Introduction
The PURAIN Rainwater Harvesting Filter, developed by INTEWA, is a self-cleaning, patented system designed for efficient rainwater filtration. It is suitable for roof areas ranging from 60m² to over 6000m² and utilizes a natural hydraulic jump process for cleaning.

Specifications
The filter is designed to provide high-quality water suitable for various applications such as flushing toilets, washing machines, and garden irrigation. It features a sturdy, break-proof sieve with a trapezoidal shape to prevent clogging. The PURAIN PR100 model includes a nonreturn valve to prevent backflow and entry of small animals.

Efficiency and Maintenance
The PURAIN filter achieves a 98% efficiency rate by utilizing high rainfall events for self-cleaning through the hydraulic jump mechanism. This design minimizes maintenance costs compared to other systems. Manual cleaning is possible with a high-pressure cleaner, and a backflushing nozzle is recommended for hard-to-reach installations.

Installation
The filter is designed for easy installation within tanks, eliminating the need for separate downpipe filters. It can be retrofitted into most tanks due to its compact size and low height offset. The PURAIN PR100 is suitable for single-family dwellings, while models PR150 to PR400 cater to industrial and commercial buildings.

Technology and Adoption
Since its launch in 2001, over 20,000 PURAIN filters have been installed worldwide, establishing it as a leader in rainwater filtering technology. The filter's design is inspired by natural water flow processes, ensuring efficient and sustainable water management.

Conclusion
The PURAIN Rainwater Harvesting Filter offers a reliable and efficient solution for rainwater management, with minimal maintenance requirements and high adaptability for various building types.