In 2026, FLEXWELL-FHK celebrates its 60th anniversary. For six decades, the flexible pipe system has stood for innovative engineering, high operational reliability and dependable solutions for demanding district heating and infrastructure projects.
What was developed in the 1960s as a response to complex routing requirements and challenging installation conditions has evolved into a globally proven pipe system for district heating, district cooling and industrial applications. Today, planners, network operators and construction companies around the world rely on FLEXWELL-FHK when standard solutions reach their limits.
Developed for exceptional challenges
The very first FLEXWELL systems already followed a clear approach: maximum flexibility combined with high operational reliability.
Thanks to its unique design, it can be used in locations where conventional rigid pipe systems can often only be installed with considerable effort. Whether in confined urban spaces, water crossings, challenging topographies or sensitive infrastructure projects – FLEXWELL-FHK has provided an economical and reliable solution for decades.
Key benefits include:
Installation directly from the drum
Long pipeline sections with few connections
Self-compensating corrugated stainless steel pipe
Self-venting and self-cleaning design
100% diffusion-tight construction
High operational reliability and long service life
Proven technology with a unique design
The heart of FLEXWELL-FHK is its double-walled stainless steel construction.
The inner and outer corrugated stainless steel pipes completely enclose the thermal insulation and permanently protect it against moisture ingress. As a result, the insulation performance is maintained for decades and operational reliability is sustainably enhanced.
The special design also ensures that temperature-related changes in length can be absorbed directly within the pipe system. Additional expansion compensators are not required in many applications, simplifying planning and installation.
Another advantage is the corrugated stainless steel inner pipe. It supports self-venting and self-cleaning operation, contributing to a high level of reliability throughout the entire service life of the system.
The solution for trenchless installation
As energy infrastructure continues to expand, trenchless installation methods are becoming increasingly important.
FLEXWELL-FHK is ideally suited for horizontal directional drilling (HDD) and is used worldwide for crossings beneath roads, bodies of water, industrial facilities and other sensitive areas.
Thanks to the system’s high flexibility, extensive civil engineering work can be reduced and interventions in existing infrastructure minimised. This saves time and costs while also reducing the impact on the surrounding environment.
Confirmed safety for railway crossings
A significant milestone in the system’s more recent history was achieved in 2025.
Following extensive testing, DB InfraGO confirmed the use of FLEXWELL-FHK for trenchless crossings beneath railway tracks. The approval underlines the system’s high quality, safety and reliability and opens up additional possibilities for demanding infrastructure projects.
Particularly for HDD applications, the pipe system therefore offers an attractive solution for network operators and engineering firms that must meet the highest requirements for safety and execution.
Proven for district heating and district cooling
It is not only impressive in traditional district heating applications. Thanks to its broad range of applications, the system is suitable for both district heating and district cooling.
With a temperature range from -170 °C to +150 °C, FLEXWELL-FHK offers exceptional application possibilities for energy and industrial projects.
60 years of experience – ready for the future
The expansion of modern heating networks is one of the key tasks of the energy transition. At the same time, requirements for efficiency, sustainability and security of supply are increasing.
Many of the characteristics that distinguished FLEXWELL-FHK 60 years ago are more relevant today than ever: flexibility, operational reliability, durability and cost-effectiveness.
This anniversary therefore represents not only a successful past, but also the future of modern energy infrastructure.
BRUGG Pipes would like to thank all customers, partners and employees who have supported and further developed FLEXWELL-FHK over the past six decades.