DOC AIRBUS | AMM A320FYELLOW MAIN HYDRAULIC POWER - DESCRIPTION AND OPERATION
** ON A/C NOT FOR ALL
** ON A/C NOT FOR ALL
** ON A/C NOT FOR ALL
1. General
The Yellow hydraulic system is one of the three systems which supply the aircraft with hydraulic power. It supplies:
Most of the components of the system are installed in the Yellow hydraulic compartment in the RH belly fairing, forward of the main landing gear compartment. The system is kept physically apart from the other two systems where possible. The system is hydraulically isolated from the other two systems. It is not possible for fluid to go from one system to a different system. The system operates at a nominal pressure of 3000 psi (206 bar). The Engine-driven Pump (EDP) can supply 140 l/min (37 US gal/min) at 196 bar (2854 psi) at its usual operating speed. The return part of the system is pressurized to 50 psi (3.5 bar). It is possible to pressurize the HP system from these different sources:
Operation of the system is usually automatic, but the crew can control parts of the system from the flight compartment if necessary.
The Electronic Centralized Aircraft Monitoring (ECAM) system monitors the condition of the system all of the time. If a fault occurs, or if the crew select it, system information is shown in the flight compartment.
The Yellow hydraulic system is one of the three systems which supply the aircraft with hydraulic power. It supplies:
Most of the components of the system are installed in the Yellow hydraulic compartment in the RH belly fairing, forward of the main landing gear compartment. The system is kept physically apart from the other two systems where possible. The system is hydraulically isolated from the other two systems. It is not possible for fluid to go from one system to a different system. The system operates at a nominal pressure of 3000 psi (206 bar). The Engine-driven Pump (EDP) can supply 140 l/min (37 US gal/min) at 196 bar (2854 psi) at its usual operating speed. The return part of the system is pressurized to 50 psi (3.5 bar). It is possible to pressurize the HP system from these different sources:
Operation of the system is usually automatic, but the crew can control parts of the system from the flight compartment if necessary.
The Electronic Centralized Aircraft Monitoring (ECAM) system monitors the condition of the system all of the time. If a fault occurs, or if the crew select it, system information is shown in the flight compartment.
** ON A/C NOT FOR ALL The Yellow hydraulic system is one of the three systems which supply the aircraft with hydraulic power. It supplies:
- the cargo doors
- the alternate and parking brake systems
- the right-hand (No. 2) engine thrust reverser
- some of the flight controls
- the Power Transfer Unit (PTU).
Most of the components of the system are installed in the Yellow hydraulic compartment in the RH belly fairing, forward of the main landing gear compartment. The system is kept physically apart from the other two systems where possible. The system is hydraulically isolated from the other two systems. It is not possible for fluid to go from one system to a different system. The system operates at a nominal pressure of 3000 psi (206 bar). The Engine-driven Pump (EDP) can supply 140 l/min (37 US gal/min) at 196 bar (2854 psi) at its usual operating speed. The return part of the system is pressurized to 50 psi (3.5 bar). It is possible to pressurize the HP system from these different sources:
- the Engine Driven Pump (EDP)
- the Power Transfer Unit (PTU)
- the ground supply connections
- the Yellow electric pump (Ref. AMM D/O 29-24-00-00)
- the hand pump for the operation of the cargo doors (Ref. 29-24-00/52-36-00).
Operation of the system is usually automatic, but the crew can control parts of the system from the flight compartment if necessary.
The Electronic Centralized Aircraft Monitoring (ECAM) system monitors the condition of the system all of the time. If a fault occurs, or if the crew select it, system information is shown in the flight compartment.
The Yellow hydraulic system is one of the three systems which supply the aircraft with hydraulic power. It supplies:
- the cargo doors
- the alternate and parking brake systems
- the right-hand (No. 2) engine thrust reverser
- some of the flight controls
- the Power Transfer Unit (PTU)
- the Nosewheel Steering.
Most of the components of the system are installed in the Yellow hydraulic compartment in the RH belly fairing, forward of the main landing gear compartment. The system is kept physically apart from the other two systems where possible. The system is hydraulically isolated from the other two systems. It is not possible for fluid to go from one system to a different system. The system operates at a nominal pressure of 3000 psi (206 bar). The Engine-driven Pump (EDP) can supply 140 l/min (37 US gal/min) at 196 bar (2854 psi) at its usual operating speed. The return part of the system is pressurized to 50 psi (3.5 bar). It is possible to pressurize the HP system from these different sources:
- the Engine Driven Pump (EDP)
- the Power Transfer Unit (PTU)
- the ground supply connections
- the Yellow electric pump (Ref. AMM D/O 29-24-00-00)
- the hand pump for the operation of the cargo doors (Ref. 29-24-00/52-36-00).
Operation of the system is usually automatic, but the crew can control parts of the system from the flight compartment if necessary.
The Electronic Centralized Aircraft Monitoring (ECAM) system monitors the condition of the system all of the time. If a fault occurs, or if the crew select it, system information is shown in the flight compartment.
2. Component Location
Component Location - Engine and Wing ** ON A/C NOT FOR ALL
Component Location - Engine and Wing ** ON A/C NOT FOR ALL
Component Location - Engine and Wing ** ON A/C NOT FOR ALL
** ON A/C NOT FOR ALL Component Location - Engine and Wing ** ON A/C NOT FOR ALL Component Location - Engine and Wing ** ON A/C NOT FOR ALL Component Location - Engine and Wing ** ON A/C NOT FOR ALL | FIN | FUNCTIONAL DESIGNATION | PANEL | ZONE | ACCESS DOOR | ATA REF |
|---|---|---|---|---|---|
| ** ON A/C NOT FOR ALL | |||||
| 3002GM | LP FILTER | 196BB | 196 | 29-13-44 | |
| 3048GM | HP FILTER Y | 196BB | 196 | 29-13-45 | |
| ** ON A/C NOT FOR ALL | |||||
| 3017GM | CHECK VALVE Y | 196BB | 196 | 27-20-00 | |
| 3083GM | CHECK VALVE Y | 196BB | 196 | 29-24-21 | |
| ** ON A/C ALL | |||||
| 3000GQ | HYD. RESERVOIR YELLOW | 196BB | 196 | 29-13-41 | |
| 3006GM | GND CNCTR-SELF SEAL. | 198CB | 198 | 27-20-00 | |
| 3008GM | GND CNCTR-SELF SEAL. | 198CB | 198 | 27-20-00 | |
| 3018GM | CHECK VALVE Y | 151 | 27-20-00 | ||
| 3019GM | CHECK VALVE Y | 151 | 27-20-00 | ||
| 3020GM | CHECK VALVE Y | 146 | 27-20-00 | ||
| 3022GM | CHECK VALVE Y | 196BB | 196 | 27-20-00 | |
| 3024GM | CHECK VALVE Y | 148 | 27-20-00 | ||
| 3030GD | PUMP VARIABLE DTS | 445 | 29-13-51 | ||
| 3041GM | CHECK VALVE-ENG 2 PUMP CASE DRAIN, Y | 415 | 29-13-37 | ||
| 3046GD | FIRE-S.-O.V. | 674 | 29-13-52 | ||
| 3050GM | CHECK VALVE-ENG 2 PUMP DELIVERY, Y | 415 | 29-13-36 | ||
