Chapter hvac engineering Fundamentals: Part 1 Introduction

7.3.1
Steam plant controls
In a very small steam system, a space thermostat may cycle the boiler
on and off, and the steam drum-level control will activate the feed-
Design Procedures: Part 5
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Design Procedures: Part 5
195
water pump. In a more complex system, the boiler(s) will maintain a
constant steam pressure in the main header, and a pressure control
will modulate the fuel input to match the load. For multiple-boiler
operation, there may be a plant master control which will apportion
the load to the several boilers on a proportional or a programmed
basis.
7.3.2