Durso adjustment
- Thread starter rayn
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Going through a 1" durso drain means volumes of ~600gph if I'm not mistaken. The Jebao DC(T) pumps are pretty powerful (especially when clean). One thing people don't realize with those pumps is that their speed control is not linear from 0-100%. For instance the DC-6000 is rated 1586 gph at 0 head. So on the max that's what it will deliver. Now, on the minimum setting it won't be 1586/10 but (and you have to look a lot for that) about 1100 gph. Of course that's at 0 head but from what you're saying the head is 1.5 to 2 feet. So the point I'm trying to make is that the speed is probably too much regardless. On the other hand, if you were able to make it not gurgle like a toilet after you flush it you were in it's range.
I don't know if any of my ranting makes sense at this point haha
AllSignsPointToFish
"No Longer The Guy Without FaceBook"
It's not ranting...it's a very good point. I've pulled the performance curve for Jebao pumps. The yellow line is approximately 1.5 ft of head (0.5m). For the DCT-4000, you will see the flow at that head requirement is approximately 850 gph (3200 l/h). If the pump is a DCT-6000, the flow at 1.5 foot head is approximately 1320 gph (5000 l/h). The black lines are just there to make the x-axis intercept easier to spot.
Now, these flows (I'm assuming) are at 100% output. Similar, parallel curves will fall beneath each characteristic line for less than 100% output.
Smo
Well-Known Member
You mentioned it was a 1" drain. I assume the Durso is at least 1 1/4" or larger to a reducer on the 1" bulkhead? A 1 1/4" or larger drain pipe within the overflow box seems to reduce noise. The water rolls down the pipe wall while air flows in the center.
I doubt very seriously you only have 1.5' of head. Static head is calculated by the difference in elevation of the water lines. If the tank is 18" tall and the sump is below it, the static head alone is probably closer to 3' if you have a 36" stand. Add in some losses from the pipe and fittings, you probably have more like 6' of head.
OP
OP
rayn
Bluefin Believer
It's not ranting...it's a very good point. I've pulled the performance curve for Jebao pumps. The yellow line is approximately 1.5 ft of head (0.5m). For the DCT-4000, you will see the flow at that head requirement is approximately 850 gph (3200 l/h). If the pump is a DCT-6000, the flow at 1.5 foot head is approximately 1320 gph (5000 l/h). The black lines are just there to make the x-axis intercept easier to spot.
Now, these flows (I'm assuming) are at 100% output. Similar, parallel curves will fall beneath each characteristic line for less than 100% output.
So is it possible the return is just to powerful? It has two 90 degrees in there, but that's it. Maybe it needs valved off
AllSignsPointToFish
"No Longer The Guy Without FaceBook"
Depending on the model, yes, it is possible to move too much water for the 1" drain to handle. If there is a valve in the pump discharge, you can throttle that valve while the pump is on the lowest speed and see if that helps.
AllSignsPointToFish
"No Longer The Guy Without FaceBook"
Looks like that model will move somewhere between 500-750 L/h (130-200 gph), depending on whether there is 1.5-3' head required. It appears that a 1" PVC drain should easily handle that amount of flow.
Are you sure it's 1200 and not 12000? The 1200 is a little more rare to come by that's all (not usually stocked in the US to my knowledge). And if it's 12000 then it's definitely too much. If it's 1200 then you're definitely OK haha
AllSignsPointToFish
"No Longer The Guy Without FaceBook"
Good catch! I didn't even think about the 12000!
AllSignsPointToFish
"No Longer The Guy Without FaceBook"
WAY too big. The DC-12000 with 6' (~2m) head resistance puts out 7000 L/h (1850 gph). You will need to dial the pump all the way down and possibly throttle the discharge valve to get to a more recommended flow rate.
Yah I would strongly suspect that it might be too much. It's rated at 3150 gph at 0 head. Of course that's not what you have there (head, elbows, slowing of the pump etc).
The way you can tell that the durso is over it's capacity is when it flushes like a toilet. It fills up and then "blups" down with a big noise and then again and again. That tells you that the overflow is overwhelmed. If you do not have that then you are within the capacity of the pipe. But that doesn't mean you're not going too fast.
I had a similar problem when I over designed my overflow. I got the jebao dc 6000 on a 30 gallon so even when the overflow was within limits the splashing was on the sump was pretty severe. What I did was put a spill back on the pump (a tee right after the pump, direct connection to the return and then on the other side of the tee a needle valve to control the spill back). I prefer that to a valve on the pump since putting back pressure on the pump is not my favorite.
I hope what I said makes sense and helps!
The way you can tell that the durso is over it's capacity is when it flushes like a toilet. It fills up and then "blups" down with a big noise and then again and again. That tells you that the overflow is overwhelmed. If you do not have that then you are within the capacity of the pipe. But that doesn't mean you're not going too fast.
I had a similar problem when I over designed my overflow. I got the jebao dc 6000 on a 30 gallon so even when the overflow was within limits the splashing was on the sump was pretty severe. What I did was put a spill back on the pump (a tee right after the pump, direct connection to the return and then on the other side of the tee a needle valve to control the spill back). I prefer that to a valve on the pump since putting back pressure on the pump is not my favorite.
I hope what I said makes sense and helps!
AllSignsPointToFish
"No Longer The Guy Without FaceBook"
Throttling the valve on the pump discharge just moves it back on the curve and is not really different than having a larger piping network with higher friction losses. The spillback idea is a good one, though!