| 3056GM | CHECK VALVE Y | 196 | 27-20-00 | ||
| 3058GM | CHECK VALVE Y | 198 | 27-20-00 | ||
| 3063GM | RELIEF VALVE Y SYS | 196BB | 196 | 29-13-32 | |
| 3064GM | PRIORITY VALVE | 146 | 29-13-33 | ||
| 3067GM | BRAKE RELIEF VALVE | 198 | 32-44-15 | ||
| 3070GM | HYD ACCU YELLOW | 196BB | 196 | 29-13-42 | |
| 3071GM | N2 CHARGING VALVE | 196BB | 196 | 29-13-22 | |
| 3072GM | Y SYS ACCU PRESS GAGE | 196BB | 196 | 29-13-21 | |
| 3084GM | FILTER-ENG PUMP CASE DRAIN | 445 | 29-13-43 | ||
| 3093GM | CHECK VALVE-PTU DELIVERY, Y | 145 | 27-20-00 | ||
| ** ON A/C NOT FOR ALL | |||||
| 3002GM | LP FILTER | 196 | 29-13-44 | ||
| 3048GM | HP FILTER Y | 196 | 29-13-45 | ||
| ** ON A/C NOT FOR ALL | |||||
| 3017GM | CHECK VALVE Y | 196 | 27-20-00 | ||
| 3083GM | CHECK VALVE Y | 196 | 29-24-21 | ||
| ** ON A/C ALL | |||||
| 3170GM | CHECK VALVE-FLAP WTB Y RETURN, L WING | 575DB | 500 | 29-13-48 | |
| 3187GM | SAMPLING-V.-Y.-SYS. | 196BB | 196 | 29-13-34 | |
| 3188GM | CHECK VALVE Y | 198 | 27-20-00 | ||
| 3524GM | CHECK VALVE-SLAT CASE DRAIN, Y | 147 | 29-10-00 | ||
| 3618GM | CHECK VALVE Y | 146 | 27-20-00 | ||
| 1WD | ENG/APU FIRE PNL | 210 | 26-12-12 | ||
| 3010GM | COMPENSATED SLIDE-SUCTION, Y | 674AB | 641 | 29-13-47 | |
| ** ON A/C NOT FOR ALL | |||||
| 3060GM | SELF SEALING COUPLING | 420 | 29-13-36 | ||
3. System Description
Yellow Hydraulic System - Schematic ** ON A/C NOT FOR ALL
Yellow Hydraulic System - Schematic ** ON A/C NOT FOR ALL
Yellow Hydraulic System - Schematic ** ON A/C NOT FOR ALL
Yellow Hydraulic System - Schematic ** ON A/C NOT FOR ALL
Yellow Hydraulic System - Schematic ** ON A/C NOT FOR ALL
The Yellow hydraulic system has two sub-systems:
The EDP is attached to the engine accessory gearbox with key-hole fasteners. The hoses between the EDP and the system have quick-disconnect, self-sealing couplings. This makes it possible to change the EDP quickly with minimum changes necessary to the system.
There are two different types of EDP which are permitted. VICKERS make one type, ABEX the other. The two types are completely interchangeable. They give equivalent supplies of hydraulic power and their mechanical and electrical connections are the same.
The Yellow hydraulic system has two sub-systems:
The HP circuit is usually pressurized by an engine-driven pump (EDP), 3030GD, connected to the right (No. 2) engine. The EDP has a direct mechanical connection (through the accessory gearbox) to the engine and turns together with it. A solenoid valve on the EDP makes it possible to stop the supply of fluid to the system. A pushbutton switch (P/BSW) in the flight compartment controls the operation of the solenoid valve. The EDP can pressurize the system to 206 +3 -0 bar (3000 +45 -0 psi) at zero flow or to 196 bar (2854 psi) with a flow of 140 l/min (37 US Gal/min). This flow is set at the rated delivery speed of the pump (3702 rpm - equivalent to 100% engine N2 speed).
The EDP is attached to the engine accessory gearbox with key-hole fasteners. The hoses between the EDP and the system have quick-disconnect, self-sealing couplings. This makes it possible to change the EDP quickly with minimum changes to the system.
There are two different types of EDP which are permitted. VICKERS make one type, ABEX the other. The two types are completely interchangeable. They give equivalent supplies of hydraulic power and their mechanical and electrical connections are the same.
The Power Transfer Unit (PTU) 1088GM can also pressurize the Yellow HP circuit (Ref. 29-23-00). The PTU gets its power from the Green hydraulic system (Ref. 29-11-00). It supplies power to the Yellow hydraulic system if the pressure in the system falls to approximately 500 psi (34.48 bar) below the pressure in the Green hydraulic system. There is no hydraulic connection between the two hydraulic systems so no fluid can go from one system to the other.
If the EDP fails, or for maintenance on the ground, it is possible to pressurize the Yellow hydraulic system with the electric pump (Ref. AMM D/O 29-24-00-00). The output of the electric pump is connected to the HP supply downstream of the check valve 3050GM. A check valve 3083GM is installed in the output line from the electric pump to stop reverse flow of fluid to the pump.
On the ground, it is possible to pressurize the Yellow hydraulic system from a ground supply. The system has self-sealing connectors for a ground supply installed on the ground service panel.
The ground service panel for the Yellow hydraulic system is installed in the right belly fairing aft of the main gear compartment. The components and connections necessary to service the Yellow hydraulic system (not including the reservoir air pressurization connection and the reservoir drain) are installed in a group together on it. The ground service panel has these components on it:
If the EDP fails, or for maintenance on the ground, it is possible to pressurize the Yellow hydraulic system with the electric pump (Ref. AMM D/O 29-24-00-00). The output of the electric pump is connected to the HP supply downstream of the pylon manifold 3030GM. A check valve 3083GM is installed in the output line from the electric pump to stop reverse flow of fluid to the pump.
On the ground, it is possible to pressurize the Yellow hydraulic system from a ground supply. The system has self-sealing connectors for a ground supply installed on the ground service panel.
The ground service panel for the Yellow hydraulic system is installed in the right belly fairing aft of the main gear compartment. The components and connections necessary to service the Yellow hydraulic system (not including the reservoir air pressurization connection and the reservoir drain) are installed in a group together on it. The ground service panel has these components on it:
A pylon manifold (3030GM) with integral check valve and a pressure switch (3074GK) are installed downstream of the EDP. The pressure switch monitors the output pressure of the pump (Ref. 29-32-00). The check valve stops the flow of fluid to the pump if a different source is used to pressurize the system.
The supply to most of the consumers goes through the HP and Leakage Measurement System (LMS) manifolds. Thus it is possible to isolate some consumers to measure the internal leakage of parts of the system. The supply to the alternate and parking brake systems goes from the HP manifold through the brake manifold.
The HP manifold has ports which connect it to the other parts of the system as follows:
A solenoid valve (3160GP) on the HP manifold controls the flow of fluid to the LMS manifold. The solenoid valve is usually operated from the flight compartment but it also has an automatic function. This function is related to the operation of the cargo doors. When the cargo doors are set to open or close (and the Yellow electric pump starts), the solenoid valve is automatically closed. This stops the supply of fluid to the flight controls. Thus there is no danger of movement of flight controls because of operation of the cargo doors.
