How do you size a tank?
Where does the tank have to be positioned?
What is the burial depth of an Rainstream tank?
Can the tank be buried lower than the water table?
Does the tank have to be encased in concrete?
Can the system be connected to Syphonic Drainage?
How high can you pump the water from the tank?
Where does the mains water back-up feed into?
What pressure is the water delivered at?
Is the water clean?
Is there an audible alarm on the system?
How much energy does the pump use?
How does the system get delivered to site?
What maintenance is required?
What guarantee does Polypipe offer?
What if I have a problem – what do I do?
How do you size a tank?
Tanks are sized on a two week demand period, which according to the MET office is the average period the UK experiences without rainfall. Free assessments are available through the Polypipe WMS Technical Department on 01509 615100, or by downloading an assessment form. It is essential to have details of the site location, roof area, proposed applications, number of appliances and number of people within the building.
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Where does the tank have to be positioned? – What is the min/max distance from the building?
There are no building regulations concerning the position of an Rainstream system, therefore our guidelines are based on the building regulations for septic tanks, which states that a tank must be positioned at least 5m from a building. The maximum distance that a tank can be positioned from a building is 100 metres.
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What is the burial depth of an Rainstream tank?
Rainstream has a burial depth up to 3.5m.
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Can the tank be buried lower than the water table?
Yes, Rainstream (our GRP Tanks) will however need to be ordered as a super heavy duty tank and will need to be encased in concrete.
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Does the tank have to be encased in concrete?
Rainstream should be encased in concrete unless there is definitely no water table present, in which case a gravel surround can be used. However, Polypipe WMS always recommends a concrete surround for GRP tanks to ensure the tank is protected from any possible movement of the water table.
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Where does the mains water back-up feed into?
For a gravity system the mains water back up is fed directly into the header tank.
For a pressurised system the mains back-up is fed directly into the underground storage tank and controlled to allow for a small amount of water to be fed into the tank.
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Can the system be connected to Syphonic Drainage?
Yes the Rainstream system is ideal for this, as all roof water can be directed to one outlet which is connected to the Rainstream tank, therefore reducing additional pipework and ground work costs. Polypipe Terrain, a division of Polypipe is able to supply a complete system for syphonic drainage.
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How high can you pump the water from the tank?
In order to obtain the most efficient system, the maximum height recommended is 15m on the standard pump. Larger pumps can be supplied if necessary.
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What pressure is the water delivered at?
The water pressure delivered into the building is 2.5 bar.
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Is the water clean?
The main aim of any rainwater harvesting system is to produce non-potable water that is clean, clear and odourless. Three stages of filtration take place to ensure the water is clean and clear prior to it reaching any non-potable appliance.
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Is there an audible alarm on the system?
Yes the Rainstream pressurised system comes with an audible alarm in the event of a problem with the solenoid valve, and mains water is being pumped into the tank. Otherwise the system is easily connected to the BMS.
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How much energy does the pump use?
The pump uses £0.03/m3
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How does the system get delivered to site?
The tank and leaf filter will be delivered to site ready for installation. The components will be packaged separately and it is essential that the contractor stores them in a dry, safe and secure area. It is also the contractors responsibility to ensure suitable lifting equipment is on-site to take delivery of the tank. Please contact Polypipe WMS on 01509 615100 to discuss the exact requirements needed.
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What maintenance is required?
Regular maintenance is vital to prolong system performance and lifespan.
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What guarantee does Polypipe offer?
Polypipe offers a 2 year guarantee from point of sale on all component parts, excluding the tank. As a responsible manufacturer with the scale and support of Polypipe Group, Polypipe is on-hand to provide continued assistance and technical support.
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What if I have a problem – what do I do?
Polypipe has its own team of engineers, who are on hand to respond quickly to any queries you may have concerning your Rainstream system. In the first instance please make contact with us on 01509 615100 and our technical team may be able to address your query over the phone. Otherwise an engineer can be on site within 48 hours to assist you.
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