The combined pressure vacuum relief valve DUU DN 2“is used as a safety device for flame transmission proof in- and outbreathing on gasoline storage tanks which have a vapour balancing system installed and are drained via a fuel pump with internal gas return. The valve offers reliable protection against excess pressure and vacuum, prevents the inbreathing of air and product losses almost up to the set pressure and also protects against atmospheric deflagration for substances of explosion group IIA and IIB1.

The tank pressure is maintained up to the set pressure. After the excess pressure is discharged and the vacuum is balanced, the valve reseats and provides a tight seal.

If the set pressure is exceed, explosive gas/product-vapour air mixtures are released to the atmosphere. If this mixture ignites, the integrated flame arrester element prevent flame transmission into the tank resulting from atmospheric deflagration.

Type–tested according to ATEX Directive 94/9/EC and EN ISO 16852. An EC-type-examination certificate exists.

The deflagration proof pressure/vacuum relief valve is not appropriated for stabilized burning.

The valve can be used up to an operating temperature of +60°C/ 140°F and meets the requirements of European tank design standard EN 14015 – Appendix L and API 2000.

Settings: pressure: +10mbar, +16mbar +22mbar, vacuum: –5mbar –13mbar Higher

Higher and lower settings upon request.

The relief valve consists of a housing of ductile iron, a weather hood of cast brass. Valve seats and valve pallet of brass. The flame arrester element is of stainless steel.. ,

Deflagration arresters are delivered along with a declaration of conformity and with operating and maintenance instructions.

December 2011