RELIEF VALVE TEST

To follow this description, you will find it helpful to refer back to figure 11-4 of the test stand in chapter 11. To perform the relief valve test, proceed as follows:

1. Disconnect low and high capacitance cable assemblies from lower probe terminals.

2. Disconnect the buildup tube assembly from the buildup port of the fall, buildup and vent valve, and from the pressure closing valve. Hold the 45-degree elbows with open-end wrench to prevent turning while loosening tube nut connections.

3. Cap 45-degree elbow in buildup port of fill, buildup and vent valve.

4. Using Test Stand Hose Assembly, P/N 59A120-B5-14, connect test stand BELL JAR BOTTOM COUPLING C-1 to the 45-degree elbow on converter pressure closing valve.

5. Using the Test Stand Hose Assembly P/N 59A120-B5-52, connect the converter quickdisconnect coupling to the test stand FLOW-METER CONNECTION, NIP-4.

6. Turn the FLOWMETER SELECTOR valve V-1 to the 0-150 lpm position. Open the TEST PRESSURE GAUGE-TO-BELL JAR valve, V-2.

7. Open the OXYGEN SUPPLY valve, V-6, slowly. Damage to test stand gauges could result from rapid surges in pressure if this valve is opened too rapidly. Pressure applied will be indicated on TEST PRESSURE GAUGE, PG-1.

8. The relief valve relieves a minimum rate of 100 lpm, as indicated on the FLOWMETER

INDICATOR GAUGE, PG-2, with a pressure of 100 to 120 psig, as indicated on the TEST PRESSURE GAUGE, PG-1, applied to the converter. Record these readings on the Performance Test Sheet.

9. Using the OXYGEN SUPPLY valve, V-6, and the SYSTEM BLEED valve, V-5, reduce the pressure applied to the converter to 95 psig as indicated on gauge PG-1.

10. Disconnect the test stand hose from the FLOWMETER CONNECTION, NIP-4 and reconnect it to the FLOWMETER CONNEC-TION, NIP-1.

11. Turn the FLOWMETER SELECTOR valve V-1 to the 0.0-0.25 lpm position.

120 While maintaining 95 psig to the converter with valve V-6, check for leakage indicated on the FLOWMETER INDICATOR, PG-2. Maximum allowable leakage is 0.01 lpm. Record this reading on the Performance Test Sheet.

13. If leakage is excessive, or if the relief valve fails to vent at the required flow and pressure, locate the probable cause using Troubleshooting Chart Relief Valve Test (Table 12-19).

14. Close OXYGEN SUPPLY valve, V-6. Bleed the test stand using SYSTEM BLEED valve, V-5. Close TEST PRESSURE GAUGE-TO-BELL JAR valve, V-4.

15. Disconnect both the test stand hose assemblies from the converter and from the test stand.

16. Uncap the 45-degree elbow that you capped in step 3, and reconnect the buildup tube, which you removed in step 2.

17. Reconnect the high and low capacitance cable assemblies, which you removed in step 1. At this time, ensure that all safety wired setscrews have the proper Glyptal dots applied.

CONVERTER LEAKAGE TEST

To test the converter for leaks, proceed as follows:

1. Using Test Stand Hose Assembly, P/N 59A120-B5-47, connect the test stand BELL JAR BOTTOM COUPLING C-1 to the converter quick-disconnect coupling.

2. Open the TEST PRESSURE GAUGE-TO-BELL JAR valve, V-2.

3. Using the OXYGEN SUPPLY valve, V-6, slowly apply 95 psig, as indicated on TEST PRESSURE GAUGE, PG-1, to the converter.

4. Maintain 95 psig and inspect for leakage at all connections using leak detection compound (MIL-L-25567). There should be no leakage. If any leakage is found, locate its probable cause using the troubleshooting chart (table 12-20).

Table 12-19.-Troubleshooting (Relief Valve Test)

Table 12-20.-Troubleshooting (Converter Leakage Test)

5. Close OXYGEN SUPPLY valve V-6. Bleed the test stand using SYSTEM BLEED valve V-5. Close TEST PRESSURE GAUGE-TO-BELL JAR valve V-2.

6. Remove the converter assembly from test stand.