The storage of recovered water ranges from small tanks for potable water and service water to large open or closed tanks. Large capacity storage, mostly in open tanks, is required for off-line storage of peak flows, storage in pipelines under load, and long-term storage of seasonal flows that are discharged at different seasons.
Level monitoring is necessary for water storage tanks of every one size. Level switches are particular according to the dimension and geometry of the storage tank. Level detectors located in open-air tanks are frequently confronted with difficult climatic conditions.
Option of resources in contact with drinking water
When designing or renewing a drinking water storage tank, care will be taken to use suitable materials, paying particular attention to the choice of the coating of surfaces in contact with drinking water. The nature of the coating of drinking water storage tanks is a major problem, in particular its resistance, its compatibility with the characteristics of the water and, more importantly, its sanitary compliance. Basically, the coating of the tank must meet the following criteria so that it can preserve the quality of the stored water:
The storage of water for fire reserves is a special feature. Businesses have a fire fighting plan. Their geographical location may require them to have a fire water reserve on the site (because of a network that is too far away or insufficient inflow or volume). Their availability is compulsory, but there are no regulations. However, there are no specific regulations. Response services are based on one rule: ensure a flow of 60 m3 of water per hour to extinguish a medium fire and limit its spread. It has also been established that it takes an average of 2 hours to bring a disaster under control.
Depending on the dimension of the site and the danger involved, the local SDIS may decide to increase the capacity if deemed necessary. It defines the required equipment.
The dual-energy sanitary water tank
The domestic hot water tank is fitted with a solar exchanger at the bottom of the tank and a backup exchanger (and/or electrical resistance) at the top of the tank. The entire volume of sanitary water contained in the tank can be heated by solar energy; any additional heat is provided by the backup. These tanks are generally made of stainless steel and insulated by a jacket in polyurethane foam or mineral wool with a thickness of 8 to 15 cm. In a residential installation, the solar tank usually acts as the sole storage tank for DHW.
The buffer tank
The buffer tank contains a large volume of dead water, which serves only to store heat energy. This water is never drawn or renewed (closed circuit). This type of tank, with a capacity generally greater than 500 litres, is often used in combined solar systems and systems intended to produce hot water for a community.