1. What is HDPE Pipe SDR?

The Standard Dimension Ratio (SDR) is a method for rating pressure piping based on the dimension ratio of the pipe's outer diameter to its wall thickness. It is commonly used for HDPE (High-Density Polyethylene) pipe sizing and pressure rating.

2. How Does the Calculator Work?

The calculator uses the SDR formula:

Where:

• \( SDR \) — Standard Dimension Ratio (unitless)
• \( D \) — Outer diameter (mm)
• \( t \) — Wall thickness (mm)

Explanation: The SDR value determines the pressure rating of HDPE pipes, with lower SDR numbers indicating thicker walls and higher pressure ratings.

3. Importance of SDR Calculation

Details: Accurate SDR calculation is crucial for proper pipe selection, ensuring the pipe can handle the required pressure while maintaining structural integrity and longevity.

4. Using the Calculator

Tips: Enter the outer diameter and wall thickness in millimeters. Both values must be positive numbers greater than zero.

5. Frequently Asked Questions (FAQ)

Q1: What is the relationship between SDR and pressure rating?
A: Lower SDR numbers indicate thicker walls relative to diameter, resulting in higher pressure ratings for the pipe.

Q2: What are common SDR values for HDPE pipes?
A: Common SDR values include SDR 11, SDR 17, and SDR 26, each with different pressure ratings and applications.

Q3: Can SDR be used for other pipe materials?
A: While SDR is primarily used for plastic pipes like HDPE, the concept can be applied to other materials, though specific standards may vary.

Q4: How does temperature affect SDR calculations?
A: Temperature affects material properties, so pressure ratings based on SDR may need adjustment for different operating temperatures.

Q5: Are there limitations to SDR-based pipe selection?
A: SDR provides a standardized rating but doesn't account for all factors like installation conditions, soil loads, or chemical compatibility.