piping material in cistern from pump to exit

I will be installing my submersible pump in the cistern next week. I will be laying in at a 15 to 20 degree angle down on concrete blocks near the bottom, inside of a 4" pvc flow sleeve (per the tech staff at Goulds). I have 1 1/4" outlet at the side of the cistern tank near the top. I planned on using schedule 40 pvc to pipe from the pump up to the outlet. Is this a good choice? Would the pump torque affect this at all? Should I use galvanized pipe? I am limited to the pvc outlet at the pipe exiting the tank as I have a pvc bulkhead fitting there.

Schd. 40 PVC should be ok. There's no weight on the piping to speak of, so you should be fine.
Ron

By the way, I see no reason for the motor sleeve. The water in the cistern is all the same temperature, so what's the use?

bob...

A sleeve is intended to force the flow of water over the motor. If there is a sleeve, it is essential that the sleeve prevent water from coming in at the discharge end. Otherwise, it is worse than nothing and will probably CAUSE the motor to overheat.

Unless the cistern water is warm, there is no need of a sleeve. You will get enough circulation over the motor to keep it within its required operating temperature. I can't imagine that an underground cistern would be warm enough to require a sleeve.

And I'd stand the pump up just off the bottom of the tank rather than laying it down at any angle. Submersible pumps are meant for vertical installation and don't do well otherwise; regardess what that tech told you. I can't believe you told him about laying the pump down and he okayed that... and like Bob says, there's no need for the "flow sleeve".

I wouldn't hang it on an elbow going out of the tank, use a tee, a ball valve and a piece across the tank that is supported and space the tee to hang the pump on, away from the side of the tank by 6-12".

You don't want anything but water against the pump/motor or the torque to cause the pump to rub on anything.

Like Ron says, I'd use 1" sch 40. I'd use a sch 80 union above the pump. That allows easy installation/removal of the pump. Install it at a comfortable height for you to hold the pump while you screw the union together. Galvanized rusts, blocks up and adds iron to the water and is not needed.

I'd use a 1/2 hp 10-13 gpm pump.

Virtually all of the water systems in my area use underground cisterns fed by canals. Jet pumps are used to pressurize the home water system. However, some customers are asking for ways to do the same thing, without having a pump and tank sitting in their nicely landscaped yards.
I've spoken with both Goulds and Grundfos reps about using submersibles in the cisterns and both have recommended that a flow inducer sleeve be used over the motor.
I, like Speedbump, don't really see the need. I think the pump manufacturers are just covering their tushes with both hands. But, if they recommend it, I would do it for warranty reasons, if nothing else.
Ron

when i spoke to the tech at goulds, i told them i was going to plan on standing the pump upright because i wanted the pump to function the best and last a long time. The tech told me it is 'completely un-necessary' to stand it up. Also told me that I could get more water out of the cistern by laying it down (obviously this is true but i'd rather my pump last), and they told me I should lay it at a 15 degree angle. They said 'make sure you take full advantage of the water and at a 15 degree angle it will not affect the pump life at all.

I am perplexed on this..

I want the pump to last a long time....my question is that if i DO stand it up, how much off the bottom do I need to position it. And how much water depth and I going to be able to pump down to.

A 1/2 HP Franklin motor is 9.5" long and the screen is just above that. You will probably get down to 13 or 14 inches off the bottom if you put the pump vertical on the bottom of the cistern.

can i go all the way to the bottom or do i need to keep it off the bottom an inch or two.

I have installed them in polyethylene tanks by adjusting the pipe so the pump is supported on the bottom. I use a minimum space from the tank wall to the pump by putting an elbow directly into the bulkhead fitting or flange.

When you consider that they are usually installed in wells where the minimum clearance is about 1/4 inch on the diameter, you can see that it would be impossible to get them too close to the wall.

You don't need a sleeve for small motors like you have. When the motor gets warm it will cause convective circulation of the water to keep the motor cool.

I wonder just how many hours these Goulds pump tec's have in the field? Especially since they don't make the motor that they so easily say can be in any position. What do they care, it's Franklin that wants the motor vertical.

bob...

Valveman

I have done lots of submersibles from 1/2 HP to 75 HP laying horizontal. Just make sure that it is at least horizontal and not pointed downward at all. I highly recommend a flow inducer sleeve. A catch basin is better than a lake install for motor cooling but, if the in flow into the basin is not just right, without the flow inducer you could be boiling water around the motor while the pump is still moving nice cool water. A flow inducer is cheap insurance. Also with the flow inducer you can just lay the pump on the bottom of the basin. The inducer will keep it off the bottom and makes sure the motor stays cool, and you can get all but the last 5" of water out of the basin. As long as the pump is working with a pressure switch, the pump will start with some back pressure. This keeps the impellers from upthrusting even though the pump is horizontal. Cycling on and off is still worse for the pump/motor than horizontal install. Use a 2 GPM Dole valve between the pump and pressure tank and it will greatly reduce the number of cycles. Also limits the cooling flow to 2 GPM so again use the flow inducer.

tickridgescott said:

when i spoke to the tech at goulds, i told them i was going to plan on standing the pump upright because i wanted the pump to function the best and last a long time. The tech told me it is 'completely un-necessary' to stand it up. Also told me that I could get more water out of the cistern by laying it down (obviously this is true but i'd rather my pump last), and they told me I should lay it at a 15 degree angle. They said 'make sure you take full advantage of the water and at a 15 degree angle it will not affect the pump life at all.

I am perplexed on this..

I want the pump to last a long time....my question is that if i DO stand it up, how much off the bottom do I need to position it. And how much water depth and I going to be able to pump down to.

Click to expand...

I wouldn't want a pump touching any surface due to the possibility of causing a noise problem or damage to the tank or pump.

What is your water quality of this water straight from the well?

If you have iron, you may not want to suck the water level down more than a foot or two off the bottom.

Sucking the water level in this tank as low as possible, may suck up sediment, or stir it up enough to cause quality problems. Another concern is that the more water you use out of the cistern, the more water at one time the well has to deliver to this tank. If you have a low producing well, how do you take all that water out of the well at once and not run it dry? Or... what is the plan to prevent that?

What are the dimensions of this tank? What material is the tank made of? Above ground or buried? In the sun or covered? These things impact the water quality out of the tank and the water quality from the well impacts the tank.