New Jersey Black Seal Low Pressure Practice Exam 2025 - Free Black Seal Exam Practice Questions and Study Guide

The most common type of pressure control device used in boiler systems is the mercury tube. This device is a traditional method for measuring and controlling pressure due to its simplicity and reliability. It operates by using a column of mercury that rises and falls in relation to the pressure changes within the boiler system.

The mercury tube's direct measurement allows for a clear indication of pressure levels, which is crucial for ensuring the safe and efficient operation of boilers. Furthermore, since water and steam systems often operate under varying pressure conditions, the accuracy and responsiveness of a mercury tube pressure control device are valuable for maintaining operational safety.

While other devices like pneumatic valves and digital pressure sensors are also used in some scenarios, the mercury tube has long been a standard in many boiler applications due to its straightforward design and effectiveness in pressure monitoring.