1. What is a Water Supply Pipe Sizing Calculator?

Definition: This calculator determines the appropriate pipe diameter for water supply systems based on flow rate, maximum velocity, and a dimensionless constant.

Purpose: It helps engineers and plumbers select the correct pipe size to ensure adequate water flow while maintaining optimal velocity.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( D \) — Pipe diameter (mm)
• \( Q \) — Flow rate (L/s)
• \( v_{max} \) — Maximum velocity (m/s)
• \( C \) — Dimensionless constant (typically 35.7)

Explanation: The formula calculates the minimum pipe diameter needed to maintain the desired flow rate without exceeding the maximum recommended velocity.

3. Importance of Proper Pipe Sizing

Details: Correct pipe sizing ensures efficient water delivery, prevents excessive pressure drops, reduces pumping costs, and minimizes water hammer effects.

4. Using the Calculator

Tips: Enter the flow rate in L/s, maximum velocity (default 2.5 m/s), and constant (default 35.7). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What is a typical maximum velocity for water pipes?
A: For residential systems, 2.5 m/s is common. For industrial systems, up to 3 m/s may be used.

Q2: Why is the constant 35.7?
A: This value accounts for unit conversions and is derived from the relationship between flow rate, velocity, and pipe diameter.

Q3: When would I change the maximum velocity?
A: Adjust for different applications - lower for quiet operation, higher for short pipe runs where noise isn't a concern.

Q4: How do I find the flow rate for my system?
A: Calculate based on fixture units or estimate using peak demand for the number of fixtures served.

Q5: Does this account for pressure loss?
A: No, this calculates minimum diameter based on velocity only. Pressure loss calculations should be performed separately.