The safety and economics of this desulphurisation are optimised by using non-return valves made by the German company Witt-Gasetechnik. These valves, which have DVGW approval, prevent the formation of flammable mixtures.
Biogas results from the fermentation of organic material in a fermenter. The main component of this energy source is combustible methane. Before the biogas can be used, eg in combined heat and power plants, air is introduced in a controlled manner into the biogas tank to desulphurise the gas. Non-return valves only allow the added air through in one direction and prevent the return of biogas into the air supply line leading to the compressor.
The German manufacturer Witt has a gas non-return valve suitable for this in its product range. The "600 ES" is a device only 65 mm long and 56 mm diameter, which has been specially developed for corrosive environments. According to the manufacturer, it can do more than any peer products: a key example is its response at very low opening pressures. The low pressure losses between the compressor and tank enable the use of smaller compressors and small pipe cross sections, thereby boosting economic viability. High-quality stainless steel as well as an integrated dirt filter enable a long service life.
As a special feature, Witt checks every fitting before delivery in accordance with EN 730-2. What is more: the non-return valve is inspected externally and certified by the DVGW (German Technical and Scientific Association for Gas and Water).
WITT gas non-return valves can be installed easily in existing air supply lines independently of location. A large selection of connection options enables installation in practically any system. Variants for high pressure and high temperature are available.