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
Description
TASK 70-10-00-100-501 General Cleaning Information For The Engine Components During Maintenance
Safety Precautions
WARNING
IT IS THE RESPONSIBILITY OF THE OPERATOR TO OBTAIN AND OBSERVE THE CONSUMABLE MATERIAL MANUFACTURER'S SAFETY DATA SHEETS FOR CONSUMABLE MATERIAL SAFETY INFORMATION (SUCH AS HAZARDOUS INGREDIENTS; PHYSICAL/CHEMICAL CHARACTERISTICS; FIRE, EXPLOSION, REACTIVITY, AND HEALTH HAZARD DATA; PRECAUTIONS FOR SAFE HANDLING; AND USE AND CONTROL MEASURES), AND ALSO TO TAKE LOCAL REGULATIONS INTO CONSIDERATION.Equipment and Materials
General Cleaning
The subsequent list shows chemical cleaning and abrasive blasting tasks that are specified for the overhaul and maintenance of the engine components.
SPM TASK 70-11-01-300-503 Procedure to Vapor Degrease
SPM TASK 70-11-03-300-503 Procedure to Degrease Parts by Aqueous Cleaning
SPM TASK 70-11-04-300-503 Remove Silicone Rubber from Components
SPM TASK 70-11-05-300-503 Procedure to Remove Paint from components (Inorganic Procedure)
SPM TASK 70-11-06-300-503 Procedure for One-step Alkaline Rust Remover Cleaning for Titanium Parts Only
SPM TASK 70-11-11-300-503 Descaling of Components (Cobalt and Nickel based Alloys and Heat and Corrosion Resistant Steels and Non-corrosion Resistant Steels)
SPM TASK 70-11-13-300-503 One-step Alkaline Rust Remover Procedure to Clean the Components (Long Soak for Cobalt and Nickel Base Alloys and Heat and Non-corrosion Resistant Steels)
SPM TASK 70-11-18-300-503 Carbon Seal Handling, Cleaning, Lapping and checking
SPM TASK 70-11-22-300-503 Procedure to Clean the Bearing (Alkaline Method)
SPM TASK 70-11-26-300-503 Procedure to Locally Swab or Wipe Clean with Solvent
SPM TASK 70-11-34-300-503 Aqueous Degreasing
SPM TASK 70-11-50-300-503 Degrease the Exterior of the Engine
SPM TASK 70-11-52-110-501 Removal of Carbon from Fuel and Oil Tubes (Bake Method)
SPM TASK 70-11-54-300-503 Procedure for Heavy Duty Scale Removal from a Component (Stainless Steel, Cobalt and Nickel Base Material)
SPM TASK 70-11-55-110-501 Local Removal of Carbon by Alkaline Gel
SPM TASK 70-11-57-110-501 Procedure to Clean Contact Point and Wiring Harness
SPM TASK 70-11-60-110-503 Paint Stripping from Aluminum
SPM TASK 70-12-01-120-501 Wet Abrasive or Vapor Blasting using Aluminum Oxide
SPM TASK 70-12-02-120-501 Dry Non-metallic Abrasive Blasting with Aluminum Oxide
SPM TASK 70-12-03-120-501 Glass Bead Blasting
SPM TASK 70-12-06-120-501 Wet Abrasive Blasting Cleaning with No. 240 or No. 320 Aluminum Oxide Grit
SPM TASK 70-12-07-120-501 Dry Plastic Blasting
SPM TASK 70-12-08-300-503 Wet Abrasive 200 or 300 Grit Novaculite Blast
SPM TASK 70-12-09-120-501 Dry Abrasive Aluminum Oxide Blast (No. 240 or No. 320 Aluminum Oxide Grit)
SPM TASK 70-12-11-300-503 Dry Abrasive 500 grit Aluminum Oxide Blast
SPM TASK 70-12-13-300-503 Wet 500 grit Aluminum Oxide Blast
SPM TASK 70-13-02-13-300-503 Ultrasonic Cleaning of Air Cooled Turbine Airfoils and Duct Segments
SPM TASK 70-28-01-280-501 Heat Tint Test
SPM TASK 70-34-18-380-501 Prepare the surface of parts for plasma and other thermal spray coatings.
SPM TASK 70-38-37-300-503 Procedure to apply water soluble corrosion inhibitors for short-term use.
