Safety Valves open

TASK 21-31-00-810-808-A
Safety Valves open

1. Possible Causes

SAFETY VALVE [6HL]
SAFETY VALVE [7HL]
OUTFLOW VALVE [10HL]
wiring
SDAC-1 [1WV1]
SDAC-2 [1WV2]

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
ASM 213102
AMM 21-31-51-000-001	Removal of the Outflow Valve (From Inside)
AMM 21-31-51-000-006	Removal of the Outflow Valve (From Outside)
AMM 21-31-51-400-001	Installation of the Outflow Valve (From Inside)
AMM 21-31-51-400-006	Installation of the Outflow Valve (From Outside)
AMM 21-31-52-000-001	Removal of the Safety Valve
AMM 31-50-00-710-001	Ground Scanning of the Central Warning System
AMM 31-55-34-000-001	Removal of the SDAC
AMM 31-55-34-400-001	Installation of the SDAC
AMM 31-60-00-860-001	EIS Start Procedure

3. Fault Confirmation
Subtask 21-31-00-710-057-A

A. Test
(1) Do a check of the safety-valve symbol position on the ECAM CAB PRESS page AMM 31-60-00-860-001.
(2) Make a print out of:

if available the ECS REPORT 19.
if possible the NON-VOLATILE MEMORY read-out CMM 213121.

4. Fault Isolation
Subtask 21-31-00-810-106-B

A. If:
(1) the safety-valves have opened during flight below delta p = 8.4 psi:

replace the SAFETY VALVE [6HL] and the SAFETY VALVE [7HL] AMM 21-31-52-000-001 and AMM 21-31-52-000-001.
add fault history on the replaced units.

(2) the safety valves have opened during flight at apprx. 8.6 psi. and the outflow valve was indicated closed at that time,
(associated failure message would be OUTFLOW VALVE with code (81) in LLR, however this message is not necessarily generated):

replace the OUTFLOW VALVE [10HL] AMM 21-31-51-000-001 and AMM 21-31-51-400-001 or AMM 21-31-51-000-006 and AMM 21-31-51-400-006.
add fault history on the replaced unit.

Subtask 21-31-00-810-067-A

B. If the safety-valve symbol is closed:

no other maintenance action is necessary.

Subtask 21-31-00-810-062-A

C. If the safety-valve symbol is open:

do a check for a ground signal at the SAFETY VALVE 1 (6HL) A/2 ASM 213102.

(1) If there is no ground signal:

replace the SAFETY VALVE [6HL] AMM 21-31-52-000-001 and AMM 21-31-52-000-001.

(a) If the fault continues:

do a check and repair the wiring from the VALVE 1 (6HL) A/1 to the GND ASM 213102.

(2) If there is a ground signal:

do a check for a ground signal at the SAFETY VALVE 2 (7HL) A/2 ASM 213102.

(a) If there is no ground signal:

replace the SAFETY VALVE [7HL] AMM 21-31-52-000-001 and AMM 21-31-52-000-001.

(b) If the fault continues:

do a check and repair the wiring from the VALVE 2 (7HL) A/1 to the GND ASM 213102.

(3) If the fault continues:

do the operational test of the central warning system AMM 31-50-00-710-001.

(a) If the test gives a different maintenance message, refer to the Fault Symptom List.
(4) If the fault continues:

replace the SDAC-1 [1WV1] AMM 31-55-34-000-001 and AMM 31-55-34-400-001.

(5) If the fault continues:

replace the SDAC-2 [1WV2] AMM 31-55-34-000-001 and AMM 31-55-34-400-001.

(6) If the fault continues:

do a check and repair the wiring between:
VALVE 1 (6HL) A/2 and SDAC 1 (1WV1) AA/9A,
SDAC 1 (1WV1) AA/9A and SDAC 2 (1WV2) AA/9A,
VALVE 2 (7HL) A/2 and SDAC 2 (1WV2) AD/9G,
SDAC 2 (1WV2) AD/9G and SDAC 1 (1WV1) AD/9G ASM 213102.

Subtask 21-31-00-710-066-A

D. Do the test as given in the Para. 3.A.

5. Close-up
Subtask 21-31-00-860-057-A

A. Put the aircraft back to its initial configuration.

[Rev.8 from Aug 2018] 2026.04.04 04:24:41 UTC