PRATT & WHITNEY CANADA

MAINTENANCE MANUAL
MANUAL PART NO. 3034342

LIST OF EFFECTIVE PAGES

CHAPTER
SECTION PAGE DATE
LEP 1 Sep 28/2007
2 blank Sep 28/2007

Contents 1 Sep 28/2007

2 blank Sep 28/2007

72-40-00 1 Nov 05/99

Description and 2 blank Nov 05/99
Operation

72-40-01 1 Nov 05/99

Description and 2 Nov 05/99
Operation

72-40-01 201 Sep 28/2007

Maintenance 202 Sep 28/2007
Practices 203 Sep 28/2007
204 Sep 28/2007
205 Sep 28/2007
206 Sep 28/2007
207 Sep 28/2007
208 Sep 28/2007
209 Sep 28/2007
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211 Sep 28/2007
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 PRATT & WHITNEY CANADA
MAINTENANCE MANUAL
MANUAL PART NO. 3034342

TABLE OF CONTENTS
SUBJECT PAGE

COMBUSTION SECTION - DESCRIPTION AND OPERATION 72-40-00

1. Description and Operation 1

COMBUSTION CHAMBER LINER ASSEMBLY - DESCRIPTION AND

OPERATION 72-40-01

1. Description and Operation 1

COMBUSTION CHAMBER LINER ASSY - MAINT. PRACTICES 72-40-01

1. General 201
2. Consumable Materials 201

3. Special Tools 201

4. Fixtures, Equipment and Supplier Tools 201
5. Removal/Installation 201

A. Removal of Combustion Chamber Liner 201

B. Installation of Combustion Chamber Liners 202
6. Inspection/Check 202

A. General 202
B. Inspection of Combustion Liners 202
7. Approved Repairs 205
A. Repair of Liners - Cracks 205

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 PRATT & WHITNEY CANADA
MAINTENANCE MANUAL
MANUAL PART NO. 3034342

COMBUSTION SECTION - DESCRIPTION AND OPERATION

1. Description and Operation

The combustion section of the engine is contained in the front part of the gas generator
case, and consists of the inner and outer combustion chamber liners and the small exit duct.
Compressor delivery air from the diffuser section discharges into the combustion section.
The air enters the liner through straight and plunged holes, mixes with the fuel from the
manifold, and is ignited. The expanding gases flow to the rear and into the exit duct
zone, where the gas flow is turned 180 degrees inward to flow forward through the compressor
turbine stator to the compressor turbine.

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 PRATT & WHITNEY CANADA
MAINTENANCE MANUAL
MANUAL PART NO. 3034342

COMBUSTION CHAMBER LINER ASSEMBLY - DESCRIPTION AND OPERATION

1. Description and Operation (Ref. Fig. 1)

The combustion chamber assembly is made up of two heat-resistant steel liners bolted
together at the front (domed) end to create an annular space open to the rear. The outer liner
extends rearward to form the large exit duct, incorporates a bolting flange by which it is
fastened to the gas generator case at the compressor stator assembly mounting flange. The
inner liner has a sliding joint at the rear to engage the outer diameter of the small exit
duct.

Igniter sleeves and fuel manifold adapter ports and support collars are located in the front of
the outer liner. A series of straight and shielded holes let P3 air to enter the combustion
zone of the liner assembly. The shape, size and locations of the holes and shields, as well
as the locations of the igniter sleeves, provide the best fuel/air ratios for starting and sustaining
combustion, and form efficient primary and secondary zones within the combustion zone.
Primary air introduced near the fuel manifold adapter ports, supports combustion. Secondary
air provides a layer of cooling air over the inner walls of the liners, which also prevents
the flame from touching the liner walls, cools the gases leaving the combustion zone to a
temperature the compressor turbine can tolerate, and provides air for combustion.

The domed end of the combustion chamber liner assembly is supported inside the front
section of the gas generator case by the fuel manifold adapter sheaths and is located by the
spark igniter. The rear of the assembly is supported at the small exit duct and compressor
turbine stator assembly interface.

