A pressure relief valve for packages in which the valve element comprises {HEAD ~ a liquid impregnated porous element} covering {TAIL ~ outlet openings} in the package, with the liquid layer in the porous element being torn open by package contents pressures in excess of a predetermined value to permit gas outflow from the package 
covering
A pressure relief valve for packages in which the valve element comprises { HEAD ~ a liquid impregnated porous element } covering { TAIL ~ outlet openings } in the package , with the liquid layer in the porous element being torn open by package contents pressures in excess of a predetermined value to permit gas outflow from the package
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