I’m trying to appropriately coordinate the pressure switch on my well’s jet pump and the air pressure in my pressure tank. The tank is in the house basement, maybe 125 feet from the pump, and is currently set at 24#. 1 1/4 PVC between the pump and tank and I don’t think there’s much elevation change.
As I understand it, I’m supposed to set the tank’s pressure at 2 pounds less than the switch cut-in pressure. When I do this, and the pump should start up, the points ‘chatter’ rather than just switching on.
If I increase the cut-in point on the switch it seems to work more correctly.
Does this make sense, due to a drop in pressure over that 125′, or do I have a different problem, that I don’t understand (weak pump, bad switch, etc)? <g>
In looking into this, I’ve also found that with the system pressurized (50#) and all water turned off, I’m losing 20#s of pressure in 12 minutes. I’m suspicious of the foot valve, but I did replace it 3-4 years ago with what I thought was a better quality one–brass screen rather than plastic, etc. It’s not terribly hard to pull it and look at it, but if it looks OK, would the addition of a one way valve above it be a good idea? (REALLY hard water around here and the occasional sand particle.)
Thanks.
Thon
Replies
You probably need a check valve just above the foot valve to eliminate the bleed back that's causing your 12 minute pressure loss.
The kick on pressure for your pressure switch should be at the low end of your desired pressure range (at least it's that way on my system and others I've worked on). Example: My pressure range is set at 35# to 60 #'s. Switch is set to kick on at 35#'s. Kicks off at 60#'s.
My pump is a submersible and is about 100' elevation below my house so a check valve is a must. I had one fail once and, not only was my pressure falling off but the system would pull in air so when I'd take a morning shower, I'd be greeted by blasts of air and water.....the toilet reaction was really interesting.
The other question that I have is if you are using the same guage to messure the tank pressure and the system water pressure.
There can be enough difference if you are using different guages that the 2 psi "disapears".
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A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
Where is the pressure switch in relation to the storage tank? If they are separated by a large distance, you can get unusual switch operation. It needs to be at the storage tank. Or, if the switch is at the pump, add a small precharged tank at the pump/switch location to absorb fluctuations, this works as well. Setting the switch 2# below the tank is the norm. Ditto BillH's comment regarding gauge inaccuracies - inexpensive gauges don't read very accurately.
A properly working foot-valve is the check-valve. You shouldn't need a secondary check-valve.
You might have either a broken spring on the foot-valve or a piece of crud lodged in the seat where it's preventing the foot-valve from sealing when it attempts to close.
Or you might have a leak in one of the pipes.
If I were you, I'd at least consider replacing this jet pump with a submersible. You'd not only eliminate the potential of problems with a foot-valve, but you'd also eliminate one of those pipes (potential for leaks there) and pump your water for less money. By design, jet pumps are not that efficient.
I know the foot valve is supposed to work as a check valve. IF this one has something lodged in it, causing it to leak, I'm asking if a one-way valve above it might work better, or give me a longer interval before I need to pull the pipe again? Kind of a suspenders and belt approach? If not, how do I know what a quality foot valve is?The pressure switch and the guage are on the pump, 125' from the pressure tank. There is no guage at the pressure tank and I don't know what the system pressure is, other than what I'm reading on that guage. Pressure tank charge was measured with a good tire guage.<Or, if the switch is at the pump, add a small precharged tank at the pump/switch location to absorb fluctuations, this works as >This is interesting, as there was a small 7 gallon (?) tank at the pump, when I moved here. I couldn't figure out why it was there, nor could Amtrol, and it had pinhole leaks so I removed it. Could you elaborate on 'absorb fluctuations'?<inexpensive gauges don't read very accurately.>How do you know a 'good' quality guage vs. a not so good one? Is it that critical? If off by a couple of pounds, the system won't work correctly and could be adjusted up, then down--trial and error--until it does work? Or not??Thanks for all the help!Thon
I have a shallow jet pump that I use for irrigation. Just go a Sears pump with a pressure switch mounted on it. And ran it about 50 ft to a pressure tank.That was alwasy a pain to keep from cycling. When the pump starts the pressure at the pump immediate jumps up and it takes some "time" for the pressure to start moving water through the line to the tank.Every year I was playing with the adjustments on the pressure switch.I suspect that cycling is what cause the start windings to burn out.When I got a similar new pump I redid the who thing. Removing the switch and mounted it up by the tank and ran switch power to the pump.Worked perfectly the first time.(Except when I precharged the tank with city water which was about 120 psi) and had water spurting out around the flange on the tank. But that is another story)..
