###### Editorial Note on [Part 173](/current/title-49/part-173?toc=1)

#### Editorial Note:

Nomenclature changes to part 173 appear at [70 FR 56098](https://www.federalregister.gov/citation/70-FR-56098), Sept. 23, 2005.

#### § 173.5a Oilfield service vehicles, mechanical displacement meter provers, and roadway striping vehicles exceptions.

(a) *Oilfield service vehicles.* Notwithstanding [§ 173.29 of this subchapter](/on/2024-09-24/title-49/section-173.29), a cargo tank motor vehicle used in oilfield servicing operations is not subject to the specification requirements of this subchapter provided—

(1) The cargo tank and equipment contains only residual amounts (*i.e.*, it is emptied so far as practicable) of a flammable liquid alone or in combination with water,

(2) No flame producing device is operated during transportation, and

(3) The proper shipping name is preceded by “RESIDUE: LAST CONTAINED \* \* \* ” on the shipping paper for each movement on a public highway.

(b) *Mechanical displacement meter provers.*

(1) A mechanical displacement meter prover, as defined in [§ 171.8 of this subchapter](/on/2024-09-24/title-49/section-171.8), permanently mounted on a truck chassis or trailer and transported by motor vehicle is excepted from the specification packaging requirements in [part 178 of this subchapter](/on/2024-09-24/title-49/part-178) provided it—

(i) Contains only the residue of a Division 2.1 (flammable gas) or Class 3 (flammable liquid) material. For liquids, the meter prover must be drained to not exceed 10% of its capacity or, to the extent that draining of the meter prover is impracticable, to the maximum extent practicable. For gases, the meter prover must not exceed 25% of the marked pressure rating;

(ii) Has a water capacity of 3,785 L (1,000 gallons) or less;

(iii) Is designed and constructed in accordance with chapters II, III, IV, V and VI of ASME Standard B31.4 (IBR, see [§ 171.7 of this subchapter](/on/2024-09-24/title-49/section-171.7));

(iv) Is marked with the MAWP determined from the pipe component with the lowest pressure rating; and

(v) Is equipped with rear-end protection as prescribed in [§ 178.337-10(c) of this subchapter](/on/2024-09-24/title-49/section-178.337-10#p-178.337-10(c)) and [49 CFR 393.86](/on/2024-09-24/title-49/section-393.86) of the Federal Motor Carrier Safety Regulations.

(2) The description on the shipping paper for a meter prover containing the residue of a hazardous material must include the phrase “RESIDUE: LAST CONTAINED \* \* \* ” before the basic description.

(3) *Periodic test and inspection.*

(i) Each meter prover must be externally visually inspected once a year. The external visual inspection must include at a minimum: checking for leakage, defective fittings and welds, defective closures, significant dents and other defects or abnormalities which indicate a potential or actual weakness that could render the meter prover unsafe for transportation; and

(ii) Each meter prover must be pressure tested once every 5 years at not less than 75% of design pressure. The pressure must be held for a period of time sufficiently long to assure detection of leaks, but in no case less than 5 minutes.

(4) In addition to the training requirements in subpart H, the person who performs the visual inspection or pressure test and/or signs the inspection report must have the knowledge and ability to perform them as required by this section.

(5) A meter prover that fails the periodic test and inspection must be rejected and removed from hazardous materials service unless the meter prover is adequately repaired, and thereafter, a successful test is conducted in accordance with the requirements of this section.

(6) Prior to any repair work, the meter prover must be emptied of any hazardous material. A meter prover containing flammable lading must be purged.

(7) Each meter prover successfully completing the external visual inspection and the pressure test must be marked with the test date (month/year), and the type of test or inspection as follows:

(i) V for external visual inspection; and

(ii) P for pressure test.

The marking must be on the side of a tank or the largest piping component in letters 32 mm (1.25 inches) high on a contrasting background.

(8) The owner must retain a record of the most recent external visual inspection and pressure test until the next test or inspection of the same type is successfully completed. The test or inspection report must include the following:

(i) Serial number or other meter prover identifier;

(ii) Type of test or inspection performed;

(iii) Test date (month/year);

(iv) Location of defects found, if any, and method used to repair each defect;

(v) Name and address of person performing the test or inspection;

(vi) Disposition statement, such as “Meter Prover returned to service” or “Meter Prover removed from service”.

(c) *Roadway striping.* In addition to conformance with all other applicable requirements of this subchapter, non-DOT specification cargo tanks used for roadway striping are authorized provided all the following conditions in this [paragraph (c)](/on/2024-09-24/title-49/section-173.5a#p-173.5a(c)) are met.

(1) *Authorized materials.* Only the hazardous materials listed in the table 1 to this [paragraph (c)(1)](/on/2024-09-24/title-49/section-173.5a#p-173.5a(c)(1)) may be transported in roadway striping vehicles. Cargo tanks may not be filled to a capacity that would be greater than liquid full at 130 °F.

