**************************************************************************
**************************************************************************
NOTE: Repetitive self checking circuits are
required only on boilers with modulating controls
which operate for long periods of time without
burner shutdown.
**************************************************************************
**************************************************************************
NOTE: Steam operated feedwater injectors should be
specified only for boilers operating at or above 345
kPa (gage) 50 psig.
**************************************************************************
**************************************************************************
NOTE: Combustion units should have metering
combustion controls. Investigate energy savings.
Combustion units larger than 7034 kW 24,000,000
Btu/hr input should have oxygen trim in order to
optimize fuel usage. CO trim should be considered
for larger boiler installations as an adjunct to
oxygen trim for increased efficiency.
**************************************************************************
Provide boilers that conform to FS F-B-2902 and have a gross output
capacity of at least [_____] kW Btu per hour when operating at a steam
pressure of [_____] kPa (gage) pounds per square inch gage (psig) at the
site under design conditions when the burner is firing No. [_____] oil
conforming to [ASTM D 396] having a higher heating value of [_____] MJ/kg
Btu per gallon [or] [[natural] [manufactured] [mixed] [liquified petroleum]
gas having a higher heating value of [_____] MJ/kg Btu per cubic foot and a
pressure of [_____] kPa (gage) psig at the fuel train connection]. Provide
[air-atomizing] [or] [steam atomizing] burners. Rotary type burners are
unacceptable. Provide burners capable of operating at a turn down ratio of
[_____]. Provide automatic [recycling] [nonrecycling] programming controls
and incorporate means for automatic self-checking of the circuit beginning
of each start-up cycle. [Include a repetitive self-checking circuit to
check all components at not more than the specified time interval in
MIL-B-18796 during the entire period of burner operation, and sensor shall
be of the ultraviolet type.] [Connections shall be provided for remote
starting or stopping of the boilers.] [Provide steam operated feedwater
injectors.] Provide combustion control system of the [modulating
positioning type where the final control elements for fuel and air inputs,
between minimum and maximum limits, are positioned in proportion to load]
[semi-metering type where the final control element for one input, either
fuel or air, is positioned in proportion to load; flow of the other input
is measured and controlled in proportion to load as indicated by the
position of the control element for the first input] [full metering (fuel
flow/air flow basis) type where the final control element for one input,
either fuel or air, is positioned in proportion to load, or the flow for
that input is controlled in proportion to load, and the other input is
measured and controlled in proportion to the measured flow of the first
input] [Provide with oxygen compensation where one of the control elements
is biased, modified slightly, on the basis of continuous flue gas analyses,
to maintain the proper percentage of oxygen for various firing rates.]
Boilers shall be designed in accordance with the applicable provisions of
ASME BPVC SEC I and current addenda therein. Boilers shall be equipped
with combustion control safety devices conforming to NFPA 8501. The
SECTION 15517N
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