Ohio Revised Code Title XLI. Labor and Industry § 4104.04

(1) Boilers, pressure vessels, and stationary steam engines under federal control or subject to inspection under federal laws;

(2) Air tanks located on vehicles operating under the rules of other state authorities and used for carrying passengers, or freight;

(3) Air tanks installed on the right of way of railroads and used directly in the operation of trains;

(4) Pressure vessels that are under the regulation and control of the state fire marshal under Chapter 3737. of the Revised Code.

(1) Portable boilers or pressure vessels when located on farms and used solely for agricultural purposes;

(2) Steam or vapor boilers carrying a pressure of not more than fifteen psig, which are located in private residences or in apartment houses of less than six family units;

(3) Hot water boilers operated at pressures not exceeding one hundred sixty psig, or temperatures not exceeding two hundred fifty degrees fahrenheit, which are located in private residences or in apartment houses of less than six family units;

(4) Pressure vessels containing only water under pressure for domestic supply purposes, including those containing air, the compression of which serves only as a cushion or airlift pumping system, when located in private residences or in apartment houses of less than six family units;

(5) Portable boilers used in pumping, heating, steaming, and drilling, in the open field, for water, gas, and oil;

(6) Portable boilers used in the construction of and repair to public roads, railroads, and bridges;

(7) Historical steam boilers of riveted construction, preserved, restored, or maintained for hobby or demonstration use.