Food Truck LP Gas Pressure Testing ($350)

We pressure test LP gas systems on food trucks and food trailers for $350. You get the test, the leak check on every connection, and the documentation the fire inspector asks for. This page explains what the test actually is, what the code requires, and why the version of it most operators are told about is wrong.

There Are Two Different Propane Tests, and People Mix Them Up

Almost every argument about propane testing comes from treating one test as if it were the other. The code describes two, and they are not interchangeable.

Two things in that table surprise people.

You are allowed to test with propane itself. The widely repeated line that you must never test with LP gas is not what the code says. NFPA 58 16.6.10.2 permits air, nitrogen or LP gas as the test medium, and 16.6.10.2.1 prohibits only oxygen. The annual test at 16.11.1 has to be done with LP gas, at operating pressure.

The soap test is not a shortcut. For the annual test it is the method the code prescribes. NFPA 58 16.11.2 requires every connection to be checked with a noncorrosive leak detecting fluid or another approved method. The gauge and pressure drop test is the installation test, not the annual one. A tester who only does one of these has done half the job.

If any leak shows up, 16.11.2.1 requires the gas shut off immediately, and it stays off until the fault is repaired and the system retested. We do not hand over paperwork on a system that leaks.

The Documentation Is Part of the Requirement

This is the part operators lose points on at inspection. NFPA 58 16.11.3 and 16.11.3.1 require the test to be documented and the documentation to be kept in the mobile food facility and produced to the fire official on request. A test that happened but cannot be evidenced on the truck does not help you at the curb.

Most Colorado jurisdictions do not enforce through NFPA 58 directly. They enforce through whichever International Fire Code edition they have adopted, and the two current editions differ:

• 2021 IFC 319.10.3. LP containers and fuel gas piping inspected annually by an approved inspection agency, or by a company registered with USDOT to requalify LP gas cylinders. On a satisfactory inspection the agency affixes a tag showing the agency name and the date.
• 2024 IFC 4106.4.3.3. Adds an explicit annual leak check: all fuel gas piping and appliances checked for leakage at the operating pressure of the system using a manometer or pressure gauge. Where leakage is indicated, the gas stays off until repairs are made. 4106.4.3.4 requires the annual tag.

Worth knowing: the manometer requirement is a 2024 addition. The genuine 2021 IFC text does not contain it. If someone tells you the 2021 code requires a manometer test, they are quoting the newer edition.

Watch How a Food Truck Gas System Is Put Together

Understanding the layout makes the failure list below make sense. This is our walkthrough of how the propane system on one of our builds is run.

What Actually Fails, and the Code Behind It

These are the faults we find most often. Each one has a real section behind it, which is why arguing with the inspector rarely works.

1. Expired cylinder requalification. Cylinders are qualified for a period from their manufacture date and must be requalified before refilling, under 49 CFR 180.205 and 180.209. The practical rule is twelve years from manufacture, then a further five years per visual requalification or twelve per volumetric. Beyond the calendar, 180.205(d) requires retest before further use if a cylinder shows dents, corrosion, cracks, abrasion, leakage or accident damage. A truck with out of date cylinders cannot legally be filled, whatever the rest of the system looks like.
2. Cylinders inside the vehicle. NFPA 58 16.10 and 16.3.2. Cylinders live outside, in a vented compartment or an approved cage.
3. Hose inside the vehicle, or flex over length. 16.6.8.4 prohibits hose inside the unit. 16.6.8.3 limits connectors to 5 ft.
4. Flex used instead of rigid pipe. 16.6.8.1 permits a connector between the regulator outlet and the fixed piping. It is not permission to plumb the whole run in flex. Under or outside a motorized vehicle the run has to be Schedule 80 pipe, or tubing in conduit, under 16.6.9.5.
5. Unsecured cylinders. 16.3.5 and 16.3.5.1 require securing to four times the filled weight. Cylinders that can rotate or shift in transit fail.
6. Wrong or missing regulator. 16.6.11.2 requires two stage regulation at 100,000 Btu per hour and above. 16.6.11.1 requires a UL 144 regulator. The vent has to point down, 16.6.11.4.1, and be weather protected, 16.6.11.4.2.
7. Corroded or unprotected piping. 16.6.9.3 and 16.6.9.4 for corrosion resistance outdoors, and 16.6.9.6 for a grommet at every penetration.
8. Piping run through concealed spaces or inside walls. 16.6.7.6.
9. Fuse plug relief devices. Prohibited outright, 16.5.4.
10. No LP gas alarm. Required by IFC 319.8.5 and carried into the 2024 renumbering.
11. No documentation on board. NFPA 58 16.11.3.1 and the IFC tag requirement. This is a spot check item in Denver.