Aircraft Engine Component Cleaning
Aircraft engine component cleaning is designed to:
Permit a thorough examination of components for the presence of service flaws:
By visual and dimensional inspection for loss of dimensions through abrasion and wear.
CAUTION
FAILURE TO FIND SERVICE FLAWS OR DISCONTINUITIES BY THESE INSPECTION METHODS ON ROTATING OR PRESSURIZED PARTS CAN RESULT IN MAJOR FAILURE OF THE ENGINE IF THE FLAW CAUSES THE PART TO FAIL IN SERVICE.CAUTION
AFTER CLEANING, PARTS MUST BE FULLY DRY BEFORE YOU APPLY FLUORESCENT PENETRANT. FAILURE TO SUFFICIENTLY DRY THE PART CAN PREVENT THE PENETRANT FROM ENTERING A DISCONTINUITY. REFER TO SPECIFIC DRYING INSTRUCTIONS AT THE END OF THE CHEMICAL CLEANING TASKS.By the necessary FPI, MPI, Eddy Current, X-Ray or visual inspection.
Remove deposits that:
Have a harmful effect on the efficiency of engine components
Reduce the effectiveness of FPI, MPI, Eddy Current, X-Ray or visual inspection.
Prepare surfaces for repair and salvage processes. These include:
Brazing
Plating
Welding
Peening
Plasma
Painting
Remove various organic and inorganic coatings for which replacement is necessary either for inspection of the underlying surfaces or to remove deteriorated coatings that are unsatisfactory for another engine run.
Before you start repairs, be sure the necessary applicable procedures are completed. These procedures include:
Cleaning
Stripping
Inspections that include:
FPI
MPI
Eddy Current
X-Ray
Cleaning personnel must be sufficiently trained so they are fully knowledgeable with the TASKS that they do in their department. They must also be knowledgeable of the general cleaning information that is in this section. If training is not sufficient, damage to parts and/or coatings or the scrapping of parts can occur.
Cleaning personnel who do chemical cleaning SPOP must complete training that agrees with the requirements of the latest revision of SAE ARP6240 Training for Quality Control of Overhaul Chemical Process Operators (Parts Cleaners).
It is necessary to qualify and re-qualify cleaning personnel for chemical cleaning SPOPs in accordance with the requirements of SAE ARP6240 Training for Quality Control of Overhaul Chemical Process Operators (Parts Cleaners).
Compressed air used for Cleaning and Drying
Compressed air used for cleaning and drying must not be more than 30 psig (206.8 kPa).
The compressed air must be filtered with an air/oil filter and trap to remove moisture and oil to prevent contamination of clean parts.
Flash Drying
When used
At the end of most chemical cleaning, stripping and plating tasks, flash drying is used when hot water is specified for drying.
Purpose
Flash drying increases the temperature of the part so that the water will evaporate at an accelerated rate from the part surface.
This flash drying process reduces rusting, spotting, and extensive blow drying afterwards.
Exceptions
Parts that will go directly into another wet process
Cleaning bearings by SPM TASK 70-11-22-300-503.
NOTE
In SPM TASK 70-11-22-300-503, it is necessary for bearings to stay wet until dewatering oil can remove the water that is caught in cavities and recesses within the bearing and until the application of an oil film on all surfaces at the same time to prevent flash rusting of the bearing.
Effective Procedures (use one of the subsequent steps)
Immersion
Put the part fully in 150 deg F to 200 deg F (66 deg C to 93 deg C) water until the part temperature increases sufficiently to flash dry.
NOTE
Time in hot water depends upon the number of parts in a basket and the size and mass of the parts.Remove the part from the hot water. If the part has cavities or recesses, rotate (that is, turn) the part as soon as possible to flash off and blow off all remaining water from these areas.
NOTE
If the water on the part surface does not flash off when the part comes out of the hot water, then the time interval that the part stayed in the hot water was too short to increase the part temperature sufficiently.
Spray wash machine
Put the part in a spray wash machine with a final hot water rinse at 150 deg F to 200 deg F (66 deg C to 93 deg C) until the part temperature sufficiently to flash dry.
Remove the part from the spray wash machine. If the part has cavities or recesses, rotate (that is, turn) the part as soon as possible to flash off and blow off all remaining water from these areas.
