Cylinder Terminology

Common Cylinder Terminology

Demurrage: Cylinder rental charge when a cylinder is retained beyond a specific time allowed to empty and return the cylinder. Oxygen Support begins demurrage charges 30 days following delivery. Usage for 30 days is included within the cost of the oxygen contents. See also "Rental."

FDA: US Food and Drug Administration (FDA), regulates the filling of oxygen cylinders due to oxygen's therapeutic properties, i.e. a prescription drug.

USP: US Pharmacopeia is the standard of a drug's purity following manufacture set by the FDA. The USP standard for oxygen being distributed is no less than 99.5% purity as determined by a paramagnetic analyzer.

Heat Sensitive Coating: During manufacture aluminum cylinders are coated with a clear material which turns yellow when exposed to high temperatures. Since high temperatures weaken the metal any cylinder displaying a distinct yellow hue cannot be refilled.

Hydrostatic Testing: Prior to refilling a cylinder the hydro test status of a cylinder must be checked according to the US FDA. A current, or recent, hydrotest date allows the cylinder to be refilled. Hydrotesting must be performed on an aluminum cylinder if it has been more than 5 years since the last test. Steel cylinders remain within testing for 10 years. Testing requires special equipment and facilities and is accomplished by pressurizing the cylinder higher than the normal operating pressure to detect cracks or other stress points in the cylinder which would make it dangerous to fill and use.

Labeling: Oxygen cylinders must be clearly labeled to identify the contents and the filler. Identification includes the HAZMAT designations “oxidizer” and “non-flammable” and the US Pharmacopeia (USP) seal which means that the contents are no less than 99.5% pure oxygen. The cost to label a new cylinder is $15.

Loaner Cylinders: Like any opened drug package, a full cylinder may not be returned for credit. To protect consumers from drug tampering or contamination the FDA does not permit returned drugs, including oxygen, to be resold. The solution we offer is to provide customers a cylinder to use up to 30 days only charging for the contents. Whatever contents are returned to us are emptied. 

Ownership Labeling: Tracking cylinders by their unique serial number is often helpful for your inventory purposes. A label affixed to the cylinder that specifies the SN# in numerical and bar-code format, the hydrotest expiration date and your name as the cylinder’s owner, provides easy tracking information. We attach this label for $5/cylinder.

Rental: Referring to a customer's use of a container (cylinder, tank, bottle, etc.) while the contents are being held for later use or until emptied. Since the "rental" of the cylinder for the first 30 days of use is included in Oxygen Support Systems' charge for contents, no rental charges accrue to the customer until 30 days is reached. Rental charges begin on that date and are charged every 30 days until the cylinder's return to Oxygen Support.