Exhibit 31.1

                                  CERTIFICATION

I, Kenneth A. Swanstrom, certify that:

     1. I have reviewed this quarterly report on Form 10-Q of Penn Engineering
        and Manufacturing Corp.;

     2. Based on my knowledge, this report does not contain any untrue statement
        of a material fact or omit to state a material fact necessary to make
        the statements made, in light of the circumstances under which such
        statements were made, not misleading with respect to the period covered
        by this report;

     3. Based on my knowledge, the financial statements, and other financial
        information included in this report, fairly present in all material
        respects the financial condition, results of operations and cash flows
        of the registrant as of, and for, the periods presented in this report;

     4. The registrant's other certifying officer and I are responsible for
        establishing and maintaining disclosure controls and procedures (as
        defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) for the
        registrant and have:

        (a)  Designed such disclosure controls and procedures, or caused such
             disclosure controls and procedures to be designed under our
             supervision, to ensure that material information relating to the
             registrant, including its consolidated subsidiaries, is made known
             to us by others within those entities, particularly during the
             period in which this report is being prepared;

        (b)  Evaluated the effectiveness of the registrant's disclosure controls
             and procedures and presented in this report our conclusions about
             the effectiveness of the disclosure controls and procedures, as of
             the end of the period covered by this report based on such
             evaluation; and

        (c)  Disclosed in this report any change in the registrant's internal
             control over financial reporting that occurred during the
             registrant's most recent fiscal quarter (the registrant's fourth
             fiscal quarter in the case of an annual report) that has materially
             affected, or is reasonably likely to materially affect, the
             registrant's internal control over financial reporting; and

     5. The registrant's other certifying officer and I have disclosed, based on
        our most recent evaluation of internal control over financial reporting,
        to the registrant's auditors and the audit committee of the registrant's
        board of directors (or persons performing the equivalent functions):

        (a)  All significant deficiencies and material weaknesses in the design
             or operation of internal control over financial reporting which are
             reasonably likely to adversely affect the registrant's ability to
             record, process, summarize and report financial information; and

        (b)  Any fraud, whether or not material, that involves management or
             other employees who have a significant role in the registrant's
             internal control over financial reporting.

Date: May 10, 2004
                                        /s/ Kenneth A. Swanstrom
                                        ------------------------------------
                                        Kenneth A. Swanstrom
                                        Chairman and Chief Executive Officer