Exhibit 3.4

BY-LAWS

OF

AIR-RELIEF, INC.

ARTICLE I

OFFICES

The registered office of the corporation in the Commonwealth of Kentucky shall be at the address stated in its Articles of Incorporation but such address may be changed from time to time by the Board of Directors.

The corporation shall have a principal office, and such other offices, either within or without the Commonwealth of Kentucky, as the Board of Directors may designate or the business of the corporation may require from time to time. The principal office of the corporation may be, but need not be, the same as its registered office and, until otherwise determined, shall be located at Route #6, Box 10, Murray, in Calloway County, Kentucky.

ARTICLE II

SHAREHOLDERS

SECTION 1.    ANNUAL MEETING. The annual meeting of shareholders shall be held on the second Wednesday ( Wed.) of August in each year, beginning with the year 1985, at the hour of 9 A.M., local time, for the election of directors and such other business as may properly come before the meeting. If the day fixed for the annual meeting shall be a legal holiday, such meeting shall be held on the next succeeding business day. If the election of directors shall not be held on the day designated for any annual meeting, or at any adjournment thereof, the Board of Directors shall cause the election to be held at a special meeting of the shareholders as soon thereafter as may be practicable. The annual meeting shall be held at the law office of Lookofsky & Null, Mayfield, Kentucky.

SECTION 2.     SPECIAL MEETINGS. Special meetings of the shareholders may be called by the Board of Directors, by the president or by the holders of not less than one-fifth of the outstanding shares entitled to vote at such meeting.

SECTION 3.     PLACE OF MEETING. The Board of Directors or the president may designate any place, either within or without the Commonwealth of Kentucky, as the place of meeting for any annual meeting, or for any special meeting called by the Board of Directors or by the president, respectively. A waiver of notice signed by all shareholders entitled to vote at a meeting may designate any place, either within or without the Commonwealth of Kentucky, as the place for the holding of such meeting. If no designation is made, or if a special meeting be otherwise called, the place of meeting shall be the principal office of the corporation, except as otherwise provided in Section 5. of this Article.

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SECTION 4.     NOTICE OF MEETING. Written notice stating the place, day and hour of the meeting and, in case of a special meeting, the purpose or purposes for which the meeting is called, shall be delivered not less than ten nor more than fifty days before the date of the meeting, either personally or by mail, by or at the direction of the president, secretary, or the persons calling the meeting. If mailed, such notice shall be deemed to be delivered when deposited in the United States mail addressed to the shareholder at his address as it appears on the stock transfer books of the corporation, with postage thereon prepaid.

SECTION 5.     MEETING OF ALL SHAREHOLDERS. If all of the shareholders shall meet at any time and place, either within or without the Commonwealth of Kentucky, and consent to the holding of a meeting, such meeting shall be valid without call or notice and at such meeting any corporate action may be taken.

SECTION 6.     CLOSING OF TRANSFER BOOKS OR FIXING OF RECORD DATE. For the purpose of determining shareholders entitled to notice of or to vote at any meeting of shareholders or any adjournment thereof, or shareholders entitled to receive payment of any dividend, or in order to make a determination of shareholders for any other proper purpose, the Board of Directors of the corporation may provide that the stock transfer books shall be closed for a stated period but not to exceed, in any case, fifty days. If the stock transfer books shall be closed for the purpose of determining shareholders entitled to notice of or to vote at a meeting of shareholders, such books shall be closed for at least ten days immediately preceding such meeting. In lieu of closing the stock transfer books, the Board of Directors may fix in advance a date as the record date for any such determination of shareholders, such date in any case to be not more than fifty days and, in case of a meeting of shareholders, not less than ten days prior to the date on which the particular action, requiring such determination of shareholders, is to be taken. If the stock transfer books are not closed and no record date is fixed for the determination of shareholders entitled to notice of or to vote at a meeting of shareholders, or shareholders entitled to receive payment of a dividend, the first date on which notice of the meeting is mailed or the date on which the resolution of the Board of Directors declaring such dividend is adopted, as the case may be, shall be the record date for such determination of shareholders. When a determination of shareholders entitled to vote at any meeting of shareholders has been made as provided in this section, such determination shall apply to any adjournment thereof.

