Sodastream thread size

[Sausages]

I use a sodastream bottles connected to a CO2 regulator using an adaptor (its this one from Malt Miller)
Had no issues with the first sodastream bottle on it at all.
Just bought a second bottle and the damn thing doesn't work!
The bottle screws onto the adaptor most of the way but jams up near the end. No gas is coming out so I assume it's stopping before the pin contacts the valve in the bottle.
The threads on the new one are slightly thicker then the old bottle. The outer diameter is the same, it's just the thread form itself is a bit thicker, and hence the gap between each is a little tighter. The new bottle is otherwise identical to the old one, both 425g bottles (the blue ones not the pick ones).
Has anyone encountered similar before? I thought I'd seen a thread on a similar issue but can't find anything.

 

[peebee]

This was baffling at first. Sodastream haven't changed the thread for eons. It's a weird "trapezoid" thread designated "TR21-4". The thread on the regulator is equally weird but more "normal" looking - W21.8-14. Originally Sodastream used 1/2" BSPP, and still do in Australia area (it is "normal" looking).

Enough of that! I don't think thread size is your problem.

The adapter has a pin. If it isn't adjusted (screwed) just right it will either fail to open the cylinder (not protruding enough), or, as seems to be with you, protruding too much forcing the valve on the bottle to shut again (and it stops the adapter being tightened further). I think this is a "made for Sodastream only" device, but a bit lame if it is.

Screw back the pin until it stops closing the valve. Or put in another sealing washer (check it's still there first!).

 

[Brewelder]

This was baffling at first. Sodastream haven't changed the thread for eons. It's a weird "trapezoid" thread designated "TR21-4". The thread on the regulator is equally weird but more "normal" looking - W21.8-14. Originally Sodastream used 1/2" BSPP, and still do in Australia area (it is "normal" looking).

Enough of that! I don't think thread size is your problem.

The adapter has a pin. If it isn't adjusted (screwed) just right it will either fail to open the cylinder (not protruding enough), or, as seems to be with you, protruding too much forcing the valve on the bottle to shut again (and it stops the adapter being tightened further). I think this is a "made for Sodastream only" device, but a bit lame if it is.

Screw back the pin until it stops closing the valve. Or put in another sealing washer (check it's still there first!).

I have recently bought a regulator from AliExpress so i can connect a soda stream bottle to my Fermzilla, basically cos I’m too lazy to disconnect my full size Co2 bottle from my kegs. ( I ferment in a different place to my kegs)

Anyway, where can i get an adaptor to fit the male W21.8-14 thread on the regulator so I can hook up some tubing and a quick disconnect fitting?

 

[peebee]

A male W21...y-thingy-thread on the regulator? It's a male thread on a CO2 cylinder. Best if you describe what you're up to in more detail?

Anyway, an adapter to hook up some tubing? It does need to be very specific tough tubing, and I'm too terrified to attach even the properly rated flexible tubing direct to a gas cylinder! It's a lot of pressure, even for CO2 (which being a liquified gas is under far less pressure than found in nitrogen, mixed gas, etc. cylinders). Approx 57 BAR I think ... that's (57x14.7) PSI. Give or take 100 or 200 PSI if I have the detail slightly wrong (don't matter, the bang sounds just as loud).

 

[Brewelder]

A male W21...y-thingy-thread on the regulator? It's a male thread on a CO2 cylinder. Best if you describe what you're up to in more detail?

Anyway, an adapter to hook up some tubing? It does need to be very specific tough tubing, and I'm too terrified to attach even the properly rated flexible tubing direct to a gas cylinder! It's a lot of pressure, even for CO2 (which being a liquified gas is under far less pressure than found in nitrogen, mixed gas, etc. cylinders). Approx 57 BAR I think ... that's (57x14.7) PSI. Give or take 100 or 200 PSI if I have the detail slightly wrong (don't matter, the bang sounds just as loud).

Basically what i have is the soda stream regulator, with a female thread that screws onto the soda stream gas bottle (think it’s the TR21. The other thread (outlet) is a male W21.8-14.

I’m not concerned with the pressure as the tubing is the usual 5/16” or 8mm in new money that i use on my full size cylinder. The soda stream regulator is just that, it regulates the output pressure so can be turned down to zero if needed.

I want to hook it up to my Fermzilla to use during closed transferring. Basically i need to get from the W21.8-14 down to either a barbed fitting or John Guest push in type fitting if that helps?

 

[peebee]

Panic alarms start ringing in me 'ead when people start asking for adapters to connect threads that should only be found on the cylinder pressure side of a regulator. I know you can get such adapters from Chinese sources, but they have a different attitude to such things over there, and I prefer not to encourage such attitudes.

A *regulator* with a TR21-4 high pressure input and W21.8-14 "low pressure" output makes no sense to me (I may have confused you with my earlier description?). I'd need a picture.

As I still can't understand why you want to connect a W21.8-14 thread to a "low-pressure" (<10 BAR) circuit (and there may be "legitimate" reasons - all dodgy!) I stay "Mum"!



