Nfpa 291 Hydrant Flow Testing

NFPA 291 HYDRANT FLOW TESTING Fire Flow Testing and Marking of Hydrants

4.2 Procedure •

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Tests should be made during period of ordinary demand. One hydrant, designated the RESIDUAL hydrant, is chosen to be the hydrant where the normal static pressure will be observed with the other oth er hydr hydrants ants in the group closed, and where the residual pressure p ressure will be observed with the other hydr hydrants ants flowing.

FIGURE 4.3.4

SECTION 4.3.6 •

To obtain satisfactory test results of theoretical calculation of expected flows or rat rated ed capacities, achieved to causesufficient a drop indischarge pressure should at the be residual hydrant hydrant of at least 25 percent, or to flow the total demand necessary n ecessary for firefirefighting purposes.

4.5 Test Procedure