Successful night campaign with Hawle Combiflex

Hawle Combiflex gate valves type 442-00 were recently used in the municipality of Unterensingen (Stuttgart region). A section of the main water pipe in the centre of the town urgently needed to be renewed and relocated. The work was carried out in co-operation with the Wendlingen am Neckar waterworks. The aim was to minimise disruption to the local water supply, which is why it was decided to carry out the work at night. The DN 300 main line was bridged with B-hoses and a basic supply was provided from the high zone to the low zone via two Hawle pressure-reducing valves. A total of three concrete shafts with gate valves and hydrants had to be integrated into the new pipeline.

In order to keep the three gate valves as small as possible, the decision was made to use the Hawle Combiflex, a modular Combi valve that allows reductions and expansions to be realised in the smallest possible space. This allowed the shafts to be designed smaller and construction costs to be saved.

Two Combiflex DN 300 with horizontal outlets reduced to gate valves in nominal width DN 150 in PN 10 and one Combiflex DN 300 with full passage PN 10, each with vertical outlets DN 100 for connection to the Württemberger manhole system using an XR reducing flange to DN 65 and with ZAK outlets for the corrosion-free connection of ZAK house connections, were used.

After just a few hours, the connection to the main pipeline and the integration of the manholes was completed. The pipeline could be put back into operation after midnight. The employees of the municipality and the waterworks were completely satisfied with the speed with which the water pipe was reconnected.

The Hawle CombiFlex with the proven E3 valve technology is suitable for installation in manholes as well as in the ground. The Combi valve is available in pressure ratings PN 10 and PN 16 and for connections DN 150 to DN 400. The vertical outlet can optionally be fitted with a flanged outlet in DN 100 or DN 150. This allows full access for service and maintenance work in the supply network or the installation of an air release valve or hydrant.

The additional option of integrating ZAK connections extends the flexible use of the Hawle-Combiflex for house connections.