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The monobloc DUNGS model MB-ZRDLE B1..S... consists of:
a) Min. gas pressure pressure switch (10) adjustable from 5 to 120 mbar.
b) Gas filter (8).
c) Pressure regulator (stabiliser) (7).
d) Safety valve (incorporated in the pressure regulator), rapid opening and closing (9).
e) Main valve with two positions (1st and 2nd flame), slow opening with adjustable initial rapid release and rapid
closing (6).
Adjustment instructions:
1) Entry filter (8) accessible for cleaning by removing the closing plate situated in the lower valve wall near the filter
seat
2) Pressure stabilisation adjustable from 4 to 32 mbar through the accessible screw by displacing the cover (13)
laterally. The full stroke from minimum to maximum and vice versa requires ca. eighty full turns, do not force
against the limit switches. Before starting the burner, turn at least 15 times towards the sign (+). Around the
access hole there are the arrows with the symbols showing the direction of rotation to increase pressure (clock-
wise rotation) and to reduce it (anticlockwise rotation).
Initial rapid release adjustment affecting both the first and the second valve opening position. The rapid release
adjustment and the hydraulic brake affect the 1st and 2nd position of the valve proportionally to delivery adjustments.
To carry out adjustments, loosen the protection cover (1) and use its rear part as tool to rotate the pin.
Clockwise rotation
= smaller rapid release
Anticlockwise rotation
= bigger rapid release
The stroke from “completely closed” to “completely open” is approx. three turns.
FIRST POSITION ADJUSTMENT (1st FLAME)
Loosen the screw with projecting cylindrical head (3).
Rotate the second flame delivery adjustment handle by least one turn in the direction shown by the arrow with
the sign (+) (anticlockwise rotation).
CAUTION: if said adjusting handle for the 2nd flame is not rotated by at least one turn towards (+), the valve does
not open for the first position.
Rotate the adjusting ring (5) of the 1st position in the direction shown by the arrow with the sign (+) (anticlockwise
rotation), i.e. a little more than two turns considering the limit switch. The regulator clockwise rotation brings about a
supply reduction, while an anticlockwise rotation brings about a supply increase.
SECOND POSITION ADJUSTMENT (2ND FLAME)
Loosen the screw with projecting cylindrical head (3).
Rotate the handle (2) in the direction shown by the arrow with the sign (+) (anticlockwise rotation) and adjust the
quantity You regard as necessary to obtain the desired gas supply for the second flame. The regulator clockwise
rotation brings about a supply reduction, while an anticlockwise rotation brings about a supply increase.
After adjusting the gas supply for the first and second flame do not forget to tighten the screw (3) to avoid undesired
displacements.
COMBINED GAS VALVE (monobloc)
mod. MD-ZRDLE 415 B01 S22 (1"1/2) /
MB-ZRDLE 420 B01 S22 (2")
N° 0002910580
Rev. 25/01/00
