What 173.301H-HMGP means in plain language
When you transport compressed gas cylinders as hazardous materials, those cylinders must have proper valve protection. This protection—typically a valve cap, valve cover, or protective device—prevents damage to the cylinder valve during transport. A damaged valve can create a safety hazard: it may allow gas to escape, damage the cylinder's structural integrity, or create an unsafe condition if the cylinder shifts or impacts cargo.
173.301H-HMGP covers the general packaging requirement for valve protection on cylinders. If an inspector finds that your cylinders lack adequate valve protection, or that the protection is missing, damaged, or improperly installed, you will be cited. The regulation requires that every cylinder in your load has the appropriate protective equipment in place before you leave the shipper.
What our enforcement data actually shows
Across our 13 million+ inspection records, 173.301H-HMGP has been cited only 37 times in the entire database, and 20 times in the last 12 months. Over the last 90 days, we recorded 5 citations. This code ranks #1717 out of 3,036 FMCSR codes by citation volume—it is exceptionally rare.
More importantly for your situation: the out-of-service rate for 173.301H-HMGP is 0.0%. None of the 37 all-time citations resulted in an out-of-service order. This stands in stark contrast to the all-FMCSR average OOS rate of 31.4%. The reason is straightforward: a valve protection deficiency on a compressed gas cylinder, while a violation, is typically correctable at the roadside or does not rise to the severity threshold for immediate removal from service.
Who gets cited most
Our inspection records show that 173.301H-HMGP citations are geographically concentrated over the last 180 days. Florida leads with 3 citations, all resulting in 0 out-of-service orders (0.0% rate). California and Puerto Rico each have 2 citations, both with 0.0% OOS rates. Virgin Islands also recorded 2 citations with a 0.0% OOS rate. Alaska and Georgia each have 1 citation, both at 0.0% OOS rates.
Historically, our data shows fleets such as SUNTECH GROUP INC and ANTILLES GAS CORPORATION have each received 4 citations for this violation. These patterns do not suggest systemic negligence; rather, they reflect that certain carrier operations, particularly those in gas distribution and specialized transport, are exposed to this citation more frequently simply because of their hazmat handling volume.
How severe is this compared to similar codes
Hazmat packaging and placarding violations span a wide severity spectrum. General loading and unloading hazmat violations (177.834A-HMC) are cited 3,954 times with a 99.2% out-of-service rate—far more serious than 173.301H-HMGP. Placarding violations like 177.817(a) occur 2,274 times with a 75.1% OOS rate. Even damaged placard violations (177.817(e)) are cited 2,038 times with a 5.2% OOS rate, still higher than 173.301H-HMGP's 0.0%.
The closest peer by enforcement outcome is code 172.602(c)(1), covering maintenance and accessibility of emergency response information, which has a 0.0% OOS rate like this code. However, 172.602(c)(1) has been cited 1,464 times compared to 173.301H-HMGP's 37—indicating that valve protection issues are far less frequently flagged during inspections.
How to avoid it
Pre-trip inspection of compressed gas cylinders:
- Before leaving the shipper, visually inspect every cylinder you are loading. Confirm that each has a valve cap or protective cover in place and that it is secure.
- Check that the valve cap is not cracked, missing, or loose. A cap that is partially seated is not adequate protection.
- If you notice a cylinder without protection or with damaged protection, do not accept the load. Inform the shipper and wait for corrective action.
During transport:
- Secure cylinders so they cannot roll, tip, or strike one another. Movement during transit can dislodge or damage valve protection.
- Inspect cylinders again during any stops, especially if you hear unusual sounds or suspect impact.
- Do not remove or tamper with valve protection at any point during transport, even if you think it will make loading or unloading easier.
Documentation and communication:
- When you accept a hazmat load, confirm in writing that all cylinders have proper valve protection. This creates a record that protection was present at origin.
- If an inspector cites you for missing or inadequate valve protection, ask to document whether the damage occurred during transport or was present at origin. This distinction matters for determining liability.
Our inspection data shows that Ford vehicles account for 18 of the 37 all-time citations for this code—if you drive a Ford, pay extra attention to load security and any vibration or movement that might compromise valve protection during transport.