(4)  
Restore Airplane to Normal

(a)  
Release pressure; disconnect air supply; and install engine bleed valve (Ref 36-11-11 R/I).

(b)  
Close circuit breakers opened in steps (2)(b) and (2)(c).

NOTE:  Install engine bleed valve with special consideration given to proper mating due to the fact that individual tests may not be accomplished prior to airplane operation.

(c) 
 Close engine cowl.

(d)  
Remove electrical power if no longer required.

36-11-0  May 01/00
Page 504B
BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details.

F.  Pneumatic Ducts Downstream from Engine Bleed Valves Leakage Test - Flow Rate Method
(1) 
 General

(a)  
This test determines leakage rates between the APU and engine bleed valves and the pack valves. The pack installation leakage check determines leakage rates between the pack valves and both, the warm air supply duct check valve upstream of the main distribution manifold and just downstream of the ACM water separator.

(b)  
The air pressure source is common for both tests as are the closures of engine bleed valves, wing anti-ice valves and turbofan valves. The difference is that the pack valves are open for the pack installation leak check.

(2)  
Equipment and Materials

(a)  
Air source capable of delivering a minimum of 40 psig at 7.2 pounds per minute flow

(b)  
Pneumatic Duct Pressurization Plug Set, F80211-( )

(3)  
Prepare to Test Pneumatic Ducts Downstream from Engine Bleed Valves

(a)  
Provide electrical power.

(b)  
Check that the following switches on the forward overhead panel are OFF: 1) WING ANTI-ICE 2) NO. 1 BLEED 3) NO. 2 BLEED 4) L PACK 5) R PACK 6) APU BLEED

(c)  
On forward overhead panel, position ISOLATION VALVE switch to OPEN.

(d)  
Check that turbofan control valve indicator is in CLOSE.

(e)  
Install closure plates between right and left turbofan and turbofan supply ducts.

(f)  
Gain access to APU relief valve by opening access panel 3701.

(g)  
Remove APU duct relief valve and insert closure plug in duct boss.

(h)  
Remove APU bleed air valve and cap upstream duct.

(i)  
Install closure plug with air source fitting on inlet of APU bleed air duct.

(4)  
Test Pneumatic Ducts Downstream from Engine Bleed Valves

(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. 501.

WARNING:  SUDDEN PARTING OF VESSELS HIGHLY PRESSURIZED WITH AIR CAN ENDANGER LIFE AND PROPERTY.

(b)  
While pressure is applied, check all joints and connections 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.

May 01/00  36-11-0
Page 505
BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details.

Engine Supply Ducts Leakage Rate Chart  500 
36-11-0  Figure 502  Feb 20/85 
Page 506 
BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details. 

(5)  Restore Airplane to Normal
(a)  
Release pressure, disconnect air supply, remove duct closure plates and connect turbofan supply ducts to turbofans.

NOTE:  All joints disturbed for testing shall be reassembled with special consideration given to mating and seals due to the fact that individual tests may not be accomplished prior to airplane operation.

(b)  
Position isolation valve switch to AUTO.

(c)  
Install access panel 3701.

(d)  
Remove electrical power if no longer required.

G.  Pack Installation Pneumatic Ducts Leakage Test - Flow Rate Method
(1) 
 General

(a)  
This test will check leakage between the APU and engine bleed valves and both the warm air supply duct check valve upstream of the main distribution manifold and just downstream of the water separator.

(b)  
The air pressure source and the closures of engine bleed valves, wing anti-ice valves and turbofan valves is the same for this test as the previous test. The differences are that the pack valves will be opened and different blocking plates will be installed for the pack installation leak check.

(c)  
The allowable leakage rate for this test will be approximately 5.4 lb/min at 45 psig and 700 F with isolation valve closed, and 8.4 lb/min at 45 psig and 700F with isolation valve open.
　
中國航空網 www.k6050.com
航空翻譯 www.aviation.cn
本文鏈接地址：737 AMM 飛機維護手冊 PNEUMATIC(9)