Mississippi Code Title 45. Public Safety and Good Order § 45-23-15

(a) Boilers and pressure vessels located on United States Government property and/or under federal government control and pipelines, including compressors and related facilities, which are subject to inspection by any agency of the federal government or other agency of the State of Mississippi;

(b) Pressure vessels used for transportation and storage of compressed gases when constructed in compliance with specifications of the U.S. Department of Transportation and when charged with gas, marked, maintained and when periodically requalified for use, as required by appropriate regulations of the U.S. Department of Transportation;

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

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

(e) Pressure vessels that do not exceed (i) five (5) cubic feet in volume and two hundred fifty (250) psig pressure, or (ii) one and one-half (1- 1/2 ) cubic feet in volume and six hundred (600) psig pressure, or (iii) an inside diameter of six (6) inches or less with no limitation on pressure;

(f) Pressure vessels operating at a working pressure not exceeding fifteen (15) psig;

(g) Vessels with a nominal water-containing capacity of one hundred twenty (120) gallons or less for containing water under pressure, including those containing also air, the compression of which serves only as a cushion;

(h) Boiler and pressure vessels constructed and operated under licenses and permits granted by the U.S. Atomic Energy Commission;

(i) Boilers and pressure vessels used in connection with the production, treating, processing, storage or transportation of oil or natural gas, when located in areas which are remote from places of human habitation or public congregation.

(a) Heating boilers which are located in private residences or in apartment houses of less than six (6) family units;

(b) Pressure vessels containing only water under pressure for domestic supply purposes, including those containing also 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 (6) family units, or those serving rural water systems;

(c) Pressure vessels which are covered under the Liquefied Compressed Gas Equipment Inspection Law of Mississippi, being Sections 75-57-1 through 75-57-63, Mississippi Code of 1972;

(d) Air receiving tanks and attached tanks used in connection with automobile filling stations that do not exceed fifteen (15) cubic feet in volume and two hundred fifty (250) psig pressure and that are used primarily to increase air pressure in automobile tires.