The hydraulic supply to the flight controls in the rear section, the LH wing and the RH wing goes through the HP manifold. Thus it is possible to measure the internal leakage of groups of consumers in the related sections. The supply to the alternate and parking brake systems goes from the HP manifold through the brake manifold.
The HP manifold has ports which connect it to the other parts of the system as follows:
A solenoid valve (3150GP) in the HP manifold controls the flow of hydraulic fluid to the flight controls in the rear section, the LH wing and the RH wing. The solenoid valve is usually operated from the flight compartment but it also has an automatic function. This function is related to the operation of the cargo doors. When the cargo doors are set to open or close (and the Yellow electric pump starts), the solenoid valve is automatically closed. This stops the supply of hydraulic fluid to the flight controls. Thus the flight controls will not move when the cargo doors are operated.
The system pressure inlet to the HP manifold has a filter 3048GM with a filtration rating of 15 microns. A check valve is installed on the manifold. A sampling valve 3187GM makes it possible to take samples of fluid from the system for analysis. You can take the sample when the system is at full pressure.
A pressure relief valve (PRV) 3063GM is installed on the HP manifold to protect the system against overpressure. The PRV opens when the pressure is greater than or equal to 237 bar (3436 psi) and closes at 220 bar (3190 psi). Two pressure switches 3151GN, 10CE-3 and a pressure transducer 3065GN are also installed on the HP manifold to monitor the pressure in the system (Ref. 29-32-00).
The system accumulator 3070GM has direct hydraulic connections to the HP and brake manifolds and to the cargo door selector valve. The accumulator keeps the pressure in the system free of small changes. It also makes a supply of fluid available to replace any temporary shortage. This can occur if there is a sudden large demand and the pump has not had time to respond. The accumulator is pre-charged with nitrogen at 1885 psi (130 bar) and holds 0.18 l (0.0476 USgal) of the useable fluid when it is full. A gas charging valve 3071GM and a pressure gage 3072GM are installed on the accumulator.
The LMS manifold 3146GM makes it possible to measure the internal leakage of groups of consumers. The HP supply is divided into three separate outputs, one to each of the following:
Measurement of internal leakage is done with a ground hydraulic supply and a flowmeter.
The LMS manifold also makes it possible to isolate parts of the system for maintenance.
The main system is connected with the PTU through the PTU manifold 3015GM. The PTU manifold also has a connection to the flap system. The PTU connections are:
A solenoid valve installed on the PTU manifold controls (together with the equivalent solenoid valve of the Green hydraulic system ) the flow of fluid to/from the PTU. A single pushbutton switch 1802GL in the flight compartment controls the operation of the two solenoid valves. When the pushbutton switch is operated, the two solenoid valves are energized and the supply of fluid to/from the PTU is stopped.
The ultrasonic flowmeter (USF) (Ref. AMM D/O 29-19-00-00) makes it possible to measure the internal leakage of groups of consumers. The HP supply through the solenoid valve 3150GP is divided into three separate outputs, one to each of the following:
The internal leakage is measured with the hydraulic supply from the Yellow electric pump and the USF.
The main system is connected with the PTU through the PTU manifold 3015GM. The PTU manifold also has a connection to the flap system. The PTU connections are:
A solenoid valve installed on the PTU manifold controls (together with the equivalent solenoid valve of the Green hydraulic system ) the flow of hydraulic fluid to/from the PTU. A pushbutton switch 1802GL in the flight compartment controls the operation of the two solenoid valves. When the pushbutton switch is operated, the two solenoid valves are energized and the supply of hydraulic fluid to/from the PTU is stopped.
The priority valve 3064GM is installed on the PTU manifold. It stops the supply of fluid to non-essential consumers if the system pressure is too low. The priority valve closes at 130 +0 -3 bar (1885 +0 -43 psi) and opens at 140 +0 -5 bar (2030 +0 -72.5 psi).
Two check valves are installed on the PTU manifold. The check valve 3093GM and the other check valve control the flow of fluid in the manifold.
The Yellow hydraulic system supplies these consumers:
It is possible to supply all of the consumers from the ground supply connections.
The priority valve 3064GM is installed on the PTU manifold. It stops the supply of fluid to non-essential consumers if the system pressure is too low. The priority valve closes at 130 +0 -3 bar (1885 +0 -43 psi) and opens at 140 +0 -5 bar (2030 +0 -72.5 psi).
Two check valves are installed on the PTU manifold. The check valve 3093GM and the other check valve control the flow of fluid in the manifold.
The Yellow hydraulic system supplies these consumers:
It is possible to supply all of the consumers from the ground supply connections.
The priority valve 3064GM is installed on the PTU manifold. It stops the supply of hydraulic fluid to non-essential consumers if the system pressure is too low. The priority valve closes at 130 +0 -3 bar (1885 +0 -43 psi) and opens at 140 +0 -5 bar (2030 +0 -72.5 psi).
Two check valves are installed on the PTU manifold. The check valve 3093GM and the other check valve control the flow of hydraulic fluid in the PTU manifold.
The Yellow hydraulic system supplies these consumers:
It is possible to supply all of the consumers from the ground supply connections.
The Low Pressure (LP) circuit returns the fluid from the consumers to the reservoir. The case drains of the EDP and PTU, and the returns from the HP manifold are also connected to the LP circuit. The circuit has check valves where applicable to control the flow of fluid. Some of the return lines are connected together at the LP manifold. Part of the LP circuit is also used in the reservoir filling system (Ref. AMM D/O 29-16-00-00).
The LP fluid goes through the LP filter 3002GM before it gets to the reservoir. The filter has a filtration rating of 3 microns. If the filter element clogs, a by-pass operates and unfiltered fluid goes to the reservoir. The temperature sensor (3318GR), which is attached to the outlet of the LP filter, monitors the temperature of the return fluid. The temperature information is sent to the ECAM and warning systems (Ref. AMM D/O 29-33-00-00).
A filter 3084GM is installed in the EDP case drain line to the LP system. It has a filtration rating of 15 microns.
The reservoir 3000GQ is installed in the Yellow hydraulic compartment. It holds a supply of fluid and also makes allowance for differences of the quantity of the fluid in the system (because of different positions of jacks for example). The reservoir holds 12 l (3.18 USgal) of hydraulic fluid when it is filled to the correct level.
The reservoir is filled through the reservoir filling system (Ref. AMM D/O 29-16-00-00) which is operated from the ground service panel of the Green hydraulic system. A reservoir drain valve is installed on the reservoir.
The reservoir is pressurized with air to 50 psi (3.5 bar) to stop cavitation at the inlet to the EDP (Ref. AMM D/O 29-14-00-00). The supply of air comes from the pneumatic system of the aircraft (Ref. AMM D/O 36-00-00-00). It is also possible to pressurize the reservoir from a ground supply. A depressurization valve is installed on the ground service panel of the Yellow hydraulic system. A PRV and air pressure gage are installed on the reservoir.
A motorized fire valve 3046GD is installed in the suction line between the reservoir and the EDP. It operates when the engine fire pushbutton in the flight compartment is operated. The valve stops the supply of fluid to the EDP if there is a fire in the nacelle.
