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NASA-LLIS-0525
Lessons Learned – Acceptance Testing, Inspection, and Securing of Air Lines
Year: 1994
Abstract: Description of Driving Event:
On 1-20-93, contractor technicians were tracing a 1/4" stainless steel air line in Building 1247E. The line, part of the 5000 PSI air system, was in an overhead support channel and the technician was tracing it with his fingers while standing on a 4' step ladder.
While tracing the line, the pressure of the technician's fingers was sufficient to cause the line to separate at a union fitting. The tubing was clamped into the support channel on one side of the fitting and this section of tubing held fast. On the other side of the fitting the tubing was not clamped into the channel; on this side, after separation, a section of line approximately 10' long whipped into the air and became lodged in other piping in the area. Damage was minor (a 1/4" plastic water line was severed) and there were no injuries. Fortunately, neither technician was in the path of the loose tubing. Had they been, serious injury could have occurred.
It appears that the cause of the fitting separation was the result of improper assembly of the union. A "bite" ferrule in the fitting failed to secure the stainless steel tubing in the union. Thus, the line was only secured by air pressure. Movement of the line for any reason would have been sufficient to cause joint separation.
On 1-20-93, contractor technicians were tracing a 1/4" stainless steel air line in Building 1247E. The line, part of the 5000 PSI air system, was in an overhead support channel and the technician was tracing it with his fingers while standing on a 4' step ladder.
While tracing the line, the pressure of the technician's fingers was sufficient to cause the line to separate at a union fitting. The tubing was clamped into the support channel on one side of the fitting and this section of tubing held fast. On the other side of the fitting the tubing was not clamped into the channel; on this side, after separation, a section of line approximately 10' long whipped into the air and became lodged in other piping in the area. Damage was minor (a 1/4" plastic water line was severed) and there were no injuries. Fortunately, neither technician was in the path of the loose tubing. Had they been, serious injury could have occurred.
It appears that the cause of the fitting separation was the result of improper assembly of the union. A "bite" ferrule in the fitting failed to secure the stainless steel tubing in the union. Thus, the line was only secured by air pressure. Movement of the line for any reason would have been sufficient to cause joint separation.
Subject: Facilities
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| contributor author | NASA - National Aeronautics and Space Administration (NASA) | |
| date accessioned | 2017-09-04T18:42:11Z | |
| date available | 2017-09-04T18:42:11Z | |
| date copyright | 08/23/1994 | |
| date issued | 1994 | |
| identifier other | JZBEQCAAAAAAAAAA.pdf | |
| identifier uri | http://yse.yabesh.ir/std;query=authoCA5893FD081D49A96159DD6EFDEC014A/handle/yse/223737 | |
| description abstract | Description of Driving Event: On 1-20-93, contractor technicians were tracing a 1/4" stainless steel air line in Building 1247E. The line, part of the 5000 PSI air system, was in an overhead support channel and the technician was tracing it with his fingers while standing on a 4' step ladder. While tracing the line, the pressure of the technician's fingers was sufficient to cause the line to separate at a union fitting. The tubing was clamped into the support channel on one side of the fitting and this section of tubing held fast. On the other side of the fitting the tubing was not clamped into the channel; on this side, after separation, a section of line approximately 10' long whipped into the air and became lodged in other piping in the area. Damage was minor (a 1/4" plastic water line was severed) and there were no injuries. Fortunately, neither technician was in the path of the loose tubing. Had they been, serious injury could have occurred. It appears that the cause of the fitting separation was the result of improper assembly of the union. A "bite" ferrule in the fitting failed to secure the stainless steel tubing in the union. Thus, the line was only secured by air pressure. Movement of the line for any reason would have been sufficient to cause joint separation. | |
| language | English | |
| title | NASA-LLIS-0525 | num |
| title | Lessons Learned – Acceptance Testing, Inspection, and Securing of Air Lines | en |
| type | standard | |
| page | 2 | |
| status | Active | |
| tree | NASA - National Aeronautics and Space Administration (NASA):;1994 | |
| contenttype | fulltext | |
| subject keywords | Facilities | |
| subject keywords | Industrial Operations | |
| subject keywords | Pressure Vessels |