My camp stove is an Optimus Nova+. It’s a good little stove that has served us quote well. One thing I noticed was the some of the O-rings were starting to get a bit worse for wear.

The gray one in the front is from the connector of the hose to the fuel bottle. I don’t know how hard it is, but I can tell you that it’s softer than a Durometer 75 by bunches.

That’s where it was prior to replacement… but more on that later.

The blue ones in the back are the ones where the hose connects to the stove itself, and that’s later too. One thing I did notice is that all of them are the same size. So I went and measured them.

They are right around .251″ outer diameter (OD). Looking at my sources (Amazon and McMaster-Carr) this is a #006 size o-ring. The actual OD is 0.254 and ID (inner) is 0.114″. This is close enough to what I’ve measured — especially since I’m sure I’ve compressed it a bit in the measurement. I went and ordered a pack of them. They’re around $0.04 each in packs of a 100 for the goo Viton type.

When I opened them up yesterday I couldn’t help but actually laugh out loud.

So many little circles!

They fit perfectly as you saw earlier. Same with the spindle end of the hose.

Basically, fuel squirts out from just past the O-rings, past the threaded bit on the right and gets metered out to the stove through an orifice that the needle on the right. Since the fuel is pressurized by the tank, the O-rings on the hose prevent fuel from squirting out, which is important when you have a flammable liquid right next to open flame!

You would think that I have measure before with the micrometer, but you’d be wrong.

The measurement I was interested in was one of heat. Would the new O-rings survive on the stove end? You saw up front that the rings were blue. Blue O-rings are typical of fluoroelastomer O-rings which are typically rated as high temperature. McMaster, for instance, sells blue mil-spec ones rated to 450-F, but they are pricey. You can even get ones rated higher but you get stratospheric in price by that point.

The ones I got are rated to 400-F. Time to check what the heat is. Time for the Fluke! :-D

All the way at the stove end is less that 400-F! Sweet!

Where the O-rings live is around 170-F. Nice and cool! (Oh, and the stove is on when I’m taking these pictures. The flash was brighter than the flame by bunches!)

The spindle itself is only 125-F. So the O-rings are somewhere in between with plenty of safety margin!

Just shot of how hot this thing really gets! Based on the color this is between 900-1000-F for the inner enclosure!

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