ANSI/ISA 77.43.01-2002 (R2008)

The scope of this document is to address the unit/plant demand development subsystem for boilers withsteaming capacities of 200,000 lbs/hr (25 kg/s) or greater. This subsystem includes firing rate demanddevelopment, throttle/header pressure control, and unit megawatt/steam flow control as applicable.

This document will address two types of process applications:

a) a single boiler supplying a single turbine, typical of an electric utility power plant; and
b) a single boiler or multiple boilers supplying a common distribution header, typical of an industrialpower plant.

Specifically excluded from consideration are:

a) dispatch control;
b) turbine/generator control (other than turbine demand);
c) combustion controls (covered separately by ANSI/ISA-77.41-1992, Fossil Fuel Power Plant BoilerCombustion Controls);
d) steam distribution control systems;
e) economic loading of boilers; and
f) fluidized bed boilers.

This product replaces:ANSI/ISA 77.43-1994 - Fossil Fuel Power Plant Unit - Plant Demand Development, Drum Type : S77.43