What is the first digit method?
1st Digit Method
What is the first digit method of fire?
First Digit Method: To use the First Digit Method, note the difference between the static pressure and the residual pressure. If that difference is less than or equal to the first number in the static pressure reading, then you can provide three times the initial fire flow.
What is the formula for fire pumping?
The equation EP = NP + FL + APP + ELEV is the basic equation every pump operator needs to calculate when operating the fire pump. Today, many pump panels have flow meters that allow the pump operator to match the readout on the pump panel with the gallon-per-minute (gpm) flow of the selected nozzle.
What is the formula for friction loss in firefighters?
FL = C * (Q / 100) ^2 * L / 100
Where FL = Friction Loss in PSI, C = friction loss Coefficient (or friction loss factor), Q = Flow rate in GPM, and L = hose Length.
What is the formula for pump discharge pressure?
If an R-5 nozzle were added to the end of the hoselay, pump discharge pressure would have to be increased to supply an effective water stream. Solving the formula; PDP = NP +/-H, the result is PDP = 50psi (desired NP) + 50psi (+H), PDP = 100psi.
What method do firefighters use as first method to extinguish a fire?
Firefighters control a fire's spread by removing one of three ingredients fire needs to burn: heat, oxygen, or fuel. They remove heat by applying water or fire retardant on the ground with pumps or wildland fire engines, or by air using helicopters or airplanes.
What are the 4 main stages of fire?
There are four stages of fire development: ignition, growth, fully developed, and decay.
How do you calculate pumping number?
Assuming turbulent flow, Pumping number Nq is estimated based on generic agitator curves. Agitator speed is then determined using relation Nq = Q/ND3, where N is the Agitator speed.
What are the firefighting formulas?
- Iowa Fire Flow: Required Volume = (length X width X height) / 100.
- NFA Fire Flow: Needed Flow = [(Length X Width) / 3] X percent of involvement.
How many GPM is a fire hose?
depends on size of hose and pump pressure. Typical Flows for hand lines - 1 inch hose 30–60 gpm; 1.5 inch hose 125 gpm; 1.75 inch hose 200 gpm; 2.5 inch hose 250–300 gpm. For supply lines depends on the water system, but a 4 inch supply line could be 1000–1500 gpm.
What PSI is a smooth bore nozzle?
Type - Smooth Bore Nozzles typically provide a simple ball-valve "shut-off" with an attached tip - usually a 7/8", 15/16", or 1 1/8". Operating Pressure & Volume Capacity - Smooth Bore Handlines are designed to be pumped at a range of 40-60 psi, with 50 psi being the optimal standard.
How many GPM is a 3 inch fire hose?
While the two 2½-inch setup must account for nearly 50 psi per 100 feet of the supply line with a fire flow of 900 gpm, the two 3-inch setup will allow for a fire flow of 1,500 gpm to be produced with the same amount of friction loss in the supply hoselines.
What is the condensed Q method?
This method is known as Q2 or condensed Q. The process of calculating friction loss in 2½” hose is accomplished by figuring the friction loss as you would for 3” hose and then doubling the result. For example, if the flow in 100 feet of 3” hose is 300 gpm, then the friction loss is 9 psi per 100'.
What is head flow rate?
Flow rate, the quantity of fluid (or volume) that goes through the pump in a specific unit of time. Hydraulic head of a pump, the actual energy that the pump can deliver to the fluid.
What is the suction lift?
A suction lift simply means the maximum level of the liquid to be pumped is physically below the centerline of the pump impeller. Most centrifugal pumps can operate with a suction lift if they are primed first.
What does the C in race stand for?
R.A.C.E.: Remove, Alarm, Confine and Extinguish or Evacuate
R.A.C.E. stands for 'Remove, Alarm, Confine and Extinguish or Evacuate. This easy to remember acronym is our University procedure in the case of a fire.
What are the golden rules when fighting a fire?
Only tackle a fire when it is in its very early stages. Give consideration to your own safety and the safety of other people and make sure you can escape from the fire if you need to. Never let a fire block your exit. Think about the position of yourself, the fire and the escape route.
How many seconds if you Cannot extinguish a fire?
If you cannot put out the fire in 5 seconds, evacuate. On your way out, warn others. Move away from fire and smoke. Close doors and windows behind you, if time permits.
What causes a fire backdraft?
A backdraft (North American English) or backdraught (British English) is the abrupt burning of superheated gases in a fire caused when oxygen rapidly enters a hot, oxygen-depleted environment; for example, when a window or door to an enclosed space is opened or broken.
What colors of fire are the hottest?
Blue flames are the hottest, followed by white. After that, yellow, orange and red are the common colours you'll see in most fires. It's interesting to note that, despite the common use of blue as a cold colour, and red as a hot colour – as they are on taps, for instance – it's the opposite for fire.
What is the cause of most fire deaths?
Most fire deaths are not caused by burns, but by smoke inhalation. Often smoke incapacitates so quickly that people are overcome and can't make it to an otherwise accessible exit.
What is the RPM of an agitator?
Agitator designed for low-viscosity products. The speeds available range from 400 to 1,800 rpm, depending on the diameter, with a typical peripheral velocity of between 3 and 15 m/s. According to the agitator's speed, the agitation system generates a high product recirculation flow rate inside the tank.
How many types of agitators are there?
| Agitator models | Application |
|---|---|
| Disk and cone | Polymers and dispersion preparation |
| Free shaft suspension | Sugar processing |
| Impeller type | Emulsion preparations |
| Turbine agitator Straight blade Pitched blade Vaned disk Curved blade Hydrofoil Impeller | Liquid and gas reactions |
What is scale of agitation?
This 1-to-10 agitation scale is based on the impeller pumping capacity divided by the tank cross-sectional area, resulting in a bulk fluid velocity. This velocity, in feet/minute (ft/min.), then is divided by 6 to obtain the scale of agitation.
What are the 3 P's of firefighting?
That you can take measures to prevent fires entirely? It starts with the 3 Ps: Prevent, Plan & Practice.
