What is the typical flow range and the corresponding constant nozzle pressure range for master stream automatic fog nozzles?

What is the typical flow range and the corresponding constant nozzle pressure range for master stream automatic fog nozzles?

• A. 100-800 gpm; 60-80 psi
• B. 150-1250 gpm; 100-105 psi
• C. 200-1500 gpm; 120-140 psi
• D. 50-500 gpm; 80-100 psi

Answer: (B)

Master stream automatic fog nozzles are designed to deliver a wide range of water flow while keeping the discharge pressure around a steady, relatively low level. This makes it easier for the operator to predict performance and maintain the desired spray pattern as flow is increased or decreased. The typical pairing is a flow range from about 150 to 1250 gpm with a constant nozzle pressure of roughly 100 to 105 psi. At the low end, you’re opening the nozzle enough to deliver larger volumes than a handline, while at the high end you can reach up to about 1250 gpm without pushing nozzle pressure well above 100 psi. The slight variation to 105 psi accounts for minor system losses and variations in setup. Other ranges either fall short of what a master stream handles (too small a flow) or require nozzle pressures well above what these nozzles are designed to maintain, which can alter pattern, reach, and equipment wear.

Master stream automatic fog nozzles are designed to deliver a wide range of water flow while keeping the discharge pressure around a steady, relatively low level. This makes it easier for the operator to predict performance and maintain the desired spray pattern as flow is increased or decreased.

The typical pairing is a flow range from about 150 to 1250 gpm with a constant nozzle pressure of roughly 100 to 105 psi. At the low end, you’re opening the nozzle enough to deliver larger volumes than a handline, while at the high end you can reach up to about 1250 gpm without pushing nozzle pressure well above 100 psi. The slight variation to 105 psi accounts for minor system losses and variations in setup.

Other ranges either fall short of what a master stream handles (too small a flow) or require nozzle pressures well above what these nozzles are designed to maintain, which can alter pattern, reach, and equipment wear.