Fire Hydrant Flow Test Formula

The rated capacity calculation is useful in determining the total water supply at a given point in the hydrant or water main.

Fire hydrant flow test formula.

Secondary psi before flowing. Water main pressures are recorded by conducting a residual fire flow test per nfpa 291. Use this when fire flow testing hydrants. Hydrant flow test procedures 4.

Residual testing requires at least 2 hydrants. The example below enables you to find the predicted flow rate at 20 psi residual pressure. The calculation offers more useful information than the test flow by itself and is used by insurance underwriters. Determine outlet nozzle coefficient 5.

Fire hydrants are tested regularly to ensure that they are capable of providing water at an acceptable pressure and flow rate foe public health and firefighting operations. A fire hydrant flow test is a process of flowing water out of at least one fire hydrant while obtaining the required pressures static residual and pitot needed to calculate the amount of water in gallons per minute gpm that the water system is capable of providing between the tested hydrants. One person at residual hydrant one at the flow hydrant b. Then an adjacent flow hydrant is opened and flow rates are measured at the same time the residual pressure is recorded on the residual.

This is the static pressure p s. Secondary psi while flowing. The calculation offers more useful information than the test flow by itself and is used by insurance underwriters. Then hydrant 1 is opened so that water discharges from it.

The main can be expected to flow about. The hydrant flow test calculator measures the rated capacity at 20 psi of a fire hydrant. Fire hydrant flow test determine the flow rate and pressure in any location through out a water company s or water authority s underground water distribution system. Referring to the figure prior to flowing hydrant 1 pressure is measured at hydrant 2.

This hydrant is flowing. Print this page send by email. 52 fire hydrant flow and pressure tests fire hydrants are tested to determine flow and pressure. Fire hydrant flow test results calculator.

Take readings simultaneously after pressure at the residual hydrant has stabilized d. Conduct the flow test a. Measure record i d. The hydrant flow test calculator measures the rated capacity at 20 psi of a fire hydrant.

Static pressure is taken on a residual hydrant with other hydrants closed. Qr qf x hr 0 54 hf 0 54 qr flow rate predicted at the desired residual pressure in gpm. The rated capacity calculation is useful in determining the total water supply at a given point in the hydrant or water main. Home information tools knowledgebase fire hydrant flow test results calculator.

Open flow hydrant fully c. Computes the flow rate available at a specified residual pressure a k a.