A pressure relief valve for a container having a liner therein for holding
food products includes a hollow body incorporated into a lid of the
container and extends inwardly therefrom. A cutter member is mounted in
an opening at an outer end of the body and has a knife extending inwardly
through the valve body. A piston is slidably connected to the body and
has an opening therein for receiving the knife and a compression spring
is mounted around the knife and positioned between a top of the cutter
and a bottom of the piston to bias the piston inwardly away from the
wall. Pressure buildup in the liner causes the liner to expand and push
the piston outwardly towards the lid to expose the knife which then
punctures the liner and relieves the pressure therein and allows a
product to be discharged from the container through the valve.