What pressure should be pumped to automatic nozzles?
Automatic nozzles greatly simplify pump operation. Since automatic nozzles are designed to operate at 100 psi nozzle pressure, this becomes the minimum starting point for any operation.
The basic formula for calculating pump discharge pressure is PDP=NP+TPL-PDP is the pump discharge pressure, NP is the nozzle pressure and TPL is the total pressure loss (that's hose line friction loss plus apparatus friction loss plus elevation pressure).
With an automatic, the nozzle pressure will remain constant and the formula can be rewritten as: PDP = 100 + TPL. So, for a 200-foot pre-connected 1 3/4-inch hose, what pump pressure will be required to flow 150 gpm? Friction loss in 1 3/4-inch hose for 150 gpm is about 28 psi per 100 feet of hose.
The answer: PDP = 100 + (2 x 28); PDP = 100 + 56; PDP = 156.
To flow 150 gpm in this scenario, a pump discharge pressure of 156 psi is required. The required pump pressure will vary depending on the friction loss produced, the amount of flow desired, and the length and size of the hose lay.
The advantage of using an automatic nozzle is that any flow can be delivered by the pump operator and still be controlled by the nozzle operator. Variable flow, constant nozzle pressure, and nozzleman flow control are three essential elements to successful fire streams and fire attack.
FOREDE® products with wide range and include Fire Sprinkler Systems, Fire Nozzles, Fire Monitors, Foam Equipment, Foam Systems, Fire Hydrant &Valves, General Valves, Fire Fittings, Water Delivery Equipment. Fire Fighting Foam and much more. If you have any demands for the fire fighting equipments, welcome to contact FOREDE.
Contact person: Seth Yuan
Email: sales5@forede.com
Whatsapp: +86 132 1506 5797