NOTE
If the water on the part surface does not flash off when the part comes out of the spray wash machine, then time interval of the spray wash machine cycle was too short to increase the part temperature sufficiently.
Oven drying or vacuum oven drying can be used to supplement the hot water flash drying step but they are not a replacement for the hot water step in a task. The hot water step is necessary to remove all remaining silicates from the part that can cause unsatisfactory FPI results.
Selection of cleaning Procedures
NOTE
The subsequent information is supplied to help the operator to find the best cleaning procedure when more than one task is given by an engine publication for a specific part.General
WARNING
MANY OF THE SOLUTIONS AND THEIR COMPONENTS USED IN CLEANING ARE HARMFUL TO SKIN AND CLOTHING AND SUFFICIENT PROTECTION IS NECESSARY TO PREVENT CONTACT WITH THEM. BECAUSE CERTAIN SOLUTIONS ARE EXTREMELY CORROSIVE AND/OR TOXIC, YOU MUST USE PROTECTIVE APRONS, GLOVES AND GOGGLES. BECAUSE OTHER SOLUTIONS RELEASE HARMFUL VAPORS, SUFFICIENT VENTILATION IS NECESSARY.NOTE
Only cleaning/stripping tasks authorized in the Engine Manual and SPM for a specific part are permitted on that part.Selection of the cleaning task specified in the Engine Manual and SPM for each engine part is dependent on the nature of the soil, type of metal, type of coating and degree of cleanliness necessary for a full inspection and subsequent repair process.
Cleaning requirements for engine parts.
NOTE
The subsequent cleaning processes involve carefully controlled alkaline and/or acid solution baths and water rinses which are specified in various combinations.When aqueous degreasing is specified for a part in an Engine Manual, it is necessary to clean the part to remove grease and oil by the SPM TASK 70-11-03-300-503 aqueous degreasing before you do other Cleaning tasks. The SPM TASK 70-11-03-300-503 will not remove carbon, varnish, rust or heat scale. The SPM TASK 70-11-03-300-503 is typically specified in repairs after machining operations to remove coolant, chips or dust.
Use one of the subsequent tasks when specified in the Engine Manual for a part, before the initial FPI:
NOTE
The SPM TASK 70-11-13-300-503 Cleaning of Components (Long Soak, for Cobalt and Nickel Base Alloys and Heat and Corrosion Resistant Steels) is not necessary to do if the SPM TASK 70-11-54-300-503 Descaling of Components (Cobalt and Nickel Based Alloys) is used.
Use one of the subsequent tasks, when specified in the Engine Manual for the parts, before initial MPI:
NOTE
The SPM TASK 70-11-13-300-503 Cleaning of Components (Long Soak, for Cobalt and Nickel Base Alloys and Heat and Corrosion Resistant Steels) is not necessary to do if the SPM TASK 70-11-54-300-503 Descaling of Components (Cobalt and Nickel Based Alloys) is used.
After the chemical processes above are done, they are sometimes supplemented by wet, or dry blasting processes, such as the subsequent procedures, when they are specified in the Engine Manual cleaning sections for the parts:
SPM TASK 70-12-01-120-501 (wet)
SPM TASK 70-12-08-300-503 (wet)
SPM TASK 70-12-13-300-503 (wet)
SPM TASK 70-12-07-120-501 (dry)
SPM TASK 70-12-09-120-501 (dry)
SPM TASK 70-12-11-300-503 (dry).
The cleaning procedure must meet all of these requirements for part durability:
The procedure must clean parts sufficiently so that a correct inspection by recommended methods is possible.
It is important to disassemble the parts to the level specified by the Engine Manual/SPM so the solution does not get caught in the assembly when the SPM TASK 70-11-54-300-503 is used as specified. If it is possible for the solution to become caught in and not get fully flushed from the part, then do not use the SPM TASK 70-11-54-300-503.
The cleaning solution must not change very much the physical quality of the engine parts. Material weight loss on base metals and coatings must be within specified limits.
It is possible that materials (for example, chromium plating or plasma coating) applied during repair can become damaged or stripped with the cleaning tasks that are recommended.
The primary purpose of cleaning is to prepare jet engine parts for a sufficient inspection. Only the type and degree of cleaning for correct inspection are necessary. The subsequent instructions are important to prevent cleaning that is not necessary:
With either FPI or MPI, it is not necessary to remove heat discoloration that is a result of the usual engine operation.
