Bergen B35:40, Project Manual

Page: 30 / 74

2.01
, Gas Starting and control air system
Page 3 : 5
0615 BC
Control air
Dry and clean air is required for problem-free opera-
tion of oil mist detector, I/P-converters and solenoid
valves in the control air system.
From the start air receiver(s), 30 bar air is reduced to
7 bar in the control air unit (95SA).
Also called pressure reducing station; see figure 3.
The control air unit is of a double type, located
between start air receiver(s) and the engine(s).
It is equipped with a filter and a rod for manual
draining of condensed water.
The capacity is: ................................... 1100 nl/minute,
provided 30 bar inlet air pressure, adjusted outlet
pressure 7 bar and system pressure 6 bar.
The capacity is: ..................................... 670 nl/minute,
if inlet pressure is 20 bar, under equal conditions.
Particle size: ......................................... max. 1.0 micron
Normal control air consumption per engine includ-
ing pneumatic operated valves and oil mist detector,
is approx.: ........................................................ 2,5 Nm
3
/h
Consumption of control air for gas valves and com-
bustion air throttle control, occurs only at start/stop
of engines, with insignificant quantities.
I/P-converters in the engine’s control air system, are
located on a separate mounting plate. In order to
avoid vibrations, the mounting plate must be in-
stalled outside, but close to the engine.
If there is other control air consumers in the system,
the control air unit capacity must be checked ac-
cordingly.
An air dryer for control air is required in order to
provide dry and clean air (96SA).
Control air requirements is based on ISO 8573-1:
Particle size: ......................................... max. 1,0 micron
Dew point: ...................................................... 3 °C (7 bar)
Particle density: ......................................... 1,0 mg/Nm
3
Oil content: .......................................max. 1,0 mg/Nm
3
Pressure: .........................................................7 ± 0,5 bar
g
Temperature: ...................................................... 20-50 °C
Pipe materials
Steel pipes according to the classification societies
requirements are used in the starting and control air
system.
The piping system for starting air is to be designed for an operat-
ing pressure of minimum 30 bar.
Fig. 1 Control air unit (Pressure reducing station)