Coverage of Boiler and Pressure Vessel Laws

What is a boiler?

A boiler is a vessel used to heat liquid, create vapor, or superheat vapor by direct application of heat under vacuum or pressure.

What is an unfired steam pressure vessel?

A vessel or container used for the containment of steam pressure in which the pressure is obtained from an external source.

Which boilers and unfired steam pressure vessels are not covered by the regulations?

  • Objects designed to operate and operating at less than 3 psi.
  • Low pressure heating boilers that are not located in a place of public assembly.
  • Water heaters for potable water if the capacity is less than  or equal to 50 gallons, the burner input rating is less than or equal to 50,000 Btu, and the maximum allowable working pressure is less than 160 psi.  Effective July 1, 2018, the capacity limits will increase to 120 gallons and 200,00 Btu's.
  • Heating boilers in a residence.
  • Antique steam engines.
  • Many railway and locomotive boilers.
  • Boilers under federal jurisdiction.
  • Many objects used exclusively for agricultural purposes.
  • Objects that are regulated by the Iowa Department  of Public Health and are designed for heating nonpotable water stored at atmospheric pressure such as water in a swimming pool or hot tub.
  • Unfired steam pressure vessels not greater than 5 cubic feet in volume with pressure of 250 psi or less.
  • Unfired steam pressure vessels not greater than 1.5 cubic feet in volume.

What is a place of public assembly?

The assembly of people in any of the following:

  1. A building or structure primarily used as a theater, motion picture theater, museum, arena, exhibition hall, school, college, dormitory, bowling alley, physical fitness center, family entertainment center, lodge hall, union hall, pool hall, casino, place of worship, funeral home, institution of health and custodial care, hospital, or child care or adult day services facility.
  2. A building or structure, a portion of which is primarily used for amusement, entertainment, or instruction.
  3. A building or structure owned by or leased to the state or any of its agencies or political subdivisions.

However, “public assembly” does not include the assembly of people in buildings or structures containing only eating and drinking establishments or in any building used exclusively by an employer for training or instruction of its own employees.