Sizing Your System Example

(Single-Point Injection)

Determine maximum and minimum  flow and pressure for all foam capable discharges:

Maximum:  One deck gun:  500 gpm (1893 l/min) at 150 psi (10.3 bar)

Minimum:   One 1-1/2" line flowing 35 gpm (132 l/min) (mop-up), = 35 gpm (132.5 l/min) at 100 psi (6.9 bar)

 

Determine maximum and minimum foam concentrate levels to be utilized:

Maximum:  1.0% AFFF

Minimum:   0.5% Class A

 

Determine size of proportioner to meet requirements:

Maximum Concentrate Requirement = Maximum flow x maximum concentration

500 gpm (1893 l/min) x 1.0% = 5.0 gpm (18.9 l/min)

Minimum Concentrate Requirement = minimum flow x minimum concentration

35 gpm (132.5 l/min) x 0.5% = 0.18 gpm (.68 l/min)

 

Determine proper plumbing size and FoamPro flowmeter tee to cover range of flows in the first step:

A 3" diameter pipe will be used to supply these discharges.  The 3" flowmeter will accurately read

between 30 gpm (113.6 l/min) and 1150 gpm (4353 l/min).  The required range is 35 gpm to

500 gpm (132.5 - 1893 l/min).  Therefore, one flowmeter in a 3" tee will handle the requirements. 

If the flows should exceed the capacity of the flowmeter tee, then the installation would require two

or more appropriate size flowmeters and a MultiFlo.