I'm headed down the road to fermentation in corny kegs and the next step is construction of a nice, solid spunding valve (for fermenting under pressure, which along with Fermcap will reduce krausen and allow natural carbonation and maybe other benefits, plus transfer under pressure to a serving keg). Poindexter and WortMonger have previously posted very detailed information regarding this handy apparatus.
Spunding valve - video
- shows how Poindexter put it together
Closed-system pressurized fermentation technique!
- Post #39 in particular includes some McMaster part numbers
It's been several years since those posts. Following those instructions, and wishing to put together something as functional and solid as possible, I came up with the following McMaster-Carr parts list-
$31.64 - 99045K46 - Adj Pressure-Maintaining Plastic Relief Valve 1/8 NPT Female, 0.5-60 PSI (recommended by WortMonger)
$45.48 - 4066K512 - Stainless Steel-Case Gauge +/-2% Accuracy Dry, 2-1/2" Dial, 1/4" NPT Male Ctr Back, 0-60 PSI (recommended by WortMonger)
$12.58 - 5469K101 - Aluminum Manifold 2 Outlets, 1/4" NPT Inlet X 1/8" NPT Outlet
$1.29 - 4830K111 - Std-Wall Type 304/304L SS Thrd Pipe Nipple 1/8" Pipe X 3/4" Length, Fully Threaded (To connect the relief valve)
$2.44 - 4464K331 - Type 304 Stainless STL Threaded Pipe Fitting 1/8" Pipe Size, Hex Head Plug, 3000 PSI (Plug the extra hole in the manifold)
$3.23 - 5670K84 - Type 303 SS Multi-Barbed Tube Fitting Adapter for 1/4" Tube ID X 1/4" NPT Male Pipe
I like the idea of the manifold construction rather than putting it together with a tee and a bunch of tubing. I believe this would give me everything I need right up to the 1/4" barb to connect to the gas line on my corny keg. (Anyone with bright ideas on how to directly build the gas connect into this, maybe using one of these stainless steel bad boys
, I'm all ears.)
The gauge and pressure relief valve are obviously the bulk of the cost. People also mention parts from Grainger-
Pressure Relief Valve
That would bring the cost for those two parts down to the $30 range instead of $80ish, and the whole project to about $50 instead of $100. I'd just need to use a slightly different arrangement on the manifold.
Any thoughts on how to approach this project? Better to use a 0-30psi gauge for finer control? Different materials? This will spend some time in a fermentation chamber with some potential for condensation. The other possibility is a loss of krausen control and that for some foam (or more than foam, I guess) to come through here, but that's not the plan. Maybe add a check valve of some kind