R-1 to maintain 160 psig with 1,800 psig supply pressure  applied,  proceed  as  follows: CAUTION VALVES  V-2,  V-5,  V-6,  V-7,  AND  V-10 ARE METERING (NEEDLE) VALVES. OVERTIGHTENING  THESE  VALVES WILL  DAMAGE  THE  VALVE  SEAT. ONLY   FINGERTIGHT   PRESSURE SHOULD   BE   USED   WHEN   YOU CLOSE  THESE  VALVES. 1.  Ensure  that  all  test  stand  valves  are  closed, and  plug  the  bell  jar  bottom  coupling  C-1. WARNING WHEN  YOU  WORK  WITH  OXYGEN, MAKE  CERTAIN  THAT  CLOTHING, TUBING   FITTINGS,   AND   EQUIP- MENT  ARE  FREE  OF  OIL,  GREASE, FUEL,  HYDRAULIC  FLUID,  OR  ANY COMBUSTIBLE   MATERIALS.   FIRE OR EXPLOSION MAY RESULT WHEN EVEN   SLIGHT   TRACES   OF   COM- BUSTIBLE   MATERIAL   COME   IN CONTACT  WITH  OXYGEN  WHEN  IT IS UNDER PRESSURE. 2.  Open  the  oxygen  supply  cylinder  valve. NOTE:  When  you  set  regulator  R-1,  a MINIMUM  of  1,800  psig  of  oxygen pressure is applied to the regulator. 3.  Open  the  test  pressure  gauge  to  bell  jar valve  V-2  slowly,  and  fully  open  the  oxygen  supply valve  V-6. 4. Loosen the hex locknut located on the front of regulator R-1. Turn the T-handle until 160 psig registers  on  the  test  pressure  gauge  PG-1.  Tighten the hex locknut, and your oxygen pressure gauge is  now  set. 5. Close the oxygen supply cylinder valve and open the system bleed valve V-5 to bleed pressure from  the  system.  After  bleeding  the  pressure, remove the plug from the bell jar bottom coupling C-1. LEAKAGE   TEST,   ACCESSORIES SECTION.— TO perform the leakage test on the accessories  section  of  the  test  stand,  proceed  as follows: 1.  Install  the  nipple  assembly  in  the  bell jar bottom coupling C-1. Connect one end of the hose  to  the  adapter,  and  the  other  end  to  the differential  pressure  connection  NIP-7. 2. Ensure that the test pressure gauge to bell jar valve V-2 is open. The system bleed valve V-5, the test pressure gauge buildup, and the vent valve V-10  and  the  differential  pressure  bleed  valve  V-7 are  closed. 3. Open the differential pressure shutoff valve V-8  and  the  oxygen  supply  cylinder  valve. 4.  Slowly  open  the  oxygen  supply  valve  V-6 until 160 psig is indicated on test pressure gauge PG-1. 5.  Now  close  the  oxygen  supply  valve  V-6. Leakage will be indicated by a drop in pressure on PG-1. Leakage should not be more than 2 psig in 10 minutes. 6. Leave all hoses and valves in their present position  and  start  your  test  stand  leakage  test. LEAKAGE  TEST,  TEST  STAND.—   T O perform the leakage test on the entire test stand proceed  as  follows: 1.  Open  the  converter  supply  flow  control valve V-9 and test pressure gauge buildup and the flow  valve  V-10. 2. Plug the converter supply outlet NIP-5 and the  supply  converter  connection  NIP-6.  Ensure that  the  system  bleed  valve  (V-5)  is  closed. 3. Open the supply valve V-6 until the relief valve  RV-11  unseats.  (The  relief  valve  is  set  to relieve at approximately 110 psig, and be leaktight at  100  psig.)  Using  the  system  bleed  valve  V-5, decrease pressure until 100 psig is indicated on test pressure  gauge  PG-1.  Close  valve  V-6.  Leakage will be indicated by a drop in pressure on PG-1. Leakage  should  be  no  more  than  10  psig  in  10 minutes. 4. Bleed the test standby opening the system bleed valve (V-5). Close all the test stand valves. Remove  the  plugs  from  the  converter  supply  outlet NIP-5  and  the  plug  from  the  supply  converter connection  (NIP-6). BELL   JAR   ASSEMBLY   LEAKAGE TEST.— To perform a leakage test on the bell jar assembly,  proceed  as  follows: 1. Remove the hose assembly and the nipple assembly  from  the  bottom  bell  jar  coupling  C-1. Disconnect  the  opposite  end  of  the  hose  from differential  pressure  connection  NIP-7. 11-19