pump intake

[Capt_Cully]

My Reeflo Snapper has a 2" intake, which may or may not make a difference. Anyway, does it matter if the intake plumbing goes straight out of the sump into the pump? I plan on having It take at least one, possibly two 90 degree turns before entering the pump.

Will that make enough of a difference to affect the pumps longevity or performance?

 

[Tonynlo]

It depends on how the turns are oriented. If the 90' turns are left and right, then you will experience a little head loss which isn't a big deal. If they are up and over a sump wall, then you may run into an issue of needing to prime the pump whenever you turn the power off (for cleaning/maintenence etc.). This could be resolved by installing a check valve in your plumbing in order to keep the pump wet.

 

[Capt_Cully]

It would basically 2 right hand 90s after exiting the sump via a bulkhead. No change in elevation for the plumbing.

 

[jacksonpt]

Could the 90s restrict flow into the pump, thus affect its performance/gph?

I ask for cully's benefit as much as my own...

 

[Tonynlo]

Yes it will. Basically, when you are designing your plumbing, consider everything in a complete loop. This includes, sump size, baffle width, overflow capacity, hose and PVC size etc. Everything has an impact on GPH. In this case, the two 90's will have the same impact in the front of his pump as they would in the rear. Water should be flowing towards your pump at the speed it is getting pushed away, or else you will either run dry or flood.

 

[captain7359]

You should be fine with the 90's. Make sure to include a union or best a true union ball valve for future service. Make sure to keep everything 2" into the pump and consider bumping the discharge piping up to 2" as well to cut some of the losses on the outlet piping.

 

[Capt_Cully]

Tony, I get what you're saying. But once flow is established via pump, overflow, baffles, etc...it will be in equillibrium. The amount in the return compartment should remain constant with the exception of evaporation. My plan is to have flow exit the sump via 2" bulkhead and plumbing into the 2" intake of the Snapper. But in exiting the sump, it will need to take 2 right hand 90s before it enters the pump. This will allow it to sit in a better ventilated area of the stand. I was hoping the 2 inch plumbing would essentially act as more reservoir space on its way to the pump.

Check these bad boys out. On right is a standard 1" bulkhead with the bit used to drill holes for the overflow. O. Left is pumps 2" intake. In middle is the 85 mm bit I just got from BRS for the monster 2" bulkhead that will allow a continuous 2" plumbing from sump to pump.

 

[Capt_Cully]

Oh, Walter, outlet is 1.5" on the pump. Still go 2" on efferent plumbing?

 

[marks69]

reeflo told me 1 1/2" was fine for intake.

 

[Capt_Cully]

Then that should more than account for the head 2 parallel 90's would create, I'd think.

What was the context under which you spoke with Reeflo, if I might ask?

 

[Tonynlo]

You're exactly right cully. I had trouble wording what I meant. Your explanation is a little more clean than my choppy response.

 

[captain7359]

Oh, Walter, outlet is 1.5" on the pump. Still go 2" on efferent plumbing?

It's only going to help you with more flow.

 

[rbredding]

I've got this same pump... great pump, btw...

I'd recommend not using anything under 2" if you're talking about having 2ea 90* fittings between the sump and the pump..

actually, if you can increase their size outside of the bulkhead to 2.5" that would be even better.... (if you do, then keep it larger until you get to the pump intake)

bottom line.. you don't want the pump to move more water than can fill that pipe using only gravity and the "water column" of pressure in the return section of your sump..

for instance.. if your return section is small and doesn't have but a couple inches of water over the top of the outflow bulkhead, then it wouldn't be a good idea..

but if you've got a rather large return area and using an ATO you've always got at least 10" of water above the top of the bulkhead, then you'll be fine..

(there are a LOT of factors that come into play.. )

 

[SkiFletch]

Agreed, don't use anything under 2", you're just asking for trouble if you do. Centrifugal pumps are pretty picky about their inlet restrictions, and the snapper and dart are especially so in my experience. Too small of a pipe diameter, or too many 90's before the inlet and they can either really struggle and draw a lot of current, or straight up cavitate. Cully, since I know your goals are both silence and electrical energy consumption, nothing less than 2" will do. I agree with rbredding, 2.5" would be better for sure, but if you're locked into 2" it should work.