A compensated slide 3010GM is installed in the suction line between the reservoir and the EDP. It compensates for differences in pipe length, caused by changes in temperature, or normal movement of the wing in flight.
** ON A/C NOT FOR ALL Yellow Hydraulic System - Schematic ** ON A/C NOT FOR ALL Yellow Hydraulic System - Schematic ** ON A/C NOT FOR ALL Yellow Hydraulic System - Schematic ** ON A/C NOT FOR ALL Yellow Hydraulic System - Schematic ** ON A/C NOT FOR ALL Yellow Hydraulic System - Schematic ** ON A/C NOT FOR ALL - a High-Pressure (HP) circuit which supplies the consumers
- a Low-Pressure (LP) or return circuit through which the fluid returns to the reservoir.
The EDP is attached to the engine accessory gearbox with key-hole fasteners. The hoses between the EDP and the system have quick-disconnect, self-sealing couplings. This makes it possible to change the EDP quickly with minimum changes necessary to the system.
There are two different types of EDP which are permitted. VICKERS make one type, ABEX the other. The two types are completely interchangeable. They give equivalent supplies of hydraulic power and their mechanical and electrical connections are the same.
The Yellow hydraulic system has two sub-systems:
- a High-Pressure (HP) circuit which supplies the consumers
- a Low-Pressure (LP) or return circuit through which the fluid returns to the reservoir.
The HP circuit is usually pressurized by an engine-driven pump (EDP), 3030GD, connected to the right (No. 2) engine. The EDP has a direct mechanical connection (through the accessory gearbox) to the engine and turns together with it. A solenoid valve on the EDP makes it possible to stop the supply of fluid to the system. A pushbutton switch (P/BSW) in the flight compartment controls the operation of the solenoid valve. The EDP can pressurize the system to 206 +3 -0 bar (3000 +45 -0 psi) at zero flow or to 196 bar (2854 psi) with a flow of 140 l/min (37 US Gal/min). This flow is set at the rated delivery speed of the pump (3702 rpm - equivalent to 100% engine N2 speed).
The EDP is attached to the engine accessory gearbox with key-hole fasteners. The hoses between the EDP and the system have quick-disconnect, self-sealing couplings. This makes it possible to change the EDP quickly with minimum changes to the system.
There are two different types of EDP which are permitted. VICKERS make one type, ABEX the other. The two types are completely interchangeable. They give equivalent supplies of hydraulic power and their mechanical and electrical connections are the same.
The Power Transfer Unit (PTU) 1088GM can also pressurize the Yellow HP circuit (Ref. 29-23-00). The PTU gets its power from the Green hydraulic system (Ref. 29-11-00). It supplies power to the Yellow hydraulic system if the pressure in the system falls to approximately 500 psi (34.48 bar) below the pressure in the Green hydraulic system. There is no hydraulic connection between the two hydraulic systems so no fluid can go from one system to the other.
If the EDP fails, or for maintenance on the ground, it is possible to pressurize the Yellow hydraulic system with the electric pump (Ref. AMM D/O 29-24-00-00). The output of the electric pump is connected to the HP supply downstream of the check valve 3050GM. A check valve 3083GM is installed in the output line from the electric pump to stop reverse flow of fluid to the pump.
On the ground, it is possible to pressurize the Yellow hydraulic system from a ground supply. The system has self-sealing connectors for a ground supply installed on the ground service panel.
The ground service panel for the Yellow hydraulic system is installed in the right belly fairing aft of the main gear compartment. The components and connections necessary to service the Yellow hydraulic system (not including the reservoir air pressurization connection and the reservoir drain) are installed in a group together on it. The ground service panel has these components on it:
- the ground test pressure and suction self-sealing connectors 3008GM and 3006GM
- the Yellow reservoir depressurization valve 3087GM (Ref. AMM D/O 29-14-00-00)
- the hand pump lever 3270GM (which is for the reservoir filling and cargo door hand-pumps)
- the EL/MAN selector valve 2500MJ of the cargo door system (Ref. AMM D/O 52-36-00-00)
- the hand pump 3009GM of the cargo door system (Ref. AMM D/O 52-36-00-00).
If the EDP fails, or for maintenance on the ground, it is possible to pressurize the Yellow hydraulic system with the electric pump (Ref. AMM D/O 29-24-00-00). The output of the electric pump is connected to the HP supply downstream of the pylon manifold 3030GM. A check valve 3083GM is installed in the output line from the electric pump to stop reverse flow of fluid to the pump.
On the ground, it is possible to pressurize the Yellow hydraulic system from a ground supply. The system has self-sealing connectors for a ground supply installed on the ground service panel.
The ground service panel for the Yellow hydraulic system is installed in the right belly fairing aft of the main gear compartment. The components and connections necessary to service the Yellow hydraulic system (not including the reservoir air pressurization connection and the reservoir drain) are installed in a group together on it. The ground service panel has these components on it:
- the ground test pressure and suction self-sealing connectors 3008GM and 3006GM
- the Yellow reservoir depressurization valve 3087GM (Ref. AMM D/O 29-14-00-00)
- the hand pump lever 3270GM (which is for the reservoir filling and cargo door hand-pumps)
- the EL/MAN selector valve 2500MJ of the cargo door system (Ref. AMM D/O 52-36-00-00)
- the hand pump 3009GM of the cargo door system (Ref. AMM D/O 52-36-00-00).
A pylon manifold (3030GM) with integral check valve and a pressure switch (3074GK) are installed downstream of the EDP. The pressure switch monitors the output pressure of the pump (Ref. 29-32-00). The check valve stops the flow of fluid to the pump if a different source is used to pressurize the system.
The supply to most of the consumers goes through the HP and Leakage Measurement System (LMS) manifolds. Thus it is possible to isolate some consumers to measure the internal leakage of parts of the system. The supply to the alternate and parking brake systems goes from the HP manifold through the brake manifold.
The HP manifold has ports which connect it to the other parts of the system as follows:
- a system pressure inlet from the pumps and ground supply
- two outlets to the LMS manifold
- one outlet to the PTU manifold
- one inlet from the PTU manifold
- one connection to the system accumulator/cargo doors/brake manifold.
A solenoid valve (3160GP) on the HP manifold controls the flow of fluid to the LMS manifold. The solenoid valve is usually operated from the flight compartment but it also has an automatic function. This function is related to the operation of the cargo doors. When the cargo doors are set to open or close (and the Yellow electric pump starts), the solenoid valve is automatically closed. This stops the supply of fluid to the flight controls. Thus there is no danger of movement of flight controls because of operation of the cargo doors.
The hydraulic supply to the flight controls in the rear section, the LH wing and the RH wing goes through the HP manifold. Thus it is possible to measure the internal leakage of groups of consumers in the related sections. The supply to the alternate and parking brake systems goes from the HP manifold through the brake manifold.
The HP manifold has ports which connect it to the other parts of the system as follows:
- A system pressure inlet from the pumps and ground supply
- One outlet to the flight controls in the rear section, the LH wing and the RH wing
- One outlet to the PTU manifold
- One inlet from the PTU manifold
- One connection to the system accumulator/cargo doors/brake manifold.
