Technical Training Manual Boeing 737, Bostonair Technical Training

BOSTONAIR Technical Training

BOSTONAIR TECHNICAL TRAINING LIMITED UK.147.0085 TECHNICAL TRAINING MANUAL BOEING 737-600/-700/-800/-900

Table of Contents

Pneumatic System Introduction

1 Pneumatic system - introduction - 5 - 1.1 Purpose - 5 - 1.2 System description. - 5 - 1.3 General - 6 - 1.3.1 Engine Bleed Air - 6 - 1.3.2 APU Bleed Air System. - 6 - 1.3.3 Pneumatic Ground Air Connection. - 6 - 1.3.4 Controls and Indications. - 6 - 1.4 Component locations. - 8 - 1.4.1 Engine Bleed air. - 8 - 1.4.2 Pneumatic Manifold. - 8 - 1.4.3 APU Bleed Air. - 8 - 1.4.4 Controls and lndication. - 8 - 1.5 Controls and indications - 9 - 1.5.1 Description - 9 - 1.5.2 Training information point: 11 -

Distribution System Overview

2 Distribution system 12 - 2.1 Purpose 12 - 2.2 General Description 12 - 2.3 Engine Bleed Air System. 12 - 2.4 APU Bleed Air System. 12 - 2.5 Pneumatic Ground Air Connection - 12 - 2.6 Pneumatic Manifold System - 12 -

Engine Bleed Air System

3 Engine bleed air - 14 - 3.1 Introduction. - 14 - 14 - 3.1.1 Purpose. 3.1.2 General Description - 14 - 3.2 System description. 16 - 3.2.1 Bleed air check valve - 16 - 3.2.2 High stage regulator/valve - 17 - 3.2.3 Bleed air regulator & pressure regulator and shutoff valve .- 21 - 3.2.4 Thermostat 232℃ (450°F) 23 - 3.2.5 254℃ overtemperature switch 27 - 3.2.6 Bleed air control circuit - 29 - 3.2.7 Bleed air precooler system - 31 - 3.2.8 Precooler 33 3.2.9 Precooler control valve 34 3.2.10 Precooler control valve 199℃ temperature sensor 35 - 3.3 Bleed air system functional description - 36 - - 36 - 3.3.1 Purpose 3.3.2 Functional Description. - 36 - 3.4 Precooler system operation 38

APU Bleed System

4 APU Bleed system 40 - 4.1 Introduction - 40 - Maintenance Course B1/B2 ATA 36 PNEUMATICS Issue 4 - October 2024 - 1 -BOSTONAIR Technical Training BOSTONAIR TECHNICAL TRAINING LIMITED UK.147.0085 TECHNICAL TRAINING MANUAL BOEING 737-600/-700/-800/-900 4.1.1 Purpose 40 - 4.1.2 General Description. - 40 - 4.1.3 Location. 40 - 4.2 System description 42 - 4.2.1 APU bleed air valve 42 - 4.2.2 APU pressure relief valve 44 -

Pneumatic Ducts

5 Pneumatic ducts - 45 - 5.1 Introduction. 45 - 5.1.1 Purpose 45 - 5.1.2 Physical Description. 45 - 5.1.3 Location. 45 - 5.2 Duct insulation - 47 - 5.2.1 Purpose 47 - 5.2.2 General Description. 47 - 5.2.3 Location. 47 - 5.2.4 Functional Description. 47 - 5.3 Bleed isolation valve - 48 - 5.3.1 Purpose 48 - 5.3.2 Physical Description. 48 - 5.3.3 Location. 48 - 5.3.4 Functional Description. 48 5.3.5 Indications. - 48 - 5.3.6 Operational Controls. 48 - 5.3.7 Isolation valve control. - 50

Ground Pneumatic Connector

5.4 Ground pneumatic connector check valve 52 - 5.4.1 Introduction 52 -

Indication and Warning Systems

6 Indication and warning 54 - 6.1 Pressure indication - 54 - 6.1.1 Duct Pressure Transducer. 54 - 6.1.2 Dual Duct Pressure Indicator. 54 - 6.1.3 Training Information Point - 54 - 6.2 Bleed trip off 56 - 6.3 Dual bleed light. - 58 - 6.3.1 Purpose 58 - 6.3.2 Functional Description. 58 - Maintenance Course B1/B2 ATA 36 PNEUMATICS Issue 4 - October 2024 - 2 -BOSTONAIR Technical Training BOSTONAIR TECHNICAL TRAINING LIMITED UK.147.0085 TECHNICAL TRAINING MANUAL BOEING 737-600/-700/-800/-900