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 PRATT & WHITNEY CANADA
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MANUAL PART NO. 3034342

LOUVERED
COOLING RING OUTER LINER

COOLING RING

INNER
LINER
SEALING RING
COOLING RING

SEALING RING

BOLTING FLANGE
FUEL MANIFOLD
SUPPORT COLLAR

SPARK IGNITER
SUPPORT COLLAR

C10219C

Combustion Chamber Liner Assemblies

Figure 1

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 PRATT & WHITNEY CANADA
MAINTENANCE MANUAL
MANUAL PART NO. 3034342

COMBUSTION CHAMBER LINER ASSY - MAINT. PRACTICES

1. General

A. Maintenance personnel should make reference to the INTRODUCTION section and

Chapter 70-00-00 STANDARD PRACTICES of this manual to familiarize themselves
with general procedures.

B. Install suitable protective caps/covers over all disconnected tubes/lines and component
openings.

C. Lockwire used, unless otherwise specified, shall comply with specification AMS 5687,
heat and corrosion resistant steel wire MS9226-03, which is 0.025 inch diameter, and
will not be specified in instructions.

2. Consumable Materials

The consumable materials listed below are used in the following procedures.

Item No. Name

PWC05-151 Wire, Filler
PWC11-014 Alcohol, Isopropyl
3. Special Tools

The special tools listed below are used in the following procedures.

Tool No. Name

PWC34414 Puller
4. Fixtures, Equipment and Supplier Tools

Not Applicable

5. Removal/Installation

A. Removal of Combustion Chamber Liner

(1) Remove power section/power section module (Ref. 72-00-00, REMOVAL/

INSTALLATION).

(2) Mark index line at 12 o’clock position on inner liner, with an approved marker (Ref.
70-00-00, MAINTENANCE PRACTICES, Marking of Parts).

(3) Remove bolts (1, Fig. 201).

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MANUAL PART NO. 3034342

CAUTION: DO NOT ATTEMPT TO PRY LINER LOOSE WITH SHARP EDGED OR

POINTED TOOLS.

(4) Withdraw the combustion chamber inner liner (2) from the combustion chamber
outer liner (3) using puller (PWC34414).

NOTE: If it is difficult separating inner and outer liner, strike inside wall of inner
liner with palm of hand to dislodge it from small exit duct joint.

(5) If applicable, remove the combustion chamber outer liner (3) from the gas
generator case (4) (Ref. 72-50-01, Removal/Installation).

B. Installation of Combustion Chamber Liners

(1) Install combustion chamber outer liner (3, Fig. 201) in gas generator case (4), if
removed (Ref. 72-50-01, Removal/Installation).

(2) Install combustion chamber inner liner (2) in combustion chamber outer liner (3)
with index line at 12 o’clock position, engaging flange of small exit duct with
sealing ring on rear of inner liner.

(3) Align bolting flanges on inner liner (2) with flanges on outer liner (3), and install
bolts (1). Tighten bolts 36 to 40 lb.in.

(4) Install power section/power section module (Ref. 72-00-00, REMOVAL/INSTALLATION).

NOTE: Verify and confirm the T5 immersion thermocouples are compatible with
the configuration of combustion chamber liner installed in GGM.

6. Inspection/Check

A. General

Examine combustion chamber liners for cracks, buckling and burning. Cracks in the liner
surface are usually of a stress relieving nature and are usually not serious as rate of
growth decreases as crack lengthens. Thermal stresses, in effect, relieve original stress
conditions. It is normal to observe a given type of deterioration repeated from liner to
liner in the same engine, or engines of the same model. Typical liner distress consists of
buckling and cracking of cooling rings and cracking at inner wall of the exit duct
section of the outer liner.

B. Inspection of Combustion Liners

(1) Acceptable Conditions, Repair Unnecessary:

(a) Localized buckling and/or burning of cooling rings, except louvered type,
accompanied by cracking is acceptable provided cracks do not extend into the
seam weld (Ref. Fig. 206, Detail B).

(b) Cracks in louvered type cooling ring (Detail A) are acceptable provided that
circumferential cracks in the seam weld (Ref. Fig. 202) not exceeding 0.300
inch in length are stop drilled using a 1⁄16 (0.0625) inch drill.