CoMat 02-054 Tampico Brush or CoMat 02-058 Tampico Brush or CoMat 05-125 Abrasive Pad or CoMat 05-126 Abrasive Pad can be used to help with the removal of unwanted particles from parts.
The abrasive pads are not permitted on antifriction bearings or carbon seals.
Wire brushes are not permitted to use for the removal of unwanted particles from parts unless specified differently in the Engine Manual.
It is not necessary to remove oxide coatings unless a part must have critical penetrant inspection.
Materials to Clean the Component
It is not possible for the engine manufacturer to test and approve all the different potential and/or proposed processes or chemicals used to clean the components. The engine manufacturer does qualify materials specified by the Engine Manual and SPM. This is to make sure the material will not have an unsatisfactory effect on the component.
All of the alternative materials are listed in the applicable task.
Exceptions to these necessary approvals are the consumable materials identified as LOCAL (that is, Local Purchase/any source). All AMS (Aerospace Material Specification) and MIL-S consumables are available as local purchase in addition to the sources given. These products can be purchased from local chemical suppliers.
Cleaning Quality Control
General
Information related to the cleaning of jet engine parts is specially important and must receive careful attention.
Obey cleaning procedure instructions carefully and do a continuous check of the parameters in the subsequent list that are specified in the cleaning tasks. That is very important to prevent possible damage to engine parts.
Temperature of solutions
Strength of solutions
Time fully in each solution
Water Temperature
Cold water is unheated water.
The temperature of warm water is between that of cold water and hot water. If temperature limits for the warm water are not specified, then use a water temperature that feels warm (between cold/cool and hot) to the touch.
The necessary temperature of hot water is 150 - 200 F (66 - 93 C) unless a different temperature range is specified.
Chemical cleaning and stripping
If one time through the chemical cleaning or stripping task does not sufficiently clean the part, it is permitted to do the task one more time.
It is permitted to do a chemical cleaning or stripping task two times maximum during each shop visit. This limit is not applicable to aqueous degreasing procedures.
If it becomes usual to do the cleaning or stripping procedure again to sufficiently clean the part, do a check of the concentration, temperature and maintenance of solution. Refer to Quality Control of cleaning and Stripping Solutions below.
Agitation
Mechanical agitation (corrosion resistant stainless steel solution pump, mixer or up/down lift to cause continuous movement of the solution) is recommended for acidic scale conditioner, and alkaline solutions (for example, alkaline rust remover, alkaline permanganate and aqueous cleaner). Do not use air agitation for these solutions.
NOTE
Air agitation decreases the solution temperature and causes chemical changes that decrease the life of the solution.Mechanical or air agitation is recommended for cold water rinse tanks.
Paint strippers and RTV strippers must not be agitated.
Heat scale on hot section parts
Description
Heat scale is hard, gray-to-black material that can show as a flaky or smooth deposit/material on the part surface.
Heat scale can show as a dark or black material in corrosion pits.
Heat scale can occur on all surfaces that have contact with the combustion gases and can have an irregular shape.
The abrasive blast machine operator must examine the pressure face surfaces of blade slots on turbine disks and hubs for remaining heat scale before the operator puts the part in the machine.
NOTE
This procedure will help to show where it is necessary to blast the pressure face surfaces to remove remaining heat scale.Illuminate each blade slot from one end with a white fluorescent light.
Look at each blade slot from the end that is opposite the fluorescent light, and examine the pressure face surfaces for remaining scale.
The visual standards in the subsequent list are pictures to help in the inspection of fir-tree areas on turbine disks and hubs that have been processed through the chemical clean, abrasive grit blast and FPI tasks
IAE 2P16572 Turbine Fir-Tree Abrasive Grit Blast Standard is a visual standard that shows fir-tree areas before and after abrasive grit blasting.
IAE 2P16573 Turbine Fir-Tree Chemical Cleaning Standard is a visual standard that shows fir-tree areas before, during and after chemical cleaning.
IAE 2P16574 Turbine Fir-Tree Inspection Standard is a visual standard that shows fir-tree areas under white light and the same area under UV/Black light.
Fretting/galling
Fretting and galling are conditions of the part surface that occur only on mating surfaces that make frequent short movements against each other.
Platform mating surfaces, root pressure faces, and blade slot pressure faces on blades, disks, hubs and drums sometimes show fretting and/or galling after the specified cleaning and stripping procedures.
