Will this work fine.. HEX size

Im in the planning stages of a 2 vessel 1 pump eHERMS. Currently i am trying to figure out all my fittings and sizes. I plan on using a March 809 pump and after reading many threads have decided to go with brass quick disconnects from McMaster. The ones many people linked to were
#6739k64 and #6739K59.
If i do those I then will of course use 1/2" ID high temp tubing.
My actual question comes down to the HEX and size. I (because im cheap) would like to do 3/8" copper tubing but of course the other choice is 1/2" (not as cheap) I have read many things going back to forth on what people use. But basically with my setup is it okay using 3/8", the reason i ask this is the pump intakes are 1/2" and say to limit flow on outtake not intake. Does this setup limit flow at all to it or will it just pass at a faster rate? I believe i should be fine but i thought i should ask people with some experience before i buy anything haha.

Last question is it seems people average around 20-25ft HEX. Anybody not agree with this? more or less?

thanks alot, any help is much appreciated and if i said anything stupid or it didn't make sense just lmk i'm an idiot haha.
-josh

Your coil will be attached to the output of your pump, where flow restriction is OK. In fact, flow restriction will be NECESSARY. If you open your pump fully during the mash circulation, it will likely compact the grain bed and cause you problems. (Been there, done that.)

I wish I had realized this sooner, because I actually heavily modified my 3/8" IC to use as a HEX. I wanted as little flow restriction as I could get, so I cut the coil in half and put T's on it. 1/2" pipe goes to a T, two 3/8" coils flow in parallel, then back to another T and out through another 1/2" pipe.

All of that work was TOTALLY unnecessary. To get a good flow rate during my mash, I have to almost completely close the ball valve on the output of my pump to avoid the compacted grain bed, so I could have just left the 3/8" coil as one single piece instead of cutting and soldering a bunch of stuff together.

Oh... and my 3/8 coil is 25' long.... or I guess I should say it WAS 25' long. It's now two parallel coils, each 12.5' long.

Only brewed one real batch so far with it, but I have played with it a lot and it seems to be working fine.

haha cool well thanks for answering the questions. But at least you got to mess around and build something... even if it ended up being more work, at least it makes beer. Im pretty excited to start building this, been planning and pricing stuff out for way to long now, time to actually get something going.

ellijo89 said:

at least it makes beer.

Click to expand...

That remains to be seen. thatr first HERMS batch is still in primary with a couple inches of kraeusen on top.

I have been pondering the same question. I will do mostly 5gal batches but will occasionally brew a 10gal batch on my rig (currently a bunch of parts in my basement). I was thinking closer to 50' to fill the keggle, and trying to decide between 1/2 and 3/8 since I'll use it as a HERMS during mash and an IC during cooling.

yeah 50ft would be cool but i just think it might not be efficient for me with cost vs effectiveness. I know they used to sell copper tubing by the ft at ACE by my house so im hoping then i can get away from having to buy the 50ft coil at home depot or Lowe's.