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(c) Straight line cracks between two adjacent cooling holes.

CAUTION: CRACKS RUNNING IN SAME DIRECTION, AND WHICH COULD

ULTIMATELY JOIN, ARE NOT ACCEPTABLE UNLESS THEY ARE
SEPARATED BY AT LEAST THREE INCHES OF PARENT METAL.

(d) Cracks along, or next to, outer liner flange to wrapper seam weld (Ref. Fig.
203, Sheet 1), are acceptable provided there are not more than seven and
they are no nearer than one-half inch to the fuel manifold support collar.

(e) Maximum seven cracks, each crack not exceeding one inch long, is acceptable
in the inner wall of domed end of inner liner (Ref. Fig. 204).

(f) Localized areas that have been heated to an extent as to cause buckling of the
liner are considered acceptable provided the buckling is shallow, and it is not
associated with burning, which would reduce the wall thickness and weaken the
structure (Ref. Fig. 203, Sheet 2).

(g) Cracks up to 1.00 inch long in the large exit duct section inner wall are
acceptable provided they are stop drilled using a 1⁄16 (0.0625) inch drill.

(h) Coating loss of any amount is acceptable on large exit duct section provided
there is no evidence of burning or erosion of parent metal.

(i) Multiple hairline cracks in outer liner flange heat shield (Ref. Fig. 203, Sheet 3)
are acceptable provided they do not converge or extend into the radius and are
at least 1.5 in. apart. Stop drill cracks using a 1⁄16 (0.0625) inch drill.

(j) Erosion of outer liner flange heat shield lip up to 0.125 in. below original profile.

(k) Examine cooling holes in liners after repairs. Make sure they are not
obstructed by excessive plasma coating or weld repair. Make sure shank of
correct size drill, outer liner 1⁄16 (0.0625) inch and ’E’ size (0.025 inch) (Ref. Fig.
203, Sheet 2), or inner liner No. 43 (0.089 inch) (Ref. Fig. 204) will pass
through each cooling hole in lines indicated. Clean out cooling holes if necessary.

(2) Acceptable Conditions, Repair Necessary:

(a) Buckled cooling rings where the gap has been eliminated must be reworked.
Use a suitable bar to restore a uniform gap to dimensions shown (Ref. Fig.
205).

(b) Cracks not exceeding two inches in length must be repaired (Ref. Para. 7.).

(c) Circumferential cracks next to seam welds must be repaired (Ref. Para. 7.).

NOTE: Crack openings in excess of 0.030 inch are not repairable.

(d) When cracks progress from a free edge so that their meeting is imminent, and
could subsequently allow a piece of liner material to break loose, they must be
repaired by welding (Ref. Para. 7.).

(e) If necessary, clean out cooling holes in liners with appropriate size drill.

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MANUAL PART NO. 3034342

2
1

C10193

Removal/Installation of Combustion Chamber Inner Liner

Figure 201

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MANUAL PART NO. 3034342

Key to Figure 201

1. Bolt
2. Combustion Chamber Inner Liner
3. Combustion Chamber Outer Liner
4. Gas Generator Case

(3) Unacceptable Conditions, No Repair Permitted:

NOTE: Rejected combustion chamber inner and outer liners removed during
maintenance activities should be returned to an overhaul facility for
possible restoration to a usable condition. It is recommended that ‘‘run’’
inner and outer liners be kept together in pairs, if possible.

(a) Multiple cracks that are not repairable (Ref. Fig. 204).

(b) Cracks in outer liner flange heat shield (Ref. Fig. 203, Sheet 3), which extend
into the radius, are less than 1.5 inch apart or which could join to cause loss of
material.

(c) Severe buckling causing kinked metal (Ref. Fig. 203, Sheet 4).

(d) Cracks exceeding two inches in length, except where otherwise stated.

(e) Circumferential cracks which are opened more than 0.030 inch and are next to
seam welds.

