FICTION: Fill Station Operators do not have to be trained
FACT:  The truth is that the US Code of Federal Regulations, Title 49, requires "Function Specific" training for all employees.  If they fill cylinders they need Fill Station Operator training.

​​In Canada the rules are even more specific.  Transport Canada regulation CSA-B340 requires that persons filling containers be trained although it does not specify the exact nature of that training. 

FICTION: The Code of Federal Regulations is not law.
FACT:  "Law" is a broad term that includes statute law (laws enacted by legislatures with executive approval), administrative, or regulatory, law (law written by agencies usually in direct support of statute law) and common law (precedential law largely from judicial decisions). All are enforceable in court.  The Code of Federal Regulations codifies US administrative law. 

FICTION: Compressed air is not a designated Hazardous Material.
FACT:  Compressed air is a HAZMAT.  49CFR173.115 defines a compressed air at 40.6 psia or greater at 68ºF as a Class 2, Division 2.2 HAZMAT.

FICTION: Formal training in HAZMAT is not required.
FACT:  Absolutely wrong!  49CFR172.702 requires a hazmat employer to ensure that each of its hazmat employees is provided appropriate function specific training and to ensure that each of its hazmat employees is tested by appropriate means. 49CFR172.704 goes on to specify what this training must consist of.  This training must be completed within 90 days of employment or change in job function and then every three years thereafter. 

FICTION: Persons who receive no compensation but who handle high pressure cylinders are not required to have formal and documented HAZMAT training.
FACT:  This is one of the most onerous myths of all. 49CFR171.8 defines a HAZMAT employee as one who, among other things, is employed by a hazmat employer and who in the course of employment directly affects hazardous materials transportation safety. This term includes an individual, including a self-employed individual, employed by a hazmat employer who, during the course of employment loads, unloads, or handles hazardous materials.

Do not confuse “employed” with “paid”.  Employ means to use, whether there is compensation involved or not. Those divers who just hang around a dive store asking to help and who are used by the dive store to move, load and fill cylinders require formal and documented function specific training just as much as do paid employees.  Not conducting this training can be very costly.

​Furthermore. § 1910.101   Compressed gases (general requirements) provides for: (a) Inspection of compressed gas cylinders. Each employer shall determine that compressed gas cylinders under his control are in a safe condition to the extent that this can be determined by visual inspection. Visual and other inspections shall be conducted as prescribed in the Hazardous Materials Regulations of the Department of Transportation (49CFR parts 71–179 and 14CFR103). Where those regulations are not applicable, visual and other inspections shall be conducted in accordance with Compressed Gas Association Pamphlets C–6, C-6.2, C-6.2 and C6.3 which are incorporated by reference as specified in §1910.6.

FICTION: The inspection guidelines of Compressed Gas Association (CGA) Pamphlets C-6, C-6.1, C-6.2, and C-6.3 are not mandatory.
FACT: 49CFR180.205 incorporates these publications “by reference” into the CFR itself.  As such, the guidance on these publications are to be considered by US courts as being part of the Code of Federal Regulations and treated as if they were Federal Law.
CGA C-6 is entitled Standards for Visual Inspection of Steel Compressed Gas Cylinders
CGA C 6.1 is entitled Standards for Visual Inspection of High Pressure Aluminum Compressed Gas Cylinders
CGA C-6.2 is entitled Guidelines for Visual Inspection and Requalification of Fiber Reinforced High Pressure Cylinders
​CGA 6.3 is entitled Guidelines for Visual Inspection and Requalification of Low Pressure Aluminum Compressed Gas Cylinders

FICTION: A steel cylinder may not be authorized for a 10% excess fill after the first hydrostatic retest.
FACT: The US Code of Federal Regulations establishes the requirements for pressurizing steel cylinders beyond their stamped service pressure.  49CFR173.302 sets forth the requirements for pressurizing cylinders 10% in excess of its marked service pressure. 
These requirements are:
1. Cylinder must be 3A or 3AA (steel)
2. Cylinder must be equipped with the proper frangible (burst) disc.
3. Cylinder’s must have been tested or retested using the hydrostatic water jacket method
4. Neither the average nor maximum wall stresses exceed the limits established in the CFR
5. An external and internal visual inspection made at the time of the test or retest shows the cylinder to be free of excessive corrosion, pitting or dangerous defects.
6. A plus sign “+” is added following the test date marking.  The use of the term “test or retest” clearly authorizes hydrostatic retest facilities to reauthorize an appropriate cylinder for a 10% excess fill.  Is this common?  No.  Is it legal?  Yes. 

