MH chose the best material for the O-rings, Vitton/FKM made with Fluorocarbon.
Better than silicone, they are heat and Iso resistant and have about 15 years for shelf life.
From the Tempest design, no air/vapor flows directly on the 8 O-rings, but the one that keeps the Secondary Cooling Unit in place is pretty close though.
Some spares O-rings already come with the Tempest Titanium or Wood Kit, but to get a spare bigger O-ring for the Radiator insert/Heatshield, is only from this O-rings kit.
If you want to use the Secondary Cooling Unit (MP spiral) and keep the Mouthpiece from spinning freely, you have to add a second small O-ring to the Airflow tube.
With the Mouthpiece on locked mode, turning it can spin and change the older Revolve V1V2 DRC airflow tube setting, inside the Cooling Unit.
Always condition them after a liquid bath, choose your weapon; wood conditioner, saliva, nose grease, reclaim, I prefer Vegetable Glycerin or unscented lip balm.
When I use the quartz sleeve or any glass stem, I do not moisturize the Bowl O-rings as much, to keep the Bowl from spinning too easily.
Overall, the Tempest O-rings tolerance is better than the Revolve stem, which was already nice.
From the online manual:
"The double o-rings next to each other on the Tip and Cooling Unit are different sizes.
You can find the specific sizes on the airflow diagram below where the sizes are marked with different colours. (ID x CS mm) 7x1mm - Green, 6x1mm - Grey , 5x1mm - Black."
The text isn't right next to the diagram so...let's complete it
Top to bottom / MP to Bowl
Airflow tubes ; inside the Cooling Unit O-ring ; Second outside of the Cooling Unit O-ring ; First near the stem, Bowl O-ring = 5mm Inside Diameter x 1mm Thickness = 7mm Outside ø
First outside (near the Mouthpiece side) of the Cooling Unit O-ring ; Second near the Bowl screen, Bowl O-ring = 6mm ID x 1mm (Dynatip size)*
Tempest Radiator insert/Heatshield O-ring = 7mm ID x 1mm
*can be changed to 5mm ID x 1 mm for a looser fitment, but be careful, if your handling is strong (Reload magnet), for unwanted Bowl or CU disassembly.
Depending on the stem, using two 6mm ID x 1mm O-rings for the Bowl could make a better fit.
