AMENDMENT NUMBER FOUR

                                TO THE

                         PAUL MUELLER COMPANY
                  CONTRACT EMPLOYEES RETIREMENT PLAN

    WHEREAS, Paul Mueller Company (the "Company") adopted the Paul 
Mueller Company Contract Employees Retirement Plan (the "Plan") effec-
tive July 1, 1965; and

    WHEREAS, the Company amended and restated the Plan effective 
January 1, 1992; and

    WHEREAS, the Company retained the right to amend the Plan pursuant 
to Section 9.01 hereof;

    NOW, THEREFORE, BE IT RESOLVED, that the Plan is hereby amended as 
follows:

    1.  The definition of "Actuarial Equivalent" in Section 1.02 is 
amended to read as follows:

            ACTUARIAL EQUIVALENT means equality in the value of the 
        aggregate amounts expected to be received under different 
        forms of payment based on the rates determined below.  The 
        amount of each payment under an optional form shall be 
        determined by multiplying the amount payable on the Normal 
        Form by the ratio of (a) the applicable rate for the Normal 
        Form, to (b) the applicable rate for the optional form at the 
        time benefits are determined.  The benefit from a single sum 
        on an optional form shall be the Actuarial Equivalent of the 
        benefit payable on the Normal Form based on the applicable 
        rates.  These applicable rates will be determined using the 
        rates of interest and mortality (male table) used (as of the 
        first day of the calendar quarter preceding the calendar 
        quarter in which occurs the Annuity Starting Date) by the 
        Pension Benefit Guaranty Corporation for a trusteed single-
        employer plan to value a benefit upon termination of an 
        insufficient trusteed single-employer plan.  In the event the 
        basis for determining Actuarial Equivalent is changed, 
        Actuarial Equivalent of the Participant's Accrued Benefit on 
        and after the date of the change shall be determined as the 
        greater of (a) the Actuarial Equivalent of the Accrued Benefit 
        as of the date of the change computed on the old basis, or (b) 
        the Actuarial Equivalent of the total Accrued Benefit computed 
        on the new basis.

    2.  The definition of "Present Value" in Section 1.02 is amended 
to read as follows:

            PRESENT VALUE means the current value of a benefit payable 
        on a specified form and on a specified date.  The method of 
        determining Present Value is based upon assumed rates of 
        mortality and the rates of interest used by the Pension 
        Benefit Guaranty Corporation for a trusteed single-employer 
        plan to value a benefit upon termination of an insufficient 
        trusteed single-employer plan.  Such rates shall be determined 
        without regard to sex and shall be those rates on the first
        day of the calendar quarter preceding the calendar quarter in 
        which occurs the Annuity Starting Date.  In the event the 
        basis for determining Present Value is changed, the Present 
        Value of the Participant's Accrued Benefit on and after the 
        date of the change shall be determined as the greater of 
        (a) the Present Value of the Accrued Benefit as of the date of 
        the change computed on the old basis, or (b) the Present Value 
        of the total Accrued Benefit computed on the new basis.

    3.  A new Section 3.04 is added as follows:

            SECTION 3.04--LIQUIDITY SHORTFALL LIMITATIONS.  

            If the Plan has a liquidity shortfall within the meaning 
        of Section 412(m) of the Internal Revenue Code, the Plan shall 
        not pay benefits in excess of the amounts payable as a monthly 
        Accrued Benefit, plus any applicable Social Security supple-
        ments, to a Participant or Beneficiary the payment of whose 
        benefits commences during the period of the liquidity short-
        fall.  Additional restrictions shall apply to a period of a 
        liquidity shortfall to the extent required by section 
        401(a)(32) of the Internal Revenue Code and Section 206(d) 
        of ERISA.

    4.  Section 4.01 is amended to read as follows:

            SECTION 4.01--ACCRUED BENEFIT.

            An Active Participant's monthly Accrued Benefit as of any 
        date will be calculated according to subsections (a), (b) and 
        (c) below:

            (a)  If a Participant was an Active Participant on April 
                 1, 1996, or first became an Active Participant after
                 that date, his monthly Accrued Benefit as of any date 
                 will be an amount equal to $25.00 multiplied by his 
                 Accrual Service (not to exceed 35 years) on such 
                 date.

            (b)  If a Participant was not an Active Participant on 
                 April 1, 1996, and did not first become an Active 
                 Participant after that date, but was an Active Par-
                 ticipant on September 19, 1994, or first became an 
                 Active Participant after that date, his monthly 
                 Accrued Benefit as of any date will be determined 
                 as follows:

                 (1)  An amount equal to:

                       (i)  Before January 1, 1996, $21.00; and

                      (ii)  On and after January 1, 1996, $25.00.

