(a) The LP-Gas Safety Rules in this chapter apply to the design, installation, and operation of liquefied petroleum gas systems, equipment, and appliances. These standards also apply to truck and railcar loading racks, but do not apply to marine terminals, natural gasoline plants, refineries, tank farms, gas manufacturing plants, plants engaged in processing liquefied petroleum gases, or to railcar loading racks used in connection with these excluded establishments.
  (1) Subchapter A, General Requirements, applies to various types of LP-gas activities, including licensing, examination, and training requirements.
  (2) Subchapter B, LP-Gas Installations, Containers, Appurtenances, and Equipment Requirements, applies to proposed and existing LP-gas installations, containers, and equipment, including cylinder exchange racks.
  (3) Subchapter C, Vehicles, applies to transports and bobtails that deliver LP-gas, and school buses and other vehicles that are powered by LP-gas.
  (4) Subchapter D, Adoption by Reference of NFPA 54 (National Fuel Gas Code), applies to the adoption by reference of NFPA 54 and specifies additional or alternative requirements from those found in NFPA 54.
  (5) Subchapter E, Adoption by Reference of NFPA 58 (LP-Gas Code), applies to the adoption by reference of NFPA 58 and specifies additional or alternative requirements from those found in NFPA 58.
(b) If any term, clause, or provision of these rules is for any reason declared invalid, the remainder of the provisions shall remain in full force and effect, and shall in no way be affected, impaired, or invalidated.
(c) Nothing in these rules shall be construed as requiring, allowing, or approving the unlicensed practice of engineering or any other professional occupation requiring licensure.
(d) Unless otherwise stated, the LP-Gas Safety Rules in this chapter are not retroactive. Any installation of an LP-gas system, containers, and appliances shall meet the requirements of this chapter at the time of installation.
(e) As stated in Texas Natural Resources Code, Chapter 113, any LP-gas container with a water capacity of one gallon or less, or any LP-gas piping system, or appliance attached or connected to such a container is exempt from the LP-Gas Safety Rules in this chapter, including any adopted NFPA pamphlets. For the purpose of consistency, the figure of 4.20 lb is the equivalent of one gallon of LP-gas.
(f) This chapter shall not apply to vehicles and fuel supply containers that:
  (1) are manufactured or installed by original equipment manufacturers; and
  (2) comply with Title 49, Code of Federal Regulations, the Federal Motor Vehicle Safety Standards.
(g) Vehicles and fuel supply containers excluded from the requirements of this chapter pursuant to subsection (f) of this section shall comply with the requirements of §9.203 of this title (relating to School Bus, Public Transportation, Mass Transit, and Special Transit Vehicle Installations and Inspections), and the Commission's exception to NFPA 58, Chapter 11, in Table 1 in §9.403 of this title relating to Sections in NFPA 58 Not Adopted by Reference, and Adopted with Changes or Additional Requirements.

Source Note: The provisions of this §9.1 adopted to be effective February 1, 2001, 26 TexReg 947; amended to be effective July 28, 2003, 28 TexReg 5867; amended to be effective September 1, 2005, 30 TexReg 4810; amended to be effective February 1, 2008, 33 TexReg 122; amended to be effective January 6, 2020, 45 TexReg 127