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A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
tab,
If it's the foot-valve that's leaking, allowing the water to drain out of the pressure pipe, then you *could* mount a check-valve above the foot-valve to prevent this. But.......a check-valve that would prevent the water from leaking down and out when the system is idle would also prevent the pump from jetting water down that same pipe which then renders the whole pumping system inoperative.
If your pressure switch and gauge are mounted on top of your jet pump, they're in the right/normal location for a jet system. Sometimes folks get the switch or gauge in less than ideal locations when mounting them up on a tank-tee arrangement with a submersible pump. This can sometimes cause enough water turbulence and inherent pressure flucation immediately around the devices to cause erractic switch and gauge behavior.
It's gonna be kinda tough to get your tank pressure set to its ideal pre-charge until the problem you're experiencing with water losses is remedied. (Unless you have a valve in the right location to isolate the well pipes from the pressure tank) That because as the water is lost, drop by drop, the pressure varies. Currently your pressure switch is trying to find a target that's dodging around a bit because of the leak.....particularly so at the bottom end while you're adjusting the pre-charge air pressure. And frankly IMO, there's not really much point in worrying about those ideal pump-down gallons from the tank with an ideal pre-charge pressure because the pump will be cycling excessively anyway.......until the leak problem is resolved. I'd personally go after a leak fix, then set the tank pre-charge.
Edited to add this possible resolution if installing a submersible isn't in the cards right now: If you want that backup to the foot-valve, you could hypothetically add a short section of pipe to the suction side of the jet assembly down there and then add a secondary check-valve on that and then install the foot-valve on the bottom of the whole deal. This should give you a back-up to the foot-valve which wouldn't interfere with pump operation because it would be installed on the suction side. Similar to the "tailpiece" illustration shown here (about 2/3rds of the way down the page), but instead for the purpose of getting that secondary check-valve placed. http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/agdex639?opendocument
PS- Not that I've ever done such a thing, but make sure you orient the check-valve properly or you'll be taking things apart again to turn it end for end. ;-)
Edited 6/9/2007 9:10 pm ET by HootOwl
Edited 6/9/2007 9:12 pm ET by HootOwl
Edited 6/9/2007 10:03 pm ET by HootOwl
< Sometimes folks get the switch or gauge in less than ideal locations when mounting them up on a tank-tee arrangement with a submersible pump. >The switch is mounted on the side of the pump--pretty much where I've always seen them, around here. The guage is mounted horizontally about 1.5' above the pump. I'm not sure about 'ideal' but I'm thinking I want to change this to a vertical installation just to keep condensation in the well pit off the face of it.I meant to mention earlier that this is a single pipe system in the well, so what you described as a check valve above the foot valve was what I had in mind. What I don't know is if check valves are any more or less prone to getting stuck open, than foot valves?I do intend to fix the slow leak--presuming it's the foot valve, just don't want to pull it until I decide whether to put in the 'extra' check valve.Thanks again.Thon
tab,
One pipe system. Got it. Knowing that woulda changed alot of my responses. Shoulda asked ahead of time I guess, but around here the term foot-valve is only used for that device when it's attached to the jetting assembly on a two-pipe deep well jet pump. When referring to a single-pipe jet system, it's simply referred to as a check-valve.
So if this is a single suction pipe system, then it seems you should be able to add a flapper type check-valve(s) as a back-up(s) to the current screened foot-valve assembly. (All submersible pumps must also have one of these above the pump) They seem to be far less prone to trouble than a conventional foot-valve. I can't remember ever having to pull things to replace a failed flapper style check-valve. I'm pretty sure that it must happen on occasion, but I haven't run into one yet.
If you're lucky, your current problem is the valve down there or a leak in the pipe that's inside the well. Easy enough to replace. A leak somewhere down the length of buried pipe from the well pit to the house won't likely be so easy and a whole lot less fun to replace.