A solenoid valve (3150GP) in the HP manifold controls the flow of hydraulic fluid to the flight controls in the rear section, the LH wing and the RH wing. The solenoid valve is usually operated from the flight compartment but it also has an automatic function. This function is related to the operation of the cargo doors. When the cargo doors are set to open or close (and the Yellow electric pump starts), the solenoid valve is automatically closed. This stops the supply of hydraulic fluid to the flight controls. Thus the flight controls will not move when the cargo doors are operated.
The system pressure inlet to the HP manifold has a filter 3048GM with a filtration rating of 15 microns. A check valve is installed on the manifold. A sampling valve 3187GM makes it possible to take samples of fluid from the system for analysis. You can take the sample when the system is at full pressure.
A pressure relief valve (PRV) 3063GM is installed on the HP manifold to protect the system against overpressure. The PRV opens when the pressure is greater than or equal to 237 bar (3436 psi) and closes at 220 bar (3190 psi). Two pressure switches 3151GN, 10CE-3 and a pressure transducer 3065GN are also installed on the HP manifold to monitor the pressure in the system (Ref. 29-32-00).
The system accumulator 3070GM has direct hydraulic connections to the HP and brake manifolds and to the cargo door selector valve. The accumulator keeps the pressure in the system free of small changes. It also makes a supply of fluid available to replace any temporary shortage. This can occur if there is a sudden large demand and the pump has not had time to respond. The accumulator is pre-charged with nitrogen at 1885 psi (130 bar) and holds 0.18 l (0.0476 USgal) of the useable fluid when it is full. A gas charging valve 3071GM and a pressure gage 3072GM are installed on the accumulator.
The LMS manifold 3146GM makes it possible to measure the internal leakage of groups of consumers. The HP supply is divided into three separate outputs, one to each of the following:
- flight controls in the LH wing,
- flight control in the RH wing,
- flight controls in the tail section.
Measurement of internal leakage is done with a ground hydraulic supply and a flowmeter.
The LMS manifold also makes it possible to isolate parts of the system for maintenance.
The main system is connected with the PTU through the PTU manifold 3015GM. The PTU manifold also has a connection to the flap system. The PTU connections are:
- one inlet/outlet from/to the PTU,
- one inlet from the HP manifold,
- one outlet to the HP manifold,
- one outlet to the RH motor of the flap power control unit.
A solenoid valve installed on the PTU manifold controls (together with the equivalent solenoid valve of the Green hydraulic system ) the flow of fluid to/from the PTU. A single pushbutton switch 1802GL in the flight compartment controls the operation of the two solenoid valves. When the pushbutton switch is operated, the two solenoid valves are energized and the supply of fluid to/from the PTU is stopped.
The ultrasonic flowmeter (USF) (Ref. AMM D/O 29-19-00-00) makes it possible to measure the internal leakage of groups of consumers. The HP supply through the solenoid valve 3150GP is divided into three separate outputs, one to each of the following:
- flight controls in the LH wing,
- flight control in the RH wing,
- flight controls in the tail section.
The internal leakage is measured with the hydraulic supply from the Yellow electric pump and the USF.
The main system is connected with the PTU through the PTU manifold 3015GM. The PTU manifold also has a connection to the flap system. The PTU connections are:
- one inlet/outlet from/to the PTU,
- one inlet from the HP manifold,
- one outlet to the HP manifold,
- one outlet to the RH motor of the flap power control unit.
A solenoid valve installed on the PTU manifold controls (together with the equivalent solenoid valve of the Green hydraulic system ) the flow of hydraulic fluid to/from the PTU. A pushbutton switch 1802GL in the flight compartment controls the operation of the two solenoid valves. When the pushbutton switch is operated, the two solenoid valves are energized and the supply of hydraulic fluid to/from the PTU is stopped.
The priority valve 3064GM is installed on the PTU manifold. It stops the supply of fluid to non-essential consumers if the system pressure is too low. The priority valve closes at 130 +0 -3 bar (1885 +0 -43 psi) and opens at 140 +0 -5 bar (2030 +0 -72.5 psi).
Two check valves are installed on the PTU manifold. The check valve 3093GM and the other check valve control the flow of fluid in the manifold.
The Yellow hydraulic system supplies these consumers:
- direct from the EDP/electric pump/ground supply,
- the RH (No. 2) engine thrust reverser. - from the HP manifold (through the LMS manifold),
- the LH and RH spoiler 2,
- the LH and RH spoiler 4,
- the LH flap Wing-Tip Brake (WTB),
- the RH elevator,
- the rudder,
- the Trimmable Horizontal Stabilizer (THS),
- the yaw damper. - from the HP manifold (not through the LMS manifold),
- the FWD and AFT cargo doors,
- the brake manifold. - from the brake manifold,
- the alternate and parking brakes. - from the PTU manifold (downstream of the priority valve)
- the PTU,
- the RH motor of the flap PCU.
It is possible to supply all of the consumers from the ground supply connections.
The priority valve 3064GM is installed on the PTU manifold. It stops the supply of fluid to non-essential consumers if the system pressure is too low. The priority valve closes at 130 +0 -3 bar (1885 +0 -43 psi) and opens at 140 +0 -5 bar (2030 +0 -72.5 psi).
Two check valves are installed on the PTU manifold. The check valve 3093GM and the other check valve control the flow of fluid in the manifold.
The Yellow hydraulic system supplies these consumers:
- direct from the EDP/electric pump/ground supply,
- the RH (No. 2) engine thrust reverser. - from the HP manifold (through the LMS manifold),
- the LH and RH spoiler 2,
- the LH and RH spoiler 4,
- the LH flap Wing-Tip Brake (WTB),
- the RH elevator,
- the rudder,
- the Trimmable Horizontal Stabilizer (THS),
- the yaw damper. - from the HP manifold (not through the LMS manifold),
- the FWD and AFT cargo doors,
- the brake manifold,
- the nosewheel steering. - from the brake manifold,
- the alternate and parking brakes. - from the PTU manifold (downstream of the priority valve)
- the PTU,
- the RH motor of the flap PCU.
It is possible to supply all of the consumers from the ground supply connections.
The priority valve 3064GM is installed on the PTU manifold. It stops the supply of hydraulic fluid to non-essential consumers if the system pressure is too low. The priority valve closes at 130 +0 -3 bar (1885 +0 -43 psi) and opens at 140 +0 -5 bar (2030 +0 -72.5 psi).
Two check valves are installed on the PTU manifold. The check valve 3093GM and the other check valve control the flow of hydraulic fluid in the PTU manifold.
The Yellow hydraulic system supplies these consumers:
- direct from the EDP/electric pump/ground supply,
- the RH (No. 2) engine thrust reverser. - from the HP manifold (through the solenoid valve 3150GP),
- the LH and RH spoiler 2,
- the LH and RH spoiler 4,
- the LH flap Wing-Tip Brake (WTB),
- the RH elevator,
- the rudder,
- the Trimmable Horizontal Stabilizer (THS),
- the yaw damper. - from the HP manifold (not through the solenoid valve 3150GP),
- the FWD and AFT cargo doors,
- the brake manifold,
- the nosewheel steering. - from the brake manifold,
- the alternate and parking brakes. - from the PTU manifold (downstream of the priority valve)
- the PTU,
- the RH motor of the flap PCU.
It is possible to supply all of the consumers from the ground supply connections.
