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