What do tri cocks or gauge cocks indicate on a steam boiler?

Tri cocks, or gauge cocks, on a steam boiler play an essential role in providing insight into the actual water level within the boiler. They are small valves located at different levels on the boiler that allow operators to sample the water inside the boiler. By opening these cocks, you can confirm whether the water level is above or below the specific points where the cocks are installed.

The presence of water at the tri cocks indicates the true water level, giving operators a visual indication that aids in monitoring the boiler’s water level effectively. Maintaining the appropriate water level is crucial for safe operation, preventing issues such as overheating or boiler damage. This is why the primary function of tri cocks is closely associated with indicating the true water level rather than any other parameters like steam flow rate, temperature, or pressure, which are monitored through different instruments.