In the field of water filtration systems, component reliability is never a matter of chance. A filter failure can cause serious damage. Material, geometry and wall thickness determine a product’s ability to withstand real operating conditions over time: variable pressures, fluctuating temperatures and cyclic stress.

The image below shows a polyethylene filter from a competing product that suffered a longitudinal crack, a typical case of structural failure caused by pressure in the water network.

At first glance, the filter looks similar to GWS products. The difference, however, is far from negligible:

• Competitor filter wall thickness: 3 mm
• GWS filter wall thickness: 5 mm

The filter body has a diameter of 80 mm, is made of polyethylene, and operates at pressures between 2 and 6 bar, values that are entirely common in both residential and industrial systems.

How Pressure Stresses a Filter

From an engineering standpoint, a pressurized cylindrical filter behaves like a thin-walled tube. The most critical stress is the hoop stress (also known as burst stress), which tends to split the filter body along its axis.

This stress depends on three factors:

• internal pressure
• diameter
• wall thickness

The relationship is simple and clear: 👉 for the same pressure and diameter, increasing the thickness reduces the stress on the material.

Numerical Comparison: 3 mm vs 5 mm

Considering a diameter of 80 mm (radius ≈ 40 mm) and a maximum pressure of 6 bar:

• Competitor filter, 3 mm thickness → hoop stress ≈ 8 MPa
• GWS filter, 5 mm thickness → hoop stress ≈ 4.8 MPa

✅ The GWS filter operates with over 40% less stress compared to a 3 mm solution.

This results in:

• greater safety margin
• lower risk of microcracking
• better resistance to pressure spikes
• improved long-term reliability

The Role of Temperature: An Often Overlooked Factor

Polyethylene is an excellent material for hydraulic applications, but it is also a thermoplastic, meaning its mechanical properties vary with temperature.

As temperature increases:

• stiffness decreases
• tensile strength is reduced
• creep and permanent deformation increase

Indicatively, the mechanical strength of polyethylene decreases by:

• ~20% at 40°C
• ~35–40% at 60°C

Pressure and Temperature: Combined Effect

In real operating conditions, water can easily reach temperatures above ambient due to:

• poorly ventilated technical rooms • direct sunlight exposure • industrial environments

At 40–50°C, wall thickness becomes a critical factor.

What happens at 6 bar?

3 mm filter • ~8 MPa • close to the critical range

5 mm filter (GWS) • ~4.8 MPa • wide safety margin

👉 A 3 mm filter can quickly enter a risk zone, especially in the presence of:

• water hammer
• molding tolerances
• material aging

A 5 mm GWS filter, on the other hand, continues to operate well within a safe range.

Why the crack is longitudinal

The crack visible in the image above is:

• elongated along the axis
• localized
• typical of failure caused by excessive hoop stress

When wall thickness is limited, internal pressure tends to “open” the filter body along the direction of maximum stress.

Even a brief overpressure can be enough to exceed the material’s limits.

Thickness = Long-Term Reliability

In real-world applications, it’s not just nominal values that matter, but also:

• durability
• consistency
• performance under non-ideal conditions

Thanks to the increased 5 mm thickness, GWS filters:

• operate under significantly lower stress
• are less sensitive to temperature
• better resist fatigue and creep
• ensure system continuity and safety

The GWS Difference

With the same material and diameter, thickness is not just a construction detail, but a true design factor.

✅ With 5 mm walls, GWS filters provide:

• greater structural strength
• reliability even under severe conditions
• longer service life
• a safer investment for installers and end users

Because when it comes to pressure, temperature and safety, a few extra millimeters make all the difference.