Hdpe Pipe Flow Rate Calculator

High-Density Polyethylene (HDPE) pipes are widely used in water supply, irrigation, sewage, and industrial applications due to their durability, flexibility, and resistance to corrosion. Accurately calculating the flow rate capacity of an HDPE pipe is essential for designing efficient piping systems and ensuring they meet operational demands.

This calculator determines the volumetric flow rate of fluid passing through an HDPE pipe based on the pipe's internal diameter and the fluid's flow velocity. It provides results in several common units for practical engineering and agricultural use.

HDPE Flow Rate Estimator

function calculateHDPEFlow() { // Get input values var diameterMM = parseFloat(document.getElementById("hdpe_diameter").value); var velocityMS = parseFloat(document.getElementById("hdpe_velocity").value); var resultDiv = document.getElementById("hdpe_result"); // Validate inputs if (isNaN(diameterMM) || diameterMM <= 0 || isNaN(velocityMS) || velocityMS <= 0) { resultDiv.style.display = "block"; resultDiv.innerHTML = "Please enter valid positive numbers for both diameter and velocity."; return; } // — CALCULATION LOGIC — // 1. Convert Diameter from millimeters (mm) to meters (m) var diameterMeters = diameterMM / 1000; // 2. Calculate Radius in meters var radiusMeters = diameterMeters / 2; // 3. Calculate Cross-Sectional Area in square meters (A = π * r^2) var areaSqMeters = Math.PI * Math.pow(radiusMeters, 2); // 4. Calculate Base Flow Rate (Q = A * v) in Cubic Meters per Second (m³/s) var flowM3S = areaSqMeters * velocityMS; // — UNIT CONVERSIONS — // Convert to Cubic Meters per Hour (m³/h) // 1 m³/s = 3600 m³/h var flowM3H = flowM3S * 3600; // Convert to Liters per Second (L/s) // 1 m³ = 1000 Liters var flowLS = flowM3S * 1000; // Convert to Liters per Minute (L/min) var flowLMin = flowLS * 60; // — DISPLAY RESULTS — resultDiv.style.display = "block"; resultDiv.innerHTML = "

Flow Rate Results:

" + "Cubic Meters per Hour: " + flowM3H.toFixed(2) + " m³/h" + "Liters per Second: " + flowLS.toFixed(2) + " L/s" + "Liters per Minute: " + flowLMin.toFixed(2) + " L/min" + "

---

" + "Based on a calculated internal pipe cross-sectional area of " + areaSqMeters.toFixed(5) + " m²."; }

Understanding HDPE Pipe Flow Rate Calculations

The flow rate through a pipe is a measure of the volume of fluid that passes a specific point in a given amount of time. The fundamental formula used in this calculator is the continuity equation for incompressible fluids:

Q = A × v

Where:

• Q = Volumetric Flow Rate (e.g., m³/s)
• A = Cross-sectional Area of the pipe's interior (m²)
• v = Average Fluid Velocity (m/s)

Importance of Inner Diameter (ID)

Crucially, HDPE pipes are often specified by their Outside Diameter (OD) and Standard Dimension Ratio (SDR), which determines wall thickness. To get an accurate flow calculation, you must use the Inner Diameter (ID). The ID is the calculated area where the water actually flows. Using the OD will result in a significant overestimation of the flow rate.

The area (A) of the circular pipe is calculated using the formula: A = π × (ID/2)².

Fluid Velocity Considerations

Velocity is the speed at which the water travels through the pipe. While higher velocities allow for smaller pipes to carry more water, excessively high velocities can lead to:

• Increased friction loss (pressure drop).
• Water hammer issues (pressure surges when flow stops suddenly).
• Increased wear on the pipe interior over time.

For general water supply applications, a design velocity between 1.0 m/s and 2.0 m/s is often considered good practice to balance efficiency and head loss.

Example Calculation

Let's assume you are designing an irrigation system using an HDPE pipe. You have determined that the specific pipe you are using has an actual Inner Diameter (ID) of 90 mm. Based on your pump specifications and system design, you expect a water velocity of 1.5 m/s.

Using the calculator above:

1. Input 90 into the "HDPE Pipe Inner Diameter (mm)" field.
2. Input 1.5 into the "Fluid Velocity (m/s)" field.
3. Click "Calculate Flow Rate".

The calculator determines the area is approximately 0.00636 m² and yields the following results:

• 34.35 m³/h (Cubic meters per hour)
• 9.54 L/s (Liters per second)
• 572.55 L/min (Liters per minute)

This means your 90mm ID pipe operating at that velocity can deliver approximately 34 cubic meters of water every hour.