Export Control
EAR Export Classification: Not subject to the EAR per 15 C.F.R. Chapter 1, Part 734.3(b)(3), except for the following Service Bulletins which are currently published as EAR Export Classification 9E991: SBE70-0992, SBE72-0483, SBE72-0580, SBE72-0588, SBE72-0640, SBE73-0209, SBE80-0024 and SBE80-0025.Copyright
© IAE International Aero Engines AG (2001, 2014 - 2021) The information contained in this document is the property of © IAE International Aero Engines AG and may not be copied or used for any purpose other than that for which it is supplied without the express written authority of © IAE International Aero Engines AG. (This does not preclude use by engine and aircraft operators for normal instructional, maintenance or overhaul purposes.).Applicability
All
Common Information
70-12-14-300-503 Dry Abrasive Grit Pencil Blast (240-Grit Aluminum Oxide)
Introduction
This task contains three procedures:
Procedure A, Step, is approved to remove debris from turbine airfoil cooling holes.
Procedure B, Step, is approved to remove localized corrosion from platform and airfoil areas of turbine blades and vanes.
Procedure C, Step, is approved to clean an area of the part when specified in the engine manual cleaning section.
General
Work cabinets and air extraction equipment are not usually included with the pencil grit blast units, but are available from the manufacturers. It is permitted to use these units in an existing dust extraction booth.
It is necessary to refer to the equipment manufacturer's instructions for the maintenance components wear in time, which decreases the performance of the abrasive blast.
To identify the consumable materials, refer to the Consumable Materials Index.
Preliminary Requirements
Pre-Conditions
NONESupport Equipment
| Name | Manufacturer | Part Number / Identification | Quantity | Remark |
|---|---|---|---|---|
| Comco AccuFlo | 50325 | Comco AccuFlo | ||
| Comco Microblaster | 50325 | Comco Microblaster | ||
| Texas Airsonics HPD Series | X444X | Texas Airsonics HPD Series | ||
| Texas Airsonics HPB Series | X444X | Texas Airsonics HPB Series | ||
| 3-10X Magnifying Glass | LOCAL | 3-10X Magnifying Glass | For Procedure B. | |
| White light | LOCAL | White light | For Procedure B. |
Consumables, Materials and Expendables
| Name | Manufacturer | Part Number / Identification | Quantity | Remark |
|---|---|---|---|---|
| CoMat 05-022 ALUMINUM OXIDE ABRASIVE | 62596 | CoMat 05-022 | ||
| CoMat 05-197 ALUMINUM OXIDE, 240-GRIT | 1280N | CoMat 05-197 |
Spares
NONESafety Requirements
WARNING
Procedure
Apply a mask or maskants, if specified in the engine manual section. Use a grit blast tape from SPM TASK 70-34-18-380-501.
Use a 0.018 inch (0.457 mm) size or 0.025 inch (0.635 mm) size round nozzle.
Set machine air pressure to 20 - 30 psi (137.9 - 206.8 kPa).
Use CoMat 05-022 ALUMINUM OXIDE ABRASIVE or CoMat 05-197 ALUMINUM OXIDE, 240-GRIT 240-grit aluminum oxide abrasive.
Set the powder flow rate between 50 - 100 percent of the machines adjustment range.
Blast one cooling hole at a time as necessary to remove the debris, but do not blast the cooling hole for more than two seconds at a time. There must be a 0 to 0.25 inch (0 - 6.4 mm) nozzle-to-part working distance.
Dry abrasive pencil grit blast the cooling holes by the operational parameters that follow:
Blow area clean with air at 30 psi (206.8 kPa) maximum to remove the abrasive media.
SUBTASK 70-12-14-120-001-A00 Procedure A - Removing Debris/Blockage From Turbine Airfoil Cooling Holes
Make sure that all chemical stripping and cleaning that is specified for the part in the engine manual cleaning section and in the repair is completed before you do this procedure.
NOTE
If you send parts through the chemical cleaning and stripping procedures specified in the engine manual cleaning section and in the repair before you do the pencil grit blast, the blasting pressure and blasting time that are necessary to remove the corrosion can decrease substantially.Apply a mask or maskants if specified in the engine manual section. Use a grit blast tape from SPM TASK 70-34-18-380-501.
Use a 0.018 inch (0.457 mm) size or 0.025 inch (0.635 mm) size straight round nozzle.
Set machine air pressure to 20 - 45 psi (137.9 - 310.3 kPa).
Use CoMat 05-022 ALUMINUM OXIDE ABRASIVE or CoMat 05-197 ALUMINUM OXIDE, 240-GRIT 240-grit aluminum oxide abrasive.
Set the powder flow rate between 50 - 100 percent of the machines adjustment range.
CAUTION
IF YOU LET THE ABRASIVE BLAST STREAM DWELL IN AN AREA FOR MORE THAN TWO SECONDS AT A TIME, DAMAGE TO THE PART CAN OCCUR.Slowly sweep the abrasive blast stream across areas of corrosion in a continuous motion as necessary to remove corrosion. Keep a 0.250 to 1.000 inch (6.4 - 25.4 mm) nozzle-to-part working distance. Do not dwell in an area for more than two seconds.
Dry abrasive pencil grit blast the area by the operational parameters that follow:
Blow area clean with air at 30 psi (206.8 kPa) maximum to remove the abrasive media.
Make sure that all the localized corrosion was removed. Use a White light and 3-10X Magnifying Glass do a visual inspection and/or heat tint inspection by SPM TASK 70-28-01-280-501.
Examine the pencil blasted areas to the engine manual visual/dimensional inspection pitting/erosion limits.
SUBTASK 70-12-14-120-001-B00 Procedure B - Removing Localized Corrosion From Platform And Airfoil Areas Of Turbine Blades And Vanes
Apply a mask or maskants if specified in the engine manual section. Use a grit blast tape from SPM TASK 70-34-18-380-501.
Use a 0.060 inch (1.524 mm) size straight round nozzle.
Set machine air pressure to 25 - 30 psi (172.4 - 206.8 kPa).
Use CoMat 05-022 ALUMINUM OXIDE ABRASIVE or CoMat 05-197 ALUMINUM OXIDE, 240-GRIT 240-grit aluminum oxide abrasive.
Set the powder flow rate of the machine to the maximum setting of the adjustment range.
CAUTION
IF YOU LET THE ABRASIVE BLAST STREAM DWELL IN AN AREA FOR MORE THAN TWO SECONDS AT A TIME, DAMAGE TO THE PART CAN OCCUR.Slowly sweep the abrasive blast stream across areas of corrosion in a continuous motion as necessary to remove corrosion. There must be a 1.000 inch (25.400 mm) minimum nozzle-to-part working distance. Do not dwell in an area for more than two seconds.
Dry abrasive pencil grit blast the area by the operational parameters that follow:
Blow area clean with air at 30 psi (206.8 kPa) maximum to remove the abrasive media.
Degrease, if necessary. Use SPM TASK 70-11-03-300-503.
SUBTASK 70-12-14-120-001-C00 Procedure C - Cleaning An Area Of The Part When Specified In The Engine Manual Cleaning Section