Table 1 to Paragraph (c)(1)—Hazardous Materials Description

| Proper shipping name | Hazard class/ division | Identification No. | Packing group |
| --- | --- | --- | --- |
| Acetonea | 3 | UN1090 | II. |
| Adhesives, *containing a flammable liquid* | 3 | UN1133 | II. |
| Amines, liquid, corrosive, n.o.s.b or Polyamines, liquid, corrosive, n.o.sb | 8 | UN2735 | III. |
| Corrosive liquid, basic, organic, n.o.sb | 8 | UN3267 | III. |
| Corrosive liquids, n.o.sb | 8 | UN1760 | III. |
| Dichloromethanea | 6.1 | UN1593 | III. |
| Elevated temperature liquid, n.o.s., *at or above 100 °C and below its flash point (including molten metals, molten salts, etc.)*c | 9 | UN3257 | III. |
| Environmentally hazardous substance, liquid, n.o.sb | 9 | UN3082 | III. |
| Ethyl acetatea | 3 | UN1173 | II. |
| Ethyl methyl ketone or Methyl ethyl ketonea | 3 | UN1193 | II. |
| Flammable liquids, n.o.sd | 3 | UN1993 | II. |
| Gasoline | 3 | UN1203 | II. |
| Methanola | 3 | UN1230 | II. |
| Organic peroxide type E, liquid (Dibenzoyl peroxide)b | 5.2 | UN3107 | NA. |
| Paint *including paint, lacquer, enamel, stain, shellac solution, varnish, polish, liquid filler, and liquid lacquer base* | 3 | UN1263 | II. |
| Paint related material *including paint thinning drying, removing, or reducing compound* | 3 | UN1263 | II. |
| Petroleum distillates, n.o.s. *or* Petroleum products, n.o.sa | 3 | UN1268 | III. |
| Toluenea | 3 | UN1294 | II. |
| 1,1,1-Trichloroethanea | 6.1 | UN2831 | III. |
| Xylenesa | 3 | UN1307 | II, III. |
| | | | |
| --- | --- | --- | --- |
| a: Solvent. | | | |
| b: Catalyst. | | | |
| c: Thermoplastic material non-hazardous at room temperature. | | | |
| d: Adhesive containing ethyl acetate. | | | |

(2) *Cargo tank requirements.* Each non-DOT specification cargo tank used for roadway striping must be securely bolted to a motor vehicle and must—

(i) Be constructed and certified in conformance with the HMR in effect at the time of its manufacture and must be marked accordingly. For questions regarding these requirements, contact PHMSA by either: (1) Telephone (800) 467-4922 or (202) 366-4488 (local); or (2) by electronic mail (e-mail) to: *[infocntr@dot.gov](mailto:infocntr@dot.gov)*;

(ii) Have a minimum design pressure of 100 psig;

(iii) Have a maximum capacity of 500 gallons;

(iv) For solvents and organic peroxides, the cargo tank may not contain more than 50 gallons;

(v) Be given an external visual inspection prior to each use to ensure that it has not been damaged on the previous trip;

(vi) Be retested and reinspected in accordance with [§ 180.407(c) of this subchapter](/on/2024-09-24/title-49/section-180.407#p-180.407(c)) as specified for an MC 331 cargo tank motor vehicle; and

(vii) Be securely mounted to a motor vehicle in accordance with the securement provisions prescribed in [§§ 393.100](/on/2024-09-24/title-49/section-393.100) through [393.106 of this title](/on/2024-09-24/title-49/section-393.106).

(3) *Test records.* The owner or operator of the roadway striping vehicle must maintain hydrostatic test records in accordance with [§ 180.417(b)](/on/2024-09-24/title-49/section-180.417#p-180.417(b)) and must make those records available to any representative of the Department of Transportation upon request.

(4) *Marking.* A non-DOT specification cargo tank used for roadway striping must be plainly marked on both sides near the middle in letters at least two inches in height on a contrasting background “ROADWAY STRIPING”.

(5) *Operational controls.* A non-DOT specification cargo tank used for roadway striping may not be pressurized when the motor vehicle is traveling to and from job sites. Additionally, the distance traveled by a non-DOT specification cargo tank used for roadway striping may not exceed 750 miles. Thermoplastic resin may only be heated during roadway striping operations.

[[70 FR 3308](https://www.federalregister.gov/citation/70-FR-3308), Jan. 24, 2005, as amended at [75 FR 27213](https://www.federalregister.gov/citation/75-FR-27213), May 14, 2010; [76 FR 5492](https://www.federalregister.gov/citation/76-FR-5492), Feb. 1, 2011; [83 FR 55807](https://www.federalregister.gov/citation/83-FR-55807), Nov. 7, 2018]