Engine | 900.91/92 in model 000.001 |
with BlueTec | |
Engine | 902.91/93 in model 000.001 |
with BlueTec | |
Engine | 904.94/95/96/97 in model 000.001 |
with BlueTec | |
Engine | 906.93/94/95/96/98/99 in model 000.001 |
with BlueTec | |
Engine | 924.91/93/94 in model 000.001 |
with BlueTec | |
Engine | 925.9 in model 000.001 |
with BlueTec | |
Engine | 926.91/92/93/95/97/98 in model 000.001 |
with BlueTec |
Location
The pressure limiting valve with ventilation is part of the compressed-air controller unit (10).
10 | Compressed air control unit |
7.03 | Overflow valve without return flow |
30.03 | Pressure limiting valve with vent |
Y106 | SCR air pressure limiter solenoid valve |
G49.20-A050-02
Task
The pressure limiting valve with ventilation regulates the pressure in the working line (low-pressure side).
Structure
1 | Compression spring |
2 | Inlet |
3 | Piston |
4 | Piston |
5 | Outlet |
6 | Valve |
7 | Valve |
8 | Housing |
30.03 | Pressure limiting valve with vent |
A | Connection (supply line) |
B | Connection (operating line on the low pressure side) |
C | Ventilation |
D | Compressed air chamber |
E | Hole |
F | Compressed air chamber |
G | Compressed air chamber |
G49.20-A065-03
Function
The pressure limiting valve with ventilation is set so that only a certain pressure is applied at connection (B). Compression spring (1) acts constantly on pistons (3 and 4). This holds the piston (3) in its final position whereby it lies against the housing (8). The inlet (2) is opened. The supply air that enters at connection (A) flows from compressed-air chamber (F) to compressed-air chamber (G) and is routed via connection (B) to the working line (low-pressure side).
If the pressure that builds up in compressed-air chamber (G) exceeds the force of compression spring (1), the pistons (3 and 4) move downwards. The valve (7) closes the inlet (2) and reaches its end position.
The pressure equilibrium at the piston (3) is removed due to air consumption at the low-pressure side. Compression spring (1) presses pistons (3 and 4) upwards again. The inlet (2) opens and air is supplied until the pressure has reached the set level and equilibrium is restored.
If the pressure on the low-pressure side at connection (B) exceeds the planned value then the piston (3) acting as a safety valve opens the outlet (5). The excess pressure escapes over the ventilation pipe (C) into the open.
If the pressure in compressed-air chamber (F) drops below the value of the pressure present in compressed-air chamber (G), valve (6) will open as a result. The compressed air flows out of compressed air chamber (G) now flows back through the hole (E) to the connection (A) until the force of the compression spring (1) again reigns and the inlet (2) opens. A pressure compensation takes place between the connections (B and A).