baltur GI MIST 350 DSPGM, Инструкция

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0006080103 ed2005/10
GAS FEED SYSTEM AT AVERAGE PRESSURE (a few bars)
(see BT 8058 - BT 8530/1 - BT 8531/1)
When high delivery is required, the Gas Distributing Company requests the installation of a unit comprising a
pressure reducer and a meter, and then connects it to the gas pipe network at average pressure (a few bars).
This unit can be supplied by the Gas Distributing Company or by the user, but should be according to the Gas
Company’s precise instructions. The unit’s pressure reducer should be large enough to supply the maximum
gas delivery required by the burner at the rate of pressure normally estimated for it.
From experience, we would recommend utilizing a
large-scale reducer in order to attenuate the notable
increase in pressure which occurs when the burner
comes to a standstill, with a high delivery. (Regula-
tions require that the gas valves close in less than
one second).
As an indication, we would advise using a reducer ca-
pable of producing a delivery (m
3
/h) about double that
of the maximum amount estimated for the burner.
If several burners are to be used, each one should
have its own pressure reducer; this will enable the
gas feed pressure to the burner to be maintained at
a constant level even if only one burner is operating
at the time. Consequently, it is possible to accurately
regulate the delivery and therefore the combustion,
and thus improve yield.
The dimension of the gas pipeline should be in function
with the quantity of gas it has to deliver. We advise
maintaining the load loss at a low level (not more
than 10 % of the gas pressure value at the burner); it
should be kept in mind that the load loss is added to
the pressure existing when the burner stops and the-
refore a subsequent start up will occur at a pressure
that rises in accordance with an increase in the pipe’s
load loss. Should the gas pressure reach unaccep-
table values when the burner stops (rapid closure of
the gas valves), it is necessary to install between the
reducer and the fi rst valve of the burner an automatic
overfl ow valve and relative conveying pipe, of suitable
section, in the open air. The end of the conveying pipe
in the open air should terminate in a suitable place, be
protected from rain and have a fl ame trap.
The overfl ow valve should be regulated in such a way
as to completely unload excessive pressure.
See diagram n° BT 8058 for gas pipeline dimensions.
Near to the burner should also be fi tted a cut-off ball
cock, a gas fi lter, an anti-vibration joint and a fl anged
fi tting (see BT 8530/1 and BT 8531/1).
DIAGRAM FOR CALCULATING THE DIAMETER OF THE
PIPES IN RELATION TO THEIR LENGTH AND GAS FLOW
N° BT 8058
DIAMETER OF PIPES IN INCHES
PRESSURE DROP
IN mm OF H
2
O
LENGTH OF PIPES IN METERS
FLOW IN m
c
/h OF METHANE p.a. 0,60