Rain Plus - Siphonic Roof Drainage System

Rain Plus is a siphonic roof rainwater drainage system that has been designed to guarantee maximum drainage performance with the lowest levels of water accumulation on the roof.

Valsir technology fully meets the increasing levels of rainfall and guarantees the drainage of medium to large large size buildings in total safety.

Rain Plus

Rain Plus

Rain Plus

Rain Plus

Rain Plus

Rain Plus

Rain Plus

Rain Plus features the most up to date technology in the building market and in rainwater drainage from the roofs of medium to large size buildings.

The system uses the building height as the driving force to generate high speed flow rates thus maximising drainage efficiency.

Rain Plus allows the entire flow of water to be directed to any part of the building whatsoever, thus enabling the most modern rainwater harvesting systems to be installed as required by the Green Building programs.

This technology offers numerous advantages, such as the significant reduction in cost and installation time as well as an increase in the performance of the entire drainage system.

The Rain Plus siphonic system is made up of special roof outlets that are designed and tested according to the American standard ASME A112.6.9 and European Standard En 1253. These outlets are connected to Valsir HDPE pipes and fittings, which are sized in order to work under negative pressures, at high flow rates and with a full bore.

This is possible thanks to the special configuration of the Rain Plus roof outlets, which prevent air entering the pipes when the design rainfall intensity value is reached. In this way the “hydraulic engine” of the system is given by the height of the roof in relation to the drainage point and not by the amount of water that has accumulated on the roof.

The hydraulic principles of Rain Plus are therefore different from those of conventional drainage systems thus requiring decidedly more advanced technical preparation in design and calculation as well as in system installation, in that the accurate and proper design and installation of the hydraulics circuits has a direct influence on the performance of the entire siphonic system.

Economical – when compared to conventional systems Rain Plus requires a lesser number of roof outlets and allows a substantial reduction in pipe diameters, in the number of fittings required and the number of downpipes: this results in saving up to 80% on vertical pipes and 20 to 30% across the entire system.

Space saving – the roof outlets are connected to single horizontal collector pipes that are fitted without fall and the downpipes are positioned anywhere along the building perimeter thus avoiding interference.

High performance – when in operation drainage pipes flow at 100% full over the entire system, draining velocity is therefore greater resulting in the self cleansing action of the pipe work.

Eco sustainability – the ease in directing the pipes to storage tanks makes the collection of rainwater easier for reuse in irrigation systems, fire ponds and tanks for non potable uses in general.

Time and labour saving – construction programmes are accelerated due to reduced installation times and less groundwork is required due to the reduced number of embedded pipes.

Increased design flexibility – complete control over downpipe location and absence of embedded pipes gives increased design flexibility of the siphonic system.

Perfect integration with Valsir HDPE pipes and fittings.