Riello DB 4 SM BLU Installation, Use And Maintenance Instructions page 30

4
Fuel supply
4.1 General gas supply layout (example)
Fig. 12
D7543
Key
Anti-vibration joint
C
Gas filter
GF
HPG High gas pressure regulator
Low gas pressure regulator
LPG
Pressure gauge
MM
Minimum air pressure switch
PA
PGM Maximum gas pressure switch
10
PGm Minimum gas pressure switch
Gas butterfly valve
RG
Pressure limiting valve with outlet into the environment
SRV
Fan
VE
Leak detection control device
VPS
Gas pressure regulator solenoid valve
VR
Gas safety solenoid valve
VS
max. 500 mbar
0.5 ÷ 4 bar