TASK 70-11-54-300-503 The Procedure For Heavy Duty Scale Removal from a Part (Stainless Steel, Cobalt And Nickel Base Material)

DMC:V2500-00-70-11-54-00A-251A-D|Issue No:009.00|Issue Date:2020-11-01

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

TASK 70-11-54-300-503 The Procedure For Heavy Duty Scale Removal from a Part (Stainless Steel, Cobalt And Nickel Base Material)

Table of Contents

Introduction (Methods and Applicable Subtasks)

Safety Precautions

General Information

Method 1 Procedure

Method 2 Procedure

Introduction

This task specifies two methods to remove heavy duty scale from stainless steel, cobalt and nickel base material. Method 1 is a multi-step procedure that uses an alkaline rust remover solution, an acid scale conditioner solution, an alkaline permanganate solution and a last chemical step of alkaline rust remover solution or inhibited phosphoric acid solution. Method 2 is a multi-step procedure that uses an optional alkaline rust remover solution, a neutral deoxidizer solution and an alkaline permanganate solution.

Safety Precautions

Refer to SPM TASK 70-11-48-110-501.

General

Some of the steps in TASK 70-11-54-300-503 will degrade or cause corrosion of chromium plate, aluminized coatings and some thermal spray coatings (for example, some flame sprayed, plasma sprayed, Praxair Flame Sprayed and High Velocity Oxy Fuel (HVOF) coatings), which 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 of the Engine Manual specifies this procedure.

To clean a part that has one or more repair coatings that are not compatible with TASK 70-11-54-300-503, it is necessary to use only the specified cleaning procedures that are compatible with the applied repair coatings if you will not replace the incompatible (not compatible) repair coatings before the part goes back into service,. If you will replace the incompatible (not compatible) repair coatings before the part goes back into service, then it is permitted to use TASK 70-11-54-300-503 to clean the part.

Refer to the applicable Engine Manual to find the specified cleaning procedures that are compatible with the applied repair coatings.

If a part is heavily scaled, remove the part from the solution, two times maximum during one or more of the chemical solution steps in the cleaning cycle and pressure spray rinse to remove degraded scale before you put the part in the solution again. Make sure that the total time in each solution is not more than the maximum time specified for that solution.

Some engines operate at higher temperatures and/or operate for more hours and cycles between shop visits than past engine models. These operating conditions can make the engine parts not easy to clean when the solution temperatures and concentrations are near the minimum operating limits. This TASK will clean such parts more easily if the solution temperatures and concentrations are between the maximum and the middle of the specified operating limit ranges.

The Method 1 procedure has an alternative final chemical cleaning step that permits you to use either an inhibited phosphoric acid solution or an alkaline rust remover solution. The process that uses the inhibited phosphoric acid solution makes the parts brighter.

The Method 2 procedure includes an alkaline rust remover step for removal of coke and baked-on carbon. This step is not necessary for parts that do not have coke or baked-on carbon.

Refer to TASK 70-10-00-100-501, General Cleaning Information for additional requirements

Preliminary Requirements

Pre-Conditions

NONE

Support Equipment

NONE

Consumables, Materials and Expendables

NONE

Spares

NONE

Safety Requirements

WARNING

IT IS THE RESPONSIBILITY OF THE OPERATOR TO OBTAIN AND OBSERVE THE MANUFACTURER'S MATERIAL SAFETY DATA SHEETS FOR CONSUMABLE MATERIALS INFORMATION (SUCH AS HAZARDOUS INGREDIENTS; PHYSICAL/CHEMICAL CHARACTERISTICS; FIRE, EXPLOSION, REACTIVITY, AND HEALTH HAZARD DATA; PRECAUTIONS FOR SAFE HANDLING; USE AND CONTROL MEASURES), AND ALSO TO TAKE LOCAL REGULATIONS INTO CONSIDERATION.

CAUTION

DO NOT DO THIS PROCEDURE MORE THAN THE SPECIFIED NUMBER OF TIMES DURING EACH SHOP VISIT BECAUSE TOO MUCH STOCK LOSS CAN OCCUR.