FICTION: Steel cylinders do not have to be visually inspected for cracks.
FACT:  Yes they do.  CGA Pub. C-6 lists a crack inspection as part of the inspection procedure – and remember that C-6 has been “incorporated by reference” into the CFR.

FICTION: A condemned cylinder must be rendered incapable of holding air by drilling a hole in the sidewall or by destroying the neck threads.
FACT:  49CFR180.207 prescribes the procedures for the condemnation of cylinders.  They are to be condemned by stamping a series of “X”s over the DOT specification number and the service pressure or by stamping “CONDEMNED” on the cylinder shoulder. Only at the direction of the cylinder owner may the requalifier render the cylinder incapable of holding pressure.  Additionally, the cylinder owner must be notified IN WRITING that the cylinder is condemned and may not be filled with a hazardous material.

​Cylinders failing hydrostatic retest or visual inspection cannot be returned to their owner without being condemned.  However, those facilities that destroy your cylinder neck threads or drill a hole in the sidewall WITHOUT YOUR PERMISSION are in violation of the law.

FICTION: The law requires all 6351-T6 alloy aluminum cylinders to be inspected with an eddy current tester.
FACT:  49CFR180.205 requires only that 6351 alloy cylinders in SCUBA, SCBA and oxygen service be eddy current tested at time of hydrostatic requalification.

FICTION: 6351-T6 alloy aluminum is still authorized for the manufacture of high pressure 3AL cylinders.
FACT: 49CFR178.46 is the specification for 3AL seamless aluminum cylinders.  It specifies 6061-T6 alloy only.  

​This DOES NOT mean that existing 6351-T6 alloy cylinders are to be pulled from service.  It only means that no new 3AL cylinders can be manufactured from this alloy.

FICTION: All 6351-T6 alloy cylinders have been recalled.
FACT: This is closely related to the above myth and is absolutely untrue.   49CFR178.46 simply no longer authorizes 6351-T6-T6 for future manufacture on 3AL cylinders (all new 3AL cylinders must be manufactured using 6061-T6 alloy).  6351-T6 cylinders in use may be used so long as they remain within established hydrostatic testing and visual inspection standards for continued service.   Postulating this myth to customers is unethical.  

FICTION: No special training is required to visually inspect the Luxfer fiber wrapped (FRP2) SCUBA cylinder E12479
FACT: DOT Special Permit SP-12479 specifically requires that the cylinder be given an annual visual inspection by a Professional Scuba Inspectors, Inc. (PSI) certified person.

FICTION: An external visual inspection of a cylinder is not required before filling
FACT: 49CFR173.301 requires that before each cylinder filling the person filling it must visually inspect the outside of the cylinder for cracks, leaks, bulges, defective valve, leaking or defective burst disc, evidence of physical abuse, fire or heat damage, and detrimental corrosion.  Any such cylinder may not be filled.

Failure of the Fill Station Operator (FSO) to conduct this routine informal visual inspection may have a highly memorable consequence.

FICTION: Paintball and Spare Air cylinders do not require hydrostatic retesting
FACT:  Even though paintball and Spare Air cylinders are filled by the cylinder owner, they still require periodic requalification.  49CFR180.205 requires that each cylinder bearing a DOT specification marking be requalified (hydrostatically retested) as specified in the Requalification Table of section 180 of the CFR. Cylinders bearing a DOT Special Permit number (SPxxxxx) must be requalified in conformance the terms of the applicable Special Permit.

​There is an exception.  49CFR180.209 Table 1 exempts cylinders not exceeding 2 inches outside diameter AND less than 2 feet in length from periodic volumetric expansion tests.  If either dimension exceeds the limit a periodic requalification is required.   Paintball cylinders and most Spare Air cylinders usually exceed at least one of these limits. 

FICTION: Steel cylinders with a marked service pressure of 2400 psig are low pressure cylinders
FACT:  Nothing could be further from the truth.  CGA Pub C-6 defines a high pressure steel cylinder as one containing pressures of 900 psig or greater – and don’t forget that CGA Pub C-6 has been “incorporated by reference” into the CFR.

​Strangely, the high pressure definition for aluminum cylinders is different. CGA C-6.1 defines a high pressure aluminum cylinder as one containing pressures of 1800 psig or greater.

FICTION: Aluminum cylinders manufactured prior to 1990 are no good.
FACT: To tell a customer this boders on fraud.  The only place where the US DOT has established a terminal use date for cylinders are in the various  Special Permits for the fiber wrapped cylinders.  The terminal date for wrapped cylinders is usually 15 years, but some Carbon Fiber wrapped cylinders are now authorized a 30 year life.  3A, 3AA and 3AL cylinders, even 6351 alloy aluminum cylinders,  are authorized for continued service as long as they are within established hydrostatic test and visual inspection standards.