Cold section parts
On higher time compressor blades, disks, hubs and drums, remaining fretting and/or galling after chemical cleaning and the removal of antigallant, RTV rubber, high temperature sealant and/or adhesive by the approved Engine Manual tasks usually shows as a dark or discoloration of the part material.
The dark areas or discolorations on these part surfaces usually have the shape of a line or stripe.
Hot section parts
On turbine blades, disks and hubs, remaining fretting and/or galling after the specified chemical cleaning and abrasive blasting usually shows as a rough area that has the shape of a line or stripe.
CAUTION
REMOVAL OF FRETTING OR GALLING BEFORE FPI CAN MASK/HIDE CRACKS IN ADJACENT AREAS AND CAN CAUSE FAILURE OF THE FPI TO FIND THESE CRACKS, WHICH CAN CAUSE SUBSEQUENT PART FAILURE DURING ENGINE OPERATION.If a part surface shows remaining fretting and/or galling after the specified cleaning and stripping procedure, do not try to remove the remaining fretting or galling before FPI.
If the part must have FPI, then do the FPI before you do the SPM TASK 70-38-13-380-501 shotpeening to remove the fretting and/or galling. It is not permitted to shotpeen the surface before FPI.
If the part must have eddy current inspection (ECI), then remove the fretting and/or galling by the Engine Manual requirements before ECI. Fretting or galling can prevent a correct ECI.
Blasting
General
CAUTION
TOO MUCH DWELL TIME CAN CAUSE THE ABRASIVE BLAST TO SMEAR OVER (CLOSE) CRACK OPENINGS, WHICH CAN CAUSE FAILURE OF THE FLUORESCENT PENETRANT INSPECTION TO FIND THESE CRACKS AND SUBSEQUENTLY CAUSE PART FAILURE DURING ENGINE OPERATION.CAUTION
TOO MUCH DWELL TIME CAN CAUSE PART DIMENSIONS IN THE BLASTED AREAS TO BE OUT OF PERMITTED LIMITS, WHICH CAN CAUSE PART FAILURE DURING ENGINE OPERATION.CAUTION
TOO MUCH DWELL TIME CAN CAUSE BLASTED SURFACES TO HAVE AREAS WHERE MATERIAL REMOVAL IS NOT EQUAL, WHICH CAN CAUSE PART FAILURE DURING ENGINE OPERATION.CAUTION
YOU MUST NOT USE ABRASIVE BLASTING UNLESS DIRECTLY SPECIFIED IN THE ENGINE MANUAL. IF YOU DO NOT OBEY THIS INSTRUCTION THE PART(S) CAN BE DAMAGED.Do not use a dwell time that is longer than the specified maximum in the blasting procedure.
Use of blasting procedures that are not specified for the part in the Engine Manual can smear over (close) crack openings, which can cause failure of the FPI to find such cracks.
Do not use an abrasive blasting procedure to remove fretting or galling.
The abrasive blast procedures specified for the part in the Engine Manual Cleaning sections are approved to remove carbon, heat scale, or corrosion from corrosion pits on turbine blades, disks or hubs, but it is not permitted to use abrasive blast to blend or remove these corrosion pits.
It is permitted to do each specified abrasive blast task two times maximum during each shop visit.
CAUTION
TOO MUCH ABRASIVE BLAST DWELL TIME ON SLOT AREAS OF TURBINE DISKS AND HUBS CAN CAUSE UNEVEN WEAR (THAT IS, MATERIAL REMOVAL THAT IS NOT EQUAL IN ALL AREAS) IN THE SLOTS, WHICH CAN CAUSE LOADS TO BE HIGHER ON SOME AREAS OF THE PRESSURE FACE SURFACES THAN OTHERS. THESE UNEQUAL LOADS CAN CAUSE CRACKS IN THE FIR TREES (LUGS).To clean fir-tree slot (blade slot) areas of the turbine disks or hubs, use only hand-held nozzles or nozzles on fixtures in the blasting machines
It is necessary to keep the nozzle-to-part distance to a minimum of 5 inches (127 mm).
Hand-held nozzles let the operator hold the nozzle at the best angle and distance for each fir-tree lug surface. This helps keep to a minimum the time that the operator must blast the part to sufficiently clean the fir trees, and thus decrease the risk of uneven wear (that is, material removal that is not equal in all areas) on the fir trees.