The shallow well jet pumps that I have seen have built in checkvalves in the pump "nose".But I have only had experience with 2 Sears units, from Sear surplus.The first was a convertable jet and the pump had a place for 2 pipes on the firt. I installed an adapter on the front of the pump that contained the jet and the other end had the fitting for the suction pipe.The other one was a shallow only pump where the jet was part of the pump.I pump out of a lake and never used a foot vavle on the suction line. Just a strainer..
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A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
from Sears surplus.
Hey Bill, do those stores still exist somewhere? All the Sears surplus stores in Seattle area closed in 1996.
Have 4 pumps from there.
"Daily driver" is a sears jet pump with the jet 60 feet down.
Had a pebble in the foot valve once, had to pull the line to remove pebble, otherwise absolutely no pumping action.
If as the original poster said it is no problem to pull the pipe (mine is a 2 hour effort even with a 30 foot tall pump house tower and permanently installed winch), that is the first thing I'd do.
Well, I pulled it today, without too much effort. Water table looks to be about 9 or 10 feet--normally 10 to 12. <g>Found blue/green 'grit' on the outside of the brass foot valve, and though I didn't see it, I suspect that was possibly what was holding the valve very slightly open, but it could also have been some fine sand. Ran water through it and cleaned it as best I could. I think it's still leaking but at a MUCH slower rate.This is a heavy brass valve with a stainless steel strainer but I wonder if there is a better quality valve or type? This one has a spring loaded stopper, kind of like a car thermostat. Not what I would call a 'flapper' as was previously mentioned.Thanks.Thon
Good to hear that things are improved.
Can't tell from your description exactly how you went about cleaning this foot-valve. Maybe you did everything as should be. Just washing off the outside of the screen wouldn't get all the problem grit or gunk out from under the valve itself. Depending upon the valve, you can likely remove the screen, then depress the valve stem to open up the orifice which will allow you to see the business end of things and clean that.
Or you can remove the foot-valve from the pipe and come at it from that end by pulling the valve open for attempts at cleaning.
If it needs a new o-ring or washer because the existing one is damaged, you'll need to do a bit more disassembly.
If the spring is broke, that should be easy to see.
While you have the foot-valve off of the pipe would be an easy time to install a backup flapper style check-valve . Your local plumbing supply house should have these suitable for your purpose. Add a coupling on the pipe, then a 3" or so nipple, then the flapper check-valve, then another nipple, then the refurbished foot-valve on the bottom again.
FWIW, you really shouldn't eliminate that spring-loaded foot-valve from the bottom of array altogether because it closes much quicker than a flapper style. A slower closing valve is fine for backup, but really shouldn't be the only check-valve in this instance. The slower closing flapper valve alone would allow sudden reverse waterflow to occur when the pump shuts off and before it closes. Consequently, water-hammer can occur when it does flip to the closed position. Even if that quick closing spring-loaded foot-valve should leak a little bit, it'll still do the lion's share of the job of preventing that potential water-hammer.
Or maybe you did get all the gunk out from under the foot-valve seat and the remaining slower leak is from a hole somewhere in a pipe. You might have to pressure test that underground line.
Edited to add: Don't know if you have a bladder tank, but if you do, are you getting occasional shots of air out of your faucets? If you are, that would normally indicate that there's likely a leak somewhere between your tank and the water line of the well.
Edited 6/12/2007 1:03 pm ET by HootOwl
Well there is no Sears Surplus stores as such anymore.But there are place that they sell "surplus".Locally they have an appliance outlet store and repair depot/parts sales.Don't know if they are run as one or not.In the front they have appliances; overstocked, scratch and dents, used returns, etc.in the back they sell parts and drop off for repairs. Surplus tools and other random items such as the pumps where back there..
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A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
tab1,
If you are losing pressure that fast you have a sizable leak somewhere.
It may well be or have been the foot valve/check valve if you now are sustaining pressure .
I must assume that when you watched that pressure drop you had the pump shut off otherwise it would have hit the low pressure and kicked back on.
If cleaning the screen didn't solve it I would place a temporary check valve ( Or simply a shut off valve) between the pump and line , it would isolate the potential areas of leaks and tell you where the problem lies.