ISA 77.43 PDF

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

This Standard will address two types of process applications:

1) a single boiler supplying a single turbine, typical of an electric utility power plant; and

2) a single boiler or multiple boilers supplying a common distribution header, typical of an industrial power plant.

Specifically excluded from consideration are:

1) dispatch control;

2) turbine/generator control (other than turbine demand);

3) combustion controls (covered separately by ISA-S77.41, Fossil Fuel Power Plant Boiler Combustion Controls);

4) steam distribution control systems;

5) economic loading of boilers; and

6) fluidized bed boilers.