Midco 400B-02 - Manual (Page 6)

Standard burners are approved
for use with NATURAL or
PROPANE gas only, and should
be used only with the gas spec-
ified on rating plate.
A Standard Model 400B-02
burner is equipped with a single
seated Combination Valve and
is suitable for NATURAL gas
only. A Standard Model 400B-
02P is equipped with a double
seated (redundant)
Combination Valve and is suit-
able for PROPANE gas use.
WARNING: The
Model 400B-02 is not suit-
able for conversion to
PROPANE gas. Using
PROPANE gas in the
Model 400B-02 is a safety
hazard and will void the
approval listing and the
burner warranty.
Model 400B-02 (NATURAL gas burner is shipped with a .343 diameter orifice installed for an
input capacity range of approximately 200 to 325 MBH. A Standard Model 400B-02P
(PROPANE) gas burner is shipped with a .180 diameter orifice installed for an input capacity
range of approximately 225 to 260 MBH. If the required rate does not fall within the capacity
range of the installed spud, select the correct input capacity range from Table 3 and install the
spud with the correct orifice size (stamped with inch diameter) from the SPUD KIT bag. If the
required firing rate is at the minimum of a capacity range, select the next lower range spud.
TO CHANGE SPUD: Turn Manual Gas Cock Knob on Combination Valve to OFF. Remove
the Spud Holder. See Table 3, and Figure 6 or 7.
The Combination Valve Gas Pressure Regulator is set to provide 2.0" W.C. NATURAL (8.0"
W.C. PROPANE) manifold gas pressure for low to minimum spud capacity input. Both models
are shipped with the primary air controlling shutter set WIDE OPEN to provide a lean gas/air
mixture during the initial start-up. Do not change the Combination Valve Gas Pressure
Regulator setting at this time.
CAUTION: The approximate air and gas settings described above are for
initial start-up only. Final settings must be made in accordance with Section
VIII. Instructions for adjustment of the manifold gas pressure are detailed in
Section XI.
* Main Gas Spud Orifice
Size, approximate
Manifold Pressure.
Data shown is approxi-
mate and based on "0"
overfire pressure at sea
level.
6
VII Main Gas Spud
Figure 6: Piping Connections
Table 3: Main Gas Spud Capacity and Preliminary Gas
and Air Settings
VI Piping Continued