Cookers are no more simple cooking utensils of the yesteryear where there was not an iota of safety element built-in. Cookers have come a long way since the World War II and in addition to having countless safety features, they are also aesthetical and eye pleasing plus user friendly, not to mention their functionality and utility.
Ever since man discovered cooking was delicious than eating raw, cookers began commanding kitchens across the globe. Modern cookers come in a huge variety of designs and safety features. Still others like the solar variety sport the smart tag of not consuming any power at all.
Pressure cookers have features characteristic of their categories. Rice cookers have single inside containers while normal cookers comes with multi deck containers. Another distinguishing feature of rice cookers is relatively thinner construction.
Cookers provide pressurized (10Ksc) cooking which helps cook 30-50% faster. Cooking under sealed condition, as dictated by high pressures, has dual advantages. One: Faster cooking saves time and energy; two: prevents loss of nutrients.
Pressure cookers build up to 10ksc of pressure in quick time. This asks for fail proof safety features. A release valve lifts off just before the threshold pressure is reached regulating the inside pressure. The gasket in the lid expands and comes out of a recess in the lid when the release valve fails to operate or reduce pressure even after operating. Of course, the gasket has to be replaced later. Another important safety feature is the blow off safety valve. This operates only when both the above fail. This is directly fitted to the top of the lid and is made of a special alloy of aluminum which melts exactly at the threshold pressure.
The body is made of extra strong aluminum of thickness 5mm. The bottom is 10mm thick in some models. The lids are designed to fit either from inside or outside depending on the design. Inside lids are safer than the other design as their entire rim grips the mouth better under pressure. The electric variety cookers have thermostats which switch off at a particular temperature preventing higher pressure buildup.