Rainplus®: a unique solution in heavy rainfall.
The Valsir technology fully satisfies the demands of today’s market for efficiency and functionality and introduces Rainplus®, the syphonic rainwater drainage system designed to guarantee maximum drainage performance with the lowest levels of water accumulation on the roofs of medium to large size buildings.
One outlet for a wide range of drainage flows.
Greater installation speed and reduced groundwork.
More economical when compared to conventional drainage systems.
Space saving in that the collector pipes are fitted without any fall and the downpipes are positioned along the building perimeter.
Extremely reliable connections with the Valsir PE® system.
Drainage pipes flow completely full resulting in the self-cleansing action of the pipework.
Eco-sustainability: High flexibility in directing the pipes to storage tanks.
Maximum design flexibility in the definition of the drainage circuits.
SYSTEM CHARACTERISTICS
Maximum drainage efficiency
The Rainplus® system uses the building height as the driving force, which, combined with the negative pressure that is generated inside the pipes, maximises water drainage speed and, therefore, drainage efficiency. This system 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 Buildings Program, regarding the construction of buildings according to the design techniques used in sustainable architecture.
This technology offers numerous advantages, such as the significant reduction in costs and installation times as well as an increase in the performance of the entire drainage system.
Rainplus® syphonic outlets
Rainplus® is made up of special roof outlets that are designed and approved to American Standard ASME A112.6.9 and European Standard EN 1253, connected to Valsir PE® pipes and fittings in high density polyethylene, which are sized in order to work under negative pressures, at high flow rates and with a full bore.
The tests carried out during the development phase allowed a wide range of drainage flows to be achieved, reaching flow rates of up to 65 l/sec as well as a high functional stability.
The particular conformation of the Rainplus® outlet allows connection to the Valsir PE® pipes with a special push-fit socket with two rubber rings for a watertight seal and a steel clip that prevents loosening.
The outlets are made of molded aluminium alloy, protected by a special resin which makes its fully weatherproof. Furthermore, the anti-vortex disc has been designed to eliminate water turbulence at the entrance and the height of the water on the roof, required to trigger the syphonic effect, is extremely reduced.
Connection to the Valsir PE® pipework system
The light weight and wide range of pieces available make Valsir PE® the ideal solution for the construction of syphonic drainage circuits and offers elevated control in the assembling process. Valsir PE® pipes and fittings are manufactured to EN 1519 and have been approved to many standards worldwide (CSTB, IIP, KIWA, DNV, SKZ, ETA, Lloyd’s Register, SABS, etc.). The system parts can be prefabricated and then assembled on the installation site, thus optimizing preparation, cutting and welding times. An exceptional installation flexibility is guaranteed by the possibility of butt-welding the pipes or by using electro-fusion couplers
RAINPLUS® vs CONVENTIONAL DRAINAGE SYSTEMS
The hydraulic principles of Rainplus® are different from those of conventional drainage.
There are two types of rainwater drainage systems: conventional systems that are incorrectly called gravity systems, and the Rainplus® syphonic system, also known as vacuum system or full section system.
Both systems use the force of gravity but in a decidedly different manner, resulting in differences in performance, design and calculation.
Conventional drainage systems can be designed for draining large surface areas but they do not cut off the flow of air into the pipes. The outlet does not incorporate any type of insert or device, hence the flow entering the system is characterised by a vortex that sucks air into the pipe with a consequent reduction in flow rate.
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For this reason they are sized for filling ratios of 20% or 33% (depending on national or local standards and regulations) allowing considerable amounts of air into the pipes of 80% or 67% of the pipe section. In traditional roof drainage the outlets are simple “funnels” installed on the roof covering of the building and connected to the downpipes which are as high as the building and the water collectors which require a gradient of at least 1%, are dimensioned for a maximum filling factor of 70%. When the water collectors are very long and it is not possible to provide the minimum slope necessary due to the limited space available, the only solution is to increase the size of the pipes with a subsequent rise in installation costs.
The Rainplus® syphonic drainage system is made up of special outlets that incorporate an anti-vortex plate that prevent air from being sucked into the pipes thus ensuring the system is completely full of water.
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The outlets are connected via short pipes of relatively small diameters to the horizontal water collector which is located just under the building roof. The collector pipe, generally installed at the highest possible position, runs horizontally, without any fall, till it reaches connection with the downpipe. The downpipe drops into the drainage line which is buried in the ground and conveys the water straight into a collection tank or the municipal mains. The absence of air in the system allows it to run 100% full of water making use of the entire pipe section and vastly increasing flows that are 10 times faster when compared to conventional drainage systems.
The performance of the Rainplus® syphonic drainage system is therefore decidedly better than a conventional system where the driving force is generated exclusively by the amount of water that accumulates on the roof. When the syphonic drainage system runs at full capacity, the “syphon” effect is triggered resulting in a driving force that is proportionate to the height of the roof and the end of the circuit, which is typically located at ground level. This power generates levels of positive and negative pressures in specific points of the circuit such as to rapidly increase the velocity and, as a consequence, the flow rates of the system.
SERVICE AND PROJECT DESIGN
Valsir has gained EN ISO 9001 accreditation and is in a position to provide full service, ranging from training to designing and after sales technical assistance. The design phases are constantly followed by a technical staff of engineers with international experience, in a position to provide solutions for all applications.
The hydraulic principles of Rainplus® are therefore different from those of conventional drainage systems thus requiring a decidedly more advanced technical preparation in design and calculation as well as in system installation.
The accurate and proper design and installation of the hydraulic circuits has a direct influence on the performance of the entire syphonic system.
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Valsir boasts an impressive training structure for customers, distributors, installers and designers. In Valsir’s training centres, theoretical and practical courses on the design and installation of plumbing systems are held periodically.
Syphonic drainage systems are designed with the use of the advanced and accurate Rainplus® software that was developed by the team of Valsir experts that is capable of calculating and sizing in compliance with technical Standards VDI 3806 and BS 8490.