If You Operate in Denver, Read This Part Twice

Denver Fire publishes its own mobile vendor policy, and several of its rules are stricter than NFPA 58. Building to the national code alone will not get you through a Denver inspection.

• Copper is prohibited. Denver’s policy states no copper or other tubing is allowed. NFPA 58 permits copper. This is the clearest example of a rule you can only fail by trusting the national code.
• Painted black iron pipe, minimum 0.049 inch wall, for the under vehicle system. Exceptions only for approved UL 21 stainless rubber coated flex connectors.
• Interior flex connectors 5 ft or less, connecting to rigid pipe through an excess flow valve.
• Under vehicle flex limited to 18 inches, purely to relieve stress.
• Two stage regulator wherever multiple appliances share a tank.
• Cylinder mounting. Bottom of rear mounted cylinders no lower than 28 inches above the bumper or A frame, with an impact resistant cage on corner or rear mounts. No roof mounting and nothing ahead of the front axle.
• A DOT 1075 placard and a flammable decal on the propane access hatch.
• No on site refilling, no cylinder swaps during an event, and no spare cylinders stored on site.
• An LPG permit is required at one pound of LPG and up, and a copy has to be on the vehicle at inspection.

One caution rather than a number. Denver’s own documents disagree about how much propane you may carry. The permit application states a maximum of 80 pounds, while Denver’s inspection checklist quotes the IFC figure of 200 pounds. We tell customers to build to the 80 pound figure, because that is the number on the form the operator signs, and to confirm with the Denver Fire mobiles inspector before relying on the higher one.

There is a second thing worth saying plainly, because it cuts the other way. Denver’s published mobile vendor policy and its food truck inspection checklist do not contain a propane pressure test line item. Denver’s LP requirement is an annual fire code inspection plus the LPG permit. If you have been told Denver requires an annual propane pressure test, that requirement comes from the 2024 IFC, which Denver has not published as adopted. We would rather tell you that than sell you a test on a false premise.

One Test Now Travels Further Than It Used To

Colorado’s HB 25-1295 took effect on 1 January 2026 and it changes the economics of getting this right once. A valid fire safety permit issued to a mobile food establishment is now honored in other Colorado jurisdictions, provided it was issued by a local government that has adopted the most recent International Fire Code, or a code incorporating the state Division of Fire Prevention and Control’s minimum standards for mobile food establishments, and provided it followed an inspection by a certified fire inspector.

The conditions matter. You have to send the permit electronically to each local government at least 14 calendar days before you operate there, once per calendar year per jurisdiction. You still have to comply with that jurisdiction’s fire code, and you are still subject to its inspection. And if you fail a local inspection, the reciprocal permit is void in that jurisdiction until you pass a re-inspection.

Also worth knowing for context: Colorado’s state LP gas rule, 7 CCR 1101-15, incorporates an older edition of NFPA 58 than the 2024 one that introduced the mobile food chapter. So Chapter 16 applies where a local authority has adopted it, not automatically statewide. That is a good reason to ask your specific jurisdiction rather than assume.

What You Get for $350

• The full system checked, cylinders through regulator, piping, connectors and appliance connections
• Every connection leak checked with noncorrosive leak detecting fluid at operating pressure, the method NFPA 58 16.11.2 actually prescribes
• Gauge test where the system has been installed or modified
• Cylinder date and condition checked against the requalification rules
• A written result you keep in the truck, which is what 16.11.3.1 requires
• A plain list of anything that failed and what it will take to fix

If we find a fault we tell you what it is before we do any repair work, and you decide. A truck that leaves here with a clean test is one we are willing to put our name to.

Book a Test

Call or text 719-722-2537. Tell us the unit size, roughly what appliances are on board, and which jurisdiction you operate in, because the last one changes what your inspector will want to see.

We also do fire suppression inspections, hood cleaning and hood certification, and full fire suppression system installs. If you are getting a truck ready for its first inspection, it is usually cheaper to do them in one visit.

Code references above are to NFPA 58 (2024 edition), NFPA 1, the 2021 and 2024 International Fire Code, 49 CFR Part 180, and Denver Fire Prevention Division published policy. Local requirements vary and your authority having jurisdiction has the final say. Verified September 2026.