The Low Pressure (LP) circuit returns the fluid from the consumers to the reservoir. The case drains of the EDP and PTU, and the returns from the HP manifold are also connected to the LP circuit. The circuit has check valves where applicable to control the flow of fluid. Some of the return lines are connected together at the LP manifold. Part of the LP circuit is also used in the reservoir filling system (Ref. AMM D/O 29-16-00-00).
The LP fluid goes through the LP filter 3002GM before it gets to the reservoir. The filter has a filtration rating of 3 microns. If the filter element clogs, a by-pass operates and unfiltered fluid goes to the reservoir. The temperature sensor (3318GR), which is attached to the outlet of the LP filter, monitors the temperature of the return fluid. The temperature information is sent to the ECAM and warning systems (Ref. AMM D/O 29-33-00-00).
A filter 3084GM is installed in the EDP case drain line to the LP system. It has a filtration rating of 15 microns.
The reservoir 3000GQ is installed in the Yellow hydraulic compartment. It holds a supply of fluid and also makes allowance for differences of the quantity of the fluid in the system (because of different positions of jacks for example). The reservoir holds 12 l (3.18 USgal) of hydraulic fluid when it is filled to the correct level.
The reservoir is filled through the reservoir filling system (Ref. AMM D/O 29-16-00-00) which is operated from the ground service panel of the Green hydraulic system. A reservoir drain valve is installed on the reservoir.
The reservoir is pressurized with air to 50 psi (3.5 bar) to stop cavitation at the inlet to the EDP (Ref. AMM D/O 29-14-00-00). The supply of air comes from the pneumatic system of the aircraft (Ref. AMM D/O 36-00-00-00). It is also possible to pressurize the reservoir from a ground supply. A depressurization valve is installed on the ground service panel of the Yellow hydraulic system. A PRV and air pressure gage are installed on the reservoir.
A motorized fire valve 3046GD is installed in the suction line between the reservoir and the EDP. It operates when the engine fire pushbutton in the flight compartment is operated. The valve stops the supply of fluid to the EDP if there is a fire in the nacelle.
A compensated slide 3010GM is installed in the suction line between the reservoir and the EDP. It compensates for differences in pipe length, caused by changes in temperature, or normal movement of the wing in flight.
** ON A/C NOT FOR ALL
5. Component Description
A. Reservoir FIN: 3000-GQ
The reservoir is made of two molded light alloy sections which are welded together to make a cylindrical shape. The top of the reservoir has a manifold for the components of the air pressurization system (Ref. AMM D/O 29-14-00-00). The bottom of the reservoir has two ports for the hydraulic connections. The ports are for the suction and return line connections. A drain valve is installed in the return port. The reservoir also has flanges to attach the quantity indicator/transmitter and the low level switch (Ref. AMM D/O 29-31-00-00).
The inside of the reservoir includes baffles which give a supply (for 20 s) of fluid under negative 'g' conditions. The baffles also form an anti-emulsion device which limits the emulsion of the fluid when there is a large return flow.
The hydraulic fluid capacities of the reservoir are:
The reservoir is pressurized to 50 psi (3.45 bar) and is sealed to hold the pressure if there is no supply of air (for example, when the aircraft is parked). It is possible to pressurize the reservoir from a ground supply (Ref. 29-14-00).
The reservoir is filled with hydraulic fluid through the reservoir filling system (Ref. AMM D/O 29-16-00-00).
The reservoir is made of two molded light alloy sections which are welded together to make a cylindrical shape. The top of the reservoir has a manifold for the components of the air pressurization system (Ref. AMM D/O 29-14-00-00). The bottom of the reservoir has two ports for the hydraulic connections. The ports are for the suction and return line connections. A drain valve is installed in the return port. The reservoir also has flanges to attach the quantity indicator/transmitter and the low level switch (Ref. AMM D/O 29-31-00-00).
The inside of the reservoir includes baffles which give a supply (for 20 s) of fluid under negative 'g' conditions. The baffles also form an anti-emulsion device which limits the emulsion of the fluid when there is a large return flow.
The hydraulic fluid capacities of the reservoir are:
- The normal fill level 12 l (3.2 USgal)
- The maximum gage level 18 l (4.76 USgal)
- The low-level warning level 3 +-0.4 l or -+0.4 l (0.8 +-0.1 USgal or -+0.1 USgal).
The reservoir is pressurized to 50 psi (3.45 bar) and is sealed to hold the pressure if there is no supply of air (for example, when the aircraft is parked). It is possible to pressurize the reservoir from a ground supply (Ref. 29-14-00).
The reservoir is filled with hydraulic fluid through the reservoir filling system (Ref. AMM D/O 29-16-00-00).
B. Engine Pump Fire-Valve 3046GD
The engine pump fire-valve is installed in the RH wing between the rear spar and rear false spar, inboard of the pylon. It is in the suction line between the reservoir and the EDP. When the valve closes, it stops the supply of fluid to the EDP.
The engine pump fire-valve 3046GD is the same as the fire valve 1046GK installed in the Green hydraulic system (Ref. AMM D/O 29-11-00-00).
The engine pump fire-valve is installed in the RH wing between the rear spar and rear false spar, inboard of the pylon. It is in the suction line between the reservoir and the EDP. When the valve closes, it stops the supply of fluid to the EDP.
The engine pump fire-valve 3046GD is the same as the fire valve 1046GK installed in the Green hydraulic system (Ref. AMM D/O 29-11-00-00).
C. Engine Pump 3030GD
The engine pump 3030GD is installed on the accessory gearbox of the RH (No. 2) engine. It is the same as the engine pump 1030GK installed in the Green hydraulic system (Ref. AMM D/O 29-11-00-00).
The engine pump 3030GD is installed on the accessory gearbox of the RH (No. 2) engine. It is the same as the engine pump 1030GK installed in the Green hydraulic system (Ref. AMM D/O 29-11-00-00).
D. Manifolds
There are four manifolds in the system. They are:
All of the manifolds are aluminum castings. They are machined to make it possible to install different components on them. Some of the hydraulic connections between the manifolds and components are of the bobbin type (Ref. 29-00-00). Thus, replacement of components is possible with minimum effect on other components or pipes. The manifolds are drilled to make the internal connections between components.
The following are the components installed on their related manifolds:
There are five manifolds in the system. They are:
All of the manifolds are aluminum castings. They are machined to make it possible to install different components on them. Some of the hydraulic connections between the manifolds and components are of the bobbin type (Ref. 29-00-00). Thus, replacement of components is possible with minimum effect on other components or pipes. The manifolds are drilled to make the internal connections between components.
The following are the components installed on their related manifolds:
There are four manifolds in the system. They are:
- the HP manifold
- the PTU manifold
- the brake manifold
- the LP manifold.
All of the manifolds are aluminum castings. They are machined to make it possible to install different components on them. Some of the hydraulic connections between the manifolds and components are of the bobbin type (Ref. 29-00-00). Thus, replacement of components is possible with minimum effect on other components or pipes. The manifolds are drilled to make the internal connections between components.
The following are the components installed on their related manifolds:
There are five manifolds in the system. They are:
- the HP manifold
- the PTU manifold
- the brake manifold
- the LP manifold
- the pylon manifold.