W21.8-14 threads are very specific to high pressure gas cylinder use. Figure out what the letters and numbers actually mean - if you head allows you to handle such illogical thinking - and you will understand why I know them to be specific (I am already deranged and therefore immune to such madness).

Do be warned, a "full size cylinder" of liquid gas holds exactly the same pressure as a tiny cylinder. But being a lot heavier is capable of more damage if anything goes wrong.

 

[Brewelder]

Panic alarms start ringing in me 'ead when people start asking for adapters to connect threads that should only be found on the cylinder pressure side of a regulator. I know you can get such adapters from Chinese sources, but they have a different attitude to such things over there, and I prefer not to encourage such attitudes.

A *regulator* with a TR21-4 high pressure input and W21.8-14 "low pressure" output makes no sense to me (I may have confused you with my earlier description?). I'd need a picture.

As I still can't understand why you want to connect a W21.8-14 thread to a "low-pressure" (<10 BAR) circuit (and there may be "legitimate" reasons - all dodgy!) I stay "Mum"!



W21.8-14 threads are very specific to high pressure gas cylinder use. Figure out what the letters and numbers actually mean - if you head allows you to handle such illogical thinking - and you will understand why I know them to be specific (I am already deranged and therefore immune to such madness).

Do be warned, a "full size cylinder" of liquid gas holds exactly the same pressure as a tiny cylinder. But being a lot heavier is capable of more damage if anything goes wrong.

I understand your concern, re: Gas bottles exploding etc, i work in the fabrication industry and have seen a few, well, 2 explosions due to incorrect use/handling, thankfully neither were fatal. However, one did blow a hole in the factory roof, some 40 feet up, travel across a river (canny wide river) and hit an unsuspecting fitter in the adjacent ship yard.

Anyway, see below for sowing like what I’m looking for. The regulator i have already, it’s the fitting that connects to the outlet that i need. Outlet is W21.8-14, or so I’m lead to beleive. I’ve never come across this thread size and am told it’s a gas thread, it’s parallel and slightly over half an inch.

The photo below shows it connected to a keg for dispensing, however i want to apply a few pounds of pressure to my Fermzilla for closed transfer purposes. As mentioned earlier, i have a full sized, 6.5kg cylinder, but it’s hooked up to my 2 Corny’s and is a right pain to remove and drag round to the garage where i ferment, hence a nice little handy sized soda stream cylinder set up.

Hope that helps and if you know of anywhere that i can get an adaptor it would be greatly appreciated.

 

[peebee]

Right ... got it! And I have possible befuddled you with my original reply.

The regulator pictured has a TR21-4 nut and it is made for use with the Sodastream cylinder. The output of that regulator is screwed on to an 1/8" thread (by the looks) and will likely be American NPT thread or possibly BSP (BSP, although the "B" is for "British", is widely used in the rest of the world ... or the equivalent because some are sensitive to the "British" connection!). NTP and BSP are not remotely compatible at these sizes. There's no W21.8-14 (Whitworth, a Victorian chappie, 21.8mm, 14 threads per inch ... get it!) thread in the picture, which will be on your big cylinder (not pictured) and mentioning it has caused our confusion.

So, you don't need an adapter!

Others here are surely using Sodastream for closed-transfers from a Fermzilla and they should chip in (I don't have a Fermzilla). You should be able to use the Sodastream assembly (with disconnect) as-is if you can turn the regulator down enough (you only need 1 or 2 PSI for a few minutes). I'd have a good over-pressure device to avoid accidentally busting the Fermzilla, but you won't be busting yourself! Surely the makers of Fermzillas have instructions?

 

[Brewelder]

Right ... got it! And I have possible befuddled you with my original reply.

The regulator pictured has a TR21-4 nut and it is made for use with the Sodastream cylinder. The output of that regulator is screwed on to an 1/8" thread (by the looks) and will likely be American NPT thread or possibly BSP (BSP, although the "B" is for "British", is widely used in the rest of the world ... or the equivalent because some are sensitive to the "British" connection!). NTP and BSP are not remotely compatible at these sizes. There's no W21.8-14 (Whitworth, a Victorian chappie, 21.8mm, 14 threads per inch ... get it!) thread in the picture, which will be on your big cylinder (not pictured) and mentioning it has caused our confusion.

So, you don't need an adapter!

Others here are surely using Sodastream for closed-transfers from a Fermzilla and they should chip in (I don't have a Fermzilla). You should be able to use the Sodastream assembly (with disconnect) as-is if you can turn the regulator down enough (you only need 1 or 2 PSI for a few minutes). I'd have a good over-pressure device to avoid accidentally busting the Fermzilla, but you won't be busting yourself! Surely the makers of Fermzillas have instructions?

Crises averted and thanks for all the valuable info, it has been very helpful indeed.

That said i have since found an alternative way of getting C02 into the Fermzilla, basically found another valve to use instead of paying around £60 for an adaptor, i found the below for less than £30, tubing i already have as well as the disconnects required to connect to the Fermzilla gas in post.

This screws onto a soda stream bottle and has an 8mm barbed outlet so that will work fine and means i can stop stripping my main cylinder from my serving set up.