Automated or semi-automated abrasive blast machines are not permitted to clean fir-tree slot areas of turbine disks or hubs because these machines can cause too much erosion in these areas.
Capping of airseals
If abrasive blasting is specified for parts with plasma coated knife-edge airseals, it is necessary to apply a CoMat 02-348 Airseal Mask to the knife-edge airseals to prevent erosion of the plasma coating. If it is necessary to give the knife-edge airseal more protection from the abrasive blast, it is permitted to apply a masking tape from SPM TASK 70-34-18-380-501 to the knife-edge airseal after you apply the CoMat 02-348 Airseal Mask.
Glass bead blasting
Do not use glass bead blasting on hot section parts in which the glass beads can become caught. Glass beads that become caught inside a part will flux and cause corrosion during engine operation.
Dry glass bead blasting can smear over cracks (that is, cause a layer of the surface material to close crack openings), which can cause failure of the FPI to find such cracks.
Blasting angle and distance
When it is not possible to use the specified angle and/or distance in the applicable task in the subsequent list because of the geometry of the part, it is permitted to use an angle and/or distance that does not agree with the specified limits if the task does not cause damage to the part at the new angle and/or distance.
Cleaning parts with chromium plating or thermal spray coatings
The task below will cause corrosion of, degrade, or remove chromium plate and many thermal spray coatings, and thus will make it necessary to replace these coatings.
Some repairs in the repair section of the Engine Manual specify to apply one or more of these coatings on parts for which the cleaning section in the Engine Manual specifies the SPM TASK 70-11-54-300-503.
To clean parts after such repairs, use one of the taskS in the list below unless you will replace the coatings. If you will replace the coatings, then it is permitted to use the SPM TASK 70-11-54-300-503 to clean these parts.
SPM TASK 70-11-54-300-503 Descaling of Components (Cobalt and Nickel Based Alloys) is compatible with the coatings in the subsequent list.
IAE 53-37 Nickel Aluminide Plasma Coating
IAE 271-37 Nickel Aluminide Dual Wire Arc Coating
IAE 53-47 Nickel-Chrome Aluminum Plasma Coating
IAE 271-47 Nickel-Chrome Aluminum Dual Wire Arc Coating.
Quality Control of Cleaning and Stripping Solutions
It will be necessary to discard cleaning solutions and stripping solutions at intervals. Make and keep a regular schedule to discard the cleaning and stripping solutions. The life of a cleaning and stripping solution does not continue forever. After sometime, the usual tests and maintenance will no longer cause the solution to give good results.
Solution Control - Cleaning and Stripping
Do the applicable stock loss test of a cleaning solution when parts show corrosion that you think is the result of the cleaning solution. Refer to Task 70-11-49-180-104.
If it is usually necessary to do the cleaning or stripping procedure again to sufficiently clean the part, do a check of the concentration, temperature, and maintenance of the solution by the procedure specified in the SPM TASK 70-11-48-110-501.
If after the specified maintenance instructions are completed, the solution does not give good results at the specified parameters in the task, do the subsequent steps:
Discard the solution
Clean the tank
Make up a new solution and test the solution by the procedure specified in the SPM TASK 70-11-48-110-501.
Before parts go into the solution, make sure that the solution temperature is between the limits that are specified in the task.
Make sure that the agitation, heaters and timers operate correctly.
Although some paint stripping procedures specify to use the same alkaline solutions as some cleaning procedures, it is very important that you do not clean parts and remove paint in the same tank of solution.
NOTE
If you remove paint from parts in a tank of solution that you use to clean parts, the solution will not clean parts correctly.
Equipment Quality Control
Solution temperature gages
Use temperature gages on tanks used for chemical solutions or water for which heat is necessary. Make sure that thermocouples do not have scale buildup (that is, a layer of scale that increases in thickness during the operation of the tank).
Calibrate gages at regular intervals to be sure of a correct calibration to a standard derived from the National Institute of Standards and Technology or to a standard specified by the equipment manufacturer. Do a check one time each day or each working shift to make sure that the gages are in satisfactory working condition.
NOTE
To be sure of a correct calibration, it is necessary to use a standard that is derived from the National Institute of Standards and Technology or a standard the equipment manufacturer specifies.
