In early 2026, a 194-meter, DN2200 stormwater pipeline buried nearly 6 meters underground was fully restored without excavation, traffic disruption, or winter delays. This project represents a landmark in ultra-large diameter, deep-buried CIPP rehabilitation in China.

Why Palatal Z455 TV-901?

The success hinged on selecting a resin that could meet the extreme requirements of water inversion CIPP. Palatal Z455 TV-901, a high-performance unsaturated polyester resin, offers:

• Rapid, uniform impregnation: Its low viscosity and superior permeability enable full saturation of thick polyester felts, ensuring consistent liner quality across hundreds of meters.

• Controlled exotherm: Optimized molecular structure provides a smooth heat release, minimizing blistering or delamination and securing the structural integrity of deep-buried pipelines.

• Low-temperature reliability: Even in -18°C conditions, Palatal Z455 TV-901 maintains flowability and curing performance, enabling defect-free, full-length liner installation.

These properties make it not just a material, but a reliable solution for extreme trenchless rehabilitation challenges.

Engineering Synergy

The project exemplifies the synergy of material expertise and process innovation:

• Customized gel time and curing characteristics aligned with water inversion requirements.

• Seamless collaboration between resin performance and field operation ensured smooth inversion, tight adhesion, and uniform curing.

The result: a zero-leakage, structurally sound, long-life rehabilitation completed under winter conditions—a first in ultra-large-diameter CIPP projects.

Expert Perspective

As UPR specialists, we see that material selection is critical in large-scale infrastructure rehabilitation. Palatal Z455 TV-901 demonstrates that high-performance unsaturated polyester resins can deliver consistent, reliable outcomes even under harsh and complex conditions.

For engineers and project teams seeking trusted, high-performance UPR solutions, Evergreen Chemicals provides Palatal Z455 TV-901 along with technical support to ensure optimal results.