Solenoid Valves Applied in

Servo-assisted solenoid valves are providing the top-up facility on rain water collection systems aimed at helping to offset the ever- growing demand for drinking water, providing an alternative water source. Although rainwater harvesting has traditionally been practised in arid and semi-arid areas, the effects of Global Warming mean that even UK householders need to reduce their water consumption substantially over the next few decades. This is because of the projected fall in the volume of water provided by UK rivers over the next 40- years.
Rainwater harvesting has a significant role to play in achieving this reduction. Presently,up to 50% of the 160 litres of water used by each person per day in the UK need not be drinking quality water; so using rain wate rfrom the roofs of buildings would greatly reduce consumption.
In addition, collecting rain water also helps to prevent flooding – especially in urban areas- by reducing the amount of storm water discharged to soak aways or storm drains.
UK company, Rain harvesting Systems, based in Stroud, has been designing rainwater collection systems since 1994. The company provides systems for domestic, as well as for schools, offices and industrial and agricultural buildings. The systems are fully automatic, and only activate when water is required.
Moreover, in the event that there is insufficient rain water in the collection tank to meet demand, the system has the facility for mains water top-up. This is provided by the Mains Water Top-Up Unit, via a solenoid valve that operates to let mains water fill the tank to the minimum level required.
The solenoid valve 6213, 2/2 servo assisted unit can be used universally on fluids. Operated by a remote low-level float switch on the rainwater tank, the 6213 is IP65 rated,and is characterised by its switching from zero bar, its high flow rate, and its low noise,anti-water hammer design: the valve is actually designed to close slowly. Moreover,the optimised design of the valve means that it requires minimal servicing, keeping maintenance requirements to a minimum.
In addition the 8175 ultra sonic level sensor and 8035 flow meter are offered as a package for easy integration with the controlsystems used for rainwater collection. Designed for liquid level or volume measurement in open or closed vessels, the 8175 level sensor provides the benefits of non contact, sensing over distances up to 10m.
The unit can be easily integrated into almost any building management system, due to its 4–20 mA output signal. The 8035 flowmeter completes the package providing users with the ability to easily totalise the amount of water they are using. Available as compact version, or for control cabinet or remote mounting, the 8035 is a robust IP65-rated, inline unit which also has a4-20mA output for connection to building management control systems.