A pressure relief valve for packages in which the valve element comprises 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 {HEAD ~ excess} of a predetermined value to permit gas outflow from the package 
A pressure relief valve for packages in which the valve element comprises 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 { HEAD ~ excess } of a predetermined value to permit gas outflow from the package
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH