Represented on vehicle 384.223 |
8.01 | Check valve |
30.03 | Pressure limiting valve with quick discharge |
30.08 | Compressed air relay valve |
33.01 | Electromagnetic pressure relief valve |
B14.40-0080-05
Position arrangement
The pressure relief valve (30.03) is part of the compressed air control unit and is located on the inner side of the chassis frame, near the SCR catalyst.
Function
The pressure relief valve (30.03) reduces the air flow pressure to a default value of 5.5 bar.
Represented on vehicle 382.177 |
8.01 | Check valve |
30.03 | Pressure limiting valve with quick discharge |
30.08 | Compressed air relay valve |
33.01 | Electromagnetic pressure relief valve |
B14.40-0078-05
Composition |
1 | Pressure spring |
2 | Intake |
3 | Piston |
4 | Piston |
5 | Exhaust |
6 | Valve |
7 | Valve |
8 | Housing |
A | Supply connector |
B | Low pressure operation connection |
C | Breather |
D | Compressed air chamber |
E | Orifice |
F | Compressed air chamber |
G | Compressed air chamber |
B14.40-0170-03
Function
The pressure relief valve (30.03) is adjusted in such a way that only a predetermined pressure can be transferred to connection (B). The pressure spring (1) acts constantly on pistons (3) and (4). This way, the piston (3) is held in its idle position against the housing (8). Intake (2) is open. Air entering supply connection (A) flows from compressed air chamber (F) until the compressed air chamber (G) and reaches the devices connected through connection (B).
The pressure that accumulates in the compressed air chamber (G) overcomes the pressure spring force (1) and moves piston (3) and (4) downwards. Valve (7) closes inlet (2) and reaches its final position. Due to air consumption on the low pressure side, the pressure balance on piston (3) is void. Pressure spring (1) presses piston (3) and (4) upwards again. Intake (2) opens, the intake air reaches the predefined pressure, and balance is set
If pressure on the low pressure side to connection (B) exceeds the value expected, piston (3) works as a safety valve and opens outlet (5). The exceeding pressure will escape through vent (C) at open air.
If the pressure in the compressed air chamber (F) lowers the pressure value in the compressed air chamber (G), valve (6) opens. The compressed air of chamber (G) flows, at this moment, it returns to connection (A), through hole (E) until the intake opening (2) prevails thanks to pressure spring (1). There is a pressure balance between connections (B) and (A).