Magefesa 09REMEJUST12 Star Pressure Cooker Gasket, 12+ Qt. Suitable for STAR 12 - 14 Qt. / ALUSTAR 16 - 23 Qt. Diameter: 10.5 Inches Remove the worn gasket and clean the channel of the lid housing carefully. The Silicone gasket is considered worn out once the pressure cooker looses steam from the side. For your safety we recommend that you change the gasket every two years. Moisten the new gasket into the channel of the lid housing. Helping yourself with a spoon, press the sealing gasket all around against the lid until it gets completely fitted into the channel of the lid housing.