737 AMM 飞机维护手册 PNEUMATIC(20)

(2)  
Remove burr or other interference observed on wear ring, threads or shims.

(3)  
Either rework wear ring or replace with oversize wear ring to reduce end gap.

(a)  
Spring the wear ring in at the gap to about 1-inch overlap and release. Repeat as necessary until natural butt is assumed by the ring at the split.

(b)  
Carefully reinstall wear ring in the nut. Avoid spreading by installing the ring on the duct at the ring split and "peeling" it on.

(c)  
Install wear ring per par. 2.C.

501 
Aug 15/76  BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details.  36-19-21 Page 203 

ENGINE BLEED PRESSURE INDICATING SYSTEM - DESCRIPTION AND OPERATION
1.  General
A.  A pressure indication system, consisting of two transmitters and a dual pressure indicator, is provided for the pressure indication of the engine bleed system. Each transmitter is connected to a sensing line which is connected to the pneumatic manifold downstream from the bleed air heat exchanger. Both transmitters are electrically connected to the dual pressure indicator on the overhead panel which has two pointers marked L and R for the left and right system respectively. One transmitter is sensing engine No. 1 bleed air pressure and the other senses engine No. 2 bleed air pressure. (See figure 1.)
B.  Each transmitter has two ports. One port is for the pressure sensing line from the pneumatic manifold and the other port is the vent to atmosphere. Next to the ports there is a zero set hex nut. The zero set hex nut is used to adjust the transmitter to obtain a zero indication on the indicator with no pressure in the ducts.
500  Engine Bleed Pressure Indicating Circuit 
May 15/68  Figure 1  36-21-0 
Page 1 
BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details. 

DUCT PRESSURE TRANSMITTER - REMOVAL/INSTALLATION
1. General
A.  Two duct pressure transmitters are provided to transmit and indicate engine bleed pressure to the forward overhead panel.
B  The pressure transmitters are installed in the outboard side of the forward air conditioning equipment bay. (See figure 401.)
C.  The removal/installation procedure is identical for both transmitters.
2.  Remove Duct Pressure Transmitter (See figure 401.)
A.  Open applicable air conditioning equipment bay door to gain access to transmitter.
B.  Disconnect pressure sensing line from transmitter.
C.  Disconnect electrical connector.
D.  Remove mounting bolts from support bracket.
E.  Remove transmitter.
3.  Install Duct Pressure Transmitter
A.  Position pressure transmitter on support bracket with electrical connector facing up.
B.  Fasten to support bracket with mounting bolts.
C.  Check that ambient vent marked V is not plugged.
D.  Connect pressure sensing line to pressure port of transmitter marked P.
E.  Connect electrical connector.
F.  Check that circuit breaker, PRESSURE IND, on panel P6-4 is closed.
G.  Adjust zero reset on pressure transmitter so the pressure gage on forward overhead panel reads zero pressure with no pressure in ducts.
H.  Close air conditioning equipment bay doors.
May 15/67 36-21-11 Page 401 BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details.

F89574
Duct Pressure Transmitter Installation  500 
36-21-11 Page 402  Figure 401 BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details.  May 15/67