Submersible pump suggestions

Guys;
Do any of you have any suggestions for submersible well pumps that are somewhat more durable than most seem to be these days? The basic issue...10 years ago, I was pulling pumps that were ancient. I even recently pulled one out that was well over 35 years old. Now, the replacements that I installed back then are going out one by one. Currently I deal with Goulds, which I was always very fond of. I have read here from several other pros that the average life seems to be 7 years, but I still find it shocking that quality has dropped so much for something so expensive. I was speaking with one of the well drillers that I sometimes work with, and he says that life span is so short any more that he is considering going to jet pumps wherever he can use them, but Im not too fond of this idea either. Im open to suggestions that any one can offer. Thanks! Paul.

Valveman

Just checking in this morn on my way out of town. Although they are not as good as they used to be, I still like the pumps with Stainless Steel impellers instead of the plastic ones. Grundfos or one of the copies like Unitra or Hydroflo. Then over size the motors by one step. A 1.5 HP sub motor is about the same length and weight as the old 1 HP motors. Gives more ump and has a bigger heat sink. Then of course limit the cycling as much as possible.

Valveman and I disagree on the stainless vs. plastic impellers. But I don't think your going to find anything to last much longer than the 7 years unless you take very good care of it. Limit cycling as much as possible, make sure it does not run dry by putting it too shallow in the well and use the next size up wiring. I know guys that are installing practically everything on #14. I know wire is high these days, but give me a break.

The other thing is to be sure it has enough backpressure to prevent upthrust (Betta Flo has an upthrust protector built in). I get people emailing all the time wanting pumps to fill a pond. They want to run the pump open discharge with a high water level. This is a no no. Upthrust will ruin the impeller stack and the motor will be pulling higher than normal amps.

bob...

Valveman

Speedbump, I agree that the Stainless Steel pumps are using metal that is paper thin these days and plastic will probably hold up just as good. The main reason I like these type pumps is the fixed stack design. Most plastic pumps these days are built using the floating stack design. This means that the impellers are not attached to the shaft and can float up and down inside the diffuser. Each impeller runs against the diffuser on upthrust and downthrust instead of being locked to the shaft which would keep the impellers from touching on top or bottom. Pumps with stainless impellers are fixed to the shaft and held up by the motor thrust bearing and down by the top of the shaft hitting an upthrust washer. This means that the only parts that actually touch anything is the shaft touching intermediate and upper and lower bushings. With the plastic floating type impellers, each impeller runs against the diffuser which creates heat and causes more wear. I understand that Lexan running against Lexan is supposed to be self lubricating and have very little wear but, it is still touching and therefore must produce more wear than an impeller that does not touch anything as with a fixed stack. The floating stack design is mainly for ease of assembly not for better performance.
Thrust bearings in motors are usually the graphite impregnated teflon Kingsbury type bearings. These bearings use a hydroplane effect and have a film of water between the lower plates and the upper stainless plate. This keeps the bearing from touching anything and should be a part that never wears. This hydroplane effect only happens when the motor RPM is above 1800 RPM so every start up is dragging away a little bit of the bearing. If the motor has not had enough time to cool down before restarting, it will drag off even more of the bearing before 1800 RPM is acheived. So the fewer starts and the lower the heat, the longer a thrust bearing will last. Most sub motors also have a canned stator design. This means that the windings are incased in epoxy. Changes in temerature from cool to warm and warm to cool will contract and expand this epoxy and further reduce the life of the motor insulation which is the epoxy. If the pump runs continuously, the temperature stays constant and increases the life of the motor insulations. I am currently testing some of the foreign designed motors such as the Sumoto. These motors have thrust and radial ball bearings and the motor is filled with oil (vegatable oil) for lubricant. This is similar to the old style Reda motors of the 60's and early 70's that stayed reliable for 30 or 40 years. These motors are not a canned stator. The windings are individually insulated with varnish and surronded by the oil. This allows for expansion and contraction without damage as would be seen with canned epoxy filled stators. If the ball bearings are of good quality, I expect to see very good longevity from these motors. However, even with my acelerated test design it will take 5 years for me to put 20 years worth of wear and tear on the motors before I can vouch for their quality.

Good points.

I like the Betta Flo because it has an upthrust set screw in the top of the impeller stack that prevents upthrust. I don't know of any other pump that has this feature.

I have very little experience with sandy wells, but the ones I did experience that had stainless impellers (this one 6" in particular) had no impeller. Just a hub that the volutes used to be attached to. And the pump wasn't that old.

I guess it has a lot to do with applications and environment. What works here may not perform so well somewhere else.

Have you had any luck with the guys from Hydroflo on pricing?

bob...