NOTE

It is permitted to use Method 1 or Method 2 when you do this TASK.

Procedure

    1. SUBTASK 70-11-54-300-001-001 Method 1 - Multi-Step Procedure with Acidic Scale Conditioner

      NOTE

      It is permitted to reverse the process order of the acidic scale conditioner and the alkaline permanganate soak operations. Some supplier's chemicals give more satisfactory results when used in the reverse order.

    1. If there is loose or powdery soil on the part, use a high pressure water spray unit to remove the loose or powdery soil from the part. Refer to SPM TASK 70-10-00-100-501 for high-pressure water spray unit (power washer) information.

    2. If there is grease or oil on the part, degrease the part by SPM TASK 70-11-03-300-503.

      3. Alkaline Rust Remover Soak.

        1. Soak the part in alkaline rust remover solution at the applicable temperature for 15 to 30 minutes.

          1. The operating temperature range of the solutions in the subsequent list (refer to SPM TASK 70-11-54-100-501) is 190 deg F to 200 deg F (88 deg C to 93 deg C):

          1. Solution Code 20

          2. Solution Code 23

          3. Solution Code 24

          4. Solution Code 25

          5. Solution Code 97

        2. The operating temperature range of Solution Code 175 (refer to SPM TASK 70-11-54-100-501) is 185 deg F to 195 deg F (85 deg C to 90 deg C).

      2. Remove the part from the alkaline rust remover solution tank. With the part above the alkaline rust remover solution tank, use a clean cold water spray to flush the alkaline rust remover solution from the part.

      3. Pressure spray rinse the part to remove scale, corrosion and oxides.

      4. Put the part fully into cold water. Remove the part from the cold water and use a clean cold water spray to clean the part again.

      4. Acidic Scale Conditioner - First Soak.

        1. Soak the part in one of the acidic scale conditioner solutions in the subsequent list at the applicable temperature for 10 to 15 minutes.

          1. The operating temperature range of the solutions in the subsequent list (refer to SPM TASK 70-11-54-100-501) is 176 deg F to 185 deg F (80 deg C to 85 deg C):

          1. Solution Code 91

          2. Solution Code 119

          3. Solution Code 160

        2. The operating temperature range of Solution Code 96 (refer to SPM TASK 70-11-54-100-501) is 185 deg F to 194 deg F (85 deg C to 90 deg C).

      2. Remove the part from the acidic scale conditioner solution. With the part above the acidic scale conditioner solution tank, use a clean cold water spray to flush the acidic scale conditioner solution from the part.

      3. Pressure spray rinse the part to remove scale, corrosion and oxides.

      4. Put the part fully into cold water. Remove the part from the cold water and use a clean cold water spray to flush the part again.

      5. Alkaline Permanganate - First Soak.

        1. Soak the part in one of the alkaline permanganate solutions in the subsequent list (refer to SPM TASK 70-11-54-100-501) at a temperature of 190 deg F to 200 deg F (88 deg C to 93 deg C) for 10 to 15 minutes:

        1. Solution Code 1

        2. Solution Code 100

        3. Solution Code 140

        4. Solution Code 161

        5. Solution Code 162

        6. Solution Code 168

      2. Remove the part from the alkaline permanganate solution. With the part above the alkaline permanganate solution tank, use a clean cold water spray to flush the alkaline permanganate solution from the part.

      3. Pressure spray rinse the part to remove scale, corrosion and oxides.

      4. Put the part fully into cold water. Remove the part from the cold water and use a clean cold water spray to clean the part again.

      6. Acidic Scale Conditioner - Second Soak.

        1. Soak the part in one of the acidic scale conditioner solutions in the subsequent list at the applicable temperature for 10 to 15 minutes.

          1. The operating temperature range of the solutions in the subsequent list (refer to SPM TASK 70-11-54-100-501) is 176 deg F to 185 deg F (80 deg C to 85 deg C):

          1. Solution Code 91

          2. Solution Code 119

          3. Solution Code 160

        2. The operating temperature range of Solution Code 96 (refer to SPM TASK 70-11-54-100-501) is 185 deg F to 194 deg F (85 deg C to 90 deg C).

