VF-VFH Butterfly valves
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ELEKTROGAS – Technical Sheet EE155 - 11/11 VF and VFH butterfly valves are designed for regulation and control of gas flow and air flow in combustion processes. Valves can be operated manually using a lever (to setup the high-fire rate of the burner) or automatically using a servomotor (modulating or staged control) or a solenoid actuator (twostage control). Valves are made of aluminium casting (VF type) or cast-iron (VFH type), with wide range of connections from DN40 up to DN150. Installation between EN 1092 flanges. Possibility to have one-size or two-size reductions of the nominal...

ELEKTROGAS – Technical Sheet EE155 - 11/11 VF/VFH butterfly valves are devices for regulation/modulation using auxiliary power supply or manually operated. - in case of combustion process being regulated by combustion air modulation, VF valves with servomotor can be used, coupled to another butterfly valve manually operated (available graduated scale and locking screw) to setup high-fire rate of the burner. VF..M VF..L Fig. 1 - In case of combustion process with excess of air or gas, VF butterfly valve can be used, coupled to a Lambda sensor for ratio correction. - In case of combustion...

ELEKTROGAS – Technical Sheet EE155 - 11/11 Technical specifications From DN40 up to DN150 for fitting between two flanges according to EN 1092 PN16 From DN40 up to DN100 for fitting between two flanges according to EN 1092 PN16 Rotation angle Ambient temperature Media type Air and non-aggressive gases according EN 437 +60° C +200° for use with air only C (special version on request) +250° C +450° with dissipators C (optional kit) Max. Pressure loss @ Vmax Flow rate Materials in contact with fluid Aluminium alloy Copper alloy Stainless steel Nitrile rubber (NBR) Fluoro elastomer (FPM)...

ELEKTROGAS – Technical Sheet EE155 - 11/11 Square shaft Round shaft Manual lever Solenoid actuator

ELEKTROGAS – Technical Sheet EE155 - 11/11 Manual lever Solenoid actuator ( ) Actuator weight excluded

ELEKTROGAS – Technical Sheet EE155 - 11/11 Flow chart - VF - blue lines: leakage @ 0° opening angle - orange lines: max flowrate @ 90° opening angle Formula of conversion from air to other gases Specific gravity

ELEKTROGAS – Technical Sheet EE155 - 11/11 Flow chart - VFH - blue lines: leakage @ 0° opening angle - orange lines: max flowrate @ 90° opening angle Pressure drop (∆p) being 30% of inlet pressure p1 assures a good flow control.

ELEKTROGAS – Technical Sheet EE155 - 11/11 Flow velocities chart Flow velocity lower than 30 m/s is recommended to avoid noise and turbulence that can affect pressure drop.

ELEKTROGAS – Technical Sheet EE155 - 11/11 Flow factor KVS (15° 1013 mbar, dry) C, Valve dimension can be calculated using flow diagrams or using characteristic flow factor (KVS) mentioned in tables 5 and 6 for several opening angles of the butterfly disc.

ELEKTROGAS – Technical Sheet EE155 - 11/11 Example (calculation using diagram): 3 Target is to select a valve for air with p2= 50 mbar and flow rate V= 800 Nm /h. DN100 pipes are advisable to avoid to overtake recommended flow velocity. Pressure drop will be: 0.3 ∆p = p 2 = 21.4 mbar 1 − 0.3 VF diagram curves suggest that DN65 valve can assure the requested flow rate. Considering DN100 pipe diameter, version DN100/65 (double reduction) can be adopted. Example (calculation using flow factor KVS): Target is to select a valve for air at 250° temper ature with p2= 30 mbar and flow rate VMAX= C...

ELEKTROGAS – Technical Sheet EE155 - 11/11 Max. Media temperature = +60° C R= +200° (air only) C = +250° (+450° with dissipators) C C Driving systems and actuators - square shaft 8 - round shaft Ø10 - manual lever - solenoid SR/SL/ST - servomotor MZ Optional For more information about actuators see their technical sheets. Manufacturer reserves the right to update or make technical changes without prior notice. The VF valve type meets current European approval requirements regarding safety use on gaseous fuels. These products conform with the Gas Appliances Directive 2009/142/EC and the...