Removal of the Isolation Valve Assembly

TASK 47-21-41-000-001-A
Removal of the Isolation Valve Assembly

WARNING: PUT THE SAFETY DEVICES AND THE WARNING NOTICES IN POSITION BEFORE YOU START A TASK ON OR NEAR:

THE FLIGHT CONTROLS
THE FLIGHT CONTROL SURFACES
THE LANDING GEAR AND THE RELATED DOORS
COMPONENTS THAT MOVE.

MOVEMENT OF COMPONENTS CAN KILL OR CAUSE INJURY TO PERSONS AND/OR CAN CAUSE DAMAGE TO THE EQUIPMENT.

FIN: 3YA ** ON A/C NOT FOR ALL

1. Reason for the Job
Self explanatory
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	1	ACCESS PLATFORM 2M (6 FT)
No specific	AR	CAP - BLANKING
No specific	AR	SAFETY CLIP - CIRCUIT BREAKER
No specific	1	TIE WRAP

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
191BB

C. Referenced Information

REFERENCE	DESIGNATION
TASK 24-41-00-861-002-A	Energize the Aircraft Electrical Circuits from the External Power
TASK 24-41-00-861-002-A-01	Energize the Aircraft Electrical Circuits from the APU
TASK 24-41-00-861-002-A-02	Energize the Aircraft Electrical Circuits from Engine 1(2)
TASK 53-35-13-000-002-A	Removal of the Quick-Release Access Panels from the Belly Fairing Structure
Isolation (Gate Valve) Assembly

3. Job Set-up
Subtask 47-21-41-860-050-A ** ON A/C NOT FOR ALL

A. Aircraft Maintenance Configuration
(1) Energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-861-002)

Subtask 47-21-41-865-050-A ** ON A/C NOT FOR ALL

B. Open, safety and tag this(these) circuit breaker(s):

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
121VU	IGGS/CTRL	7YA	N28
** ON A/C NOT FOR ALL
121VU	IGGS/CTRL	7YA	P28
** ON A/C NOT FOR ALL
122VU	CSAS / CTRL	1HW	U17

Subtask 47-21-41-010-050-A ** ON A/C NOT FOR ALL

C. Get Access
(1) Put an access platform ACCESS PLATFORM 2M (6 FT) in position at the zones 191 and 192.
(2) Remove the quick-release access panel (access panel) 191BB (Ref. AMM TASK 53-35-13-000-002).

4. Procedure
Subtask 47-21-41-020-050-B ** ON A/C NOT FOR ALL

A. Removal of the Isolation Valve (Gate Valve).

WARNING: DO NOT GO INTO THE WORK AREA UNTIL A MINIMUM OF 5 MINUTES AFTER YOU REMOVE THE ACCESS PANEL. LET AIR FLOW THROUGH THE WORK AREA. AIR FROM THIS SYSTEM HAS A LOW OXYGEN CONTENT AND CAN CAUSE INJURY OR DEATH.

CAUTION: BE CAREFUL WHEN YOU TOUCH THIS ASSEMBLY. IT HAS PRECISION- TOLERANCE COMPONENTS WITH VERY POLISHED SURFACES. IF YOU ARE NOT CAREFUL, IT IS VERY EASY TO CAUSE DAMAGE TO THESE COMPONENTS (INTERNAL CONTAMINATION, EXTERNAL IMPACT DAMAGE).

(1) Disconnect the electrical connector (13).
(2) Temporarily attach the electrical connector (13) with a TIE WRAP to the IGGS pallet.
(3) Put the CAP-BLANKING on each disconnected electrical connector and receptacle.
(4) Release and remove the coupling assembly (3).

NOTE: The clamp and the sleeve fit together to make one coupling assembly (3).

(a) Pull up the latch pawls of the clamp to remove and retain the coupling (3).
(b) Move the sleeve across the packing (2) to the outlet fitting of the Gate Valve (1).

NOTE: Do not remove the sleeve until you remove the Gate Valve (1).

(5) Release and remove the coupling assembly (11).

NOTE: The clamp and the sleeve fit together to make one coupling assembly (11).

(a) Pull up the latch pawls of the clamp to remove and retain the coupling (11).
(b) Move the sleeve across the packing (12) to the inlet fitting of the Gate Valve (1).

NOTE: Do not remove the sleeve until you remove the Gate Valve (1).

(6) Support the Gate Valve (1) and remove the screws (6) and the washers (7) from the lower part of the bracket (5).
(7) Carefully remove the Gate Valve (1) then turn it to remove the remaining screws (9) and washers (8) to release the bracket (5).

CAUTION: REMOVE OR INSTALL PACKING SEALS CAREFULLY. DAMAGE TO SEALS OR SEALING SURFACES CAN CAUSE LEAKAGE AND CORROSION.

(8) Remove and retain the sleeve, keep it with the coupling assembly (3).
(9) Remove and retain the sleeve, keep it with the coupling assembly (11).
(10) Remove and discard the packing (10) from the IGGS pallet duct assembly.
(11) Remove and discard the packing (4) inlet fitting of the filter assembly.
(12) Remove and discard the packings (12) from the inlet fitting of the Gate Valve (1).
(13) Remove and discard the packings (2) from the outlet fitting of the Gate Valve (1).

CAUTION: INSTALL CAPS AND PLUGS ON THE ORIFICES OF ALL DISCONNECTED PIPES AND PARTS FOR THEIR PROTECTION AGAINST CONTAMINATION BY UNWANTED MATERIALS.

(14) Install CAP - BLANKING on the inlet and outlet fittings of the Gate Valve Assembly and the IGGS pallet duct assembly and the inlet fitting of the filter assembly.

[Rev.10 from 2021] 2026.04.02 06:43:07 UTC