Fpe Calculator

Step-by-Step Guide to Using the FPE (Fire Protection Engineering) Calculator

This guide will help you navigate the FPE Calculator to determine essential parameters such as flow velocity, friction loss, and Reynolds number for your fire protection engineering needs. Make sure to have all necessary inputs at hand before you begin.

Step 1: Input the Flow Rate

Label: Flow Rate (Q) in GPM
Enter the flow rate in gallons per minute (GPM) in the “Flow Rate” field. This is a required field, and you must input a value greater than or equal to 0.

Step 2: Input the Pressure

Label: Pressure (P) in PSI
Enter the pressure in pounds per square inch (PSI) in the “Pressure” field. This field is required and should also have a value greater than or equal to 0.

Step 3: Select the Nominal Pipe Size

Label: Nominal Pipe Size
Choose the nominal pipe size from the dropdown menu. Available options are:

• 1 inch
• 1.25 inch
• 1.5 inch
• 2 inch
• 2.5 inch
• 3 inch
• 4 inch
• 6 inch
• 8 inch

Selecting a pipe size is mandatory for the calculations.

Step 4: Select the Pipe Type

Label: Pipe Type
Choose the pipe type from the provided options. The available pipe types are:

• Schedule 40 Steel
• Schedule 10 Steel
• Copper Type L
• CPVC

This selection is also required.

Step 5: Input the Pipe Length

Label: Pipe Length (L) in feet
Enter the length of the pipe in feet in the “Pipe Length” field. A value greater than or equal to 0 is required for accurate calculations.

Step 6: View the Calculated Results

Once all the necessary inputs are filled in, the calculator will automatically compute the following results:

• Flow Velocity: Calculated using the formula (0.4085 * flowRate) / pow(pipeSize, 2), displayed in ft/s, rounded to two decimal places.
• Friction Loss per 100ft: Determined by the formula 4.52 * pow(flowRate, 1.85) / (pow(pipeType, 1.85) * pow(pipeSize, 4.87)), displayed in psi/100ft, and rounded to three decimal places.
• Total Friction Loss: Calculated with the formula (frictionLoss * pipeLength) / 100, displayed in psi, rounded to two decimal places.
• Equivalent Length: Using the formula (pressure * 100) / frictionLoss, shown in feet, rounded to two decimal places.
• Reynolds Number: Evaluated with velocity * pipeSize * 3700, displayed without decimals.

Ensure all inputs are accurately entered to receive reliable and precise results. This calculator can significantly aid in your fire protection engineering calculations by providing key performance metrics of your piping system.