The PURAIN Rainwater filter, also known as the hydraulic jump filter, is the innovation for roof areas ranging from 60m² to more than 15.000m².

This hydraulic jump technology cleans itself automatically. The design model for PURAIN Rainwater filters comes from nature: At almost every course in a stream, you can see how the hydraulic jump functions. The water flows over one of the stones, smooth and rounded by the action of the water over time. The water flow is substantially changed by the height drop, from a sub-critical to a super- critical flow. At the bottom of the dip, the waterflow changes again to a subcritical flow in a process now commonly known as hydraulic jump. This resulting increase in water power forces any impurities over the next level and washes them away downstream.

• The PURAIN-HD (Heavy Duty) model SLW60 (Heavy duty vehicles up to 60 tons), is designed as a subsurface variant.
• PR-HD rainwater water filters are made accessible with conventional manhole lids and rings.
• For discharge pipes up to DN400
• L x B x H:                                                           2043 mm x 670 mm x 1440 mm
• Hs Height of shoulder:                                       1040 mm
• L 1:                                                                     448 mm
• L 2:                                                                     424 mm
• B 1 Width of dome:                                             370 mm
• D1 Intake:                                                           DN400/Ø400 (LP*)
• D2 Clearwater outlet:                                           DN300/Ø315 (LP*)
• D3 Emergency overflow/ wastewater outlet:       DN400/Ø400 (LP*)
• H1 Intake:                                                            572 mm
• H2 Clearwater outlet:                                           54 mm
• H3 Emergency overflow:                                      226 mm
• Δh Height offset:                                                  346 mm
• b Sealing collar:                                                   13 mm
• Width of wedge wire filter:                                    0.8 mm
• Dimensions of sieve:                                            500 mm x 330 mm
• Efficiency:                                                             98%
• Material:                                                                PE, NBR, Stainless Steel
• Weight:                                                                  188 kg