW, THEREFORE, for valuable consideration, the receipt and sufficiency
of which is hereby acknowledged, and subject to the fulfillment of the
conditions set forth below, the parties hereto agree as follows:

Section 1. Amendments to the Credit Agreement. Subject to the terms and
conditions set forth herein, the Credit Agreement is hereby amended as follows:

         (a) Section 1 of the Credit Agreement is hereby amended by deleting the
date "November 19, 2001" where it appears in the definition of "Commitment
Letter" and inserting in its place the date "November 16, 2001".

         (b) Section 2.19 of the Credit Agreement is hereby amended by deleting
the date "November 19, 2001" where it appears therein and inserting in its place
the date "November 16, 2001".



<PAGE>

         (c) Section 2.28 of the Credit Agreement is hereby amended by deleting
the reference to "$1,000,000" in clause (x) on the sixth line thereof and
inserting in its place "$3,000,000".

         (d) Section 7.1 of the Credit Agreement is hereby amended by deleting
subsections (o), (p), (q) and (r) and inserting in their place the following:

                  "(o) Intentionally Omitted;

                  (p) Intentionally Omitted:

                  (q) Intentionally Omitted;

                  (r) Intentionally Omitted;"

Section 2. Representation and Warranties. The Borrower and each of the U.S.
Guarantors represents and warrants (which representations and warranties shall
survive the execution and delivery hereof) to the Agent and Lenders that:

         (a) It has the corporate power and authority to execute, deliver and
perform the terms and provisions of this Amendment and the transactions
contemplated hereby and has taken or caused to be taken all necessary corporate
action to authorize the execution, delivery and performance of this Amendment
and the transactions contemplated hereby;

         (b) No consent of any person (including, without limitation,
shareholders or creditors of the Borrower or any U.S. Guarantor), and no action
of, or filing with any governmental or public body or authority is required to
authorize, or is otherwise required in connection with the execution, delivery
and performance of this Amendment and the other instruments and documents
contemplated hereby which has not been obtained;

         (c) Each of this Amendment and any other instruments and documents
contemplated hereby has been duly executed and delivered by a duly authorized
officer on behalf of such party, and constitutes a legal, valid and binding
obligation of such party enforceable against such party in accordance with its
terms, subject to bankruptcy, reorganization, insolvency, moratorium and other
similar laws affecting the enforcement of creditors' rights generally and the
exercise of judicial discretion in accordance with general principles of equity;

         (d) The execution, delivery and performance of this Amendment, and the
other instruments and documents contemplated hereby will not violate any law,
statute or regulation, or any order or decree of any court or governmental
instrumentality, or conflict with, or result in the breach of, or constitute a
default under any contractual obligation of such party;

         (e) After giving effect to this Amendment, there does not exist any
Event of Default or event which upon notice or lapse of time or both would
constitute an Event of Default; and

         (f) After giving effect to this Amendment, the representations and
warranties contained in the Credit Agreement and in the other Loan Documents are
true and correct in all material respects on and as of the Effective Date as if
such representations and warranties had been made on and as of the Effective
Date (except to the extent such representations and warranties expressly relate
to an earlier date in which case such representations and warranties shall be
true and correct in all material aspects as of such earlier date).


<PAGE>

Section 3. Conditions to Effectiveness.

         (a) This Amendment shall become effective on the date (the "Effective
Date") upon which the following conditions have been satisfied in full or waived
by the Agent in writing:

                  (i) the Agent shall have received in form and substance
satisfactory to the Agents and its counsel, counterparts of this Amendment
executed by the Borrower, the U.S. Guarantors, and the Lenders and such other
approvals or documents as the Agent may reasonably request;

                  (ii) all representations and warranties contained in this
Amendment shall be true and correct in all material respects;

                  (iii) no Event of Default or event which upon notice or lapse
of time or both would constitute an Event of Default shall have occurred and be
continuing;

                  (iv) the Agent shall have received such other instruments,
documents and assurances as the Agent or its counsel may reasonably request.

Section 4. Ramification: Waiver of Defenses; and Release.

         (a) The Credit Agreement and the other Loan Documents remain in full
force and effect and are hereby ratified and affirmed. The Borrower and each
U.S. Guarantor hereby (i) confirms and agrees that the Borrower is truly and
justly indebted to the Agent and the Lenders in the aggregate amount of the
Obligations without defense, counterclaim or offset of any kind whatsoever; and
(ii) reaffirms and admits the validity and enforceability of the Credit
Agreement and the other Loan Documents and the Liens in the Collateral which
were granted pursuant to the Loan Documents and otherwise.

