How to Choose the Wall Thickness of a Polycarbonate Tube? A Practical Guide
Choosing the correct wall thickness of a polycarbonate (PC) tube is one of the most important steps in designing pressure systems, technical enclosures and industrial structures. A wall that is too thin risks tube failure, while one that is too thick unnecessarily increases costs. In this article we present a proven formula, a calculation example and production tolerances to help you select a polycarbonate tube safely and economically.
How to Choose the Wall Thickness of a Polycarbonate Tube? A Practical Guide
Choosing the correct wall thickness of a polycarbonate (PC) tube is one of the most important steps in designing pressure systems, technical enclosures and industrial structures. A wall that is too thin risks tube failure, while one that is too thick unnecessarily increases costs. In this article we present a proven formula, a calculation example and production tolerances to help you select a polycarbonate tube safely and economically.
Why Does the Wall Thickness of a Polycarbonate Tube Matter?
Polycarbonate tubes (PC) are characterised by high impact resistance, mechanical strength and weather resistance, making them ideal where a standard acrylic tube would be too brittle. Despite their high strength, every tube has limits that depend on:
- the operating pressure of the system,
- the inner and outer diameter of the tube,
- the operating temperature,
- environmental conditions (UV, chemicals, dynamic loads).
To ensure a safe installation, the designer should calculate the minimum wall thickness and then select a tube with an appropriate safety margin.
Formula for the Permissible Pressure of a Polycarbonate Tube
The following formula is used to calculate the permissible internal pressure:
P₁ = (100 · S) / D¹
Condition of applicability: D⁰ / D¹ ≤ 1.2
Symbols
- P₁ – permissible pressure [bar]
- S – wall thickness [mm]
- D¹ – inner diameter of the tube [mm]
- D⁰ – outer diameter of the tube [mm]
Step-by-Step: Calculating the Wall Thickness of a Polycarbonate Tube
To determine the minimum wall thickness, rearrange the formula:
S = (P₁ · D¹) / 100
- Determine the maximum operating pressure of the system (in bar).
- Select the inner diameter suitable for the flow or application.
- Insert values into the formula and calculate the minimum wall thickness.
- Check the design condition D⁰ / D¹ ≤ 1.2.
- Account for production tolerances and a safety margin.
Calculation Example – PC Tube at 8 bar Pressure
Assumptions:
- Operating pressure: 8 bar
- Inner diameter: 40 mm
Calculation: S = (8 · 40) / 100 = 3.2 mm
Practical recommendation: After accounting for production tolerances and the safety margin, use a polycarbonate tube with a wall thickness of 4–5 mm.
Production Tolerances for Polycarbonate Tubes
Tube diameter | Tolerance |
|---|---|
Ø 7–64 mm | ±5% |
Ø 70–100 mm | ±8% |
Ø 110–200 mm | ±10% |
Ø 220–250 mm | ±15% |
Key Tips for Selecting a Polycarbonate Tube
- Always account for tolerances – nominal dimensions rarely match actual dimensions.
- Add a safety margin of 10–30%, depending on the criticality of the application.
- Check operating conditions – higher temperatures reduce the strength of polycarbonate.
- Do not design at the limit – installations at the edge of load capacity age faster.
- Pay attention to the working environment – UV radiation and aggressive chemicals accelerate degradation.
FAQ – Frequently Asked Questions about Polycarbonate Tubes
How do I select the wall thickness of a polycarbonate tube?
Use the formula S = (P₁ · D¹) / 100, then account for production tolerance and an appropriate safety margin.
Can I select the wall thickness without calculations?
As an approximation, yes — but for technical and pressure applications calculations are always recommended.
Why must production tolerances be taken into account?
Because the actual wall thickness may be smaller than the nominal value, directly affecting resistance to internal pressure.
Does temperature affect the strength of polycarbonate tubes?
Yes. Higher temperatures reduce mechanical strength, so installations above 20 °C should incorporate an additional safety margin.
What safety margin should be applied when selecting a PC tube?
Typically 10–30%, depending on the application, operating conditions and the safety requirements of the project.
Summary
Correctly selecting the wall thickness of a polycarbonate tube is key to a safe, durable and cost-effective installation. Apply the formula S = (P₁ · D¹) / 100, account for tolerances and safety margin, and your construction will meet the intended operating conditions.
Erson offers a wide selection of polycarbonate (PC) tubes in various diameters and wall thicknesses. Need help? Contact our technical advisor — we will help you choose the right tube for your application.