- Created on Friday, July 01 2011 16:25
There is a lot to know about cylinders to ensure only safe ones are in service. That is not to suggest however that cylinders are inherently unsafe. Cylinders are extraordinarily well made. Many cylinders have been in service far longer than 50 years. Unfortunately, some owners consider their high-pressure cylinders to be indestructible which they are not.
Carbon fiber wrapped cylinders are becoming the fire industry standard for self-contained breathing apparatus (SCBA). The carbon fibers have little abrasion resistance so a layer of fiberglass provides a protective over-wrap covered by a gel-cote. Even with that protection, in only moments, numerous fire fighters have damaged those expensive cylinders beyond repair. During "firefighter down" drills, the victim is often dragged across concrete floors that scrapes away the gel-cote, then the fiberglass layer and into the carbon fibers. Whenever carbon fibers are exposed, the cylinder must be condemned.
Storage brackets that hold cylinders ready within the fire truck crew cab may, over time cause damage. When brackets have rough surfaces or clamp very tightly to the cylinder abrasions occur over time. At one fire station, when new, larger diameter cylinders were purchased, brackets were not changed to a larger size. Within one week the cylinders showed damage from being forced into the too small brackets.
Scuba cylinders are routinely exposed to potentially harmful conditions. Tank Boots, while useful to protect surfaces contacted by the cylinder bottom also retain water against the cylinder for many hours or days. That allows corrosion to develop particularly when salt water is not flushed away. Compressor malfunctions and water tubs at fill stations allow water to enter the cylinder. In one year between typical internal inspections considerable corrosion can develop when water is trapped inside the cylinder.
Poor quality visual inspections by un-trained inspectors allow minor damage to progress because they do not know what corrective steps are needed. Cylinder owners should insist that their cylinders are inspected by trained technicians and it is important to ask for proof of that training.
Owners must never allow their cylinder to be filled at a rate higher than 600 psi/min. Fast filling and overfilling cylinders causes progressive and irreversible damage to the metal over time.
Fire department medical units, long term care facilities and others use large numbers of small medical oxygen cylinders. Until very recently those cylinders had information labels affixed to the sidewall with glue. Over time, the labels are damaged and the glue is exposed. Biological hazardous contaminates can transfer from the patient to the glue and be transferred to the next user. It is essential that medic teams frequently properly clean the cylinder exterior. Technicians taking PSI inspector training learn how to clean those cylinders with safe products.
Cylinder inspections are not a quick look at a few concerns but rather a complete assessment against standards. PSI, Inc. is the only cylinder inspector training agency recognized by the US Department of Transportation, the agency that administers cylinder use and safety.