Timers
It is recommended that you use timers for all chemical solution tanks, specially the SPM TASK 70-11-06-300-503, to prevent too much stock loss due to uncontrolled immersion times.
Solution tank labels
Put labels on the chemical solution tanks to show the task or approved shop process number for each tank to help make sure that parts do not go into incorrect solutions, which can cause damage to parts or coatings.
Solution level markers
Put solution level markers in the solution tanks.
NOTE
The solution level marker helps you make the solution and do the subsequent maintenance of the solution.
Blasting machines
Machine Equipment
Necessary Equipment
Pressure gauge
Regulator
Air/oil filter and trap
Dust collector with media filter to remove unwanted material and broken-down media during machine operation
White lights that are near the window of the blasting cabinet and point at the part
NOTE
These lights help the operator to monitor the blasting procedure better than a light that is mounted near the top of the chamber in the blasting machine.A turntable, platform, or fixture that holds the part at a height and angle that make sure that each part area that the operator must blast is near the window while the operator blasts that area.
NOTE
Blasting that occurs near a window helps the operator to more easily see the part surface at which the operator points the nozzle.
Optional Equipment
A pistol-grip or fist-grip handle on the nozzle can help the operator to hold the nozzle at the necessary angle. One example of such an handle that you can add to a nozzle or hose is the Peta Easi Grip (R) Add On Handle, but it is permitted to purchase or make an equivalent handle.
Machine pressure
The blast procedures specify different pressures for pressure-type machines and suction-type machines because higher pressures are necessary with suction-type machines than pressure-type machines to get a sufficient flow of abrasive media.
Pressure-type machines supply the compressed air and the abrasive media together through one hose to the nozzle.
Suction-type machines supply compressed air to the nozzle through one hose and supply the abrasive media to the nozzle through a different hose. The flow of compressed air through the nozzle causes suction that pulls the abrasive media through its hose and into the nozzle.
Pressure-type machines usually clean parts faster and more easily than suction-type machines.
Do not measure blasting machine pressure at the nozzle because the pressure at the nozzle is different from the pressure at the machine pressure gage. The specified pressure in the blasting procedures are machine gage pressure values.
Measure the blasting machine pressure during machine operation while media and compressed air flow through the nozzle. Do not use indications that show on the machine pressure gage when there is no flow of media and compressed air through the nozzle.
Set the blasting machine pressure during machine operation while media and compress air flow through the nozzle. Use the pressure regulator and gage on the machine to set the pressure at a value that is between the specified range limits in the blasting task.
If the machine procedure does not give good results at the pressures specified in the task, clean the filtration systems for the media, dust collector, and compressed air, and examine the nozzle for wear.
Blasting Equipment cleaning
Examine and clean dust collector filters at regular intervals.
Examine and clean air/oil filter and trap at regular intervals to make sure that compressed air is without water or oil contamination.
Gage calibration
To be sure of a correct calibration, calibrate gages at regular intervals to a standard derived from the National Institute of Standards and Technology or to a standard specified by the equipment manufacturer.
Machine labels
To prevent errors that can cause damage to parts, coatings or mask cracks, put a label on the blasting machine to show task or approved shop process number, operating air pressure range, grit size and type.
Nozzles
Examine nozzles regularly for wear. Worn nozzles will decrease the efficiency of the blasting machine.
Use only nozzles that have the same specification as the nozzle that the machine manufacturer supplied with the machine.
Do not make changes to the dimensions or features of the nozzle.
CAUTION
DO NOT PUT A HOOK THROUGH A TIEROD, LIGHTENING OR BALANCE HOLE OF A DISK, SHAFT, DRUM OR HUB WHEN YOU CLEAN A PART.Hooks
Coated hooks
When you use an electric hoist, it is important to use a coated hook suspended from the hoist to the part basket or part to prevent possible damage to the part from stray current from an electric hoist.
NOTE
A coated hook is not necessary if you use a bus bar to hold the basket or part.NOTE
A coated hook is not necessary if you use a pneumatic hoist.Coated hooks protect the parts from metal-to-metal contact.
Type of coating on hooks
The coating on the hook must be HALAR (R) ECTFE fluoropolymer, or an equivalent chemical resistant, non conductive coating, that is 0.020 in. (0.508 mm) thick minimum.
Coating repair
When the initial coating becomes worn, strip the old coating and apply a new coating.
