TASK 70-46-04-400-501 Expansion Of Parts By Heat And Contraction By Chilling

DMC:V2500-00-70-46-04-00A-723A-D|Issue No:001.00|Issue Date:2013-03-20

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 70-46-04-400-501 Expansion Of Parts By Heat And Contraction By Chilling

Introduction

When you assemble parts that have an interference fit, it is permitted to use heat and chill procedures to make it easier to assemble the parts and to reduce the risk of damage when you assemble the parts.

This Task is not an approved procedure for bearings.

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 SHEETS FOR CONSUMABLE MATERIALS. THESE CONTAIN INFORMATION SUCH AS, HAZARDOUS INGREDIENTS, PHYSICAL/CHEMICAL CHARACTERISTICS, FIRE, EXPLOSION, REACTIVITY, HEALTH HAZARD DATA, PRECAUTIONS FOR SAFE HANDLING, USE AND CONTROL MEASURES AND ALSO TO TAKE LOCAL REGULATIONS INTO CONSIDERATION.

Procedure

    1. SUBTASK 70-46-04-400-001 Expansion Of Parts By Heat

    1. When it is necessary to replace an old part that has a tight fit, it is permitted to apply heat to the adjacent metal to make the removal easier.

    2. Unless specified differently, this Task is an approved alternative to increase the temperature of parts other than bearings when the Engine Manual specifies to use an electric heater to expand the part by heat.

      3. Use one of these methods to help prevent distortion:

      1. Put the part in an oven and gradually increase the part temperature to the necessary temperature.

      2. Wrap the part in a heating blanket and gradually increase the part temperature to the necessary temperature.

      4. NOTE

        A temperature difference of 125 deg F (70 deg C) minimum between mating parts makes it easier to assemble or disassemble mating parts.

        Increase the temperature of the part to the temperature specified in the Engine Manual. If the Engine Manual does not specify the temperature, increase the part temperature as necessary to expand the part. Do not let the temperature increase to more than 300 deg F (149 deg C), unless specified differently. Use one of these methods:

      1. Put the part in an oven.

        2. Wrap the part in a heating blanket.

        1. Increase the temperature equally all around the circumference of the part.

        3. Use an electric heat gun (flameless torch).

        1. Use a digital thermometer (for example, a thermocouple (probe-type) thermometer, or an infrared radiation pyrometer that does not touch the part to continually monitor the part temperature.

        2. Increase the temperature equally all around the circumference of the part.

        3. CAUTION

          IF THE HEAT GUN STAYS POINTED ON ONE AREA OF THE PART FOR TOO LONG, IT CAN CAUSE DAMAGE TO SOME COATINGS AND ANTIGALLING COMPOUNDS, OR TO THE BASE MATERIAL.

          Move the heat gun continuously around the circumference of the part. Do not let the heat gun stay pointed on one area of the part.

        4. A propane torch or a natural gas torch is permitted for mating diameters on disks, shafts, drums, or hubs.

        1. Use a torch head (for example, a rosebud tip) that gives a soft (wide angle) lapping flame. Do not use a pencil-point (long and narrow) flame.

        2. Use a digital thermometer (for example, a thermocouple (probe-type) thermometer, or an infrared radiation pyrometer that does not touch the part) to continually monitor the part temperature.

        3. Increase the temperature equally all around the circumference of the part.

        4. CAUTION

          IF THE TORCH FLAME STAYS POINTED ON ONE AREA OF THE PART FOR TOO LONG, IT CAN CAUSE DAMAGE TO SOME COATINGS AND ANTIGALLING COMPOUNDS, OR TO THE BASE MATERIAL.

          Move the torch continuously around the circumference of the part. Do not let the flame stay pointed on one area of the part.

    2. SUBTASK 70-46-04-400-002 Contraction Of Parts By Chilling

    1. WARNING

      THE TEMPERATURE OF LIQUID NITROGEN IS -320 DEG F (-196 DEG C). IF COLD LIQUID OR COLD GAS TOUCHES THE EYES OR SKIN, IT CAN CAUSE SEVERE FROSTBITE. NITROGEN IS NOT TOXIC BUT CAN CAUSE RAPID ASPHYXIATION AND DEATH BECAUSE IT DISPLACES OXYGEN IN CONFINED AREAS THAT DO NOT HAVE SUFFICIENT VENTILATION. KEEP AND USE THIS MATERIAL IN A WELL VENTILATED AREA. WEAR CHEMICAL AND THERMAL SHOCK RESISTANT GOGGLES OR FACE SHIELD TO KEEP LIQUID NITROGEN AWAY FROM EYES, FACE, AND SKIN. IT IS ALSO NECESSARY TO WEAR PROTECTIVE GLOVES WITHOUT GAUNTLET, LONG SLEEVES, AND TROUSERS WITH NO CUFFS TO PROTECT SKIN.

      The chilling method is not approved for bearings.

    2. Unless specified differently, use liquid nitrogen or dry ice (solidified carbon dioxide) to chill the part.

Requirements After Job Completion

Follow-On Conditions

NONE