Ook wrote:
To continue the popular subject of wells and pumps: My current setup is
a shallow well that consists of a 2" pipe driven into the ground. The
water is at 10 feet, the bottom of the well is at 17 feet, giving me 7
feet of water. My pickup tube is a 1" pvc pipe with a 1" foot valve at
the bottom. Right now It's only a foot or two from the bottom - too
close, because it picks up sand, and I can hear it rattle through the
pump. My pump is a brand new 3/4 horse Star pump, model ES07S
(http://www.starwatersystems.com/es_jet_pumps.htm). It is entirely
possible that the capacity of this pump exceeds that of my well, but I
won't know until I pump it at capacity for a bit.
If it does I expect you'll get a cyclic sucking of air and repriming
delay. Should be pretty obvious. Not positive, but I think you can
throttle the pump back a bit with a gate valve on the output to provide
an adjustable restriction.
I'm not sure how far down the water goes during the summer, nor do I
know how far the water level drops when pumping. I seem to recall it
dropping to about 5 feet or so last summer. The bottom of my pickup tube
then was less then a foot from the bottom of the well, and I never ran
dry. I did, however, suck a lot of sand and rocks that were small enough
to make it past the screen on the foot. I popped off the front of the
pump casing, and it had quite a bit of course sand in it.
I'd suggest that it is of little consequence if the sand is sucked up
through the suction pipe as long as you prevent it from getting into the
pump.
I want a pickup pipe that is less restrictive then a 1" pipe with a 1"
foot valve. I'm thinking of using a 1 1/4 pipe with an inline valve at
the top instead of a foot valve at the bottom (I used to run this way,
so don't tell me it won't work - it worked fine). I can't put a foot
valve on the 1 1/4 pipe, because it's too big to fit into the well
opening, a 1" foot valve is the biggest I can get in there. The only
problem is that without a screen at the bottom, anything can get sucked
up from the bottom.
The spec says 15' suction lift so it should be fine.
Questions:
1) Given the above information, how far off of the bottom of the well
would you suggest I put the 1 1/4 pipe, so that sand and rocks won't get
sucked up the pipe? Would you consider 4 feet to be a safe distance?
Put it at the 15' level, 2' off your 17' bottom, and put make a cone of
SS screen to attach to the end to keep out big stuff. Don't worry about
sand.
Make a separate easily serviceable sand trap located next to the pump.
Try something of moderate diameter and depth so the incoming flow slows
enough for the sand to drop out.
2) Where can I get a screen to keep out rocks and sand and stuff? So
far, all I get are blank looks when I tell people I want something to
keep rocks and sand from being picked up. All I get is advice to raise
the inlet higher from the bottom of the well (which I'm sure is actually
good advice). We don't have sandy soil here, so sand traps may not be
very common.
Probably not. Shallow driven wells with jet pumps aren't common in many
areas either.
3) Pressure tank. I have my turn-on pressure set at about 23psi. I want
the pressure in the tank to be at ~20-21 psi for max efficiency. That
way the pump kicks in right before the tank empties. Otherwise, if the
bladder hits the bottom of the tank, there will be a rapid loss of
pressure until the pump kicks in. I'm assuming this is correct?
Sounds ok in theory, might need a little tweaking in the real world.
4) I wish I had the money to get a bigger/deeper well drilled :-). OK,
so this isn't a question, it's just wishful thinking.
Have you checked on cost? A lot of places 500'+ drilled is the norm,
sounds like your area is a lot easier.