SECTION 7.     VOTING RECORD. The officer or agent having charge of the stock transfer books for shares of the corporation shall make a complete record of the shareholders entitled to vote at each meeting of shareholders or any adjournment thereof, arranged in alphabetical order, with the address of and the number of shares held by each. Such record shall be produced and kept open at the time and place of the meeting and shall be subject to the inspection of any shareholder during the whole time of the meeting for the purposes thereof. The original stock transfer books shall be prima facie evidence as to who are the shareholders entitled to examine such list or stock transfer books or to vote at any meeting of shareholders.

SECTION 8.     QUORUM. A majority of the outstanding shares of the corporation entitled to vote, represented in person or by proxy, shall constitute a quorum at a meeting of shareholders. If less than a majority of the outstanding shares are represented at a meeting, a majority of the shares so represented may adjourn the meeting from time to time without further notice. At such adjourned meeting at which a quorum shall be present or represented, any business may be transacted which might have been transacted at the meeting as originally noted. The shareholders

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present at a duly organized meeting may continue to transact business until adjournment, notwithstanding the withdrawal of enough shareholders to leave less than a quorum.

SECTION 9.     PROXIES. At all meetings of shareholders, a shareholder may vote in person or by proxy executed in writing by the shareholder or by his duly authorized attorney-in-fact. Such proxy shall be filed with the secretary of the corporation before or at the time of the meeting. No proxy shall be valid after eleven months from the date of its execution, unless otherwise provided in the proxy. The revocation of a proxy shall not be effective until the secretary of the corporation has received written notice of the revocation.

SECTION 10. VOTING OF SHARES. Subject to the provisions of Section 12., each outstanding share entitled to vote shall be entitled to one vote upon each matter submitted to a vote at a meeting of shareholders.

SECTION 11. VOTING OF SHARES BY CERTAIN HOLDERS. Shares standing in the name of another corporation may be voted by either the president of such corporation or by proxy appointed by him unless the Board of Directors of such corporation should determine otherwise, in which event any other person authorized to vote such shares shall produce a certified copy of a resolution of the Board of Directors of such corporation so indicating.

Shares held by an administrator, executor, guardian, conservator, or committee may be voted by him, either in person or by proxy, without a transfer of such shares into his name. Shares standing in the name of a trustee may be voted by him, either in person or by proxy, but no trustee shall be entitled to vote shares held by him without a transfer of such shares into his name.

Shares standing in the joint names of three or more fiduciaries shall be voted in the manner determined by the majority of such fiduciaries, unless the instrument or order appointing such fiduciaries otherwise directs.

Shares standing in the name of a receiver may be voted by such receiver, and shares held by or under the control of a receiver may be voted by such receiver without the transfer thereof into his name if authority so to do be contained in an appropriate order of the court by which such receiver was appointed.

A shareholder whose shares are pledged shall be entitled to vote such shares until the shares have been transferred into the name of the pledgee, and thereafter the pledgee shall be entitled to vote the shares so transferred.

SECTION 12. CUMULATIVE VOTING. At each election for directors each shareholder entitled to vote at such election shall have the right to cast, in person or by proxy, as many votes in the aggregate as he shall be entitled to vote under the corporation’s Articles of Incorporation, multiplied by the number of directors to be elected at such election; and each shareholder may cast the whole number of votes for one candidate, or distribute such votes among two or more candidates.

SECTION 13. INFORMAL ACTION BY SHAREHOLDERS. Any action required or permitted to be taken at a meeting of the shareholders may be taken without a meeting if a consent in writing, setting forth the action so taken, shall be signed by all of the shareholders entitled to vote with respect to the subject matter thereof.

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ARTICLE III

DIRECTORS

SECTION 1.     GENERAL POWERS. The business and affairs of the corporation shall be managed by its Board of Directors.

SECTION 2.     NUMBER, TENURE AND QUALIFICATIONS. The number of directors of the corporation shall be five, but may be increased or decreased from time to time by amendment to this By-Law, but no decrease shall have the effect of shortening the term of any incumbent director. Each director shall hold office until the next annual meeting of shareholders and until his successor shall have been elected and qualified. Directors need not be residents of Kentucky nor shareholders of the corporation.

