1. The director, the chief inspector, or any special deputy inspector shall have free access, during reasonable hours, to any premises in the state where a boiler or pressure vessel is being constructed, or is being installed, for the purpose of ascertaining whether the boiler or pressure vessel is being constructed and installed in accordance with the provisions of sections 650.200 to 650.290.

2. Each boiler and pressure vessel used or proposed to be used within this state, except boilers or pressure vessels exempt under section 650.230, shall be thoroughly inspected as to their construction, installation and condition as follows:

(1) Power boilers and high pressure, high temperature water boilers shall receive a certificate inspection annually and shall also be externally inspected annually while under pressure if possible;

(2) Low pressure steam, hot water heating and hot water supply boilers shall receive a certificate of inspection biennially;

(3) Pressure vessels subject to internal corrosion shall receive a certificate inspection biennially;

(4) Pressure vessels not subject to internal corrosion shall receive a certificate inspection at intervals set by the board, but internal inspection shall not be required of pressure vessels, the contents of which are known to be noncorrosive to the material of which the shell, heads or fittings are constructed, either from the chemical composition of the contents or from evidence that the contents are adequately treated with a corrosive inhibitor, provided that the vessels are constructed in accordance with the rules and regulations of the board;

(5) Nuclear vessels within the scope of sections 650.200 to 650.290 shall be inspected and reported in such form and with such appropriate information as the board shall designate;

(6) A grace period of two months beyond the periods specified in subdivisions (1), (2), (3) and (4) of this subsection may elapse between certificate inspections;

(7) The board may, in its discretion, permit longer periods between certificate inspections;

(8) Under the provisions of sections 650.200 to 650.290, the board is responsible to provide for the safety of life, limb and property and therefore has jurisdiction over the interpretation and application of the inspection requirements as provided for in the rules and regulations which it has promulgated. Inspection during construction and installation shall certify as to the minimum requirements for safety as defined in the construction codes. Inspection requirements of operating equipment shall be in accordance with generally accepted practice and compatible with the actual service conditions, such as:

(a) Previous experience, based on records of inspection, performance and maintenance;

(b) Location, with respect to personnel hazard;

(c) Quality of inspection and operating personnel;

(d) Provision for related safe operation controls;

(e) Interrelation with other operations outside the scope of sections 650.200 to 650.290.

3. The inspections required in this section shall be made by the chief inspector, by a deputy inspector, or by a special inspector provided for in sections 650.200 to 650.290.

4. If at any time a test is deemed necessary for a stated cause by an inspector, it shall be made by the owner or user of the boiler or pressure vessel in the presence of and under the supervision of the inspector. A fee in accordance with the fee schedule adopted pursuant to the provisions of subsection 1 of section 650.275, shall be charged for such supervision.

5. All boilers except cast iron sectional boilers, and pressure vessels to be installed in the state after the twelve-month period from the date upon which the rules and regulations of the board become effective shall be inspected during construction as required by the applicable rules and regulations of the board by an inspector authorized to inspect boilers and pressure vessels in this state, or, if constructed outside of the state, by an inspector holding a commission issued by the National Board of Boiler and Pressure Vessel Inspectors.