(h)
Measure the time necessary for the right manifold duct pressure to decrease to 5 psi (INDICATOR END value) from one of the Duct Pressure Start values shown in the chart below.
(i)
If the decay time is more than the MINIMUM PASS TIME, then the right bleed air system and precooler is satisfactory.
(j)
If the decay time is less than the MINIMUM PASS TIME, then the right bleed air system and precooler is not satisfactory. Check all joints by feeling and listening. Diffused leakage is allowed at any joint; however, jet blasts are not permissible. Entire leakage allowed for duct joints should not be concentrated at one joint.
(k)
Position the BLEED 2 switch on the forward overhead panel to OFF.
DUCT PRESSURE START (PSI) INDICATOR END (PSI) MINIMUM PASS TIME (SEC)
50 40 30 20 5 5 5 5 7 6 5 3
36-11-0 May 01/99 Page 504
BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details.
(4)
Leak Test the Left Bleed Air System
(a)
On the forward overhead panel, position the APU BLEED switch to ON.
(b)
Position the ISOLATION VALVE switch on the forward overhead panel to OPEN.
(c)
Position the BLEED 1 switch on the forward overhead panel to ON.
(d)
Pressurize the pneumatic system with the APU.
(e)
Position the ISOLATION VALVE switch on the forward overhead panel to CLOSE.
(f)
When the bleed air duct pressure is stable, record the left duct pressure shown on the forward overhead panel.
(g)
Check that the left manifold is pressurized to a minimum of 20 psig.
(h)
At the same time on the forward overhead panel, stop the APU and position the APU BLEED switch to OFF.
(i)
Measure the time necessary for the left manifold duct pressure to decrease to 5 psi (INDICATOR END value) from one of the Duct Pressure Start values shown in the chart below.
(j)
If the decay time is more than the MINIMUM PASS TIME, then the left bleed air system and precooler is satisfactory.
(k)
If the decay time is less than the MINIMUM PASS TIME, then the left bleed air system and precooler is not satisfactory. Check all joints by feeling and listening. Diffused leakage is allowed at any joint; however, jet blasts are not permissible. Entire leakage allowed for duct joints should not be concentrated at one joint.
(l)
Position the BLEED 1 switch on the forward overhead panel to OFF.
(m)
Position the ISOLATION VALVE switch on the forward overhead panel to AUTO.
(5)
Restore the Airplane to Normal
(a)
Stop the APU if necessary.
(b)
Remove the pressure from the pneumatic system
(c)
Remove electrical power if no longer required.
DUCT PRESSURE START (PSI) INDICATOR END (PSI) MINIMUM PASS TIME (SEC)
50 40 30 20 5 5 5 5 17 14 11 8
May 01/99 36-11-0 Page 504A
BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details.
E. Engine Supply Ducts Leakage Test - Flow Rate Method
(1)
Equipment and Materials
(a)
Air source capable of delivering 10 pounds per minute at 120 +5 psig
NOTE: If there is no requirement to test pneumatic manifold pressure relief valve, an air source delivering four pounds per minute at 40 psig is sufficient.
(b)
Pneumatic Duct Pressurization Plug Set, F80211-( )
(2)
Prepare to Test Engine Supply Ducts
(a)
Open engine cowl.
(b)
Open ENGINES START VALVES circuit breaker (P6).
(c)
Open AIR CONDITIONING BLEED AIR VALVE - L and R circuit breakers (P6).
(d)
Remove engine bleed valve and insert fitting to apply air pressure into duct (Ref 36-11-11 R/I).
(e)
Deleted.
(f)
Provide electrical power (Ref 24-22-0 MP).
(3)
Test Engine Supply Ducts
(a)
Apply and maintain air pressure on system and check that leakage rate does not exceed rate corresponding to pressure applied as shown on Fig. 502.
WARNING: SUDDEN PARTING OF VESSELS HIGHLY PRESSURIZED WITH AIR CAN ENDANGER LIFE AND PROPERTY.
(b)
While pressure is applied, check all joints by feeling and listening. Diffused leakage is allowed at any joint; however, jet blasts are not permissible. Entire leakage allowed for duct joints should not be concentrated at one joint.
(c)
Slowly increase pressure until pneumatic manifold pressure relief valve opens and check that pressure is not less than 85 psig.
中国航空网 www.aero.cn
航空翻译 www.aviation.cn
本文链接地址：737 AMM 飞机维护手册 PNEUMATIC(8)
