Our portable propane cylinders need to be re-certified after a certain number of years, so I started looking for the answer. I found that portable cylinders and tanks are a much different beast.
Tanks that are permanently affixed to trailers are referred to as American Society of Mechanical Engineers (ASME) tanks and do not require testing. Although ASME tanks do not require testing, they should be inspected for excessive pitting or physical damage.
Portable cylinders are those that are not permanently affixed to your trailer. Portable cylinders are referred to as "DOT Cylinders" and are regulated by 49 CFR 180.209(e). DOT cylinders are also found on outdoor grills, space heaters, etc.
Federal Code of Regulations 49 CFR 180.209(e) table below shows how often portable cylinders need to be tested. The link provided has more detail and references to many other regulations.
https://www.ecfr.gov/current/title-...bchapter-C/part-180/subpart-C/section-180.209
Mine is a type 4BW and has to be tested per these terms:
Tanks that are permanently affixed to trailers are referred to as American Society of Mechanical Engineers (ASME) tanks and do not require testing. Although ASME tanks do not require testing, they should be inspected for excessive pitting or physical damage.
Portable cylinders are those that are not permanently affixed to your trailer. Portable cylinders are referred to as "DOT Cylinders" and are regulated by 49 CFR 180.209(e). DOT cylinders are also found on outdoor grills, space heaters, etc.
Federal Code of Regulations 49 CFR 180.209(e) table below shows how often portable cylinders need to be tested. The link provided has more detail and references to many other regulations.
https://www.ecfr.gov/current/title-...bchapter-C/part-180/subpart-C/section-180.209
Specification under which cylinder was made | Minimum test pressure (psig)2 | Requalification period (years) |
---|---|---|
3 | 3000 psig | 5. |
3A, 3AA | 5/3 times service pressure, except non-corrosive service | 5, 10, or 12 |
3AL | 5/3 times service pressure | 5 or 12 |
3AX, 3AAX | 5/3 times service pressure | 5. |
3B, 3BN | 2 times service pressure | 5 or 10 |
3E | Test not required | |
3HT | 5/3 times service pressure | 3 |
3T | 5/3 times service pressure | 5. |
4AA480 | 2 times service pressure | 5 or 10 |
4B, 4BA, 4BW, 4B–240ET | 2 times service pressure, except non-corrosive service | 5, 7, 10, or 12 |
4D, 4DA, 4DS | 2 times service pressure | 5. |
4E | 2 times service pressure, except non-corrosive service | 5, 10, or 12 |
4L | Test not required | |
8, 8AL | 10 or 20 | |
Exemption or special permit cylinder | See current exemption or special permit | See current exemption or special permit. |
Foreign cylinder | As marked on cylinder, but not less than5⁄3 of any service or working pressure marking | 5 |
Mine is a type 4BW and has to be tested per these terms:
Cylinders in non-corrosive gas service. A cylinder made in conformance with DOT Specifications 4B, 4BA, 4BW, or 4E protected externally by a suitable corrosion-resistant coating and used exclusively for non-corrosive gas that is commercially free from corroding components may be requalified by volumetric expansion testing every 12 years instead of every 5 years. As an alternative, the cylinder may be subjected to a proof pressure test at least two times the marked service pressure, but this latter type of test must be repeated every 10 years after expiration of the initial 12-year period. When subjected to a proof pressure test, as prescribed in CGA C–1, the cylinder must be carefully examined under test pressure and removed from service if a leak or defect is found.