City:

Formula: Q=(29.83(C(d2)p0.5)) Formula: AFF=Q(((S-20)0.54/((S-R)0.54)))

diameter (d)
Q (total of outlet Number of Available
Test gallons Coefficient flowed in outlets Pitot Fire Flow Total Gallons Residual Witnessed
No. Location flowing) 29.83 C = .9 inches flowing (p) (AFF) Flowing Static (S) (R) Test Date By
1 0 29.83 0.9 2.5 1 - 0
2 0 29.83 0.9 2.5 1 - 0
3 0 29.83 0.9 2.5 1 - 0
4 0 29.83 0.9 2.5 1 - 0
5 0 29.83 0.9 2.5 1 - 0
6 0 29.83 0.9 2.5 1 - 0
7 0 29.83 0.9 2.5 1 - 0
8 0 29.83 0.9 2.5 1 - 0
9 0 29.83 0.9 2.5 1 - 0
10 0 29.83 0.9 2.5 1 - 0
11 0 29.83 0.9 2.5 1 - 0
12 0 29.83 0.9 2.5 1 - 0
13 0 29.83 0.9 2.5 1 - 0
14 0 29.83 0.9 2.5 1 - 0
15 0 29.83 0.9 2.5 1 - 0
16 0 29.83 0.9 2.5 1 - 0
17 0 29.83 0.9 2.5 1 - 0
18 0 29.83 0.9 2.5 1 - 0
19 0 29.83 0.9 2.5 1 - 0
20 0 29.83 0.9 2.5 1 - 0
21 0 29.83 0.9 2.5 1 - 0
22 0 29.83 0.9 2.5 1 - 0
23 0 29.83 0.9 2.5 1 - 0
24 0 29.83 0.9 2.5 1 - 0
25 0 29.83 0.9 2.5 1 - 0
26 0 29.83 0.9 2.5 1 - 0
27 0 29.83 0.9 2.5 1 - 0
28 0 29.83 0.9 2.5 1 - 0
29 0 29.83 0.9 2.5 1 - 0
30 0 29.83 0.9 2.5 1 - 0
Some cells are protected to prevent the formulas from being changed by
accident. To change any protected cell simply go to the Review tab and select
"Unprotect Sheet." There is no password.
The values for coefficient, diameter of outlet, and number of outlets flowing are
set to typical defaults but may be changed by the user as required.

For each flow test, enter the location, pitot pressure, static pressure, residual
pressure, test date, and witness name. The spreadsheet will calculate the
total gallons flowing (Q) and the available fire flow at 20 psi residual pressure.
Save the spreadsheet to document your flow tests.
Note: The worksheet is protected to help keep the formulas from being
changed, but there is no password. To edit the spreadsheet, go to the Review
tab in the ribbon bar and select Unprotect Sheet. To add rows to the
spreadsheet, simply unprotect the sheet and copy the formulas to additional
rows.
The "Q" formula [Q=(29.83(C(d 2)p0.5))] is used by ISO and others to calculate
water flowing during a flow test.
The Hazen-Williams formula [Available Fire Flow=Q(((S-20) 0.54/((S-R)0.54)))] is
used by ISO and others to determine the available fire flow at 20 psi residual
pressure.

The user needs four pieces of data to use this spreadsheet: the static
pressure, the residual pressure, the pitot pressure, and the sixe of the opening
flowing. Generally, the 2.5" opening is used during a flowtest. Enter this
information in the spreadsheet and the spreadsheet will calculate total gallons
flowing during the test and the available fire flow at 20 psi residual pressure.
Enter the address for documentation purposes. The spreadsheet lets you
save test results for later reference.

Coefficient refers to the factor used for the type of opening in the fire hydrant
inside the barrel. Most fire hydrants have a rounded opening where the outlet
and barrel join. Such hydrants have a coefficient of 0.9. Hydrants with square
outlets have a coefficient of 0.8. Hydrants with a square outlet that projects
into the barrel have a coefficient of 0.7. Feel inside the opening and use the
correct coefficient for the hydrant being flowed. These coefficients are valid for
hydrant outlets of less than 4 inches. The spreadsheet does not make
calculation adjustments for using the pumper outlet for the flowtest. Refer to
NFPA 291, Recommended Practice for Fire Flow Testing and Marking of
Hydrants for more information.
ITEM 621 - CREDIT FOR HYDRANTS (CH)
Number of
Item Description of hydrant hydrants Points Score
620
A.
6-inch or larger branch and a
pumper outlet, with or without
2.5" outlets; or with a 6 inch or
larger dry hydrant installed in
accordance with the general
criteria of the applicable standard 0 100 0
620
B. 6-inch or larger branch, no pumper
outlet, but with two or more 2.5"
outlets, or with small foot valve, or
with a barrel less than 5 inches in
diameter 0 75 0
620
C. With only one 2.5" outlet 0 25 0
620
D. With less than a 6-inch branch 0 25 0
620
E. Flush type (flush or ground level) 0 25 0
620
F. Cistern or suction point 0 25 0
TOTAL 0 0.00
Credit for hydrants (CH) [Maximum out of 3 points] 0.00

This spreadsheet will calculate the credit available from ISO for the
number and type of fire hydrants in your community. Enter the number
of each type of hydrant in the blue cells. Refer to Section 620 in the ISO
Fire Suppression Rating Schedule for complete details on the types of
fire hydrants eligible for credit.