      2. Remove the part from the acidic scale conditioner solution. With the part above the acidic scale conditioner solution tank, use a clean cold water spray to flush the acidic scale conditioner solution from the part.

      3. Pressure spray rinse the part to remove scale, corrosion and oxides.

      4. Put the part fully into cold water. Remove the part from the cold water and use a clean cold water spray to flush the part again.

      7. Alkaline Permanganate - Second Soak.

        1. Soak the part in one of the alkaline permanganate solutions in the subsequent list (refer to SPM TASK 70-11-54-100-501) at a temperature of 190 deg F to 200 deg F (88 deg C to 93 deg C) for 10 to 15 minutes:

        1. Solution Code 1

        2. Solution Code 100

        3. Solution Code 140

        4. Solution Code 161

        5. Solution Code 162

        6. Solution Code 168

      2. Remove the part from the alkaline permanganate solution. With the part above the alkaline permanganate solution tank, use a clean cold water spray to flush the alkaline permanganate solution from the part.

      3. Pressure spray rinse the part to remove scale, corrosion and oxides.

      4. Put the part fully into cold water. Remove the part from the cold water and use a clean cold water spray to clean the part again.

      8. Do one of the subsequent procedures.

        1. Alkaline Rust Remover Final Chemical Clean Procedure

          1. Soak the part in alkaline rust remover solution at the applicable temperature for 5 to 10 minutes.

            1. The operating temperature range of the solutions in the subsequent list (refer to SPM TASK 70-11-54-100-501) is 190 deg F to 200 deg F (88 deg C to 93 deg C):

            1. Solution Code 20

            2. Solution Code 23

            3. Solution Code 24

            4. Solution Code 25

            5. Solution Code 97

          2. The operating temperature range of Solution Code 175 (refer to SPM TASK 70-11-54-100-501) is 185 deg F to 195 deg F (85 deg C to 90 deg C).

        2. Remove the part from the alkaline rust remover solution. With the part above the alkaline rust remover solution tank, use a clean cold water spray to flush the alkaline rust remover solution from the part.

        3. Pressure spray rinse the part to remove scale, corrosion and oxides.

        4. Put the part fully into cold water. Remove the part from the cold water and use a clean cold water spray to clean the part again.

        2. Inhibited Phosphoric Acid Final Chemical Clean Procedure

        1. Soak the part in Solution Code 14 (refer to SPM TASK 70-11-54-100-501) at room temperature for 15 to 30 minutes.

        2. Remove the part from the inhibited phosphoric acid.

        3. Put the part fully into cold water. Remove the part from the cold water and use a clean cold water spray to clean the part.

      9. Do an inspection of the part to make sure the part is clean.

      1. CAUTION

        IF YOU DO THIS PROCEDURE (SPM TASK 70-11-54-300-503) MORE THAN THE SPECIFIED NUMBER OF TIMES DURING EACH SHOP VISIT, TOO MUCH STOCK LOSS CAN OCCUR.

        If the part is not clean, then it is permitted to do this procedure (SPM TASK 70-11-54-300-503) again one time only.

      2. It is permitted to do this procedure (SPM TASK 70-11-54-300-503) to clean the part a maximum of two times during each shop visit.

      10. Flash dry the part with hot water.

        1. Put the part fully into hot water at a temperature of 150 deg F to 200 deg F (66 deg C to 93 deg C) until the temperature of the part increases sufficiently to flash dry.

        1. 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.

      2. Remove the part from the hot water and flash dry the part in air.

    11. Apply corrosion inhibitor as necessary to the part by SPM TASK 70-38-37-300-503.

    2. SUBTASK 70-11-54-300-001-002 Method 2 - Multi-Step Procedure with Neutral Deoxidizer

    1. If there is loose or powdery soil on the part, use a high pressure water spray unit to remove the loose or powdery soil from the part. Refer to SPM TASK 70-10-00-100-501 for high-pressure water spray unit (power washer) information.

    2. If there is grease or oil on the part, degrease the part by SPM TASK 70-11-03-300-503.

      3. Alkaline Rust Remover Soak For Parts With Coke Or Baked-On Carbon.

        NOTE

        It is necessary to do this procedure only if there is coke or baked-on carbon on the part.