FICTION: Cylinders are hydrostatically tested to 5/3 of their stamped Service Pressure
FACT:  While this is generally true, cylinders containing a stamped test Pressure (TP) are to be tested to the specified test pressure.  Usually, but not always, this is 3/2 service pressure rather than 5/3.

FICTION: A cylinder exposed to excessive heat must be condemned.
FACT: While simple exposure to high heat may require a cylinder to be pulled from service for further examination, it does not condemn a cylinder.  Condemnation requires some portion of the cylinder itself to be heated to the specified temperature.

​49CFR 180.203 defines overheating as a condition in which the temperature of any portion of an aluminum cylinder has reached 176 °C (350 °F) or higher, or in which the temperature of any portion of a steel or nickel cylinder has reached 343 °C (650 °F) or higher.  The various Special Permits governing fiber wrapped cylinders specify overheating as when any portion of the aluminum liner reached a temperature of 250 ºF.

FICTION: The Code of Federal Regulations does not apply to me because I am not in interstate commerce
FACT:  In establishing the applicability of the CFR, 49CFR171.1 uses the term “in commerce” which has been misinterpreted by many as meaning in commercial and interstate commerce.  If we read the CFR further, however, we find in 49CFR171.8 that it defines “commerce” more broadly as meaning “trade or transportation in the jurisdiction of the United States within a single state; between a place in a state and a place outside of the state; or that affects trade or transportation between a place in a state and place outside of the state” (Emphasis mine).

​Do you use state and federal roads and highways to transport your Division 2.2 Hazmat (compressed air) to/from a dive site or an emergency?  If so, the code applies to you.

FICTION: The Exemption or Special Permit number on a cylinder is the authorization to manufacture cylinders and has nothing to do with the longevity of the cylinder.
FACT:  In order for an E or SP cylinder to remain in service its Special Permit (as of 1 Jan 2006 the terminology has again changed and Exemptions are again called Special Permits) must be current.  That means it must be in effect.  Requalifiers are required by DOT to have on hand the "current" Special Permit of the cylinder being requalified.  If the Special Permit has expired it cannot be current.  Hence the cylinder is no longer authorized for service.

FICTION: DOT/TC cylinders, when in need of a requalification, may be requalified by either a DOT or a TC authorized requalifier and then be filled and transported in both the United States and Canada.
FACT:  While a cylinder manufactured to DOT/TC standards may be used and transported in both Canada and the United States, when the cylinder receives its periodic hydrostatic test requalification its usability may be limited.  To be filed and transported in the United States it MUST be requalified by a USDOT authorized requalifier.  To be filled and transported in Canada it MUST be requalified by a TC authorized requalifier.

FICTION: There is no authority for SCUBA cylinders to have an annual visual inspection.  This is just a standard of practice in the SCUBA industry
FACT:  In CGA Pub P-5 Paragraph 6.1 the Compressed Gas Association requires all cylinders in SCUBA service to be visually inspected annually.

FICTION: All UN cylinders may be used to transport hazardous material in the United States
FACT:  To be transport hazardous material in the United States UN cylinders must bear the additional marking of USA or CAN (alternatively, US or CA).

FICTION: All Aluminum cylinders manufactured prior to 1990 must be eddy current tested.
FACT:  Using the date 1990 is the lazy and inaccurate method of determining cylinder alloy.  49CFR180.209 requires only cylinders manufactured of 6351 alloy to be eddy current tested.  Not all cylinders manufactured prior to 1990 meet this criterion.  NO Catalina cylinder is made from this alloy regardless of its date of manufacture.  ALL Walter Kidde cylinders were made from this alloy.  Only SOME Luxfer cylinders were made from this alloy.  For SCUBA. SCBA and Oxygen  cylinders Luxfer phased a changeover in alloys from 6351 to 6061 over an thirteen month period from May 1987 through June 1988 and based it on cylinder size.

​To ascertain the specific alloy for Luxfer cylinders you need to refer to the Luxfer Technical Bulletin dated November 12, 2003.  Here is a link to the Luxfer document.

FICTION: The usability of the PSI Evidence of Inspection sticker expires.
FACT:  Unlike other EOI stickers which show the year of the visual as the last two digits in the century (00-99), the PSI-PCI sticker shows the year of the inspection as the last single digit in the decade (0-9).  Determining the decade of the inspection is really not significantly more difficult than determining the century of the inspection. If there is confusion as to the decade, a simple look at the hydro date should help. You NEVER have to replace your sticker inventory because you passed the highest two digit date on the sticker.  

PSI - PCI  Cylinder Facts and Fiction

This page is NOT a substitute for formal PSI training.

Phillip Rexinger