Adjustment Of The Pressure Stabiliser; Valve Adjustment - Riello MB 412/2 Instrucciones De Instalación, Uso Y Mantenimiento

5 Activation, calibration and functioning
5.1 Notes on safety for the first start-up
The first start-up of the burner must be carried out
by qualified personnel, as indicated in this manual
and in compliance with the standards and regula-
tions of the laws in force.
WARNING
5.2

Adjustment of the pressure stabiliser

Move the protection 4)(Fig. 1, page 4) and turn the screw below
in the required direction; the gas train output pressure may vary
from 4 to 20 mbar.
The greater the loss of pressure p between the inlet and the out-
let of the pressure stabiliser, the more effective its action; its func-
5.3

Valve adjustment

The ignition delivery (valve opening phase) should be adjusted,
after having unscrewed the cover 5)(Fig. 1, page 4), by rotating
the shaft below in the correct direction +/-; the cover itself may be
used as a tool by turning it upside down.
st
 1 stage delivery: partial delivery
The partial delivery (1
40% of the nominal delivery.
Rotate the ring nut 9) in the correct direction + / – to regulate
(Fig. 1, page 4).
nd
 2 stage delivery: main delivery
The steady state delivery is progressively reached starting
from the ignition delivery following the action of the hydraulic
brake.
The steady state delivery may be adjusted by rotating the
ring nut 6) in the appropriate direction + / – (Fig. 1, page 4)
after having loosened the unsealed screw 7).
5.4 Low gas pressure switch adjustment
Please refer to the burner manual.
5.5 VPS 504 valve leak detection control device (if present)
The valve leak detection device is obligatory (pr EN 676) on the
supply trains of burners with a maximum output greater than
1200 kW.
This valve leak detection control device operates by creating be-
tween the two valves an overpressure of about 20 mbar com-
pared to the pressure upstream; the testing time depends on the
volume to be pressurised as well as the pressure upstream and
varies from 10 to 26 seconds.
The yellow pilot lamp lighting up confirms the positive outcome of
the test, while a negative outcome, with the resulting lockout, is
signalled by the red pilot light; lockout continues until the valve
leak detection control device is live.
An operation check can be carried out by slackening the screw of
the pressure test point p of the equipment before the check; the
a
valve leak detection control device must lock out.
The fuse can be reached by using a screwdriver to remove the
cap near the electrical connection socket; a reserve fuse is in the
upper part of the valve leak detection control device under the
plug.
Activation, calibration and functioning
st
stage) can be regulated for up to
Check the correct working of the adjustment, com-
mand and safety devices.
WARNING
tionality increases with the increase in downstream pressure, as
an increment of obtainable pressure, compatible with the other
operational needs and with the network pressure availability, lim-
iting the opening of the upstream valve.
It is nonetheless preferable to calibrate this delivery by using the
upstream pressure of the stabiliser; the considerations made in
relation to the functionality of the pressure stabiliser already stat-
ed remain valid, optimal functioning of the valves is obtained
when they are fully opened: it is therefore necessary to seek the
best compromise between the requirements of the stabiliser and
of the valves.
It is possible to install the valve leak detection con-
trol device on trains that do not have it, by request-
ing the kit.
WARNING
9 GB
20049406