        1. Soak the part in alkaline rust remover solution at the applicable temperature for 15 to 30 minutes.

          1. The operating temperature range of the solutions in the subsequent list (refer to SPM TASK 70-11-54-100-501) is 190 deg F to 200 deg F (88 deg C to 93 deg C):

          1. Solution Code 20

          2. Solution Code 23

          3. Solution Code 24

          4. Solution Code 25

          5. Solution Code 97

        2. The operating temperature range of Solution Code 175 (refer to SPM TASK 70-11-54-100-501) is 185 deg F to 195 deg F (85 deg C to 90 deg C).

      2. Remove the part from the alkaline rust remover solution. With the part above the alkaline rust remover solution tank, use a clean cold water spray to flush the alkaline rust remover solution from the part.

      3. Pressure spray rinse the part to remove scale, corrosion and oxides.

      4. Put the part fully into cold water. Remove the part from the cold water and use a clean cold water spray to clean the part again.

      4. Neutral Deoxidizer - First Soak.

      1. Soak the part in Solution Code 193 neutral deoxidizer solution (refer to SPM TASK 70-11-54-100-501) at a temperature of 170 deg F to 190 deg F (77 deg C to 88 deg C) for 15 to 30 minutes.

      2. Remove the part from the neutral deoxidizer solution. With the part above the neutral deoxidizer solution tank, use a clean cold water spray to flush the neutral deoxidizer solution from the part.

      3. Pressure spray rinse the part to remove scale, corrosion and oxides.

      4. Put the part fully into cold water. Remove the part from the cold water tank and use a clean cold water spray to clean the part again.

      5. Alkaline Permanganate Soak.

        1. Soak the part in one of the alkaline permanganate solutions in the subsequent list (refer to SPM TASK 70-11-54-100-501) at a temperature of 190 deg F to 200 deg F (88 deg C to 93 deg C) for 15 to 30 minutes:

        1. Solution Code 1

        2. Solution Code 100

        3. Solution Code 140

        4. Solution Code 161

        5. Solution Code 162

        6. Solution Code 168

      2. Remove the part from the alkaline permanganate solution. With the part above the alkaline permanganate solution tank, use a clean cold water spray to flush the alkaline permanganate solution from the part.

      3. Pressure spray rinse the part to remove scale, corrosion and oxides.

      4. Put the part fully into cold water. Remove the part from the cold water and use a clean cold water spray to clean the part again.

      6. Neutral Deoxidizer - Second Soak.

      1. Soak the part in Solution Code 193 neutral deoxidizer solution (refer to SPM TASK 70-11-54-100-501) at a temperature of 170 deg F to 190 deg F (77 deg C to 88 deg C) for 15 to 30 minutes.

      2. Remove the part from the neutral deoxidizer solution. With the part above the neutral deoxidizer solution tank, use a clean cold water spray to flush the neutral deoxidizer solution from the part.

      3. Pressure spray rinse the part to remove scale, corrosion and oxides.

      4. Put the part fully into cold water. Remove the part from the cold water tank and use a clean cold water spray to clean the part again.

      7. Do an inspection of the part to make sure the part is clean.

      1. CAUTION

        IF YOU DO THIS PROCEDURE (SPM TASK 70-11-54-100-501) MORE THAN THE SPECIFIED NUMBER OF TIMES DURING EACH SHOP VISIT, TOO MUCH STOCK LOSS CAN OCCUR.

        If the part is not clean, then it is permitted to do this procedure (TASK 70-11-54-100-501) again one time only.

      2. It is permitted to do this procedure (TASK 70-11-54-100-501) to clean the part a maximum of two times during each shop visit.

      8. Flash dry the part with hot water.

        1. Put the part fully into hot water at a temperature of 150 deg F to 200 deg F (66 deg C to 93 deg C) until the temperature of the part increases sufficiently to flash dry.

        1. 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.

      2. Remove the part from the hot water and flash dry the part in air.

Requirements After Job Completion

Follow-On Conditions

NONE
Change Type:

Clarify repair language (REA20VC345)