Any registration certificate issued to a mechanical contractor under the provisions of this chapter shall be revoked by the mayor and city council should the holder of such registration certificate permit the insurance policy herein required to expire or lapse. Any corporation, firm, or partnership which may be registered hereunder as a mechanical contractor in the name of such corporation, firm, or partnership, shall have a master mechanical fitter who has submitted to the examination given by the examining board for mechanical fitters and has thereby shown himself or herself fit, competent and qualified to engage in the business, trade, or calling of mechanical work, HVAC installation and gas piping as a bona fide officer of such corporation or as a member of such firm or partnership and who shall at all times be in actual charge of and be responsible for the installation, removal, or repair of any mechanical work or HVAC installation or gas piping work done by such corporation, firm or partnership. Before such corporation, firm, or partnership shall be registered in its corporate, firm, or partnership name as a mechanical contractor, there shall be filed with the chief building official a certificate from the examining board of mechanical fitters showing the fitness and competency of such officer of such corporation or such member of such firm or partnership to engage in the business or calling of master mechanical fitter; provided, if, after a certificate of registration is issued such corporation, such member of such firm or partnership shall withdraw there from and cease to be connected therewith, then and in that event, the mayor and city council shall forthwith revoke the certificate of registration of such corporation, firm, or partnership upon the request of the chief building official.