What must be permanently marked on nozzles to identify their type?

Nozzles in fire protection systems must have permanent markings that indicate their type for several important reasons. The primary function of these markings is to provide clear, durable identification that can withstand the operational environment. This is crucial because fire protection equipment is utilized in high-stress scenarios, including extreme heat or exposure to substances that could wear down less robust identifiers.

Permanent markings ensure that first responders and maintenance personnel can quickly and accurately identify the specific nozzle type during emergency situations or routine inspections. This identification helps ensure that the correct nozzle is being used for a given application, aiding in optimal performance and safety.

While brand names, manufacturer's labels, and model numbers can provide some level of identification, they may not be sufficient for quick identification under pressure, especially if they are subject to fading or damage over time. Permanent markings serve the essential purpose of ensuring unambiguous and lasting identification of nozzles, which is vital for effective fire protection practices.