The Intewa PURAIN PR100 is a 4" self-cleaning rainwater prefilter utilizing patented hydraulic jump technology. Designed for residential rainwater harvesting systems, it ensures high water capture efficiency with minimal maintenance. DN100 Lite. 4" SDR female inlet, male outlets. Recommended Max. Flow: 20-90 gpm at 1.5% fall. DN100/4" SDR35 male Connections. Without rodent-Proof flapper this self-cleaning filter with alternating jump principle for roof areas up to 200 m². 

Thanks to its design, the filter achieves maximum efficiency with minimum maintenance intervals. The filter has a minimal clogging tendency due to its trapezoidal slotted screen design and guarantees continuous and reliable filtration. With integrated skimmer to remove surface dirt and a non-return valve(small animall protection). Installed directly in the cistern or in a separate shaft. Suitable for rainwater harvesting and graywater recyclce. 

Stocked in Doraville, GA Warehouse

PURAIN 100 in concrete or plastic tank

PURAIN 100 in retention tank

1.	floating throttle
2.	retention volume
3.	useful volume

PURAIN 100 in a indoor tank

PURAIN 100 in aboveground tank

1.	The minimum height differential between the lowest lying gutter an the installed filter height must be 250 mm
2.	Handy inspection T piece (must be watertight)!
3.	If multiple tanks are used they are balanced with a 1” hose or pipe 200 mm off the bottom and then fill as one, PURAIN filter and discharge overflow must be mounted in the first tank

FAQ

Where can I in­stall the PU­RAIN rain­wa­ter fil­ter?

The IN­TEWA PU­RAIN fil­ters can be eas­ily installed in most stan­dard tanks of plas­tic, con­crete, in­door and out­door con­struc­tion. Many dis­trib­u­tors de­liver your stor­age tank al­ready fit­ted with a PU­RAIN fil­ter. The PU­RAIN Fil­ter is also suit­able for in­stal­la­tion out­side the tank if re­quired. HD Fil­ters are de­signed for di­rect sub­sur­face in­stal­la­tion. While in­stalling the PU­RAIN fil­ter, make sure that a lower height off­set is pre­sent be­tween the in­flow and the out­flow.

Is there a fil­ter with­out height off­set be­tween in­flow and out­flow?

The PU­RAIN rain­wa­ter fil­ter works with the min­i­mum pos­si­ble height off­set be­tween the in­flow and out­flow. A height off­set is a pre­req­ui­site for a self-clean­ing fil­ter in order to en­sure proper op­er­a­tion. Since 1993, IN­TEWA has ac­cu­mu­lated a lot of ex­pe­ri­ence test­ing dif­fer­ent types of self-clean­ing fil­ters – none of which, func­tion with a high de­gree of ef­fi­ciency. Al­ter­na­tively, only a col­lec­tion fil­ter may be used in place of a hy­draulic jump, how­ever they have to be cleaned reg­u­larly and do not guar­an­tee the best qual­ity water fil­ter­ing.  

Is the rain­wa­ter fil­tered by PU­RAIN well suited for wash­ing ma­chines?

The water fil­tered by the hy­draulic jump fil­ter is per­fectly suited for use in toi­lets, wash­ing ma­chines etc. It should be noted that the qual­ity of water also de­pends on the stor­age of the rain­wa­ter. Fac­tors, such as tem­per­a­ture of the stor­age tank, in­flow calmer, over­flow skim­mer,  size of tank, etc. are crit­i­cal for an op­ti­mum qual­ity of water.

Does self clean­ing = main­te­nance free?

The PU­RAIN-fil­ter is ex­tremely low main­te­nance. Dirt and leaves in the sed­i­men­ta­tion cham­ber do not need to be re­moved be­cause they will be flushed away with the next heavy rain­fall. If the sieve does be­come clogged, it is eas­ily cleaned through the tank lid with a high pres­sure cleaner. Al­ter­na­tively, in rare cases, the sieve can be re­moved for clean­ing. Should a fil­ter be mounted in a hard to ac­cess place, it can also be cleaned via the in­stal­la­tion  of a back­flush­ing noz­zle. This is avail­able as a PU­RAIN ac­ces­sory. We rec­om­mend that you check your fil­ter about sieve twice a year.

How is the ef­fi­ciency in other con­di­tions of rain?

The over­all ef­fi­ciency of the PU­RAIN rain water fil­ter is rated at 98 %. Hereby, the small to medium rain­falls are col­lected 100 %, but the heavy rains (which ac­count for only about 3 % of an­nual rain­fall yield), are uti­lized for the self-clean­ing func­tion of the hy­draulic jump fil­ter. Even in areas which ex­pe­ri­ence more heavy rain­falls the ef­fi­ciency of the PU­RAIN fil­ter is well over 95 %.

How do I in­stall the non-re­turn valve and over­flow skim­mer used with the big­ger PU­RAIN rain­wa­ter fil­ters?

The non-re­turn valve and over­flow skim­mer, made from moulded parts, are sep­a­rately in­stalled in the tank.