32
DUNGS VALVE
MODEL MB-ZRDLE...B01 AND B02
The monobloc DUNGS Model MB-ZRDLE is made up of:
a) Minimum gas pressure switch (3) and maximum gas pressure (12)
b) Gas filter (6)
c) Pressure regulator (stabilizer) (2) (only for version B01)
d) Safety valve (incorporated in the pressure regulator) which opens and closes rapidly (4)
e) Principle valve with two positions (1st flame and 2nd flame) which opens slowly with an adjustable initial rapid
release and rapid closing (8).
Before proceeding with regulation, read the following:
1) It is possible to reach the gas filter (6) in order to clean it, by removing one of the two side closing plates.
2) The pressure stabilizer can be regulated from 40 to 200 mm.W.C. by manoeuvring its regulating screw. It can be
reached by sliding the cover (2) to one side. The and viceversa is about 60 turns. Do not force against the end-of-
the-run position. Before starting up the burner, give the screw at least 15 turns towards the + sign. Around the
screw are arrows with symbols which indicate the sense of rotation to increase the pressure (in a clockwise
direction) and the sense of rotation to decrease pressure (in an anti-clockwise direction).
The stabilizer hermetically closes from “upstream” to “downstream” when there is no gas flow. Different springs to
obtain different pressure values form those described above are not foreseen.
To regulate the pressure stabilizer, connect a water manometer to the rubber tube holder installed on the valve, to
tap Pa (7), in correspondence with the stabilizer exit.
3) It is not necessary to regulate the rapid opening and closing safety valve (4).
4) Principle valve (8).
Regulating the initial rapid release effects the 1st and 2nd opening positions of the valve.
Regulation of the rapid release and of the hydraulic brake modify the 1st and 2nd positions of the valve in proportion
to the output regulated. To carry out regulation, unscrew the protection cover (11) and use the back part of it as a tool
to turn the pin.
Rotation in a clockwise direction
= minor rapid release
Rotation in an anti-clockwise direction = greater rapid release
REGULATING THE FIRST POSITION (1ST FLAME)
Loosen the screw with the protruding cylindrical head (1)
Give the knob (10), which regulates the output for the 2nd flame, at least one turn in the direction of the arrow which
indicates the + sign (anti-clockwise direction).
ATTENTION:
If this knob which regulates the 2nd flame is not given at least one turn towards the + sign, the valve will
not open in the 1st position.
Rotate the regulating ring (9) of the 1st flame in the direction indicated by the arrow towards the + sign (anti-clockwise
direction). As an indication, this should be a little more than two turns from the end-of-the-run position.
Then, when the 1st flame only is alight, rotate adequately ring (9) in order to obtain the gas delivery desired.
The complete run of the output regulator, from the - position to the + position, and viceversa, is about three and a half
turns. Rotation of the regulator in a clockwise direction, determines a reduction in delivery; rotation in an anticlockwise
direction increase delivery.
REGULATING THE SECOND POSITION (2ST FLAME)
Loosen the screw with the protruding cylindrical head (1)
Rotate the knob (10) in the direction indicated by the arrow for the + sign (anti-clockwise direction) as considered
necessary in order to obtain the gas delivery required for the 2nd flame. The complete run of the regulator from the -
position to the + position, and viceversa, is about FIVE turns. Rotate in a clockwise direction to determine a reduction
in delivery and in an anti-clockwise direction to increase it. After regulating the gas delivery for the 1st and 2nd
flame,remember to tighten home the screw (1) to avoid the regulatormoving out of the position at which it has been set.
N° 0002910310
Rev. 26/09/97
1st POSITION
2nd POSITION
DETAILS OF TERMINAL BOARD
FOR VALVE MB-ZRDLE...
VALVE
INLET MAX PRESSURE
ADJUSTTABLE OUTLET PRESSURE
TYPE OF GAS
MODEL
(PE) mbar
FROM THE STABILIZER (PA) mbar
MB ...B01 S 20
200
from 4 to 20
Gas maturale
MB ... B01 S 50
360
from 4 to 50
L.P.G
MB ... B02
360
L.P.G.
