Ash Handling. Ash-handling facilities shall be mechanized and
improved to meet modern standards where required. Plants shall be provided
with completely mechanized pneumatic or mechanical ash conveying systems.
Water Treatment. Boiler water treatment is required in all plants.
Untreated raw water will cause scale deposits and cause general corrosion of
the boiler water side. Provide adequate means to analyze feed and boiler
water conditions and install adequate water treatment equipment.
Combustion Controls. Include all necessary equipment to
automatically control steam pressure or HTW temperature, water level, fuel
pressure or HTW temperature shall be maintained by automatic modulation of
fuel input. The proper fuel-air ratio is maintained by automatic modulation
of the air flow from the forced draft fan. The automatic control of the
furnace draft pressure is provided by modulation of induced draft fan speed
and inlet damper. The above controls shall include a remote means of manual
adjustment along with the panel indicator, to show the extent of adjustments.
Combustion controls shall conform, in general, to MIL-HDBK 1003/12, Boiler
Safety Controls. These controls are of prime importance in all
heating plants. Where omissions or other deficiencies exist, steps shall be
taken to correct, update, or modify the controls to perform adequately and to
meet safety standards. Boiler controls shall meet the minimum requirements
per the most recent ANSI/ASME CSD-1, Control and Safety Devices for
Automatically Fired Boiler, and NFPA 85 series. Where local or state codes
differ from the ANSI/ASME and NFPA codes the more stringent code requirements
shall prevail. The safety devices shall operate to shutoff the fuel supply to
the burners in the event of any of the following malfunctions:
Low water level,
High steam or HTW pressure,
Low fuel pressure (oil or gas),
High gas pressure,
Low oil temperature,
Loss of forced or induced draft fans.
Safety shutoff valve shall be manual reset type, and shall not be
operable until all limit controls are in the safe position. Sequence
interlocks for start-up and stop shall also be provided. Also provide
annunciator alarms to respond to any safety shutdown.