Alternatives to the coated hook
Nylon strap
Polypropylene rope
Solution Tank Requirements
Use corrosion resistant stainless steel tanks for chemical cleaning and stripping solutions
Stainless steel prevents possible chemical interaction and tank material failure.
Do not use plastic tank materials (such as polyethylene or polypropylene) for chemical cleaning or stripping tanks.
NOTE
The maximum operation temperature of plastic tanks is not sufficiently high for chemical solutions or water for which heat is necessary.
A grate or platform, if used, in the bottom of the tank, must be made of corrosion resistant stainless steel.
Polypropylene can be used for cold water tanks.
Pressure Spray Rinse Requirements
A pressure spray will give better results than a water hose without added pressure when you flush parts in the chemical cleaning and stripping tasks, and will also help keep to a minimum the amount of water that is necessary to flush the parts. Use one of these types of equipment:
High Pressure Water Spray Unit (Power Washer)
NOTE
The high pressure water spray unit (power washer) gives a more satisfactory result than the air-assisted water gun for the removal of soil from parts.The high pressure spray unit must have a fan spray nozzle or an oscillating nozzle (also known as a rotary, rotating, or turbo nozzle).
The water pressure that the high pressure spray unit can supply must not be more than 2000 psig (13789.5 kPa).
Air-Assisted Water Gun
This gun mixes compressed air and water.
Use an air-assisted water gun or a high pressure water spray unit to do the pressure spray rinse step after each chemical cleaning solution step in the task, but use a high pressure water spray unit to do the last pressure spray rinse step in the task to get best results.
It is not permitted to use a high pressure water spray on bearings, delicate parts or lightweight parts.
Baskets
Baskets must be made of corrosion resistant stainless steel. It is not necessary to use coated baskets.
If you use partitions in the baskets, do not use solid ones because the partition will prevent the flow of the solution.
The Quality of Water
Chloride Content.
NOTE
The term (ppm) equals (parts per million) or (parts/million).The chloride content of incoming water for the make-up of the chemical solution tanks, for rinsing and for the make-up of the hot water immersion tanks for flash drying must not be more than 100 PPM (200 micro-Siemen/centimeter).
The chloride content of the hot water for flash drying in immersion tanks or for spray washers must be not more than 250 PPM (500 micro-Siemen/centimeter) unless specified differently.
Do these steps to make sure that the water in the water rinse tank does not collect too much contamination.
Discard the water in the tanks at regular intervals or use tanks that have continuous overflow.
Clean the cold water rinse tanks at regular intervals to remove unwanted material from the tanks.
Keep clean those hot water tanks that you use to flash dry parts, and discard the contents of those tanks at regular intervals to help keep to a minimum the remaining contamination that the hot water can cause on the parts.
Potable Water Quality Specifications (for compressor water wash or detergent cleaning procedures that you do on-wing or in the test cell).
NOTE
Compressor wash or detergent cleaning uses potable water in its make-up in SPM TASK 70-11-48-110-501.Water for engine gaspath cleaning must agree with local quality specifications for potable water and with the subsequent requirements.
NOTE
When a property limit in the local quality specifications for potable water does not agree with the limit in the quality specifications that follow, the limit in the quality specifications that follow is applicable.Property
Permitted Value (Analysis at 70 F (24 C))
pH
6.0 − 10.0
Total Dissolved Solids
500 mg/l maximum
Resistance or Conductivity
Specific Resistance
1800 ohm−cm minimum
or
Conductivity
Conductivity 550 microsiemens/cm maximum
Chloride
250 mg/l maximum
Fluoride
2.0 mg/l maximum
Equipment Quality Control
Solution temperature gages on tanks used for chemical solutions or water for which heat is necessary. Make sure that thermocouples do not have scale build−up (that is, a layer of scale that increases in thickness during the operation of the tank).
Environment and Health
Because of changes to environmental regulations, IAE no longer recommends the use of SPM TASK 70-11-01-300-503 Vapor Degreasing. Whenever this task is specified in the Engine Manual, IAE recommends the alternative aqueous degreasing method in SPM TASK 70-11-26-300-503.
Use the solvent wipe procedure on small, local areas only.
Where chlorinated solvent is specified for local degreasing, IAE recommends that you use the alternative SPM TASK 70-11-26-300-503.