EXHIBIT (3)


                            CERTIFICATE OF AMENDMENT
                                       OF
                          CERTIFICATE OF INCORPORATION
                                       OF
                              MET-PRO CORPORATION


         The undersigned corporation, in order to amend its Certificate of
Incorporation, hereby certifies as follows:


         FIRST:  The name of the corporation is: Met-Pro Corporation.

         SECOND: The corporation hereby amends its Certificate of Incorporation
                 as follows: Paragraph FOURTH of the Certificate of
                 Incorporation, relating to the capital stock of the
                 corporation, is hereby amended to read as follows:

                 "FOURTH: The total number of shares of stock which the
                 corporation shall have authority to issue is Eighteen Million
                 (18,000,000), each share to be designated Common Stock
                 and to have a par value of Ten Cents ($.10), amounting to
                 aggregate capital of One Million Eight Hundred Thousand
                 Dollars ($1,800,000)."

         THIRD:  The amendment effected herein was authorized by the affirmative
                 vote of the holders of a majority of the outstanding shares
                 entitled to vote thereon at a meeting of stockholders, pursuant
                 to Sections 222 and 242 of the General Corporation Law of the
                 State of Delaware.

         IN WITNESS WHEREOF, we hereunto sign our names and affirm that the
statements made herein are true under the penalties of perjury, this 4th day of
June, 1997.


                                                   MET-PRO CORPORATION

                                              By:  /s/ William L. Kacin
                                                  ------------------------------
                                                   Willam L. Kacin, President

ATTEST:

/s/ WILLIAM F. MOFFITT
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William F. Moffitt, Secretary