EXHIBIT 2.1(B)

                         AMENDMENT TO MERGER AGREEMENT

            THIS AMENDMENT TO MERGER AGREEMENT (the "Amendment") is executed
effective as of the 25th day of September 1998, by and among INNOVATIVE VALVE
TECHNOLOGIES, INC., a Delaware corporation ("Invatec"), PLANT MAINTENANCE, INC.,
a Delaware corporation and successor-by-merger to Plant Acquisition, Inc. and
Plant Maintenance, Inc., WILLIAM D. DENSON, an individual residing in Oklahoma,
DARRELL G. SALLEE, an individual residing in Oklahoma, and JOHN P. JORDEN, JR.,
an individual residing in Texas. All defined terms contained herein shall have
the same meanings as contained in that certain Merger Agreement dated effective
June 29, 1998, executed by Invatec, Plant Acquisition, Inc., Plant Maintenance,
Inc., Mr. Denson, Mr. Sallee and Mr. Jorden (the "Merger Agreement"), except as
otherwise specifically indicated herein.

            WHEREAS, each of the parties has determined that it is in his or its
best interest to modify the terms of the Merger Agreement with respect to the
post-closing adjustment to the value of the Invatec Common Stock, as hereinafter
set forth;

            NOW, THEREFORE, for and in consideration of the premises, the mutual
covenants and agreements contained herein, and other good and valuable
consideration, the receipt and sufficiency of which are hereby acknowledged, the
parties hereby agree as follows:

            i. Subparagraph 6(C) of the Merger Agreement is hereby deleted in
its entirety, and substituted therefor is the following:

                  (C) SHARES OF INVATEC COMMON STOCK NOT SOLD WITHIN TWELVE
            MONTHS. If the Current Market Price as of the Subsequent Measurement
            Date is less than the Agreed Closing Value of Invatec Stock, then
            Invatec will pay each Stockholder for each share of Invatec Common
            Stock issued to such Stockholder as part of the Acquisition
            Consideration (after giving effect to any adjustment pursuant to
            PARAGRAPH 5) which is still owned by the Stockholder as of the
            Subsequent Measurement Date, the amount by which the Agreed Closing
            Value of Invatec Stock exceeds the greater of (a) the Current Market
            Price as of the Subsequent Measurement Date or (b) Two and 50/100
            Dollars ($2.50). The Parties acknowledge and agree that the
            foregoing calculation cannot result in a payment to Stockholders
            greater than Six and 85/100 Dollars ($6.85) per share of Invatec
            Common Stock. The payment, if any, to be made by Invatec pursuant to
            this PARAGRAPH 6, may be made by Invatec, at Invatec's option,
            either in cash, or by issuing to each Stockholder Invatec Common
            Stock at a per share price equal to the Current Market Price as of
            the Subsequent Measurement Date.

            ii. The parties hereby acknowledge and agree that the closing price
of the Invatec Common Stock as of September 24, 1998, was Three and 25/100
($3.25) per share.

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            iii. All other terms, conditions and covenants contained in the
Merger Agreement shall remain in full force and effect except as expressly
amended herein. The parties hereby authorize, adopt, ratify, confirm and approve
the Acquisition on the terms and conditions set forth in the Merger Agreement,
except as the same are expressly amended hereby.

            iv. Each of the undersigned representatives of each party hereto
represents and warrants that his signature constitutes the valid and binding act
of such party, and that he has been duly authorized, empowered and directed to
execute and deliver this Amendment.

            v. This Amendment embodies the entire agreement and understanding
among the parties relating to the subject matter hereof, and supersedes all
prior proposals, negotiations, agreements, commitments and understandings
relating to such subject matter. There are no unwritten agreements among the
parties. This Amendment, when executed by the parties hereto, shall be binding
upon and inure to the benefit of the parties hereto, and their respective
personal representatives, successors and assigns.

            vi. This Amendment may be executed simultaneously in a number of
identical counterparts, each of which shall be an original and all of which
together shall constitute but one and the same instrument. Facsimile signatures
shall be treated as original signatures for all purposes relating to this
Amendment.

            IN WITNESS WHEREOF, this Amendment has been executed and delivered
to be effective as of the date first set forth above.

                                        INNOVATIVE VALVE
                                        TECHNOLOGIES, INC.

                                        By: _________________________________
                                              John L. King
                                              Vice President

                                        PLANT MAINTENANCE, INC.

                                        By: _________________________________
                                             John L.King
                                             Vice President

                                        _____________________________________
                                        WILLIAM D. DENSON

                                        _____________________________________
                                        DARRELL G. SALLEE

                                        _____________________________________
                                        JOHN P. JORDEN, JR.

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