Which coupling type is most commonly used on Large Diameter Hose (LDH)?

The Storz coupling is the most commonly used type for Large Diameter Hose (LDH) due to its design, which allows for quick and easy connections without the need for threading. This feature is particularly advantageous in emergency situations where time is critical, as it can be connected and disconnected rapidly with a simple twist and lock mechanism.

Storz couplings are also known for their robust and secure connection, which minimizes the risk of leakage under high-pressure conditions that are typical in firefighting operations. This makes them ideal for the large volumes of water transported through LDH. Their flat surfaces also allow for easier handling and alignment, especially in challenging conditions.

Other coupling types, such as cam-locks and threaded couplings, are less common for LDH due to their slower connection process and potential for failure under high pressures. Flange couplings are typically used in specific industrial applications and are not standard for flexible fire hose operations.