Digital Spunding Valve idea

[brewtodrinktobrew]

Hello all,

I am fermenting in a 15.5 sanke keg using NorCals Ultimate Snake Keg Cross system. I have been tossing around the idea of building a digital Spunding Valve for my fermenter. By my research it is clear that a digital air pressure regulator will not work because it is intended for pressure reduction on the inlet side. I have read some things about hooking up a regulator backwards but that seems pretty iffy. While browsing Amazon I found a digital air flow regulator. This seems like it may be the answer I am looking for. I went ahead and ordered one, should be here in a few days. I will update this thread with my findings. Let me know your thoughts on this idea.

NorCal's Ultimate Sanke Keg Cross System
https://www.norcalbrewingsolutions.com/store/Ultimate-Sanke-Keg-Cross-Fermenter-Kit.html
Digital Airflow Regulator
https://www.amazon.com/Lematec-Regu...t=&hvlocphy=9008493&hvtargid=pla-571295447901

 

[brewtodrinktobrew]

So an update on this project. The digital air "flow" regulator didn't work. Again, it is regulating how much flow is on the output not releasing the pressure in the Keg to meet the needs of the requested pressure. It is not all lost as I ordered an adjustable 1/4" MPT Pressure Relief Valve from Amazon should be here Wednesday. I am going to install it on the output side of the air flow regulator. I am confident this will work. Essentially, The digital air flow regulator will just be a digital gauge and the normal spunding valve T.

I still think this will still end cheaper that building a standard spunding valve with a T and all the adapters to connect everything. I also think it looks much cleaner and more pleasant to look at.

Link to the Adjustable PRV

https://www.amazon.com/gp/product/B007GDY3CU/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

 

[Mr. Vern]

I do not think you will have much accuracy for relief in the bottom 6% of that 0-100 PSIG range, I may be wrong. Seems cheap enough for a test! The spring tension may vary +/- 10% which is accounted for in ASME code for most pressure-relief devices (gas side). Also, check the accuracy of your pressure transducer, often they have poor accuracy in the 4-6 PSIG range. Lematic does not even list accuracy of scale on their 2.5-160 PSIG device other than "accurate", I would add an analog gauge to compare. You are playing in the very bottom of scale which lessens accuracy even further.

The precise instrument for pressure control is a BPR (Back Pressure Regulator), basically what the spunding valve setup is doing. They are not cheap.

A less precise approach may include a pressure regulator and relief valve, you may want to pipe a short nipple between relief and regulator to provide a little space and help prevent any turbulent issues when that relief pops (for 1/4" NPT I would go 3/4" nipple to the relief valve, minimum 2 pipe diameters) You may find that the spring tension will close early/late as the valve starts to "simmer". As you are experimenting I recommend you also add a pressure gauge on the INLET and OUTLET of the regulator to verify performance. Swap out the coupling for a Tee and you have a pressure sensing location. 4-6 PSIG range might be a bugger to hold on this setup.

I look forward to hearing what you get into!