All of the manifolds are aluminum castings. They are machined to make it possible to install different components on them. Some of the hydraulic connections between the manifolds and components are of the bobbin type (Ref. 29-00-00). Thus, replacement of components is possible with minimum effect on other components or pipes. The manifolds are drilled to make the internal connections between components.
The following are the components installed on their related manifolds:
(1) HP Manifold
- the solenoid valve 3160GP
- a check valve
- the pressure relief valve 3063GM
- the HP filter 3048GM
- the check valve 3022GM
- the sampling valve 3187GM
- the pressure transmitter 3065GN (Ref. AMM D/O 29-32-00-00)
- the pressure switch 3151GN (Ref. AMM D/O 29-32-00-00)
- the pressure switch 10-CE-3 (Ref. AMM D/O 27-00-00-00).
(2) PTU Manifold
- the priority valve 3064GM
- the check valve 3093GM
- a solenoid valve
- a check valve.
(3) Brake Manifold
- the check valve 3058GM
- the brake pressure relief valve 3067GM
- the pressure transmitter 3068GN.
(4) LP Manifold
The LP manifold is the connection point for return lines from different parts of the LP system. It is attached directly to the system LP filter 3002GM.
The LP manifold is the connection point for return lines from different parts of the LP system. It is attached directly to the system LP filter 3002GM.
(5) HP Manifold
- the solenoid valve 3160GP
- a check valve
- the pressure relief valve 3063GM
- the HP filter 3048GM
- the check valve 3022GM
- the sampling valve 3187GM
- the pressure transmitter 3065GN (Ref. AMM D/O 29-32-00-00)
- the pressure switch 3151GN (Ref. AMM D/O 29-32-00-00)
- the pressure switch 10-CE-3 (Ref. AMM D/O 27-00-00-00).
(6) PTU Manifold
- the priority valve 3064GM
- the check valve 3093GM
- a solenoid valve
- a check valve.
(7) Brake Manifold
- the check valve 3058GM
- the brake pressure relief valve 3067GM
- the pressure transmitter 3068GN.
(8) LP Manifold
The LP manifold is the connection point for return lines from different parts of the LP system. It is attached directly to the system LP filter 3002GM.
The LP manifold is the connection point for return lines from different parts of the LP system. It is attached directly to the system LP filter 3002GM.
(9) Pylon Manifold
- the integral check valve
- the pressure switch 3074GK.
E. System Accumulator 3070GM
The system accumulator 3070GM is the same as the system accumulator 1070GM installed in the Green hydraulic system (Ref. AMM D/O 29-11-00-00).
The system accumulator 3070GM is the same as the system accumulator 1070GM installed in the Green hydraulic system (Ref. AMM D/O 29-11-00-00).
F. Nitrogen Pressure Gage 3072GM
The nitrogen pressure gage 3072GM is the same as the nitrogen pressure gage (1072GM) installed in the Green hydraulic system (Ref. AMM D/O 29-11-00-00).
The nitrogen pressure gage 3072GM is the same as the nitrogen pressure gage (1072GM) installed in the Green hydraulic system (Ref. AMM D/O 29-11-00-00).
G. High Pressure (HP) filter 3048GM.
The HP filter 3048GM is installed on the HP manifold. It is the same as the HP filter 1048GM installed in the Green hydraulic system (Ref. AMM D/O 29-11-00-00).
The HP filter 3048GM is installed on the HP manifold. It is the same as the HP filter 1048GM installed in the Green hydraulic system (Ref. AMM D/O 29-11-00-00).
H. Case Drain Filter 3084GM
The case drain filter 3084GM is functionally the same as the HP filter 3048GM. The only differences are in its size and the configuration of the filter head.
The case drain filter 3084GM is functionally the same as the HP filter 3048GM. The only differences are in its size and the configuration of the filter head.
I. Low Pressure (LP) filter 3002GM
The LP filter 3002GM is the same as the LP filter 1002GM installed in the Green hydraulic system (Ref. AMM D/O 29-11-00-00).
The LP filter 3002GM is the same as the LP filter 1002GM installed in the Green hydraulic system (Ref. AMM D/O 29-11-00-00).
J. Relief Valve 3063GM
The relief valve 3063GM is installed on the HP manifold. It is the same as the relief valve 1063GM installed in the Green hydraulic system (Ref. AMM D/O 29-11-00-00).
The relief valve 3063GM is installed on the HP manifold. It is the same as the relief valve 1063GM installed in the Green hydraulic system (Ref. AMM D/O 29-11-00-00).
K. Brake Relief Valve 3067GM
The brake relief valve is installed on the brake manifold. It protects the parking brake system from overpressure and makes it possible to depressurize the brake system manually. The valve assembly has two main sections, a HP relief valve and a manual depressurization valve. A double cylindrical body contains the two valves and also has a flange to attach the assembly to the manifold. The hydraulic connections to the manifold are of the bobbin type (Ref. AMM D/O 29-00-00-00).
The HP relief valve is a poppet type valve. Spring pressure holds the valve poppet against the valve seat. When hydraulic pressure increases to the crack pressure of the valve the force on the poppet is more than that from the spring. The valve opens and fluid flows from the inlet (port A) to the return (port B). When the hydraulic pressure decreases, the spring force is more than the hydraulic force and the valve closes. The valve opens at between 237 and 240 bar (3436 and 3480 psi), and closes when the pressure decreases to 220 bar (3190 psi).
The manual depressurization valve is a ball valve. Hydraulic pressure from the inlet holds the ball on its seat and thus keeps the valve shut. A light spring pressure also holds the ball on its seat and is an anti-rattle device when there is zero pressure in the valve. Operation of the push-button lifts the ball off the valve seat. Hydraulic fluid can then flow from the inlet (port A) to the return (port B).
The brake relief valve is installed on the brake manifold. It protects the parking brake system from overpressure and makes it possible to depressurize the brake system manually. The valve assembly has two main sections, a HP relief valve and a manual depressurization valve. A double cylindrical body contains the two valves and also has a flange to attach the assembly to the manifold. The hydraulic connections to the manifold are of the bobbin type (Ref. AMM D/O 29-00-00-00).
The HP relief valve is a poppet type valve. Spring pressure holds the valve poppet against the valve seat. When hydraulic pressure increases to the crack pressure of the valve the force on the poppet is more than that from the spring. The valve opens and fluid flows from the inlet (port A) to the return (port B). When the hydraulic pressure decreases, the spring force is more than the hydraulic force and the valve closes. The valve opens at between 237 and 240 bar (3436 and 3480 psi), and closes when the pressure decreases to 220 bar (3190 psi).
The manual depressurization valve is a ball valve. Hydraulic pressure from the inlet holds the ball on its seat and thus keeps the valve shut. A light spring pressure also holds the ball on its seat and is an anti-rattle device when there is zero pressure in the valve. Operation of the push-button lifts the ball off the valve seat. Hydraulic fluid can then flow from the inlet (port A) to the return (port B).
L. Priority Valve 3064GM
The priority valve 3064GM is installed on the PTU manifold. It is the same as the priority valve 1064GM installed in the Green hydraulic system (Ref. 29-11-00).
The priority valve 3064GM is installed on the PTU manifold. It is the same as the priority valve 1064GM installed in the Green hydraulic system (Ref. 29-11-00).