List of Figures

Figure 1: Pneumatic system - introduction 5 - Figure 2: Pneumatic system - overview - 7 - Figure 3: Component locations - 8 - Figure 4: Control panel description - 9 - Figure 5: Control panel description] 10 - Figure 6: Bleed air distribution - schematic. 13 - Figure 7: Engine bleed system - general. 15 - Figure 8: Bleed air check valve. 16 - Figure 9: High stage regulator/valve 18 - Figure 10: High stage regulator/valve - functional description. 20 - Figure 11:Bleed air regulator & pressure regulator and shutoff valve .- 22 - Figure 12: 232℃ thermostat 24 - Figure 13: Overtemperature switch 28 - Figure 14: Bleed control circuit 30 - Figure 15: Bleed air precooler system. 32 - Figure 16: Precooler 33 - Figure 17: Precooler control valve 34 - Figure 18: Precooler control valve temp sensor 35 - Figure 19: Engine bleed functional description 37 Figure 20: Precooler functional description 39 - Figure 21: APU check valve 40 - Figure 22: APU Bleed system 41 - Figure 23: APU Bleed valve 42 - Figure 24: APU bleed valve control. 43 - Figure 25: APU pressure relief valve 44 Figure 26: Pneumatic duct 46 - Figure 27: Duct insulation 47 - Figure 28: Bleed air isolation valve 49 - Figure 29: Bleed air isolation valve control 51 - Figure 30: Ground pneumatic connector check valve 53 - Figure 31: Pressure indication 55 - Figure 32: Bleed trip off schematic 57 Figure 33: Dual bleed schematic 58 Maintenance Course B1/B2 ATA 36 PNEUMATICS Issue 4 - October 2024 - 3 -BOSTONAIR Technical Training BOSTONAIR TECHNICAL TRAINING LIMITED UK.147.0085 TECHNICAL TRAINING MANUAL BOEING 737-600/-700/-800/-900

Abbreviations and Acronyms

ACAU air conditioning accessory unit APU auxiliary power unit BAR bleed air regulator BAV bleed air valve C Celsius CTAI cowl thermal anti-ice F Fahrenheit ISO valve isolation valve PRSOV pressure regulator and shutoff valve TAT total air temperature XFER transfer XMTR transmitter WTAI wing thermal anti-ice Maintenance Course B1/B2 ATA 36 PNEUMATICS Issue 4 - October 2024 - 4 -BOSTONAIR Technical Training BOSTONAIR TECHNICAL TRAINING LIMITED UK.147.0085 TECHNICAL TRAINING MANUAL BOEING 737-600/-700/-800/-900

Pneumatic System Introduction

Purpose of the Pneumatic System

1 Pneumatic system - introduction 1.1 Purpose The purpose of the pneumatic system is to supply compressed air for a controlled temperature and pressure environment during all phases of flight and ground operation. Air is obtained from engine bleeds, auxiliary power unit or ground sources and distributed through a system of ducts to the using systems.

Pneumatic System Description

1.2 System description. The pneumatic system controls engine bleed air source, temperature, and pressure. The pneumatic system provides high temperature, high pressure air for:

• Air conditioning pressurization,
• Wing and cowl thermal anti-icing,
• Potable water system,
• Hydraulic system
• Engine starters.

FLOW & TEMPERATURE CONTROLLED AIR USED BY : ELECTRICAL 115V AC 28V DC, 28V AC ENGINE AIR CONDITIONING & PRESSURIZATION WING & COWL THERMAL A/ICE A.P.U. PNEUMATIC SYSTEM ENGINE STARTING . GROUND CART · WATER PRESSURIZATION . HYDRAULIC SYSTEM ELECTRICAL CONTROL SIGNALS Figure 1: Pneumatic system - introduction Maintenance Course B1/B2 ATA 36 PNEUMATICS Issue 4 - October 2024 - 5 -BOSTONAIR Technical Training BOSTONAIR TECHNICAL TRAINING LIMITED UK.147.0085 TECHNICAL TRAINING MANUAL BOEING 737-600/-700/-800/-900

General Pneumatic System Information

Pneumatic Power Sources

1.3 General The pneumatic system supplies hot high pressure air to the systems on the airplane that use air. These use the sources of pneumatic power: Engine bleed air, APU Ground source.

