| Exhibit                  (10.ac) |
|----------------------------------|

**THIRD      AMENDMENT TO THE**

**MET-PRO      CORPORATION SALARIED PENSION PLAN**

**Amended      and Restated Effective September 1, 2000**

| This                Third Amendment to the Met-Pro Corporation Salaried Pension Plan                (the                “Plan”) is made by Met-Pro Corporation (the “Company”) and is effective as                of March 28, 2005. **WITNESSETH****WHEREAS,**                the Company maintains the Plan for the benefit of its eligible                employees;**WHEREAS,**Section                16.1 of the Plan permits the Company to amend the Plan; and **WHEREAS,**the                Company desires to amend the Plan, effective March 28, 2005, to eliminate                the mandatory distribution of benefits with an Actuarial Equivalent                present value not exceeding $5,000.**NOW                THEREFORE,**the                Plan is hereby amended, effective March 28, 2005, as follows:1.    Section                8.1 is amended by deleting the following parenthetical                phrase:“(if                the Actuarial Equivalent present value of such benefit as of the                Participant’s Annuity Starting Date or at the time of any prior                distribution is in excess of $5,000)”2.    Section                8.2 is deleted in its entirety and it is retitled “Reserved.”3.    The                second sentence of Section 8.3 is amended to read as follows:A                Participant’s Annuity Starting Date shall be the earliest of (a) the first                day of the month coincident with or next following the day of the                Participant’s Retirement, (b) the first day of the month coincident with                or next following the Participant’s Normal Retirement Date if the                Participant has a Separation from Service prior to that time, unless                the                Participant elects under Section 8.4 to commence to receive distribution                prior to his Normal Retirement Date, and (c) effective for all                Participants (except Participants that attained age 70½ after January 1,                1988 and before January 1, 2003, or Participants who are Five Percent                Owners during the Plan Year ending with or within the calendar year                in                which they attain age 70½ or subsequent Plan Year), the first day of April                immediately following the calendar year in which the Participant                retires                or attains age 70½, whichever occurs later.4.    The                first sentence of Section 8.4 is amended to read as follows:A                Participant who has a Separation from Service before his Normal Retirement                Date with a Vested Interest may elect to have distribution of his                Retirement Benefit commence before his Normal Retirement                Date.**IN                WITNESS WHEREOF,**                the Company has caused this Third Amendment to be executed by its                duly                authorized officer this 31st                day of August, 2005. |
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|-------------|---------------------------------|----------------------------------------|--------|-------------------------------------|--------|-----------|
| **ATTEST:** |                            | **Met-Pro                Corporation** |
|        |                            |                                   |   |                                |   |      |
| By          | /s/              Gary J. Morgan |                                   | By     | /s/              Raymond J. De Hont |
|        |                            |                                   |   |                                |   |      |
| Title:      |                            | Vice                President-Finance  |   | Title:                              |   | President |