RainTap RoofWater Filter, DIY Rainwater filter, Do It Yourself RWH filter

Designed and Developed by A.R. Shivakumar Government of India Patent Priority No. ****/CHE/2015 https://drive.google.com/file/d/1Cgzlr4Q_OwG1Y9OqDL6lAHvr6VMgwEvg/view?usp=sharing

Raintap RoofWater filter

 

 

Rainwater collected on the roof is very pure and clean.  However, there are many substances, which get mixed with this pure water on the roof (leaves, bird droppings, dust etc.).  These impurities need to be filtered before the rainwater is stored or recharged in to the ground.   “Raintap RoofWater Filter” is a scientifically developed device, which is very effective and user friendly. This filter will effectively filter roof top rainwater from residential buildings and smaller institutional or industrial buildings.

These Raintap RoofWater Filters are simple in design and are very flexible to install in varying field conditions.

An important feature in filtering rainwater is the separation of the first flush of rainwater from the relatively cleaner and purer subsequent rainwater.

 

Installation of Raintap RoofWater Filter

In a building, rainwater is normally allowed to flow down from the roof through pipes.  PVC pipes are commonly used in the present times. They are cost effective and convenient for installation.  Raintap RoofWater Filter can be installed on the wall or any flat surface with suitable inlet and outlet pipe fittings. 

Depending on the roof area and the quantity of rainwater flow, the down water pipes of a building are of varying sizes.  For a residential building one or more 3 inch or 4 inch (90mm/110mm) pipes are used.

 

Installation of filter to down water PVC pipe

The down water pipes are placed vertically on the walls.  These pipes receive water from the rooftop through 90⁰ bend or elbow attached to them at the top.  The other end of the pipe is left free for the water to flow down or attached with a 45⁰ elbow or a bend to facilitate the water to flow away from the building.

RoofWater Filter comes in a carton box and will have 6 components.  

Raintap RoofWater Filter is installed at the bottom end of the down water pipe.  The pipe running down on the wall need to be fitted with a 90⁰ elbow or a bend and connected to the inlet (rainwater inlet) of the Raintap RoofWater Filter.  The connection from the down water pipes to the inlet is through the 90mm or 110mm (3” or 4”) elbow and a connecting pipe or a reducer collar. The filter so installed must have a gap of minimum 12 inches from the floor.  This will facilitate easy flow of flush water with undesirable substances coming from the roof. Raintap RoofWater Filter has an outlet (filtered water outflow) through 110 mm Tee joint. Make sure that the Tee joint is seated on the filter body without any gap in-between. This Tee joint along with the filter cartridge can be turned in any direction (360⁰) in its place.  This will facilitate positioning of the filter outlet in any direction convenient for installation in the site.  This facility is provided in the filter to add flexibility in connecting the outlet of the filter in the required direction to allow filtered water to flow in to the tank.

The out flow of the filter through this outlet is connected to the storage tank.  The filter so installed need to be anchored to the wall by using screws at 3 locations.  Two screw holes are provided at the bottom of the filter and a clamp with holding socket is provided at the filter body top behind the outlet tee joint. A templet with three holes is provided in the packing carton box and the same may be placed on the wall at suitable location beside down water pipe for marking the screw holes’ location. Using 5 mm concrete drilling bit, three holes are drilled and the plastic screw plugs provided in the kit need to be pushed / driven in to these holes. The metal clamp provided in the kit need to be fixed first in to the top hole by using the stainless steel screw provided in the kit and the clamp should be facing downwards. Now the filter is placed on the wall and aligning the top slot on the filter to the metal clamp, filter body is gently pushed upwards to position the clamp firmly inside the slot on the filter body. The two holes facing the wall at the bottom of the filter need to be aligned in to the two holes with plastic plugs. Using the remaining two stainless steel screws the filter can be fixed firmly by tightening the screws in to the bottom two holes.

