SagiCofim blast protection valves are designed as safety devices capable of preventing any pressure wave due to sudden overpressure from entering air inlets and outlets.
These valves are widely used in petrochemical and chemical industry, whenever temporary and immediate protection is required downstream a closed environment and the nominal air flow cannot be discontinued for too long.
SagiCofim Blast Protection Valves can ensure an effective protection of all HVAC plants installed in buildings located in potentially explosive areas.
In such plants it is not possible to arrest the pressure wave by means of standard on – off type dampers because of the inertia acting on the component itself (opening – closing – opening). Moreover, dampers are not designed to resist so considerable pressure transients as the ones originated from explosions.
Blast Protection Valves are mechanical self-actuated devices operated by the elastic forces acting on blades. Valves consist of stainless steel blade shutters installed within a modular die-cast aluminum alloy body, anodized for corrosion protection.
Under normal conditions the device is at rest and its blades are fully released, positioned at the center of the valve body thus allowing the airﬂ ow passage. The blade shutters are designed to be tensioned and positioned into the valve seats by the shock force of a blast pressure wave. The valves close in one direction in response to the positive phase of the blast wave and in the opposite direction responding to the negative phase.
The valve modules have rectangular cross-sections, each 400 x 181 x 101 mm: they shall be combined together in quantities depending on the airﬂ ow capacity required and assembled in factory-made retaining frames. Said assemblies shall be installed in situ by welding the valve retaining frame onto a counterframe provided at the opening to be protected, or by bolting on the concrete wall.
The blast protection valves shall be selected for withstanding an external explosion overpressure of at least 6.5 KPa (0.065 bar) and a maximum of 1 bar lasting 100 ms. The blast valves shall be also selected for a pressure drop not exceeding 250 Pa.