CONSTANT PRESSURE AND VARIABLE LEVEL OPERATION Self-pressurised closed expansion vessels, without diaphragm, for chilled water; to be pressurised with air or nitrogen; insulated and hot-dip galvanised. Suitable for containing water expansion and maintaining a constant pressure during system operation by means of automatic gas venting and filling. Max. permissible pressure 6 bar Min. permissible temperature -10°C Max. permissible temperature +110°C CE certified according to European Dir. 2014/68/EU-PED the expanders are subject to the Declaration of Commissioning (D.M. 329 of 01/12/2004). 20 mm thick, closed-cell, cross-linked polyethylene foam insulation