New York Low Pressure Boiler COF Practice 2026 - Free Practice Questions and Study Guide

In a typical low-pressure boiler system, one expansion tank is generally sufficient to accommodate the thermal expansion of the water within the entire system, regardless of the number of boilers present. The main purpose of the expansion tank is to absorb excess pressure changes caused by water expanding as it heats up.

Having a single expansion tank simplifies the system design and maintenance while effectively managing the pressure changes that occur due to temperature variations in the water across all six boilers. It is designed to allow for the thermal expansion of the water without allowing pressure build-up that could lead to damage or safety concerns.

Additional expansion tanks might be needed in some specific scenarios, such as if the system has distinct zones with separate flow patterns or if the volume of water in the system is particularly large or complex, but these situations are exceptions rather than the norm. Hence, in most standard applications with six boilers, a single expansion tank is adequate and effective.