[joedelong]

So, I'm instrumenting my kegerator with three scales, temperature monitoring (Kegerator and fermentation chamber) and CO2 pressure monitoring.
I encountered an issue when it came time to insert a 2500 PSI pressure sending unit on my CO2 primary regulator. Left Hand Threads... the sending unit has 1/4 in RHT NPT Male but I could not find a Tee with 1/4" male LHT x 1/4" Female RHT x 1/4" Female LHT. If anyone has an idea of how to resolve the issue other thank getting rid of the high pressure gauge it would help. I did find a 1/4" male LHT to 1/4" Female RHT adapter with will allow me to replace the gauge with the sending unit (I want my cake and to eat it too).

[Slowbrew]

You probably need to get to all RHT to start with. Maybe one of these would work: https://www.homebrewing.org/Hex-Nipple-LHT-to-RHT_p_3203.html

You might need some other convertor too but something like this would get you to all one thread type at least.

Paul

[joedelong]

I am able to get out of the LHT world but to use my existing gauge I need to get back in. I cannot find a female LHT to male RHT adapter.

[Richard]

Left hand threads are used on oxygen tanks to avoid getting them mixed up with other gases. Thread converters allow one to bypass this safety measure and are considered dangerous. Some vendors will not carry them, so they are hard to find. I know of a lab at UCF that blew up their building because their gas vendor regularly mixed up threads and the lab had a lot of adapters on hand. One day they accidentally pressurized their Van de Graaff generator with oxygen instead of nitrogen. BOOM! Lesson learned, but a bit late. Fortunately there were no deaths.

You should use all RHT since you are not using oxygen.

[joedelong]

Hi Richard,

I agree and was surprised when I found the regulator had left hand threads. I wonder if there is a regulator available that has all right hand threads as this would solve my problem the easy way.

This also explains why adapters are not readily available.

Cheers,
Joe

[joedelong]

I found and ordered this regulator (turns out cheaper than a bunch of adapters) Does anyone have this regulator and can confirm the high pressure gauge has right hand threads?

MRbrew CGA-320 Keg Regulator, Quick Disconnect CO2 Kegerator Regulator with Pressure Adjustment Knob, Beer Regulator with Safety Manual Pressure Relief Valve, with 2 Swivel Nut & 1/4’’ & 5/16’’ Barbs

[Richard]

CGA-320 is specifically for carbon dioxide use, so it should be Right Hand Threads.

[joedelong]

So the new regulator works correctly, right hand threads and all. found I needed both PTFE pipe tape and liquid pipe sealant to stop it from leaking. Anyway, I now have the pressure sensor and gauge working properly. Feeding pressure and weight back to the Raspberry Pi single board computer. As well, it's displaying properly on the GUI. Cool addition, I'll get an email notification when I run low on CO2 (or beer for that matter). This is what happens when engineers get bored from COVID-19 shelter in place orders...

Thanks for the tips...

[goose]

So the new regulator works correctly, right hand threads and all. found I needed both PTFE pipe tape and liquid pipe sealant to stop it from leaking. Anyway, I now have the pressure sensor and gauge working properly. Feeding pressure and weight back to the Raspberry Pi single board computer. As well, it's displaying properly on the GUI. Cool addition, I'll get an email notification when I run low on CO2 (or beer for that matter). This is what happens when engineers get bored from COVID-19 shelter in place orders...

Thanks for the tips...

Being an engineer, I am sure you know this.  But it needs re-stating for others that might not realize this.  I posted this a couple years ago on this forum


A word of safety is warranted here.  DO NOT use something anything that is not high pressure rated to connect regulators together at the high pressure gauge point (the place where the 1000 lb gauge is located on the first regulator).  First of all the high pressure gauge is normally left hand thread an the outputs are right hand thread.  Secondly, something like threaded brass pipe (which I used to connect a very low pressure gauge)) is only rated for a couple hundred pounds of pressure and the output from the CO2 cylinder can be in the vicinity of 800-1000 lbs.  This could result in a catastrophic explosion of the non pressure rated pipe on a high pressure connection.  Be careful, don't connect anything to the high pressure gauge port other than a high pressure gauge.  Alternatively, buy a double gauge assembly from a LHBS or a mail order homebrew shop to be totally safe.

[joedelong]

Very good point. Yes, when doing this modification all components I used were rated at >2500 PSI operating pressure with a burst pressure of twice the nominal maximum.