                 (2)  Multiplied by his Accrual Service for the appli-
                      cable period(s) specified in (1) above; pro-
                      vided, however, that:

                       (i)  Regardless of when the service was ren-
                            dered, no more than 35 years of Accrual 
                            Service shall be counted; and

                      (ii)  In the event that the 35 year limitation 
                            applies to a Participant's Accrual Ser-
                            vice, his Accrued Benefit shall be calcu-
                            lated by counting last years first.

            (c)  If a Participant was not an Active Participant on 
                 September 19, 1994, and did not first become an 
                 Active Participant after that date, his monthly 
                 Accrued Benefit as of any date will be determined as 
                 follows:

                 (1)  An amount equal to:

                       (i)  Before January 1, 1981, $12.00;

                      (ii)  On and after January 1, 1981, and before 
                            January 1, 1984, $14.00;

                     (iii)  On and after January 1, 1984, and before 
                            January 1, 1994, $20.00; 

                      (iv)  On and after January 1, 1994, and before 
                            January 1, 1996, $21.00; and 

                       (v)  On and after January 1, 1996, $25.00.

                 (2)  Multiplied by his Accrual Service for the appli-
                      cable period(s) specified in (1) above; pro-
                      vided, however, that: 

                       (i)  Regardless of when the service was ren-
                            dered, no more than 35 years of Accrual 
                            Service shall be counted;

                      (ii)  For service prior to January 1, 1994, no 
                            more than 30 years of Accrual Service 
                            shall be counted; and 

                     (iii)  For service prior to January 1, 1985, no 
                            more than 25 years of Accrual Service 
                            shall be counted.

                      In the event that the 25, 30 or 35 year limita-
                      tion applies to a Participant's Accrual Service, 
                      his Accrued Benefit shall be calculated by 
                      counting last years first.

    5.  Section 4.03 is amended by deleting the existing Section in 
its entirety and substituting the following new Section in its place:

        SECTION 4.03--BENEFIT LIMITATION.

            In no event shall the monthly retirement benefit payable 
        under the Plan exceed the limitations applicable to the Plan 
        under Section 415 of the Internal Revenue Code and the regu-
        lations promulgated thereunder.  If the monthly retirement 
        benefit payable under any provision of the Plan would exceed 
        such limitations, then notwithstanding any other provision of 
        the Plan, such monthly retirement benefit shall be reduced to 
        the extent necessary to ensure that such limitations are not 
        exceeded.  If a Member's monthly retirement benefit payable 
        under this Plan, in combination with the annual additions 
        credited to him under any defined contribution plan maintained 
        by the Employer, would exceed such limitations, then the 
        monthly retirement benefit payable under this Plan shall be 
        reduced to the extent necessary to ensure that such limi-
        tations are not exceeded. For purposes of this Section, 
        "Employer" means Paul Mueller Company and all employers 
        required, pursuant to Section 415 of the Internal Revenue 
        Code, to be aggregated therewith under the rules of Sections 
        414(b) or (c) of the Code.

    6.  The first sentence of Section 6.03(b) is deleted in its en-
tirety and the following is substituted in its place:

        (b)  The optional forms of retirement benefit shall be the 
             following:  single life annuities with a certain period
             of three years; survivorship life annuities with survi-
             vorship percentages of 50 or 100; and a single lump sum, 
             as provided in Section 6.03(i).

    7.  A new Section 6.03(i) is added as follows:

        (i)  Cash Option.

             Where the lump sum Actuarial Equivalent of a Partici-
             pant's vested Accrued Benefit is not greater than 
             $10,000, he may elect with the consent of his spouse to 
             receive an immediate lump sum cash settlement in lieu of 
             the monthly payments of his vested Accrued Benefit which 
             he would otherwise be entitled to receive.  The Parti-
             cipant may elect this cash settlement to be paid at any 
             time after termination of employment but not later than 
             his Normal or Late Retirement Date.  This Cash Option may 
             also be elected by a Participant who has not terminated 
             employment but Accrued Pension must be distributed pur-
             suant to the required distribution provisions of Section 
             6.03. 

             The Cash Option will be invoked without the Participant's 
             consent if the lump sum Actuarial Equivalent of the Par-
             ticipant's vested Accrued Benefit is less than $1,750, as 
             described in the SMALL AMOUNTS SECTION of ARTICLE 9.

    The changes made by numbered paragraphs 1, 2, 6 and 7 shall be 
effective for Annuity Starting Dates on or after April 1, 1996.  The 
changes made by numbered paragraphs 3 and 5 shall be effective for 
Plan Years beginning on or after January 1, 1995.  The changes made by 
numbered paragraph 4 shall be effective as provided therein.  

    IN WITNESS WHEREOF, PAUL MUELLER COMPANY has caused this instru-
ment to be duly executed this 26th day of July, 1996.

                                        PAUL MUELLER COMPANY

                                        /S/    DONALD E. GOLIK
                                        _____________________________
                                        Donald E. Golik
                                        Senior Vice President and CFO

Attest:

/S/   RONALD W. GIELOW
____________________________
Ronald W. Gielow
Assistant Secretary