M. Sampling Valve 3187GM
The sampling valve 3187GM is installed on the HP manifold. It is the same as the sampling valve 1187GM installed in the Green hydraulic system (Ref. 29-11-00).
The sampling valve 3187GM is installed on the HP manifold. It is the same as the sampling valve 1187GM installed in the Green hydraulic system (Ref. 29-11-00).
N. Check Valves
The system has two types of check valve. They are:
Two cartridge type check valves are installed on the HP and PTU manifolds. These two check valves are the same as the check valves installed in the Green hydraulic system (Ref. AMM D/O 29-11-00-00).
The in-line type of check valve is installed in all other locations in the system. It is the same as the in-line check valve installed in the Green hydraulic system (Ref. AMM D/O 29-11-00-00).
The system has two types of check valve. They are:
- the cartridge type,
- the in-line type.
Two cartridge type check valves are installed on the HP and PTU manifolds. These two check valves are the same as the check valves installed in the Green hydraulic system (Ref. AMM D/O 29-11-00-00).
The in-line type of check valve is installed in all other locations in the system. It is the same as the in-line check valve installed in the Green hydraulic system (Ref. AMM D/O 29-11-00-00).
O. Compensated Slide 3010GM
Couplings at the housing end and at the end termination connect the compensated slide assembly to the pipework of the hydraulic system.
The housing end is screwed into the housing to make a cylinder for the piston.
Temperature changes or movement of the wing which changes the length of the pipework is compensated in the unit with the movement of the piston.
The housing end is vented by four orifices with filters and filter retainers.
The end termination is screwed into the piston. Both parts are locked by roll pins.
A scraper ring, retained by a circlip, is installed in the housing. The scraper ring prevents contamination of the cylinder during movement of the piston.
O-rings are installed in the housing and the housing end. These O-rings seal the different shaft diameters of the piston.
A single elastomer O-ring is installed at the piston to make a seal between the piston and the cylinder wall. An O-ring with an anti-extrusion ring seals the piston with the end termination.
Couplings at the housing end and at the end termination connect the compensated slide assembly to the pipework of the hydraulic system.
The housing end is screwed into the housing to make a cylinder for the piston.
Temperature changes or movement of the wing which changes the length of the pipework is compensated in the unit with the movement of the piston.
The housing end is vented by four orifices with filters and filter retainers.
The end termination is screwed into the piston. Both parts are locked by roll pins.
A scraper ring, retained by a circlip, is installed in the housing. The scraper ring prevents contamination of the cylinder during movement of the piston.
O-rings are installed in the housing and the housing end. These O-rings seal the different shaft diameters of the piston.
A single elastomer O-ring is installed at the piston to make a seal between the piston and the cylinder wall. An O-ring with an anti-extrusion ring seals the piston with the end termination.
P. Hydraulic Damper
The hydraulic damper reduces cabin noise generated by Engine Driven Pump (EDP) induced pressure ripples. It is installed at the high pressure outlet port of the EDP located in the nacelle.
The hydraulic damper reduces cabin noise generated by Engine Driven Pump (EDP) induced pressure ripples. It is installed at the high pressure outlet port of the EDP located in the nacelle.
6. Operation
The operation of the system is fully automatic. If necessary (because of a fault, or for maintenance), it is possible to stop the automatic operation of the system.
The EDP starts to supply the system as soon as the No. 2 (right) engine is started. The supply is then continuous. The EDP supplies the system with fluid at 3000 psi (206 bar) and changes its output to that which is necessary for the system. The system accumulator makes allowance for any temporary decrease because of the response time of the EDP.
If the pressure in the Yellow hydraulic system decreases to approximately 500 psi (34.5 bar) less than the pressure in the Green hydraulic system, the PTU automatically operates. It pressurizes the Yellow hydraulic system to approximately the same pressure as the Green hydraulic system (the pressure is less because the PTU is not 100 % efficient).
The condition of the system is monitored continuously. Temperature and pressure sensors send information to the flight compartment. The information is shown on the ECAM displays and as FAULT warnings on the overhead panel.
Two P/BSWs on the overhead panel 40VU control the operation of the Yellow hydraulic system. One P/BSW 3703GD controls the solenoid valve in the EDP. When the P/BSW is operated, the solenoid valve is energized and the EDP is isolated from the HP system. The EDP stays connected to the suction line and keeps an internal pressure which is sufficient for lubrication of the pump.
The second P/BSW 1802GL controls the two PTU solenoid valves (one in the Yellow hydraulic system and one in the Green hydraulic system). When the two P/BSWs are pushed, the two solenoid valves are energized and the PTU is isolated from the two systems. Thus, no transfer of power between the two systems is possible.
The P/BSW 3804GX on the overhead panel 40VU controls the operation of the Yellow electric pump (Ref. AMM D/O 29-24-00-00).
A P/BSW 1883GP at the rear of the maintenance panel 50VU controls the solenoid valve 3160GP of the leakage measurement system. This P/BSW is only used for maintenance.
The crew can stop the supply of fluid to the EDP (if there is a fire in the engine nacelle) by operation of the fire valve 3046GD. The fire valve closes when the ENG 2 FIRE P/BSW is pushed. A symbol on the HYD page of the ECAM system display shows if the fire valve is open or closed.
The operation of the system is fully automatic. If necessary (because of a fault, or for maintenance), it is possible to stop the automatic operation of the system.
The EDP starts to supply the system as soon as the No. 2 (right) engine is started. The supply is then continuous. The EDP supplies the system with fluid at 3000 psi (206 bar) and changes its output to that which is necessary for the system. The system accumulator makes allowance for any temporary decrease because of the response time of the EDP.
If the pressure in the Yellow hydraulic system decreases to approximately 500 psi (34.5 bar) less than the pressure in the Green hydraulic system, the PTU automatically operates. It pressurizes the Yellow hydraulic system to approximately the same pressure as the Green hydraulic system (the pressure is less because the PTU is not 100 % efficient).
The condition of the system is monitored continuously. Temperature and pressure sensors send information to the flight compartment. The information is shown on the ECAM displays and as FAULT warnings on the overhead panel.
Two P/BSWs on the overhead panel 40VU control the operation of the Yellow hydraulic system. One P/BSW 3703GD controls the solenoid valve in the EDP. When the P/BSW is operated, the solenoid valve is energized and the EDP is isolated from the HP system. The EDP stays connected to the suction line and keeps an internal pressure which is sufficient for lubrication of the pump.
The second P/BSW 1802GL controls the two PTU solenoid valves (one in the Yellow hydraulic system and one in the Green hydraulic system). When the two P/BSWs are pushed, the two solenoid valves are energized and the PTU is isolated from the two systems. Thus, no transfer of power between the two systems is possible.
The P/BSW 3804GX on the overhead panel 40VU controls the operation of the Yellow electric pump (Ref. AMM D/O 29-24-00-00).
A P/BSW 1883GP at the rear of the maintenance panel 50VU controls the solenoid valve 3160GP of the leakage measurement system. This P/BSW is only used for maintenance.
The crew can stop the supply of fluid to the EDP (if there is a fire in the engine nacelle) by operation of the fire valve 3046GD. The fire valve closes when the ENG 2 FIRE P/BSW is pushed. A symbol on the HYD page of the ECAM system display shows if the fire valve is open or closed.