What is indicated by the Higbee indicator on couplings?

The Higbee indicator plays a crucial role in ensuring the proper alignment of threaded couplings during the connection of hoses. Specifically, it marks the start of the first thread in the coupling, providing a visual alignment aid that helps firefighters securely connect hoses quickly and efficiently. This is particularly important in high-pressure situations where speed and accuracy are vital for safety and effectiveness.

By allowing users to identify the correct position to start threading, the Higbee indicator minimizes the risk of cross-threading or improper connections, which can potentially lead to leaks or failures under pressure. Understanding the function of this indicator is essential for firefighters to ensure smooth operations during fire suppression efforts.