7. Approved Repairs

A. Repair of Liners - Cracks

CAUTION: HOLES THAT BECOME PLUGGED AS A RESULT OF WELDING MUST

BE REDRILLED TO ORIGINAL SIZE AND THEN DEBURRED. CHECK
PATTERN AND SIZE OF ADJACENT HOLES USING SUITABLE DRILL
GAGE. LOOSE WELD MATERIAL MUST BE REMOVED.

(1) Stop drill ends of crack with a1⁄16 (0.0625) inch drill. Vee out crack using a suitable
abrasive wheel.

(2) Lightly grind area with a suitable abrasive wheel to remove all traces of coating.

(3) Thoroughly wire brush area and swab with cleaner (PWC11-014).

(4) Repair prepared area with tungsten inert gas (TIG) equipment (Ref. 70-00-00,
REPAIR, Blend Repairs) and small diameter welding wire (PWC05-151) to
minimize weld bead size. Stress relief after welding is not necessary.

NOTE: Use copper back-up plate to reduce distortion, with addition of argon gas
backup, if available.

(5) If outer liner heat shield is repaired in Area B (Ref. Fig. 203, Sheet 3), smooth weld
bead flush to parent metal. Remove ceramic coating from Area C of inner liner.

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MANUAL PART NO. 3034342

CRACKS OF THIS NATURE ARE ACCEPTABLE, PROVIDED

THEY DO NOT EXCEED 0.300 INCH IN LENGTH AND ARE
STOP−DRILLED USING 1/16 DRILL.

C225B

Acceptable Cracks in Louvered Cooling Ring Seam Weld

Figure 202

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MANUAL PART NO. 3034342

TYPICAL CRACK
NEXT TO
SEAM WELD

FUEL MANIFOLD SUPPORT COLLAR WELDS

C10213
Combustion Chamber Outer Liner
Figure 203 (Sheet 1 of 4)

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MANUAL PART NO. 3034342

LINE OF COOLING HOLES AFFECTED BY

REPAIR. CHECK BY INSERTING
SUITABLE SIZE DRILL.

THREE
LARGE
HOLES

FUEL
MANIFOLD
BOSS

ALTERNATE CONFIGURATIONS
DETAIL B
DETAIL A

C10278C

Combustion Chamber Outer Liner

Figure 203 (Sheet 2)

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MANUAL PART NO. 3034342

OUTER
LINER

B
INNER HEATSHIELD AREA
LINER
C
VIEW A

TYPICAL
HAIRLINE
CRACKS

TYPICAL A
EROSION

C41329B
Combustion Chamber Outer Liner
Figure 203 (Sheet 3)

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MANUAL PART NO. 3034342

DETAIL A

C10279A

Combustion Chamber Outer Liner

Figure 203 (Sheet 4)

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MANUAL PART NO. 3034342

LINE OF COOLING HOLES AFFECTED

BY EXCESS PLASMA SPRAY CHECK
BY INSERTING SUITABLE SIZE DRILL

DETAIL A

C10280B
Combustion Chamber Inner Liner
Figure 204

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MANUAL PART NO. 3034342

FLANGE TO WRAPPER
SEAM WELD
C

0.040
0.030
A 0.060
0.040 0.060
0.070 0.050
0.060 PRE−SB72−25
(PRE−SB72−177) LOUVERED
0.080 COOLING RING
0.065 D
(POST−SB72−177)

B
0.056
0.046 0.010
MIN.
0.010
MIN. POST−SB72−25
PRE−SB72−67
POST−SB72−67

B
VIEW A SECTION B−B

0.060 0.010 0.060

0.050 0.000 0.040

VIEW C
TYPICAL VIEW ON ARROW D

FLANGE TO 0.060 0.040

NOSE LINER 0.060 0.080 0.040 0.030
SEAM WELD 0.040 0.060

0.060
0.040

NOSE LINER TO
WRAPPER SEAM WELD

C10220D

Combustion Chamber Liners

Figure 205

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MANUAL PART NO. 3034342

LOUVERED TYPE
DETAIL A

CRACK MUST NOT

EXTEND INTO SEAM WELD

NON−LOUVERED TYPE
DETAIL B

C13627A
Cooling Rings - Inspection
Figure 206

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