SECTION 3.     REGULAR MEETINGS. A regular meeting of the Board of Directors shall be held without other notice than this By-Law, immediately after, and at the same place as, the annual meeting of shareholders. The Board of Directors may provide, by resolution, the time and place, either within or without the Commonwealth of Kentucky, for the holding of additional regular meetings without other notice than such resolution.

SECTION 4.     SPECIAL MEETINGS. Special meetings of the Board of Directors may be called by or at the request of the president or any two directors. The person or persons authorized to call special meetings of the Board of Directors may fix any place, either within or without the Commonwealth of Kentucky, as the place for holding any special meeting of the Board of Directors called by them.

SECTION 5.     NOTICE. Notice of any special meeting shall be given at least two days previously thereto by written notice delivered personally or mailed to each director at his business address, or by telegram. If mailed, such notice shall be deemed to be delivered when deposited in the United States mail in a sealed envelope, so addressed, with postage thereon prepaid. If notice be given by telegram, such notice shall be deemed to be delivered when the telegram is delivered to the telegraph company. Any director may waive notice of any meeting. The attendance of a director at any meeting shall constitute a waiver of notice of such meeting, except where a director attends a meeting for the express purpose of objecting to the transaction of any business because the meeting is not lawfully called or convened. Neither the business to be transacted at, nor the purpose of, any regular or special meeting of the Board of Directors need be specified in the notice or waiver of notice of such meeting.

SECTION 6.     QUORUM. A majority of the Board of Directors fixed by Section 2. of this Article III shall constitute a quorum for the transaction of business at any meeting of the Board of Directors, but if less than such majority is present at a meeting, a majority of the directors present may adjourn the meeting from time to time without further notice.

SECTION 7.     MANNER OF ACTING. The act of the majority of the directors present at a meeting at which a quorum is present shall be the act of the Board of Directors.

SECTION 8.     ACTION WITHOUT A MEETING. Any action required or permitted to be taken by the Board of Directors, or by a committee thereof, at a meeting may be taken without a meeting if a consent in writing, setting forth the action taken, shall be signed by all of the directors,

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or by all of the members of the committee, as the case may be. Such consent shall have the same effect as a unanimous vote.

SECTION 9.     VACANCIES. Any vacancy occurring in the Board of Directors may be filled by the affirmative vote of a majority of the remaining directors though less than a quorum of the Board of Directors. A director elected to fill a vacancy shall be elected for the unexpired term of his predecessor in office. Any directorship to be filled by reason of an increase in the number of directors may be filled by election by the Board of Directors for a term of office continuing only until the next election of the directors by the shareholders.

SECTION 10. COMPENSATION. Directors, as such, shall not receive a stated salary for their services but, by resolution of the Board of Directors, each director may be paid his expenses, if any, of attendance at each meeting of the Board of Directors or any committee thereof, and may be paid a fixed sum for attendance at each such meeting, or both. No such payment shall preclude any director from serving the corporation in any other capacity and receiving compensation therefor.

SECTION 11. EXECUTIVE AND OTHER COMMITTEES. The Board of Directors, by resolution adopted by a majority of the entire Board of Directors, may designate from among its members an executive committee and one or more other committees each of which, to the extent provided in such resolution, shall have and may exercise all the authority of the Board of Directors, but no such committee shall have the authority of the Board of Directors in reference to amending the Articles of Incorporation, adopting a plan of merger or consolidation, recommending to the shareholders the sale, lease, exchange or other disposition of all or substantially all the property and assets of the corporation otherwise than in the usual and regular course of business, recommending to the shareholders a voluntary dissolution of the corporation or a revocation thereof, or amending the By-Laws.

ARTICLE IV

OFFICERS

SECTION 1.     NUMBER. The officers of the corporation shall be a president, one or more vice-presidents (the number thereof to be determined by the Board of Directors), a secretary, and a treasurer, each of whom shall be elected by the Board of Directors. Such other officers and assistant officers as may be deemed necessary may be elected or appointed by the Board of Directors. Any two or more offices may be held by the same person, except the offices of president and secretary.

