All Your Green Blog

I received this question recently regarding the Sport Cap 27 oz. Klean Kanteen. Until then I hadn't really considered how I actually use a sports bottle.

On a plastic sport bottle, you can normally squeeze to get water out. With stainless steel, the only thing you can really do is suck on it (which some people did with plastic bottles anyway, and some manufacturers intended based on their mouth-contoured cap). Realizing that the balance of pressure would be a problem, Klean Kanteen added a pressure release nub(the little clear plastic thing next to the mouthpiece), so air can get in to replace the volume of the water you're drinking.

When you're not using the bottle, that release nub is in closed position, mounted so that it's pressed up against the hole it's fit into, sealing it. When the pressure is less on the inside of the bottle than on the outside (when you're drinking), the air pressure pulls that little plug in, allowing air to replace the water volume, and normalizing the pressure. Although, because there is limited real estate on a bottle cap, the pressure release is close to the mouthpiece, if you drink quickly, you may get some bubble feedback.

I encourage any and all questions you have! I love taking things apart and figuring out how and why they work, so no question is too silly or trivial! I will figure it out or die tryi... well that's overly melodramatic, but I'll try real, real hard to provide you with a satisfactory answer.