What is the working pressure range of the fire hose nozzle

What is the working pressure range of the nozzle?
The working pressure range of the fire hose nozzle refers to the pressure range that the nozzle can withstand and stably output water flow under normal use conditions. This range determines the nozzle's water spraying effect, applicable scenarios, matching of the connection system, and safety of use. The unit is usually expressed in "psi" (pounds per square inch) or "bar". For different types of nozzles, such as direct current water guns, adjustable nozzles, atomizing nozzles, multi-function nozzles, etc., the design of their working pressure ranges is also different.

Common working pressure range (psi/bar) classification
Low-pressure nozzles (30–100 psi / 2–7 bar)
Applicable to urban fire hydrant systems, tap water supply systems, and fixed water sources in some factory areas. Low-pressure nozzles are mostly used for training, light firefighting tasks, and early control of small and medium-sized fire sources. It has the characteristics of easy operation, small recoil, and safe use. It is suitable for novice operation or scenarios with low requirements for water spraying distance.
Medium-pressure nozzle (100–200 psi / 7–14 bar)
This is the most commonly used fire nozzle working pressure range on the market. It is widely used in municipal firefighting, industrial storage, residential high-rise buildings and forest fire truck systems. Medium-pressure nozzles have a long range and good water mist diffusion effect. They can be used for fixed-point firefighting, cooling and smoke isolation. It is the pressure range with the most balanced comprehensive performance.
High-pressure nozzle (200–400 psi / 14–28 bar)
High-pressure nozzles are mainly used for special purposes, such as long-distance firefighting, oil tank area cooling, chemical leak fire control and other scenarios. This type of nozzle can be used with a high-pressure pump system to provide extremely strong water column penetration and atomization coverage, suitable for extinguishing high-temperature, strong combustion, violent volatilization, and easy to reignite fire sources. High-pressure nozzles are usually equipped with pressure-resistant materials and seismic-resistant structures to ensure that they are stable and reliable under continuous operation.
Ultra-high pressure nozzles (above 400 psi / above 28 bar)
Mainly used in industrial pipeline cleaning, tunnel fire fighting, ship fire fighting systems or military emergency equipment. Most of these nozzles are customized products, which need to be equipped with special high-pressure hoses and pump station systems, with extreme pressure bearing capacity and precise control capabilities.

Nozzle pressure level and system matching
The working pressure design of the nozzle must be matched with the entire water supply system (including water pumps, water hoses, joints, valves, etc.). Too low pressure will lead to insufficient water mist diffusion and reduced fire extinguishing efficiency; too high pressure may cause nozzle structural damage, water hose burst or operator injury. Therefore, choosing a nozzle with a suitable working pressure range is a prerequisite for ensuring fire safety and operational efficiency.
Major standard organizations such as NFPA (National Fire Protection Association), EN (European Standards), and GB (Chinese National Standards) have strict requirements on the rated pressure and test pressure of nozzles. For example, when the rated working pressure of the nozzle is 150 psi, the hydrostatic pressure test it passes usually needs to reach more than 300 psi to verify its safety margin.