Engine Bleed Air System Details

1.3.1 Engine Bleed Air. There is one bleed air system for each engine. The engine bleed system controls bleed air temperature end pressure. Engine bleed air comes from the 5th and 9th stages of the high pressure compressor. A high stage regulator and high stage valve control the flow of 9th stage bleed air. The 5th stage check valve prevents reverse flow into the 9th stage. At low engine speeds, bleed air comes from the 9th stage. At high engine speeds, bleed air comes from the 5th stage. A bleed air regulator and the pressure regulator and shutoff valve (PRSOV) control the flow at bleed air to the pneumatic manifold. ACAU. The air conditioning accessory unit (ACAU) contains relays, and is an interface between the air conditioning/bleed air controls panel switches and lights. Engine Bleed Air Precooler System. The precooler system controls the engine bleed air temperature. The precooler control valve, precooler control valve sensor, and WTAI solenoid valve control the flow at fan air to the precooler.

APU Bleed Air System Details

1.3.2 APU Bleed Air System. The APU load compressor supplies bleed air on the ground and in the air.

Pneumatic Ground Air Connection Details

1.3.3 Pneumatic Ground Air Connection. The pneumatic ground air connection provides for the connection at a ground pneumatic cart. The pneumatic cart car supply bleed air for engine start and ground use at the air conditioning system. Pneumatic Manifold System. The pneumatic manifold system gets bleed air from the engines, APU, or pneumatic ground cart. A bleed air isolation valve divides the pneumatic manifold into leg and right sides. The normal position at this valve is closed. Because at this, a single duct failure cannot cause a loss at pressure to the whole pneumatic manifold. The pneumatic manifold has two pressure transmitters. One transmitter is on the right side of the manifold and the other is on the left side. They measure the manifold pressures. Pressure indication is so the air conditioning panel. The right side at the manifold has a pneumatic ground air connector.

Controls and Indications Overview

1.3.4 Controls and Indications. The air conditioning/bleed air controls panel has control switches and lights to control and monitor the pneumatic system. Maintenance Course B1/B2 ATA 36 PNEUMATICS Issue 4 - October 2024 - 6 -BOSTONAIR Technical Training BOSTONAIR TECHNICAL TRAINING LIMITED UK.147.0085 TECHNICAL TRAINING MANUAL BOEING 737-600/-700/-800/-900

Pneumatic System Overview Diagram

HYD RSVR DUAL BLEED RAM DOOR FULL OPEN RAM DOOR FULL OPEN WING A/I ISO VALVE WING A/I L RECIRC FAN R RECIRC FAN OFF 0 1 AUTO AUTO HYD RSVR 60 80 OVHT 40 DUCT PRESS PSI THERMOSTAT 232 C H 20 0 TEST R PACK PRECOOLER CTL. VLV. SENS. 199¡C/227¡C OVHT SW. 254 C PACK 1 PACK 2 200 C AUTO HIGH PRECOOLER WING ANT 2 ICE OPE 2 PACK RELIEF VALVE 45 psi 45 psi PRECOOLER CTL VALVE PRSOV APU BLEED VALVE PRECOOLER CTL VALVE PRSOV OFF OFF ON ON 1 APU 2 34 psi BLEED A.P.U. TO NOSE COWL A/ICE HSV APU ECU 1 ON -800 ONLY E6 FAN FAN IP 5th ST HP 9th ST IP 5th ST HP 9th ST ENGINE 1 ACAU : AIRCO ACCESS UNIT ECU HSV ENGINE 2 232 C = 450 F 199 C/227 C = 390|F/440¡F 254|C = 490|F ACAU ACAU Figure 2: Pneumatic system - overview Maintenance Course B1/B2 ATA 36 PNEUMATICS Issue 4 - October 2024 -7 - WING ANTI ICE WING-BODY OVERHEAT TRIP WING-BODY OVERHEAT BLEED TRIP OFF BLEED TRIP OFF RESET 34 psi CONTROL PANEL P5 TO NOSE COWL A/ICE HSV 2 "PACK TRIP OFF" LIGHT ON -6 & 700 : ELECTRONIC CTL UNIT : HIGH STAGE VALVE PRSOV : PRESS REG. SHUT OFF VALVE L PACK GND CONNECTOR OFF AUTO HIGH ISOLATION VALVE CLASE OFF AUTO 200 C PRECOOLER PACK WATER TANK ENG START ENG START PRESS XMTR OFF 0