SECTION 2.     ELECTION AND TERM OF OFFICE. The officers of the corporation to be elected by the Board of Directors shall be elected annually by the Board of Directors at the first meeting of the Board of Directors held after each annual meeting of shareholders. If the election of officers shall not be held at such meeting, such election shall be held as soon thereafter as practicable. Each officer shall hold office until his successor shall have been duly elected and shall have qualified or until his death or until he shall resign or shall have been removed in the manner hereinafter provided.

SECTION 3.     REMOVAL. Any officer or agent may be removed by the Board of Directors whenever in its judgment the best interests of the corporation will be served thereby, but

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such removal shall be without prejudice to the contract rights, if any, of the person so removed. Election or appointment of an officer or agent shall not of itself create contract rights.

SECTION 4.     VACANCIES. A vacancy in any office because of death, resignation, removal, disqualification or otherwise, may be filled by the Board of Directors for the unexpired portion of the term.

SECTION 5.     PRESIDENT. The president shall be the principal executive officer of the corporation and, subject to the control of the Board of Directors, shall in general supervise and control all of the business and affairs of the corporation. He shall, when present, preside at all meetings of the shareholders and of the Board of Directors. He may sign, with the secretary or any other proper officer of the corporation thereunto authorized by the Board of Directors, certificates for shares of the corporation, and deeds, mortgages, bonds, contracts, or other instruments which the Board of Directors has authorized to be executed, except in cases where the signing and execution thereof shall be expressly delegated by the Board of Directors or by these By-Laws to some other officer or agent of the corporation, or shall be required by law to be otherwise signed or executed; and in general shall perform all duties incident to the office of president and such other duties as may be prescribed by the Board of Directors from time to time.

SECTION 6.     VICE-PRESIDENTS. In the absence of the president or in the event of his death, inability or refusal to act, the vice-president (or in the event there be more than one vice-president, the vice-presidents in the order designated at the time of their election, or in the absence of any designation, then in the order of their election) shall perform the duties of the president, and when so acting, shall have all the powers of and be subject to all the restrictions upon the president. Any vice-president may sign, with the secretary or an assistant secretary, certificates for shares of the corporation; and shall perform such other duties as from time to time may be assigned to him by the president or by the Board of Directors.

SECTION 7.     SECRETARY. The secretary shall: (a) keep the minutes of the proceedings of the shareholders and of the Board of Directors in one or more books provided for that purpose; (b) see that all notices are duly given in accordance with the provisions of these By-Laws or as required by law; (c) be custodian of the corporate records and of the seal of the corporation and see that the seal of the corporation is affixed to all certificates for shares prior to the issue thereof and to all documents, the execution of which on behalf of the corporation under its seal is duly authorized; (d) keep a register of the post office address of each shareholder which shall be furnished to the secretary by such shareholder; (e) sign with the president, or a vice-president, certificates for shares of the corporation, the issuance of which shall have been authorized by resolution of the Board of Directors; (f) have general charge of the stock transfer books of the corporation; and (g) in general perform all duties incident to the office of secretary and such other duties as from time to time may be assigned to him by the president or by the Board of Directors.

SECTION 8.     TREASURER. The treasurer shall: (a) have charge and custody of and be responsible for all funds and securities of the corporation; (b) receive and give receipts for moneys due and payable to the corporation from any source whatsoever, and deposit all such moneys in the name of the corporation in such banks, trust companies or other depositaries as shall be selected in accordance with the provisions of Article V of these By-Laws; (c) in general perform all duties incident to the office of treasurer and such other duties as from time to time may be assigned to him by the president or by the Board of Directors. If required by the Board of Directors, the treasurer

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shall give a bond for the faithful discharge of his duties in such sum and with such surety or sureties as the Board of Directors shall determine.

