Repair of the Heat Shields on the Anti-Ice Valves (Pressure Regulating and Shut-Off Valve (PRSOV) 1(2))

TASK 30-21-51-300-801-A
Repair of the Heat Shields on the Anti-Ice Valves (Pressure Regulating and Shut-Off Valve (PRSOV) 1(2))

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.

WARNING: BE CAREFUL WHEN YOU USE CONSUMABLE MATERIALS. OBEY THE MATERIAL MANUFACTURER'S INSTRUCTIONS AND YOUR LOCAL REGULATIONS.

ZONE: 410

1. Reason for the Job
A. This procedure gives the instructions to do a temporary repair of the heat shields on the anti-ice valves.
B. This procedure uses high temperature speed tape to repair damage to the heat shields.
C. This is a temporary repair that makes it necessary to decrease the usual the inspection intervals. Refer to AMM TASK 30-21-51-220-801-A for information on:
- The new inspection intervals
- The fly-on limits
- The number of times this repair can be done before the anti-ice valve must be replaced.
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	1	ACCESS PLATFORM 1M(3 FT)
No specific	AR	SAFETY CLIP - CIRCUIT BREAKER
No specific	AR	WARNING NOTICE(S)

B. Consumable Materials

REFERENCE	DESIGNATION
(Material No.CPNCL01539)	DENATURED ETHYL ALCOHOL
(Material No.CPNCL02069)	LINT-FREE COTTON CLOTH
(Material No.CPNCL02758)	3M TAPE 363

C. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
410	ENG 1 PYLON BOX AND FORWARD FAIRING
FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENGINE 1)
437AL, 438AR, 451AL
FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2)
447AL, 448AR, 461AL

D. Referenced Information

REFERENCE	DESIGNATION
TASK 71-13-00-010-803-A	Opening of the Fan Cowl Doors
TASK 71-13-00-410-803-A	Closing of the Fan Cowl Doors
TASK 78-30-00-040-809-A	Deactivation of the Thrust Reverser System for Ground Maintenance
TASK 78-30-00-440-809-A	Reactivation of the Thrust Reverser System after Ground Maintenance
TASK 78-36-00-010-806-A	Opening of the Thrust Reverser Cowl Doors
TASK 78-36-00-410-806-A	Closing of the Thrust Reverser Cowl Doors
SRM 517512
SRM 517711911010
SRM 517711911018
Heat Shields on the Anti-Ice Valves (Pressure Regulating and Shut-Off Valve (PRSOV) 1(2))

3. Job Set-up
Subtask 30-21-51-941-069-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 30-21-51-865-096-A

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

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C ALL
FOR FIN: 4020KM1 (POWER PLANTDEMOUNTABLE, ENGINE 1)
122VU	ANTI ICE/ENG/1	1DN1	X10
FOR FIN: 4020KM2 (POWER PLANTDEMOUNTABLE, ENGINE 2)
122VU	ANTI ICE/ENG/2	1DN2	W10

Subtask 30-21-51-010-095-A

C. 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

Subtask 30-21-51-040-064-A

D. Deactivation of the Thrust Reverser System for Ground Maintenance

WARNING: YOU MUST DEACTIVATE THE THRUST REVERSER BEFORE YOU DO WORK ON OR AROUND IT. IF YOU DO NOT, THE THRUST REVERSER CAN OPERATE ACCIDENTALLY AND CAUSE AN INJURY AND/OR DAMAGE.

(1) Do the deactivation of the thrust reverser system for ground maintenance (Ref. AMM TASK 78-30-00-040-809).

Subtask 30-21-51-010-096-A

E. Open the left thrust reverser cowl-door (Ref. AMM TASK 78-36-00-010-806):
(1) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENGINE 1)
451AL
(2) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2)
461AL
(3) Put an ACCESS PLATFORM 1M(3 FT) in position.

4. Procedure
Subtask 30-21-51-350-050-A

WARNING: REFER TO THE PRODUCT LABEL AND THE MANUFACTURER'S (MATERIAL) SAFETY DATA SHEET (SDS) FOR INSTRUCTIONS ON THE HAZARDS, STORAGE, SAFE HANDLING AND CORRECT USE OF CONSUMABLE PRODUCTS.

