Webasto GBW 300 Installation instructions manual - page 43
NGW 300 pressure regulator
GBW 300
40
7
NGW 300 pressure regulator
7.1.
Pressure regulator installation
The maximum length of the gas supply pipe from the pressure regulator
to the heater is 1 m. The pressure regulator and heater must be installed
at a distance of less than 1 m from each other.
NOTE:
The pressure regulator must be installed longitudinally in the vehicle.
The gas intake adapter and the filter at the gas intake must not be
removed.
The pressure regulator requires servicing and it must therefore be
possible to remove and install it. An approved shut-off cock is to be
installed upstream of the pressure regulator so that the regulator can be
serviced. The drain screw must be freely accessible.
The oil that collects at the oil drain screws must be drained every three
months.
7.2.
Function
The pressure regulator regulates the storage pressure (max. 220 bar) to
atmospheric pressure in three stages.
The 9 mm reference pressure line (max. length 1 m) from the pressure
regulator to the heater must be connected (see Figure 3).
The supplied connection port must be screwed into the pressure
regulator and secured with the lock nut to connect it to the pressure
regulator. You must pay special attention to the screw-in depth and the
tightening torque of 10 ± 1 Nm (see Figure 8).
Secure the line with clips at the connectors and at intervals of approx. 250 mm.
A safety valve protects the pressure regulator in the event of pressure
surges. A hose must be connected to the safety valve and secured with
a clip.
NOTE:
The ventilation must be ducted upwards into the open air. The ingress
of water must be prevented.
7.3.
Water connection for the pressure regulator
NOTE:
The expansion of the gas in the pressure regulator results in it cooling.
To prevent it freezing the pressure regulator must be heated with water.
To prevent excessive heating the supplied thermostatic valve is to be
installed in the supply line to the pressure regulator (see Figure 10).
7.4.
Replacement interval
In keeping with the manufacturer’s instructions, the pressure regulator
must be replaced every four years. Otherwise leaks and gas release
may occur due to the ageing of the seals.
7.5.
Pressure regulator gas supply
Refer to section 11 for details of system integration.
Fig. 8:
Connection port for the reference pressure line
22 + 2 mm
22 + 2 mm