SECTION 9.     ASSISTANT SECRETARIES AND ASSISTANT TREASURERS. The assistant secretaries, when authorized by the Board of Directors, may sign with the president or a vice-president certificates for shares of the corporation, the issuance of which shall have been authorized by a resolution of the Board of Directors. The assistant treasurers shall respectively, if required by the Board of Directors, give bonds for the faithful discharge of their duties in such sums and with such sureties as the Board of Directors shall determine. The assistant secretaries and assistant treasurers, in general, shall perform such duties as shall be assigned to them by the secretary or treasurer, respectively, or by the president or by the Board of Directors.

SECTION 10. SALARIES. The salaries of the officers shall be fixed from time to time by the Board of Directors and no officer shall be prevented from receiving such salary by reason of the fact that he is also a director of the corporation.

ARTICLE V

CONTRACTS, LOANS, CHECKS AND DEPOSITS

SECTION 1.     CONTRACTS. The Board of Directors may authorize any officer or officers, agent or agents, to enter into any contract or execute and deliver any instrument in the name of and on behalf of the corporation, and such authority may be general or confined to specific instances.

SECTION 2.     LOANS. No loans shall be contracted on behalf of the corporation and no evidences of indebtedness shall be issued in its name unless authorized by a resolution of the Board of Directors. Such authority may be general or confined to specific instances.

SECTION 3.     CHECKS, DRAFTS, ETC. All checks, drafts, or other orders for the payment of money, notes or other evidences of indebtedness issued in the name of the corporation shall be signed by such officer or officers, agent or agents, of the corporation and in such manner as shall from time to time be determined by resolution of the Board of Directors.

SECTION 4.     DEPOSITS. All funds of the corporation not otherwise employed shall be deposited from time to time to the credit of the corporation in such banks, trust companies, or other depositaries as the Board of Directors may select.

ARTICLE VI

CERTIFICATES FOR SHARES AND THEIR TRANSFER

SECTION 1.     CERTIFICATES FOR SHARES. Certificates representing shares of the corporation shall be in such form as shall be determined by the Board of Directors. Such certificates shall be signed by the president or a vice-president and by the secretary or an assistant secretary and sealed with the corporate seal or a facsimile thereof. The signatures of such officers upon a certificate may be facsimiles if the certificate is manually signed on behalf of a transfer agent or a registrar, other than the corporation itself or one of its employees. Each certificate for shares shall be consecutively numbered or otherwise identified. The name and address of the person to

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whom the shares represented thereby are issued, with the number of shares and date of issue, shall be entered on the stock transfer books of the corporation. All certificates surrendered to the corporation for transfer shall be cancelled and no new certificate shall be issued until the former certificate for a like number of shares shall have been surrendered and cancelled, except that in case of a lost, destroyed or mutilated certificate a new one may be issued therefor upon such terms and indemnity to the corporation as the Board of Directors may prescribe.

SECTION 2.     TRANSFER OF SHARES. Transfer of shares of the corporation shall be made only on the stock transfer books of the corporation by the holder of record thereof or by his legal representative, who shall furnish proper evidence of authority to transfer, or by his attorney thereunto authorized by power of attorney duly executed and filed with the secretary of the corporation, and on surrender for cancellation of the certificate for such shares. The person in whose name shares stand on the books of the corporation shall be deemed by the corporation to be the owner thereof for all purposes.

ARTICLE VII

FISCAL YEAR

The fiscal year of the corporation shall begin on the first day of January and end on the 31st day of December in each year.

ARTICLE VIII

DIVIDENDS

The Board of Directors may from time to time declare, and the corporation may pay, dividends on its outstanding shares in the manner and upon the terms and conditions provided by law and its Articles of Incorporation.

ARTICLE IX

CORPORATE SEAL

The Board of Directors shall provide a corporate seal which shall be circular in form and shall have inscribed thereon the name of the corporation and the state of incorporation and the words “Corporate Seal”.

ARTICLE X

WAIVER OF NOTICE

Whenever any notice is required to be given to any shareholder or director of the corporation under the provisions of these By-Laws, or under the provisions of the Articles of Incorporation, or under the provisions of the Kentucky Business Corporation Act, a waiver thereof in writing signed by the person or persons entitled to such notice, whether before or after the time stated therein, shall be deemed equivalent to the giving of such notice.

