102
GB
Description and regulation of gas valve VCV
Variable ratio regulator for the block and regulation of the gas/air pressure ratio in modulating burners.
The ratio can be regulated from 0.6:1 to 3:1.
Using the control pressure of the combustion chamber pF it is possible to correct the pressure varia-
tions of the chamber itself.
Inlet pressure pe: 10…500 mbar.
Outlet pressure pG: 0.5…30 mbar.
The inlet pressure pe can be measured on the valve body.
The outlet pressure pG can only be measured at the regulator measuring point.
To increase the regulation precision it is possible to connect an external impulse line instead of the
measuring point pG.
Gas impulse line pG: distance from the flange ≥ 3x DN – use pipe 8x1 and screw connection 8 / R1/8.
Attention!
Do not jump the VAS downstream with the external impulse line.
Assembly
VAV assembly position: black electromagnetic actuator positioned vertically, not overturned.
The body must not be in contact with masonry. Minimum distance 20 mm.
Do not assemble or leave the appliance outdoors.
The sealant material, waste and other impurities must not enter the valve.Consider a free space suffi-
cient for assembly and regulation.
A filter must be installed upstream from every system.
On the inlet line, mount a mesh filter on the valVario valve. If one or more valves are mounted in suc-
cession, install a mesh filter on the inlet side only on the first valve.
At appliance outlet there must be a calibrated orifice, suitable for the feedback signal, with rubber seal
(G) depending on the piping.
Calibrated orifice piping dimension for the feedback signal with Ø outlet d [mm]
1 DN 15 17
1 DN 20 25
1 DN 25 30
2 DN 40 46
3 DN 50 58
The pressure stabiliser is mounted successively upstream from the VAS gas electromagnetic valve:
the calibrated orifice for the feedback signal must be mounted on the pressure stabiliser outlet.
Mount a support frame on the inlet of the VAS gas electromagnetic valve in order to fix the calibrated
orifice for the feedback signal on the regulator outlet.
Order the support frame separately.
If VAD/VAG/VAV 1 is positioned upstream from the valve VAS 1: use the DN 25 calibrated orifice for
the feedback signal with outlet hole d = 30 mm. In the case of dimension 1, mount DN 15 or 20:order
the calibrated orifice for the feedback signal DN 25 separately.
