The cooker base houses the microprocessor, pressure and temperature sensors, a heating element, and the control panel.
The microprocessor is the heart of the 3rd generation electric pressure cooker, and works with the built-in sensors to monitor and automatically regulate the cooker’s pressure & temperature based on the smart program selected.
Periodically engaging the heating element to maintain a stable temperature and level of pressure creates a ‘positive feedback’ loop, and results in precise cooking conditions. If any unsafe conditions are detected, the cooker will signal the error with a beep and cut off power to the heating element.
Instant Pot lids are made of strong 201 food grade stainless steel, and use steel braces as well as a lid locking mechanism to prevent the lid from being opened while the cooker is pressurized. If the lid is not fully closed, the microprocessor detects this and will cut power to the heating element.
The lid is comprised of several small parts that work in tandem to seal in and regulate pressure:
Steam Release: Although these differ in appearance across models, the steam release has two positions— “Venting”, which allows steam to escape, and “Sealed”, which traps steam in the inner pot in order to build pressure. If pressure increases beyond the safe operating range, the excess steam will physically push up the steam release valve to release pressure.
Sealing Ring: When the lid is closed and the steam release is set to the “Sealed” position, the lid and the inner pot exert pressure on the sealing ring to create an airtight seal. The sealing ring is made from durable silicone rubber, which allows pressure to safely build once heat is applied.
Float Valve & Silicone Cap: When enough pressure builds up in the inner pot, the float valve is pushed up and the silicone cap fully seals the cooker. Once pushed up, the float valve serves as a latch lock and prevents the lid from turning, even when force is applied.
The float valve pin can be destroyed by excessive temperature or pressure. Without the pin, the hole allows pressure to escape. Although in such a case the float valve is permanently damaged and a lid replacement may be required, this is an effective last line of defense from a safety perspective. Instant Pot employs a patented push-down pressure release mechanism to release excess pressure, even in the unlikely event that the float valve cannot be destroyed.
Anti-Block Shield: This stainless steel cover prevents food particles from clogging the steam release pipe, facilitating the steady release of steam when venting.