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ARTICLE XI

INDEMNIFICATION OF DIRECTORS AND OFFICERS

The corporation shall indemnify each of its directors and officers who was or is a party or is threatened to be made a party to any threatened, pending or completed action, suit, or proceeding, whether civil, criminal, administrative or investigative (other than an action by or in the right of the corporation) by reason of the fact that he is or was a director or officer of the corporation, or is or was serving at the request of the corporation as a director, officer, employee or agent of another corporation, partnership, joint venture, trust or other enterprise, against expenses (including attorneys’ fees), judgments, fines and amounts paid in settlement actually and reasonably incurred by him in connection with such action, suit or proceeding if he acted in good faith and in a manner he reasonably believed to be in or not opposed to the best interests of the corporation, and with respect to any criminal action or proceeding, had no reasonable cause to believe his conduct was unlawful.

Except as provided herein below, any such indemnification shall be made by the corporation only as authorized in the specific case upon a determination that indemnification of the director or officer is proper in the circumstances because he has met the applicable standard of conduct set forth above. Such determination shall be made: (a) by the Board of Directors by a majority vote of a quorum of directors who were or are not parties to such action, suit, or proceeding, or (b) by the shareholders.

Expenses (including attorneys’ fees) incurred in defending a civil or criminal action, suit, or proceeding may be paid by the corporation in advance of the final disposition of such action, or proceeding if authorized by the Board of Directors and upon receipt of an undertaking by or on behalf of the director or officer to repay such amount unless it shall ultimately be determined that he is entitled to be indemnified by the corporation.

To the extent that a director or officer has been successful on the merits or otherwise in defense of any action, suit or proceeding referred to above, or in defense of any claim issue or matter therein, he shall be indemnified against expenses (including attorneys’ fees) actually and reasonably incurred by him in connection therewith, without any further determination that he has met the applicable standard of conduct set forth above.

ARTICLE XII

AMENDMENTS

The shareholders may alter, amend or repeal the By-Laws at any annual or special meeting of shareholders at which a majority of the outstanding shares of the corporation is present by the vote of such majority, provided that the notice of such meeting shall have included notice of such proposed amendment. The Board of Directors shall have the power and authority to alter, amend or repeal By-Laws of the corporation at any regular or special meeting at which a quorum is present by the vote of a majority of the entire Board of Directors, subject always to the power of the shareholders under Kentucky law to repeal or change such By-Laws.

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WRITTEN CONSENT OF THE SOLE SHAREHOLDER OF

AIR-RELIEF, INC.

The undersigned, being the sole shareholder of Air-Relief, Inc. a Kentucky corporation (the “Company”), does hereby consent, in accordance with the provision of Article XII of the By-Laws of the Company, to the adoption of the following resolutions by unanimous written consent in lieu of a meeting.

By-Laws Amendment

Be it RESOLVED, that the By-Laws be amended to state the following:

a) Article II, Section 1, Annual Meeting: An annual meeting of the shareholders, commencing with the year 1985, shall be held each year on a date to be selected by the Board of Directors. At the meeting, the shareholders shall elect directors and transact such other business as may properly be brought before the meeting.

b) Article III, Section 2, Number, Tenure and Qualification: The Board of Directors shall consist of not more than five (5) nor less than two (2) directors, none of whom need be shareholders or residents of the State of Kentucky. Each director shall be elected at the annual meeting of the shareholders and shall hold office until the earlier of such director’s death, resignation, removal or the date on which his successor shall be elected and qualified.

Ratification of Acts of Directors and Officers

RESOLVED that all acts and proceedings of the directors and officers of the Company done and performed since the 16th day of August, 2004, to present date as evidenced by the minutes and books of account of the Company be and the same are hereby approved, ratified, sanctioned and confirmed.

The resolutions adopted by virtue of this Written Consent of the Sole Shareholder shall have the same force and effect as if adopted at an official meeting of said shareholder pursuant to the laws of the State of Kentucky.

IN WITNESS WHEREOF, the undersigned has executed this consent to be effective as of Monday, August 16, 2004.

Gardner Denver, Inc. holding 180 shares

By:

Tracy D. Pagliara

Vice President, General Counsel & Secretary

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