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                                                                    Exhibit 4.15

                 CONSENT, AMENDMENT, ASSIGNMENT AND ASSUMPTION

                                    OF THE

         DRESSER, INC. AMENDED AND RESTATED INVESTOR RIGHTS AGREEMENT

   This Consent, Amendment, Assignment and Assumption of the Dresser, Inc.
Amended and Restated Investor Rights Agreement (this "Consent") is made and
entered into as of July __, 2002, by DEG Acquisitions, LLC (the "LLC"),
Dresser, Inc., a Delaware corporation ("Dresser") and Dresser, Ltd., a Bermuda
company ("Dresser Bermuda").

                                R E C I T A L S

   WHEREAS, the LLC owns 9,700,000 shares of Class A Common Stock, par value
$.001 per share (the "Class A Common Stock") and 550,000 shares of Class B
Common Stock, par value $.001 per share (the "Class B Common Stock" and,
together with the Class A Common Stock, the "Dresser Common Stock") of Dresser;

   WHEREAS, Dresser heretofore entered into an Agreement and Plan of Merger
(the "Merger Agreement") among Dresser Mergeco, Inc., a Delaware corporation,
Dresser Bermuda and Dresser.

   WHEREAS, as a result of the transactions contemplated by the Merger
Agreement (the "Merger"), each outstanding share of Dresser Common Stock will
be cancelled and the holders thereof will receive one class A common share of
Dresser Bermuda, par value $.01 (the "Bermuda Class A Common Shares"), for each
share of Class A Common Stock and one class B common share of Dresser Bermuda,
par value $.01 (the "Bermuda Class B Common Shares" and, collectively with the
Bermuda Class A Common Shares, the "Bermuda Common Shares"), for each share of
Class B Common Stock, respectively, held by such stockholder;

   WHEREAS, Dresser and the LLC are parties to that certain Amended and
Restated Investor Rights Agreement, dated as of June 12, 2001, as amended from
time to time (the "IRA"), among the LLC, Dresser, Dresser Industries, Inc., a
Delaware corporation, and each of the stockholders and individual employees of
Dresser who become party thereto from time to time in accordance with the terms
thereof (collectively with the LLC, the "Stockholders");

   WHEREAS, Dresser wishes to assign its rights and obligations under the IRA
to Dresser Bermuda, and Dresser Bermuda wishes to assume such rights and
obligations, effective upon completion of the Merger, so that the relative
rights and obligations of the parties to the IRA as they related to the
Stockholders' ownership of shares of Dresser Common Stock prior to the Merger
will be the relative rights and obligations of the parties to the IRA as they
relate to the Stockholders' ownership of Bermuda Common Shares following the
Merger;

   WHEREAS, Dresser and Dresser Bermuda wish to amend the IRA to provide that
references to Dresser and the "Company" will be changed to refer to Dresser
Bermuda for all purposes under the IRA;

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   WHEREAS, Section 5.2 of the IRA provides that any provision of the IRA, may
be amended or waived with the written consent of at least sixty-six and
two-thirds percent (66 2/3%) of the outstanding shares of Dresser Common Stock
that are subject to the IRA and owned by the parties thereto, with certain
exceptions not relevant here;

   WHEREAS, this Consent will not disproportionately and adversely affect any
Employee Stockholder (as defined in the IRA) or the Employee Stockholders as a
group; and

   WHEREAS, the LLC holds more than 66 2/3% of the outstanding shares of
Dresser Common Stock that are subject to the IRA, and pursuant to Section 5.2
of the IRA, the LLC wishes to consent to the assignment, assumption and
amendment referred to above.

   NOW, THEREFORE:

   1.  Dresser hereby grants, transfers and assigns to Dresser Bermuda all of
Dresser's right, title and interest in the IRA and all of its obligations
thereunder.

   2.  Dresser Bermuda hereby does absolutely and irrevocably assume and agrees
to perform and discharge all of Dresser's obligations under the IRA.

   3.  The IRA is hereby amended as follows:

   a)  All references to "Dresser, Inc." shall be changed to "Dresser, Ltd."
       and the defined term the "Company" shall mean Dresser, Ltd.

   b)  All references to "Class A Common Stock, par value $.001 per share",
       shares of "Class A Common Stock" and similar phrases shall refer to the
       Class A common shares, par value U.S. $.01 per share, of the Company,
       and all references to "Class B Common Stock, par value $.001 per share",
       shares of "Class B Common Stock" and similar phrases shall refer to the
       Class B common shares, par value U.S. $.01 per share, of the Company.

   c)  All references to the "Corporation" in Section 6 shall be changed to the
       "Company".

   d)  All references to "Certificate of Incorporation" and "Bylaws" shall be
       changed to "Memorandum of Association" and "Bye-Laws", respectively.

   4.  The IRA is hereby amended to the extent necessary to permit completion
of the Merger and the receipt by the parties to the IRA of the Bermuda Common
Shares in connection therewith. To the extent applicable, the LLC hereby waives
the requirements of Section 3.5(a)(ii), the notice and delivery requirements in
Section 3.5(b) and (c) and the expense reimbursement requirements of Section
3.5(d).

   5.  The LLC hereby consents to the above mentioned assignment, assumption
and amendment.

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   6.  This Consent is intended solely for the purpose described in Sections 1,
2, 3, 4 and 5 above, and is not a general waiver of the IRA. Except as
specifically set forth herein, the IRA shall remain in full force and effect.

   7.  This Consent shall be governed by and construed exclusively in
accordance with the internal laws of the State of Delaware, excluding that body
of law relating to conflict of laws and choice of law.

                           [SIGNATURE PAGE FOLLOWS]

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   IN WITNESS WHEREOF, the undersigned have executed this Consent as of the
date first written above.

            DEG ACQUISITIONS, LLC

                FIRST RESERVE FUND VIII, L.P.,
                  a Delaware limited partnership

                       By: FIRST RESERVE GP VIII, L.P.
                             a Delaware limited partnership, its general partner

                           By: FIRST RESERVE CORPORATION,
                                 a Delaware corporation, its general partner

                                                 By: ________________________
                                                     Name:
                                                     Title:
            Dresser, Inc.

            By: ________________________
                Name:
                Title:

            Dresser, Ltd.

            By: ________________________
                Name:
                Title: