CGA 600 thread sizing

[pozidriv]

Hi,

I'm a bit lost in the colourful world of connections and fittings, so here's a thread about threads

I've been reading up on the different systems; BSP, UNF, NPT, whithworth and whatnot. But what actually prompted this search is still a mystery

Somebody gave me a soldering/brazing torch, very similar to a bernzomatic ts-something. I've found that it has a female CGA 600 fitting, but locally I can't find any propane or mapp bottles with that threadform. Here (I think this applies to the whole of Europe), most of the bottles in that size come with a 7/16 connection. I'm guessing that's 7/16 in BSP sizing, not NPT or UNF, but I'm not sure on that.

So what is CGA 600 exactly? Is it a proprietary threadform that litteraly fits nothing standard? Closest I could find was this pdf (www.asge-online.com/pdf/ASGEpg187.pdf), but ofcourse it lists over 35 CGA types, BUT the freaking 600.

Here I read: "connection 600 is the limited standard valve outlet for gaseous withdrawal of propane". Useful...

Why so complicated and hidden? Can someone enlighten me?

 

[6PTsocket]

If you are talking about the disposible 14oz and 16 oz bottles used on hand held torches, lanterns and small stoves in the US, my research just came up with 1"-20 as the thread size. That is a straight thread, not NPT.

Sent from my SM-G900V using Tapatalk

 

[rlitman]

It is commonplace here on disposable 14oz tall and 16oz fat LPG bottles, though I've seen it also used on some slightly larger refillable bottles for camping and boating use.

CGA fittings are intentionally proprietary, just as NEMA plugs are. They are used where connecting the wrong gases together can do bad things.

 

[pozidriv]

Ok, thanks, with a few more search terms, it seems that the cga600 is maybe a 1"-20 UNEF thread?
EU bottles however seem to use a 7/16" - 28UNS thread, UNS standing for Unified National Special.. What is actually meant with the special?

Also, I find it weird that the european standard would use an obscure US thread size. Is it possible that the EU 7/16 is actually based on a British Whitworth standard, but sort of relabeled in the US as a UNS thread?

 

[rlitman]

UNC is coarse, UNF is fine, UNS is special, where special is even finer than fine.
No, I do not think it possible that a UNS overlaps with a Whitworth thread.

 

[pozidriv]

Oh yeah, you're right, there's a different thread angle involved (60° vs 55°).
I got those designations from these adaptor links:
https://www.amazon.com/dp/B01CO3JYTI/?tag=atomicindus08-20
http://www.ebay.ca/itm/151644219328

Could be that they are mistaken, because on this very useful website:
http://www.gewinde-normen.de/en/unified-special-thread.html

they don't even list an UNS with 7/16 - 28, a UNEF 7/16 - 28 does exist and would (to me) make more sense.

 

[ttpete]

Here's a listing of US and Euro connections:

https://www.tedpella.com/company_html/Compressed_Gas_Cylinder_Outlet_Connections.htm

 

[pozidriv]

Thank you for that link Pete, but again it doesn't list the CGA-600, weird cause it must be a really common fitting in the US?

Also the connector threads on that page revealed another standard: NGO. From what I've read it seems to be similar to NPT but with tighter tolerances and longer.

It just doesn't end...

 

[ttpete]

Thank you for that link Pete, but again it doesn't list the CGA-600, weird cause it must be a really common fitting in the US?

Also, the connector threads on that page revealed another standard: NGO. From what I've read it seems to be similar to NPT but with tighter tolerances and longer.

It just doesn't end...

The CGA 600 is the thread on a Bernzomatic propane cylinder. It's 1"-20 UNEF. There are regulators made so those small cylinders can be used for larger gas grills.