Flow rate with multiple 90 turns

As I prepare to hard plumb our new HERMS system, I have become concerned with the use of multiple 3 way ball valves. One wort path will have 5 90 turns. I know 90s will slow down flow rate; however, how much slower will this make it? I can't redesign around the 90s. I don't need to be a speed brewer. I just don't want it to be rediculously slow.

With a March pump, you'll be just fine. Granted, the flow is reduced, but I'm able to recirculate through 150 feet of hose, a plate chiller, and 8 90 degree turns.

Wow, that is a convincing statement. I have a 90 right before my inlet (3-way valve) and that is my main area of concern; however, after reading your post I think I'm golden!

lol I forgot about the valves in my cleaning system. Add 8 more 90s so 16.

a 90* elbow is usually equal to 1.6' of hose (friction wise for 1/2" line) so you can take the number of elbows on the outlet side and multiply them by 1.6 and add that value to your total length of tubing....if your less then 40-50' I wouldn't much worry about it...you shouldn't loose enough to worry about it. The elbows on the inlet side can possibly cause you issues....if you cant avoid them then step up the plumbing size to the next size pipe or even double it if you can.

Instead of stepping up the inlet pipe size, would going to a 1/12HP pump help? Or is that compensating in the wrong way? I don't need a super fast flow rate. I just don't want to hook everything up on day one and have a trickle...I need to protect my future self.

Lopsy said:

Instead of stepping up the inlet pipe size, would going to a 1/12HP pump help? Or is that compensating in the wrong way? I don't need a super fast flow rate. I just don't want to hook everything up on day one and have a trickle...I need to protect my future self.

Click to expand...

You don't want to restrict the flow going to the pump. That can damage the pump. You can restrict and slow the flow after the pump with no issues.

If you want to keep the same pump and can live with lower/slower flow, then shrink the outlet line down to 3/8" ....assuming you are using 1/2" in your system. Either that or you can use a valve to choke the outlet and balance the system. Your flow will go down a little, so it may take a few extra minutes to transfer your liquid.
I would go to the 1/12hp model just to have the extra capacity for any future projects....you can always choke the pump down... but you can get any more out of it if its too small from the get-go

I would be more concerned with bacteria having too many places to propagate in all of those sharp bends, more than worrying about flow loss. There are few reasons to ever need to move wort or water at any very fast flow rates, so sanitation becomes the biggest issue in a closed plumbing system. Did you add or include a way to introduce a cleaner to the system? A star-San injector would be the cats meow and could be rigged on the inlet side at the very top of the system to insure that everything gets sanitized after your are done and again before you use it again. Just a thought from a germaophobe.

Wheelchair Bob

Thanks for the suggestions. I'll be running hot PBW through everything at the end of brew day, then hot water, and then blowing it out with a shop vac. I'd eventually like to introduce a new pump and some CIP spray balls.

Walter, do I have to choke it immediately after the pump outlet, or could I do that 3' up the pipe at my kettle?

It's a balancing game that I've never played. Without getting crazy into proper priming techniques and stuff, cavitation occurs when air develops on the inlet side correct? So does having air on the outlet lead to trouble, or will the pump be able to "fill" the out tube if the inlet is primed correctly?