union/ball valves

Viv · 04-08-2006, 10:36 AM

How important is it to have equal water pressure running through plumbing? If my sump returns water to the display tank, there will be one much longer run than the other side (because the sump empties one side rather than both). If valves are needed to equalize the pressure, set , and left in the position to make the pressure equal, is one type better than another?

Geoff · 04-09-2006, 07:12 AM

i am not understanding what you are asking?

usually the return plumbing is smaller than the drain plumbing. the return side is higher pressure than the drain side. a valve is just sometimes used to lower the flow from the sump because it is providing more water than the drain can handle. i prefer to run my pumps full throttle for returns.

am i close to what you are asking.

G~

Loverotties · 04-09-2006, 07:55 AM

I agree with Geoff or maybe to slow the drain a little but would never want to put extra pressure or load on the pump.

Viv · 04-10-2006, 07:34 AM

Hmm, I don't know if I can explain this correctly, or even if it matters...The sump returns water to to tank, I have to split the return line, one to the left side of the tank, one to the right side of the tank. One line will be much shorter and more direct than the other. The pressure in the shorter line is much stronger than the longer line, making the stream in the tank much stronger on the shorter side. I was thinking of putting some kind of valve on the shorter line so that I could somewhat close it, making both returns somewhat equal. There wouldn't be back pressure on the pump, I don't think, 'cause the excess would just go to the other (longer ) line. My question was as to which type of valve would be better to use. Maybe I shouldn't be doing this?.......

Geoff · 04-10-2006, 09:49 AM

i understand exactly what you are saying.

there is not problems with doing this. in the picture below the ball valve in the middle is doing exactly what you are wanting to do. it is in the wide open position now because there is an eductor on each outlet. the eductors produce a lot of head pressure so it helped equalize the outlets.

when i did not have the eductors on it i needed to close the valve in order to equalize the flow between the two outlets.

you are actually slightly increasing the head pressure to the pump. i am being very technical here.

the closing of the valve increases the back pressure to the pump so that the shorter pipe now has the same head pressure as the longer pipe, equalizing the flow between the outlets.

which valve to use depends on the length differences between the two runs. if they are close to the same length a gate valve would be my choice. they can be finely controlled. if the lengths are quite a bit different than a ball valve can be used. they are much less fine in adjustment. they are a lot easier to find though, so most opt for the ball valves. it is just tough finding that perfect possition with ball valves.

HTH,

G~

Viv · 04-11-2006, 01:43 AM

Ok,ok, you've made me think that now maybe I should go for the eductor. I would say the shorter run has about twice the flow as the longer run. If eductors were placed, would the strength of the shorter run still be stronger than the longer? I figure I'm pumping about 1225, (Little Giant pump) maybe a bit more. Two tunzes pushing around some water also. I was using vinyl tubing-currently redoing to pvc, and going BB. Was orginally thinking to get 2 more tunzes, I love their flow, full but not harsh. My return to the tank put out a very harsh flow....I really would appreciate any thoughts!

Geoff · 04-11-2006, 10:01 AM

what kind of little giant do you have? eductors like head pressure, lots of it. depending on the model you have, these maybe perfect for your system.

G~

Viv · 04-12-2006, 08:42 AM

Its a 4-MDQX-SC Max Head, 17.0ft.; pumps 1225gal 3ft., 1080-6ft.,675-12ft. At least that's what the literature says...It has a 1" Inlet and 1"Outlet....don't mean to sound dumb, but what are you figuring out, just curious...

Geoff · 04-12-2006, 08:58 AM

Quote:

Originally Posted by Viv

....don't mean to sound dumb, but what are you figuring out, just curious...

you are gonna be a DIY guinnea pig, that is all.

G~

Viv · 04-12-2006, 06:18 PM

Ok! Willing, and this time, will pay attention and listen more attentivly! Looked up eductor and learned a little...but what is the difference between eductor and penductor, size? One site showed what I think was a spray bar with eductors on each spray hole, interesting! Although, I don't think I need to go that route. Will 17.o max head be enough for the eductor and will the pressure equalize off each length, of the return? Or will the eductor on the more forceful side just become that much more powerful? This is interesting, an article I read stated that the eductor can increase the flow 5X what it is now giving. True?

Geoff · 04-12-2006, 10:09 PM

wait till Friday, then you will know all you ever wanted to know about eductors.

G~

Krux · 04-13-2006, 08:16 PM

ooh this is getting good. casually (since i am lazy and eating a corn dog right now) i think geoff wanted to know what model so he could find out if it was pressure rated or not, which basically determines how fast the water pressure drops off when back pressure is added to the pump. some pumps can have a relatively high return head height, but still are not idea for running pressurized, as in the case of an eductor.

lets see it geoff!

Geoff · 04-14-2006, 06:58 PM

here ya go Viv!

G~

Viv · 04-15-2006, 08:50 AM

Geoff, I'm lost somewhere in the threads, when I click on the (here) I get another thread....I found a eductor DIY thread in the DIY section, is that the one or have you updated your original design?

Geoff · 04-15-2006, 09:49 AM

nope, that is the one.

have i changed the design, not a whole lot. there is not much to change on them. i have played around and did some fine tuning, but nothing major.

i was thinking you could try an eductor or two and see the difference in your system with them.

G~