There are many, many methods out there that brewers use to perform what is effectively the same operation but meet different needs. Basically, it all depends on your needs and how you want to set your system up.
The Sparge Arm we sell is intended to implement the "fly sparging" technique to get an even distribution of water on the top of the grain bed and was developed for use with sparging purposes only and not recirculation. The diameter and size of the unit outlet make it inefficient for recirculation purposes. Grain granules or husks that could get through your false bottom end up getting stuck in the assembly of the sparge arm or recirc manifold piping.
The Manifold | Mash Re-Circulation was designed for users that plan on using a more complex recirculation mash setup such as a RIMS or HERMS system. The manifold will evenly distribute heated wort across the grain bed so that the temperature within the vessel remains uniform, especially in the midst of a multi-step mash regimen or aggressive temperature ramp.
Using the Manifold | Mash Re-Circulation, you could perform a similar sparging technique, but with the manifold directly on top of the grain bed rather than above it which would make it harder to control the height of the water over the grain bed ( even with throttling the flow with ball valve).
You can also use the small manifold to vorlauf, however, we created the Vorlauf | Attachment so that you could visually confirm that there are no grain bits coming through the sparge arm or small recirculation manifold. Please note the Large Manifold has larger ID tubing which allows grain to cleanly pass through.
The Vorlauf | Attachment was designed primarily to replace a pitcher or any other small container used to set the grain bed and/or clear first runnings. Essentially, you would recirculate with a pump for 5-10 mins and end up with ultra-clear wort, which is perfect for both pre-kettle transfer on infusion mashes and pre-recirculation on RIMS or HERMS systems.
|Sparging||Vorlauf / Allow
|Vorlauf | Attachment||X||✓||✓|
|Small Manifold (<20gal)||✓||X||✓|
|Large Manifold (>20gal)||✓||✓||✓|