         (b) This Amendment shall be limited precisely as written and shall not
be deemed (i) to be a consent granted pursuant to, or a waiver or modification
of, any other term or condition of the Credit Agreement or any of the
instruments or agreements referred to therein or a waiver of any Event of
Default under the Credit Agreement, whether or not known to the Agent or the
Lenders or (ii) to prejudice any other right or rights which the Agents or the
Lenders may now have or have in the future under or in connection with the
Credit Agreement or any of the instruments or agreements referred to therein.
Except to the extent hereby waived or modified, the Credit Agreement and each of
the other Loan Documents shall continue in full force and effect in accordance
with the provisions thereof on the date hereof.

Section 5. References. All references to the "Credit Agreement", "thereunder",
"thereof" or words of like import in the Credit Agreement or any other Loan
Document and the other documents and instruments delivered pursuant to or in
connection therewith shall mean and be a reference to the Credit Agreement as
modified hereby and as each may in the future be amended, restated, supplemented
or modified from time to time. This Amendment shall constitute a Loan Document.

Section 6. Counterparts. This Amendment may be executed by the parties hereto
individually or in combination, in one or more counterparts, each of which shall
be an original and all of which, taken together, shall constitute one and the
same agreement. Delivery of an executed counterpart of a signature page by
telecopier shall be effective as delivery of a manually executed counterpart.

Section 7. Governing Law. THIS AMENDMENT AND THE RIGHTS AND OBLIGATIONS OF THE
PARTIES HEREUNDER SHALL BE GOVERNED BY AND CONSTRUED IN ACCORDANCE WITH THE LAWS
OF THE STATE OF NEW YORK.




<PAGE>

Section 8. Successors and Assigns. The provisions of this Amendment shall be
binding upon and inure to the benefit of the parties hereto and their respective
successors and assigns.

Section 9. Acknowledgement by U.S. Guarantors. Each of the U.S. Guarantors
hereby acknowledges that it has read this Amendment and consents to the terms
hereof and further confirms and agrees that (a) notwithstanding the
effectiveness of this Amendment, each Loan Document to which it is a party is,
and shall continue to be, in full force and effect and is hereby ratified and
confirmed in all respects, and (b) the Security and Pledge Agreement to which
such U.S. Guarantor is a party and all of the Collateral, as the case may be,
described therein do, and shall continue to, secure the payment of all of the
Secured Obligations (in each case, as defined in the Security and Pledge
Agreement).

Section 10. Severability. If any provisions of this Amendment shall be held
invalid or unenforceable in whole or in part in any jurisdiction, such provision
shall, as to such jurisdiction, be ineffective to the extent of such invalidity
or enforceability without in any manner affecting the validity or enforceability
of such provision in any other jurisdiction or the remaining provisions of this
Amendment in any jurisdiction.

Section 11. Survival. All representations, warranties, covenants, agreements,
undertakings, waivers and releases of the Borrower and the U.S. Guarantors
contained herein shall survive the Termination Date and the indefeasible payment
in full in cash of the Obligations.

Section 12. Miscellaneous. The parties hereto shall, at any time and from time
to time following the execution of this Amendment, execute and deliver all such
further instruments and take all such further instruments and take all such
further action as may be reasonably necessary or appropriate in order to carry
out the provisions of this Amendment.

Section 13. Headings. Section headings in this Amendment are included herein for
convenience of reference only and are not to affect the construction of, or to
be taken into consideration in interpreting, this Amendment.


            [THE REMAINDER OF THIS PAGE IS INTENTIONALLY LEFT BLANK]



<PAGE>




         IN WITNESS WHEREOF, the parties hereto have caused this Amendment to be
duly executed as of the day and the year first written.

                                           BORROWER:

                                           THERMADYNE MFG. LLC


                                           By:
                                              ---------------------------------
                                              Title:


                                           U.S. GUARANTORS:

                                           THERMADYNE HOLDINGS CORPORATION


                                           By:
                                              ---------------------------------
                                              Title:


                                           THERMADYNE CAPITAL CORP.


                                           By:
                                              ---------------------------------
                                              Title:


                                           THERMADYNE INDUSTRIES, INC.


                                           By:
                                              ---------------------------------
                                              Title:


                                           VICTOR EQUIPMENT COMPANY


                                           By:
                                              ---------------------------------
                                              Title:


                                           THERMADYNE INTERNATIONAL CORP.


                                           By:
                                              ---------------------------------
                                              Title:




<PAGE>



                                           THERMADYNE CYLINDER CO.


                                           By:
                                              ---------------------------------
                                              Title:


                                           THERMAL DYNAMICS CORPORATION


                                           By:
                                              ---------------------------------
                                              Title:


                                           C&G SYSTEMS HOLDING, INC.


                                           By:
                                              ---------------------------------
                                              Title:


                                           MECO HOLDING COMPANY


                                           By:
                                              ---------------------------------
                                              Title:


                                           TWECO PRODUCTS, INC.


                                           By:
                                              ---------------------------------
                                              Title:


                                           TAG REALTY, INC.