A. Repair of the Anti-Ice Valve Heat Shields

NOTE: When you use consumable products throughout this procedure, obey all standard shop practices, local regulations, and environmental, health and safety requirements.

(1) If repaired, remove all the tape applied to the heat shield.
(2) Clean the surfaces of the heat shields as follows:

CAUTION: WHEN YOU CLEAN THE HEAT SHIELD, DO NOT APPLY TOO MUCH PRESSURE ON IT. TOO MUCH PRESSURE CAN CAUSE MORE DAMAGE TO THE HEAT SHIELD.

(a) Clean the surfaces of the heat shields with a LINT-FREE COTTON CLOTH (Material No.CPNCL02069) made moist with DENATURED ETHYL ALCOHOL (Material No.CPNCL01539) .
(b) Let the heat shields air dry for a minimum of 30 minutes.

CAUTION: DO NOT APPLY TAPE ON THE OPEN AREAS OF THE HEAT SHIELDS. IF YOU DO, THE TAPE CAN CAUSE A BLOCKAGE OF THE COOLING AIR FLOW AND DAMAGE TO THE VALVE CAN OCCUR.

(3) Apply 3M TAPE 363 (Material No.CPNCL02758) all around the heat shield cracks as follows:

NOTE: The open areas are necessary to permit ventilation of cooling air around the anti-ice valve.

(a) Apply 3M TAPE 363 (Material No.CPNCL02758) :

Prepare the repair area ( SRM 517711911010 and SRM 517711911018, Paragraph 2. B). Removal of surface protection is not necessary.
Cut 3M TAPE 363 (Material No.CPNCL02758) to the required dimensions. Cut the corners with a radius of 25 MM (1 IN.).
Apply the tape over the skin damage with an overlap of 25 MM (1 IN.)all around the damage. Smooth out from the edges to remove any air pockets. Press the edges of the tape down tightly.
If required, apply surface finish over the 3M TAPE 363 (Material No.CPNCL02758) SRM 517512

(b) If a crack is near the cooling tube connection, extend the 3M TAPE 363 (Material No.CPNCL02758) onto the cooling tube.

Use the 3M TAPE 363 (Material No.CPNCL02758) to bond the heat shield to the cooling tube.

(c) If a crack extends to the edge of the heat shield, wrap the 3M TAPE 363 (Material No.CPNCL02758) around the edge of the shield. The tape must extend a minimum of 25 mm (0.98 in.) onto the inner side of heat shield.
(4) Apply a second layer of 3M TAPE 363 (Material No.CPNCL02758) around all the edges of the first layer of tape.

5. Close-up
Subtask 30-21-51-410-083-A

A. Close Access
(1) Make sure that the work area is clean and clear of tools and other items.
(2) Remove the access platform(s).
(3) Close the left thrust reverser cowl-door (Ref. AMM TASK 78-36-00-410-806):
(a) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENGINE 1)
451AL
(b) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2)
461AL

Subtask 30-21-51-440-060-A

B. Do the reactivation of the thrust reverser system after ground maintenance (Ref. AMM TASK 78-30-00-440-809).

Subtask 30-21-51-410-084-A

C. Close Access
(1) Close the fan cowl doors (Ref. AMM TASK 71-13-00-410-803):
(a) FOR [4020KM1] (POWER PLANT-DEMOUNTABLE, ENGINE 1)
437AL 438AR
(b) FOR [4020KM2] (POWER PLANT-DEMOUNTABLE, ENGINE 2)
447AL 448AR
(2) Remove the WARNING NOTICE(S).

Subtask 30-21-51-865-097-A

D. Remove the safety clip(s) and the tag(s) and close this(these) circuit breaker(s):

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C ALL
FOR FIN: 4020KM1 (POWER PLANTDEMOUNTABLE, ENGINE 1)
122VU	ANTI ICE/ENG/1	1DN1	X10
FOR FIN: 4020KM2 (POWER PLANTDEMOUNTABLE, ENGINE 2)
122VU	ANTI ICE/ENG/2	1DN2	W10

[Rev.10 from 2021] 2026.04.01 00:30:38 UTC