baltur COMIST 20 Installation, Use And Maintenance Instruction Manual page 64

ENGLISH
The DUNGS MB-DLE... gas valve unit is made up of:
• A safety valve which closes opens rapidly (6).
• A main valve which opens in two stages (5). The first opening stage
occurs rapidly (release) and can be adjusted unscrewing the knob
(2) and inserting it overturned on the underlying adjusting pin. The
+ and - symbols on the valve head indicate the direction in which
the knob should be turned to change the gas flow to the ignition
(first valve opening stage). Rotating in a clockwise direction, the
ignition delivery is reduced; rotating in an anti-clockwise direction,
the ignition delivery is increased. The complete stroke from zero
to the maximum is slightly more than three turns (40% of the total
opening), and viceversa. When the first opening stage has taken
place, the valve continues to open slowly and takes 15 seconds
to reach the maximum open position. The maximum desired
delivery is set by loosening the locking screw with protruding head
(4) and turning the knob (3). Do not touch the screw with paint
seal. Turn in a clockwise direction to reduce delivery and in anti-
clockwise direction to increase it. It should be pointed out that when
the adjusting knob is turned, the end of stroke which limits valve
opening moves; therefore, when the adjusting knob is completely
turned to the - sign, the valve does not open and the burner does
not ignite. To get ignition, it is necessary to turn the knob in an
anti-clockwise direction towards the + sign. The complete stroke
from zero to the maximum and vice versa is nearly six complete
turns of the knob This adjusting operation for maximum and ignition
output must be carried out without forcing the corresponding end
of stroke.
• The pressure stabiliser (10) can be adjusted (see table) using the
screw which can be accessed sliding the cover (1) to one side. The
complete run from the maximum to the position and vice versa is
about 80 turns.Do not force against the end - of - the - run positions.
Do not force the end of stroke. Around the access opening there
are arrows with symbols indicating the sense of rotation for
pressure increase (clockwise) or decrease (anti-clockwise). This
stabilizer creates a hermetic closure between the "upstream" and
"downstream" sections when there is no flow. Different springs to
obtain different pressure value from those described above are not
foreseen. To regulate the pressure stabilizer, connect a water
manometer to the rubber tube holder installed on the tap (8) in
correspondence with the exit of the stabilizer (Pa).
• The inlet filter (12) can be accessed for cleaning removing one of
the two side closing plates.
• Gas minimum pressure switch (14). To adjust, it remove the
transparent cover and operate the black knob. The reference mark
is a small rectangle on the yellow disk around which the adjusting
knob rotates.
• At the inlet, a fitting (13) has been installed on the connection flange
to measure the inlet pressure. At the connection flange outlet, there
is also a fitting (7) to measure the outlet pressure.
• The side pressure fittings (9), indicated as Pe, are in communication
with the inlet pressure.
• The side pressure fittings (8) indicated as (Pa), are used to measure
the pressure coming out of the stabiliser. It might be useful to know
Valve model
MB ...403 B01 S 20
MB ... ... B01 S 20
that the pressure coming out of the valve unit (7), corresponds
to the pressure regulated by the stabiliser and is reduced by the
necessary pressure in order to overcome the crossing resistance
of the main valve (5). The valve crossing resistances vary based
on valve opening regulated by knob (3) with which the end of
stroke moves. For the pressure stabilizer adjustment, connect
the water gauge to the hose connection installed at the tap (8)
corresponding to the stabilizer output (Pa).
• The holes of the pressure stabilizer bleed (11) should be free and
to ensure a proper operation.
SUGGESTIONS FOR ADJUSTING THE GAS VALVE
• Connect the water manometer to the pressure fitting Pa (8) to
measure the pressure coming out of the stabiliser.
• Put the gas delivery regulators for ignition (2) and for maximum
delivery (3) in the position presumed necessary for the desired
delivery. Also open the combustion air regulator.
• Turn on the burner.
• With the burner on, operate under the cover (1) on the the adjusting
screw of the gas and pressure stabiliser and adjust pressure to
the value considered necessary to obtain the desired output, about
40 - 70 mm A.C. when the maximum output regulator (3) is in the
maximum opening position.
• Put the ignition flow regulator (2) in the position considered
necessary to obtain ignition with the minimum possible delivery.
CAUTION / WARNING
With irregular ignition, adjust the pressure to the stabilizer (8)
at 20 mbar.
Max intake pressure (PE) mbar
200
360
26 / 36
0006080872_201711
Stabiliser pressure adjustable at outlet (PA) mbar
from 4 to 20
from 4 to 20