 

Inlet and out let pipe connection

Down water pipe carrying the roof water need to be connected to the inlet of the filter with proper pipe fittings (90mm or 3 inch elbow or bend and if required pipe collar). Filtered rainwater outlet need to be connected to a pipe and suitable fittings (110 mm or 4 inch) to channel the filtered water in to the water storage tank or underground sump. Make sure the elbows or bends or pipe connecting to the filter at inlet and outlet are firmly anchored on to the wall with proper pipe clamps and screws.

 

Raintap RoofWater filter has a drain / flush pipe at the bottom. This pipe can be either left free or can be connected with a suitable pipe to channel the dirty water while flushing or back washing the filter cartridge in to the drain or for ground water recharge.

 

Filter element

Filter element is made of plastic net and mesh of varying sizes to effectively filter rainwater from the roof of a building. This filter cartridge is designed for the life time of the filter and normally need not be replaced.  A cap-holder rim on the top facilitates installation of the filter element inside the filter body and also positions the filter element at appropriate height inside the filter body.  While removing the filter element from the filter, gently pull the cap-holder vertically upwards.  Make sure the entire length of the filter element is pulled out of the filter before tilting.  While installing the filter element back in to its position, make sure the mesh role enters the barrel without any crinkle.  Gently push the filter element downwards up till the cap-holder sits and positions itself on the vertical column of the filter. 

 

The filter cartridge cap has a spring loaded knob and the knob need to be pushed inside before pressing down the filter cartridge in to its position. The bottom of the filter cartridge has a flow stopper arrangement and sits on a rubber O-ring. This arrangement allows the water to flow out of the filter at the bottom or stop the flow when required.

 

Important

·         Raintap RoofWater Filter must be installed in vertical position only.

·         Raintap RoofWater Filter can handle rainwater from a maximum of 1000 sq. ft. of roof area with 1000mm / 40 inch annual rainfall

·         Keep the Raintap RoofWater Filter dry during non-rainy days by lifting the filter cartridge and releasing the spring loaded knob on to the rim of the outlet. This will release stagnant water inside the filter body along with all the dirt collected and filtered.

How Raintap RoofWater Filter works?

The rainwater is allowed to flow from down pipes in to the filter and as the filter cartridge is in its top position, the initial flow with all the dust, bird droppings etc. will flow out. This need to be practiced during the first rain of the season. Subsequently the filter cartridge need to be in its position to close the flush valve at the bottom. Water received in the receptor flows upwards against gravity through the filter element to filter most of the floating elements and allow water to stabilize in this filtration zone.  Rainwater passing through this filter element is relatively cleaner and flows out through an outlet, which can be led to storage tank. 

Filter element is mounted on a vertical stabilizer barrel with a friction fit. Filter element need to be cleaned periodically during the rainy season to remove the impurities trapped and there by keep the filtration system clean.  In the event filter is not cleaned and the filter element is getting clogged, “Raintap RoofWater Filter” has a safety feature built into it.  The water pressure pushes out the clogged filter element from the stabilizer barrel and allows the water to flow out freely from the drain pipe at the bottom.  This safety feature will avoid flooding of the rooftop because of clogged filter.  For normal working condition, filter cartridge need to be in its position closing the bottom drain pipe.

 

Maintenance of filter

 

Back wash arrangement is provided to clean the filter cartridge. A hose connector provided at the top of the filter cartridge need to be connected to your tap with a hose pipe. Make sure the filter cartridge is in the open position by pulling the filter cartridge upwards till it pin comes out and the cartridge sits on the pin. This will allow the dirty water to flow out at the bottom. By allowing the tap water through the filter cartridge back wash can be achieved and the dust and other impurities embedded inside the filter cartridge get released and flow out through the bottom pipe. When the clean water start flowing out at the bottom or after three minutes of back wash, the tap water flow may be stopped and filter installed in its position for filtering rainwater.  

When the rain stops, flush the filter by gently lifting the filter cartridge from its position until the cartridge stands on the spring loaded knob.  The water with all the filtered dirt gets released and washes off.  After five minutes, push the filter cartridge back to its position by pressing the spring loaded knob.  Take care to position the filter cartridge correctly in its position and the bottom stopper sits correctly on the O-ring.