O-ring LP hose 1st stage size

[Downunder_WPB]

I'm trying to get into basic maintenance like replacing o-rings and such on the LP/HP hoses.

I bought a whole slew of 90 DURO Vinton o-rings from Orings and More | Affordable and Quality Gaskets and Seals.

I'm particularly interested in the LP hose where it meets the 1st stage. Do I use an 010 or 011 o-ring there? The 010 is a snug fit and the 011 seems a bit loose.

Most website I've checked out say:

010 LP Hose / 2nd Stage
011 Standard 3/8" LP Port

To me the `/` means or so can a 010 be used for this purpose?

My 1st stage has 3/8 LP ports.

 

[runsongas]

they mean to use 010 for the oring inside the lp hose fitting to the 2nd stage, not on the side that connects to the first stage.

the 011 should be ok being a little loose.

 

[tbone1004]

supposed to use 70/75 duro on the LP side, 90 for static HP o-rings only. 90 duro's like to shred on the hose end.
011 is the port plugs and the first stage side of regulator and LPI hoses
010 goes inside the end of the reg hose that @runsongas posted.
Only 1/16" OD difference, but do not mix them if you can help it. The second stage side especially as that one tends to get pinched and shred really easily as it is a dynamic o-ring

 

[rsingler]

But a 90 duro oring is too hard for that application. When you thread the hose into the bore of the regulator barrel, it is more likely to shear, especially if you use a 2-011.
I would recommend a 70-duro 2-010. And some old G250 regs with slightly narrower bores actually need a 2-90x, where x is a number I can't recall off the top of my head.

Oh, tbone beat me to it, lol!

 

[Downunder_WPB]

Thanks guys for all the responses! Appreciate the wealth of information.

Just because I want to understand, I get the shredding possibility however aren't all LP hoses where they connect to the 1st stage 'static' because they don't actually move except when screwed in and unscrewed?

I used this as reference when buying: Viton Master O-Ring Kit, 50 Pieces

Says: "These fluorocarbon elastomer (aka Viton®, aka FKM, aka FPM) O-rings are brown color and 90-duro (except for the -003 O-rings, which are 75-duro)."

Another point was that my Sherwood Oasis came with definitely 90 duro o-rings in the LP port as they are as think as the ones I bought when compared to the ones that I was replacing in the other hoses.

Perhaps traditional o-rings, not Viton are more likely to shred?

Again not trying to dispute anything just trying to understand

 

[tbone1004]

@Downunder_WPB thickness is not durometer. Durometer is hardness and it is independent of dimension.

The first stage side aren't going to be a problem at 90 duro, but the reg hose side is not going to last as long as a lower durometer

 

[Downunder_WPB]

@Downunder_WPB thickness is not durometer. Durometer is hardness and it is independent of dimension.

The first stage side aren't going to be a problem at 90 duro, but the reg hose side is not going to last as long as a lower durometer

Yea I meant "hard" as in when I squished it. But I'm not expert. Point taken on the reg side. That o-ring there is factory new so I don't have to replace it anyways. For the 2x SPG swivel 003 orings would you also say 70? Seems like all HP stuff is at 90. I know I should lube it a bit with Christolube as that one is for sure dynamic.

 

[rsingler]

Good deduction on that swivel o-ring. But the problem is that stretching that tiny 003 over the spindle usually cracks it. It's so well trapped inside the HP hose that a 70 actually works just fine. You can use a 90 on a few spindles with really tiny ends, but most won't accept anything but a70.

 

[herman]

I wouldn't bother with that kit. Way too expensive and there is no need to spend the extra on Viton. While they will last longer in an high O2 environment, it's not an issue in scuba reg orings since you tend to replace them way before O2 damage becomes an issue. Nor are they necessary with rec nitrox mixes. Even if you go with Viton, it's much less expensive to buy the ones you need directly.....Viton 011s are about $6/100, nitrile are $3.50/100.

As for the first stage end being static, it really isn't. Since it moves past it's mating surfaces while being installed, it is by def not static. To be truly static it can never move against its mating surface...an example of a true static oring is the yoke tank to reg oring

 

[Downunder_WPB]

I wouldn't bother with that kit. Way too expensive and there is no need to spend the extra on Viton. While they will last longer in an high O2 environment, it's not an issue in scuba reg orings since you tend to replace them way before O2 damage becomes an issue. Nor are they necessary with rec nitrox mixes. Even if you go with Viton, it's much less expensive to buy the ones you need directly.....Viton 011s are about $6/100, nitrile are $3.50/100.

As for the first stage end being static, it really isn't. Since it moves past it's mating surfaces while being installed, it is by def not static. To be truly static it can never move against its mating surface...an example of a true static oring is the yoke tank to reg oring

I didn't actually buy that kit because I agree it was way to expensive. I just used it as reference when I got them from an o-ring supplier which was considerably less expensive. Spent like 12 for 5x packs of 25 for all the different sizes I might need. Are you suggesting to not use 90 duro for the LP ports? Seems to me that is the general consensus.