Honeywell SV2 Series User Manual page 86

SV2 Series Safety Shut-off Valves
Fig. 44: V2MU mixing unit pulse line connections.
IMPORTANT (Refer to Fig.
• To avoid condensate from back draft entering any pulse line of the Fuel/Air Ratio Module, downwards pointing pressure ports
on the V2MU mixing unit or any other device shall not be used.
• Partial blockage of the air intake of the V2MU mixing unit can potentially influence the air pressure signal to the valve.
– Proper measures shall be taken to avoid the (partial) air intake blockage of the V2MU mixing unit. Inspection of the V2MU
air intake shall be part of the annual maintenance of the appliance.
• Refer to the Outdoor Air Installations section for further details regarding pulse lines.
NOTE: If the appliance is equipped with a sealed air chamber and the SV2 Series valve with FARMOD is contained in the
sealed chamber, it is allowed to not use the air pressure pulse line.
The air pre-filter is included with every premix valve and is available as a field replacement part as well. The air pre-filter MUST
be installed in every premix system, regardless of whether the Heat Exchanger is used. The air pre-filter filter must be mounted
between the V2MU mixing unit and the valve FARMOD in the air pulse line. If the Heat Exchanger is used, it must also be
mounted between the V2MU mixing unit and the valve FARMOD, with the Heat Exchanger first and the filter second. Refer to
Fig. 45.
Air Line
Air Line
Ref Line
Gas Line
Fig. 45: Pre-Filter installation.
IMPORTANT
• The filter should be mounted as close to the valve FARMOD as possible.
• The customer must furnish an appropriate filter mounting bracket for their chosen location.
– Maximum screw length is bracket thickness plus 9mm.
– Preferably use the Honeywell provided screws.
– Recommended torque 0.8 +/- 0.05 Nm (7.1 +/- 0.44 in-lbf).
44)
Air Line
Air Line
Gas Line
Ref Line
86 32-00029—02