You will NEED, and I stress NEED unions on this baby if you want to run it for years. Like mentioned, I'd suggest true unions valves, but you can get away with it with a little trick if you're doing what I think you're doing. Put a union wherever it's convenient on the inlet side and slip an oversized ball valve on the inside of the bulkhead connecter inside the sump. Say 2.5" or 3" and use a reducing coupling for it. Then of course use a true union valve on the output of the pump. This way not if, but WHEN your shaft seal starts leaking you can shut the valve off in the tank, turn the true union off on the outlet of the pump, pop the unions, and remove the pump. I've seen my share of reeflow pumps throw leaky shaft seals... You don't want to tempt fate by not putting unions/valves in line. I might also suggest putting a sacrificial towel/carpet under the pump/motor join and fitting some kind of water warning alarm in there since I know you want to protect your floors

Of course you'll need some horizontal room to fit a 2.5-3" valve inside the sump tank, hopefully you have that?

 

[rbredding]

I've got a couple pictures of how I did mine.. I'll post them when I get some time tonight..

2" true union ball valve.. (sucker was like $50, and is easily 7" long)
then an elbow into the pump inlet.. (my pump runs 90* to the intake line using about 18" of PVC, similar to how you want to run yours, minus the 2nd 90* fitting)

I used threaded street elbows in order to tighten every thing up as much as possible..


and I've already used them.. I replaced my seals less than 2 weeks ago.. because of my setup, it was as easy as turning off the pump, closing my union valve and removing the pump..

 

[Capt_Cully]

Oh man. The 85mm bit and 2" BH were the biggest I could dig up and WEREN'T cheap. So you're saying after much contemplation, Reeflo may not have been the best choice? My Hammerhead ran like a champ. Never broke down after 4 yrs of faithful service.

Anyway, I fully intend to have unions and floor protection. I appreciate the help. I can always send the bit and BH back and go 2.5-3". But where might one find such behemoth pieces parts such that I can get this right before I even start?

 

[rbredding]

nah.. don't worry about that.. (thought I said that earlier)... penetrate the sump with a 2" bulkhead... then immediately upsize to a 2.5" pipe (then back down to 2" at the pump)

think of it as a large waiting room for the water before the pump pulls it in... (the 2" bulkhead won't act like a restriction)

 

[SkiFletch]

nah.. don't worry about that.. (thought I said that earlier)... penetrate the sump with a 2" bulkhead... then immediately upsize to a 2.5" pipe (then back down to 2" at the pump)

think of it as a large waiting room for the water before the pump pulls it in... (the 2" bulkhead won't act like a restriction)

+1 especially about the waiting room part.

About the pumps... For the most part a centrifugal pump is designed for one of two applications: High head per watt, or high flow per watt. The wider the veins/fins of the pump head, the more it's biased towards flow, and the thinner veins/fin pump heads are biased more towards head. That's why the dart/snapper have such "fat" looking pump heads while the hammerheads/barracudas have thinner looking ones. If you note the pump curves, you'll see the differences. Also note that the dart/snapper have bigger fittings than their high-head cousins because thinner diameter tubes restrict flow more per-foot.

Anyway, in order for a high-flow pump like the dart to function properly, it's "hungry" for inlet flow, and it would really prefer that flow to be laminar, not turbulent. So if you're trying to slip your pump behind the sump and want it's outlet to come from the side of the tank, use a 2-2.5" slip fitting on the bulkhead and affix the 2.5" right angle to that, then another right angle to get it flowing the other way, and put a longer/straighter run to the pump if you can, stepping back down to 2" at the last moment. That way the water will be turbulent around the corner, but with a little straight-line motion it should laminar itself out. The reason laminar flow is important is because it lowers vibration of the impeller, thus lowering vibration on the pump shaft and thus lowering vibration on the all-important shaft seal which is usually the first thing to "go" on a pump like this. The vibration differences of a laminar vs turbulent setup won't really be noticeable to the average human, but the pump impeller feels it, and during continuous operation, it adds up. Set it up right and it'll be fine Cully

 

[Capt_Cully]

Do you think this will work with a 3" run of PVC before the pump. I can't find 2.5" PVC or fittings or reducers that go from 2-2.5". I can find 3" PVC and 3-2" couplers. My concern is that the 3" "waiting room" wont fill completely and will lead to cavitation.

Also, my new schematic only has one 90 heading into the pump.
Should I just go with all 2" instead?

 

[rbredding]

I'M RUNNING one 90 and about 14" of 2" PVC/union-ball-valve before my pump..

you'll be fine with that... as long as you're keeping the length of pipe short.. (disregard previous upsizing recommendations)