                                           By:
                                              ---------------------------------
                                              Title:


                                           VICTOR-COYNE INTERNATIONAL, INC.


                                           By:
                                              ---------------------------------
                                              Title:




<PAGE>



                                           VICTOR GAS SYSTEMS, INC.


                                           By:
                                              ---------------------------------
                                              Title:


                                           STOODY COMPANY


                                           By:
                                              ---------------------------------
                                              Title:


                                           THERMAL ARC, INC.


                                           By:
                                              ---------------------------------
                                              Title:


                                           C&G SYSTEMS, INC.


                                           By:
                                              ---------------------------------
                                              Title:


                                           MARISON CYLINDER COMPANY


                                           By:
                                              ---------------------------------
                                              Title:


                                           WICHITA WAREHOUSE CORPORATION


                                           By:
                                              ---------------------------------
                                              Title:


                                           COYNE NATURAL GAS SYSTEM, INC.


                                           By:
                                              ---------------------------------
                                              Title:




<PAGE>



                                           MODERN ENGINEERING COMPANY, INC.


                                           By:
                                              ---------------------------------
                                              Title:


                                           AGENT:

                                           ABN AMRO BANK N.V.
                                              AS AGENT AND AS LENDER


                                           By:
                                              ---------------------------------
                                              Title:


                                           By:
                                              ---------------------------------
                                              Title:





<PAGE>





                                           SILVER OAK CAPITAL, LLC,
                                           AS AGENT FOR FUNDS AND  ACCOUNTS
                                           MANAGED BY ANGELO, GORDON & CO.,
                                           L.P., AS LENDER


                                           By:
                                              ---------------------------------
                                              Title:


<PAGE>



                                           GENERAL ELECTRIC CAPITAL
                                           CORPORATION, AS LENDER


                                           By:
                                              ---------------------------------
                                              Title:


<PAGE>


                                           THE INDUSTRIAL BANK OF JAPAN,
                                           LIMITED, AS LENDER


                                           By:
                                              ---------------------------------
                                              Title:


<PAGE>



                                           AG CAPITAL FUNDING PARTNERS, L.P.,
                                           AS LENDER

                                           BY:  ANGELO, GORDON & CO., L.P.,
                                                ITS INVESTMENT ADVISOR

                                           By:
                                              ---------------------------------
                                              Title:



<PAGE>


                             FORM OF PROMISSORY NOTE

$_____________

                                                             New York, New York
                                                              __________, 200__

         FOR VALUE RECEIVED, THERMADYNE MFG. LLC, a Delaware limited liability
company (the "Borrower"), as Debtor and Debtor-in-Possession under Chapter 11 of
the United States Code (the "Bankruptcy Code"), DOES HEREBY PROMISE to pay to
the order of _____________________ (the "Lender") at the office of the Agent (as
defined in the Agreement hereinafter referred to) the amount of _______________
($_____________) or the aggregate unpaid principal amount of all Loans made by
the Lender to the Borrower pursuant to the Agreement, whichever is less, in
lawful money of the United States of America and in immediately available funds
on the Maturity Date or such earlier date or dates and in such amounts as are
required by the Agreement, and to pay interest on the unpaid principal amount
from time to time outstanding hereunder in like money, at such office, as set
forth in the Agreement.

         This Note is issued pursuant to Section 2.06(e) of the Revolving Credit
and Guaranty Agreement, dated as of November 26, 2001, as the same may be
amended, modified or supplemented from time to time (the "Agreement"; terms
defined in the Agreement are used herein as therein defined), among the
Borrower, the U.S. Guarantors, ABN AMRO Bank, N.V., as administrative agent and
the financial institutions from time to time party thereto. The Agreement
contains, among other things, provisions for the acceleration of the maturity
hereof upon the happening of certain events, for prepayment of the principal
hereof prior to the maturity thereof and for the amendment or waiver of certain
provisions of the Agreement, all upon the terms and conditions specified
therein. Pursuant to Section 364(c)(1) of the Bankruptcy Code, the obligations
of the Borrower evidenced by this Note constitute allowed administrative expense
claims entitled to priority over all unsecured claims in the Borrower's Chapter
11 case, including, without limitation, all administrative expenses of the kind
specified in Section 503(b) and 507(b) of the Bankruptcy Code, subject to the
Carve-Out referred to in the Agreement.

         Pursuant to Sections 364(c)(2), 364(c)(3) and 364(d)(1) of the
Bankruptcy Code, this Note is secured by certain assets and property of the
Borrower referred to in the Agreement and in the other Loan Documents.

         This Note shall be governed by, and construed in accordance with, the
laws of the State of New York and applicable federal law of the United States of
America (including, without limitation, the Bankruptcy Code).

                                                THERMADYNE MFG. LLC


                                                By:
                                                   ----------------------------

                                                Title:
                                                      -------------------------