05-06M
4.6.3 Other Types of Boilers: Apply conservative ratings. Utilize other types,
such as flex-tube boilers, only on non-critical loads.
4.7 Heat recovery boilers shall not be included in the boiler plant capacity
calculation unless they can operate with their own burners independent of the
device from which heat is being recovered.
4.8 Steam header pressure shall be sufficient to serve the pressure
requirements of the steam loads in an economical manner. If a laundry must be
served, typical header pressure requirements range 760 860 kPa (110 125
psi). If sterilizing equipment must be served, typical header pressure
requirements range 410 620 kPa (60 90 psi). When replacing an existing
boiler plant, header pressures shall not be increased above the existing
unless a complete engineering analysis is performed on affected portions of
the steam system of the facility to determine the effect of higher pressures
and temperatures on pipe expansion devices, steam traps, and other devices.
5. BOILER PLANT FUEL SELECTION:
5.1 Perform an engineering economic analysis to determine the lowest life
cycle cost of various fuel options.
the feasibility of using each fuel. Where natural gas is utilized, provide a
second fuel (such as fuel oil or propane), stored on the site, as a standby.
5.3 Conform to local, federal and state emissions regulations.
6. STANDBY FUEL STORAGE QUANTITY:
6.1 Provide fuel oil or propane storage volume equivalent to ten January days
of normal operation on plants which have capability for natural gas operation,
and provide oil or propane storage for 15 January days of normal operation
when plant has capability for oil or propane only. Where unusual local
conditions exist, the design engineer may recommend deviations from these
requirements.
7. STEAM PRESSURE CLASSES:
Low Pressure (LPS)......0 thru 103 kPa
(0 thru 15 psi)
Medium Pressure (MPS)...110 kPa thru 407 kPa
(16 thru 59 psi)
High Pressure (HPS).....414 kPa and above
(60 psi and above)
8. BOILER PLANT EQUIPMENT TYPES AND SELECTIONS:
8.1 Boilers - Gas and/or Oil Fired:
8.1.1 Boiler Types: Packaged fire tube units up thru 6900 kW (700 boiler
horsepower) are acceptable. Packaged water tube units are acceptable for any
capacity requirement. The choice between water tube and fire tube units must
be based on life cycle costs, and available space in the boiler room.
8.1.2 Quantity of Boilers: Normally, three units of equal size are the most
cost effective and operationally practical. In some cases, a smaller boiler
for use in the summer load period is necessary. The selection should be based
on the load profile developed by the design engineer.
on and off. Cycling of fire tube boilers should be minimized.
8.1.4 Burners: Provide low excess air design, with oxygen trim, on larger
water tube boilers when justified by life cycle cost analysis. Provide low NOx
burners where required by emissions authorities. Variable frequency drives
may be applied on larger motors.
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