Removal of the Non Return Valve (NRV) [CFML]

TASK 79-21-50-000-802-A
Removal of the Non Return Valve (NRV)

WARNING: BE CAREFUL WHEN YOU DO WORK ON THE ENGINE PARTS AFTER THE ENGINE SHUTDOWN. USE APPLICABLE THERMAL GLOVES. THE ENGINE PARTS CAN STAY HOT FOR ONE HOUR AFTER SHUTDOWN AND CAN BURN YOU.

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

REFERENCE	QTY	DESIGNATION
No specific	AR	CAP - PROTECTION
No specific	1	CONTAINER 5 L (1.32 USGAL)
No specific	AR	COVER - PROTECTION
No specific	AR	WARNING NOTICE(S)

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENGINE 1)
437AL, 438AR
FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2)
447AL, 448AR

C. Referenced Information

REFERENCE	DESIGNATION
TASK 12-13-79-610-803-A	Draining of the Lubrication Unit
TASK 71-13-00-010-803-A	Opening of the Fan Cowl Doors
Non Return Valve (NRV)

3. Job Set-up
Subtask 79-21-50-941-051-A

A. Safety Precautions
(1) On the center pedestal, on ENG panel 115VU:
(a) Make sure that the ENG/MODE selector switch is in the NORM position.
(b) Make sure that the ENG/MASTER 1(2) control switch was in the OFF position not less than five minutes before you do this procedure.
(c) Put WARNING NOTICE(S) in position to tell persons not to operate:

The ENG/MODE selector switch, and
The ENG/MASTER 1(2) control switch.

(2) On the ENG section of maintenance panel 50VU:
(a) Make sure that the ON legend of the FADEC GND PWR/1(2) pushbutton switch is off.
(b) Put a WARNING NOTICE(S) in position to tell persons not to energize FADEC 1(2).

Subtask 79-21-50-010-052-A

B. Get Access
(1) Open the fan cowl doors (Ref. AMM TASK 71-13-00-010-803):
(a) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENGINE 1)
437AL 438AR
(b) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2)
447AL 448AR

4. Procedure

WARNING: USE PERSONAL PROTECTION EQUIPMENT. USE THE ENGINE OIL IN A WELL-VENTILATED AREA. ENGINE OIL IS TOXIC.

WARNING: USE PROTECTIVE GLOVES AND BE CAREFUL WITH OIL SPLASHES WHEN YOU DISCONNECT OIL TUBES. HOT OIL CAN CAUSE DEEP BURNS.

Subtask 79-21-50-020-051-A

A. Removal of the Non Return Valve (NRV)
(1) Put a CONTAINER 5 L (1.32 USGAL) below the NRV (1).
(2) Drain the lubrication unit (7) (Ref. AMM TASK 12-13-79-610-803).
(3) Remove the bolt (2) that attaches the clamp (3) to the bracket (4).
(4) Remove the clamp (3) from the bracket (4).
(5) Remove the four bolts (9) that attach the oil tube (8) to the lubrication unit (7).
(6) Disconnect the oil tube (8) from the lubrication unit (7).
(7) Remove and discard the gasket (10).
(8) Remove the four nuts (5) and the four bolts (6) that attach the oil tube (8) and oil tube (11).
(9) Remove and discard the gasket (12).
(10) Remove the NRV (1).
(11) Remove and discard the gasket (13).
(12) Remove the oil tube (8) and oil tube (11).
(13) Install COVER - PROTECTION and CAP - PROTECTION on all the open ports, tubes, hoses and disconnected connectors.
(14) Remove the CONTAINER 5 L (1.32 USGAL) from below the NRV (1).

[Rev.10 from 2021] 2026.04.01 03:43:18 UTC