Chapter 7 - Fireground Hydraulic Calculations

What is the primary function of a flowmeter?

Determine the direct flow from a discharge

Based on NFPA 1900, every pumper discharge that has a flowmeter must be provided with a(n):

Pressure gauge

Flowmeters must display flow in increments of ___ or less

10 gpm (40 L/min)

With proper calibration, a flowmeter in good condition should be accurate to a tolerance of plus or minus:

5%

Which is a potential issue the D/O may identify while diagnosing water flow problems in standpipe systems while using a flowmeter?

Restrictor plates or discharge valves left open

One advantage of using a flowmeter with an automatic nozzle on a hoseline or master stream device is the ability of the D/O to:

Verify the correct gpm (L/min)

During relay pumping operations, the intake pressure should not drop below:

20 psi (140 kPa)

For FDC operations to be effective, the D/O must know the number of nozzles and lines deployed, prefire planning specific to the structure, and:

The departmental SOPs used

When firefighters shut down a nozzle on an apparatus equipped with a discharge relief valve, the discharge pressure is recirculated to:

The pump’s intake

When flow through a hoseline is reduced, such as a nozzle being shut, apparatus equipped with electronic pressure governors set in the RPM mode will:

Not compensate for the reduced flow

What tool can be used to determine the PDP required for virtually any hose layout?

Hydraulic calculator

What type of hydraulic calculator consists of a slide or dial that can be moved to cover or reveal rates of flow, size of hose, and length of hose layout?

Manual

At what point should pressure governor preset calculations be performed?

Before an incident response

Fire departments often develop ___ that contain information specific to their jurisdiction’s equipment and common hose layout operations

Pump charts