TM 1-1500-204-23-1 NOTE Never    use    flammable    solvents    to remove oil spillage. b. Exercise    caution    to    prevent    overfilling    or spilling. NOTE When oil has been spilled, immediate action    shall    be    taken    to    remove spillage   from   aircraft   and   adjacent area.      Clean   rags   may   be   used   to remove  oil  spillage  from  the  aircraft. Sand,   dirt,   sawdust,   or   commercial products  may  be  used  to  remove  oil spillage from adjacent ground. 3-7. Oxygen Servicing.  Oxygen servicing requires the utmost     precautionary     measures     due     to     the     highly explosive and flammable capabilities of oxygen.  Prior to servicing    an    aircraft    oxygen    system,    personnel    shall familiarize  themselves  with  the  system,  precautions,  and instructions   for   handling   gaseous   oxygen,   operation   of servicing equipment, and potential hazards involved. CAUTION Only    qualified    personnel    shall    be authorized  to  operate  equipment  for servicing of an aircraft oxygen system.     Damage     to     system     may otherwise result a. Safety   Precautions.      Aircraft   shall   not   be serviced with oxygen when any of the following conditions prevail. ·  Aircraft electrical switches are on. ·  Ground powered equipment is operating within 50 feet of the servicing area. ·  Aircraft  is  being  serviced  with  fuel,  oil,  or  anti- icing fluids. ·  Any  combustible  items,  such  as  fluid,  etc.    ,  are evident around oxygen servicing equipment. b. Servicing.    General  servicing  procedures  for oxygen systems are explained in the following paragraphs. CAUTION ·  Oxygen    equipment    shall    be    kept clean at all times.  No organic matter or     flammable     substance     of     any nature   shall   be   allowed   to   contact oxygen.  Ensure that all components of  the  systems  are  free  of  moisture, oil and grease at all times.  Oxygen is a    nonflammable    gas,    however,    it supports combustion and lowers the flash ignition point of all combustible materials.  Oxygen shall be handled as a flammable gas. ·  When   an   aircraft   is   being   serviced with oxygen within 50 feet of an area where    smoking    is    permitted,    NO SMOKING signs shall be placed at a 50-foot  radius  around  the  servicing area.    A  spark  in  the  servicing  area could cause an explosion and damage to equipment. (1) To prevent overfilling of tanks, personnel shall observe aircraft oxygen system gauges at all times during servicing operation. (2) Personnel    shall    be    stationed    at    the oxygen    servicing    unit    at    all    times    during    servicing operation    to    shut    off    unit    valves    immediately    upon receiving  a  command  from  personnel  watching  aircraft system gauge. (3) Service   aircraft   from   cylinders   clearly labeled    DRY    or    AVIATOR'S    BREATHING    OXYGEN. Other oxygen may have moisture which could cause flow stoppage at temperatures below freezing. (4) Always use a pressure-reducing device when   servicing   low-pressure   oxygen   system   from   high pressure bottles. (5) Fill   oxygen   system   slowly   to   prevent explosion resulting from heat generated by filling too fast. (6) An aircraft oxygen system not equipped with   shutoff   devices   at   cylinders   shall   be   completely discharged of all pressure prior to removing components. All   electrical   power   shall   be   turned   off   during   oxygen discharge operations. (7) Refer to the applicable aircraft maintenance    manual    for    additional    information    and maintenance procedures. 3-15