SST braid too low flow for HERMS?

Hi all - my first dry (well, wet) run on my homemade HERMS setup made it abundantly clear that the SST braid in my 10-gal MLT just doesn't provide enough flow to feed the March pump.



The pump is a the same level as the MLT outlet, and it's only facing about 2' of head elevation (through ~35' of 1/2 copper and back into the top of the MLT.

Anyone else have similar experiences with a cooler MLT not providing enough outlet flow for the pump? I'm wondering if a slotted copper ring would get things moving faster.

I haven't had any problems with my braid, it flows pretty good.

I suspect it's because you're cramming so much braid into your fittings, restricting flow there. My guess is a smaller braid or larger brass fittings would solve the problem.

Thx sparky - I have some sleeves inside the braid to keep it from collapsing, but I wonder if the 3/8 fittings are also restricting the flow. Funny, I have a 1/2" braid on my 2-gal MLT with the same size fittings and it virtually pours out the valve. Maybe some rougher braid is in order?

hey would this work in cooker instead of a hop stoper or a bazooka tube?

There's a good chance you're just not getting the pump primed (air trapped between the MLT and pump). Try getting your pump a few inches below the MLT or try filling up the water level higher.

That's a good thought - I also have the lower-speed of the 809 pumps (809-PL and not the 809-PL-HS). Methinks I should swap it back and spend the extra $10 for a little more oomph.

Also, if you thought it might be the braid (instead of the pump or the restriction of the fittings) you could do some trials with the cooler filled with water. Try draining with the braid, and the remove just the braid and try it againto see if it makes any difference. I suspect it won't, but it would be easy to confirm.

FlyGuy said:

Also, if you thought it might be the braid (instead of the pump or the restriction of the fittings) you could do some trials with the cooler filled with water. Try draining with the braid, and the remove just the braid and try it againto see if it makes any difference. I suspect it won't, but it would be easy to confirm.

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You read my mind. After the trial this morning, I took the MLT off the cart and let it drain right out the valve onto the driveway and it definitely was less than a 'full flow'. I'd be really surprised if the 3/8" fittings are to blame; it's a straight shot out the T, through the valve and out the barb (which is stepped up to 1/2"). I went with a 1" braid per Palmer's suggestion to avoid crushing the hose with heavy grain bills, but I'm thinking I should use the same 1/2" braid that's in my 2-gal MLT.

lostnfoam said:

hey would this work in cooker instead of a hop stoper or a bazooka tube?

Click to expand...

IIRC some folks have mentioned that boiling brass isn't the best for your brew; I think you'd want to find a way to go all-copper/sst for the fittings, but that's basically what the bazooka tube is anyway

Update - replaced the 3/8" setup with 1/2" fittings and there's a significant improvement in the flow rate. I think it'll be plenty to keep the pump fed, but I still suspect the braid is restricting the flow. I'm going to end up with a well-stocked inventory of fittings, washers & tubing by the time this is done! :cross:

Moving to 1/2 inch was the right move, I had the same problem. I've just built a new MT using a 1/2 soldered manifold with small cuts to let the wort in. The flow seems to be sufficient, I'll test it with a grain bed this weekend. I always try to keep the pump input as full as possible, if I need to reduce the flow rate I use a ball valve on the pump output since they seem to deal better with back pressure than insufficient volume.

By the way, sweet picture, I can't decide if I'm more interested in the glass beer holder or the lass beer holder. Better consult the wife.

Quick update - I did a dry-run with water last night and reached 2 conclusions:

1) The braid is restricting the flow, but not by much

2) The horizontal arrangement of the outlet valve allows air to get trapped in there - it can starve the pump unless you tip the MLT forward to let the air escape back through the braid. Once this was taken care of, it seems to run like a champ.

EDIT: Last update - bumped the size of the brass 'T' to 5/8" and the flow issues are resolved. Collected first runnings in just a couple of minutes.