What is indicated by a notch on coupling threads?

A notch on coupling threads identifies a Higabee, which is a specific marking or design feature on fire service equipment that helps firefighters quickly and accurately align and connect hose couplings. The purpose of the Higabee is to facilitate proper engagement of the threads for a secure connection, which is crucial for ensuring a tight seal and preventing leaks during firefighting operations.

This marking helps in ensuring that the couplings can be attached or detached easily, particularly in low-visibility conditions or under stressful circumstances where time is critical. It serves as a visual cue to indicate proper threading alignment, thus promoting safety and efficiency in emergency situations.

Notches or similar identifiers are not typically used to denote safety seals, flow indicators, or pressure limits, as those features are concerned with different aspects of safety and functionality in fire equipment. The presence of a Higabee enhances the operational readiness of firefighting teams by ensuring they can quickly and efficiently connect their equipment, critical for effective firefighting response.