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【范围】
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This guide is intended to promote safe designs, operations and maintenance on aircraft and ground
support oxygen systems. This is also a summary of some work by the ASTM G 4 Committee related to
oxygen fire investigations and design concerns to reduce the risk of an oxygen fire. There have been
many recent technological advances and additional test data is available for evaluating and controlling
combustion hazards in oxygen equipment. Standards that use this new information are rapidly
evolving. A guide is needed to assist organizations and persons not completely familiar with this
process to provide oxygen systems with minimum risks of combustion. This guide does not
necessarily address all the detailed issues and provide all data that will be needed. For a complete
analysis, supplemental publications need to be consulted. This guide does discuss the basics of
oxygen systems fire hazards. The hazard analysis process is discussed and a simple example to
explain this process. Also, this guide does not address the overall system safety issues normally
evaluated in aircraft programs. This guide does provide some important background and observations
about combustion in oxygen systems. Information is given describing how to accomplish a hazard
analysis. Furthermore, background is provided to explain critical locations in oxygen systems that
need to be evaluated and other locations that do not require hazard analysis.
It is important to note that any effort that requires a comprehensive and effective hazard analysis
should use the complete information in the documents referenced herein. In general, the need for a
hazard analysis applies primarily to gaseous oxygen equipment at 50 psi and higher pressures. LOX
equipment does have hazards concerns as well and is usually treated similarly to GOX equipment at
500 psi. It should be noted that there are other phenomena associated with LOX equipment that must
be considered. An example is that LOX can combine with hydrocarbons to form a gel, which explodes
under impact. On the other hand, since LOX is a very cold liquid it tends to quench most possible
ignition sources that could cause promoted ignition. When examining oxygen equipment at lower
pressures the primary concern is the increased ignition and fire concern with combustible non-metals.
1.1 Purpose:
This document is intended to provide a guide for minimizing the risk of combustion hazards
associated with the design, installation, and maintenance of aircraft oxygen systems. This guide
also discusses a process of planning and organizing a project assisting someone who wishes to
evaluate an oxygen system(s) such that combustion risks are minimized. The use of this guide and
supporting documentation in part or whole is entirely elective.strRefField
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