Any pump experts out there?

[jbarker855]

I have a Crane-Deming 4011 pump that pumps water from a nearby creek into a pond I have. We use it to help keep the ponds from becoming stagnant and to get some flow over a waterfall going from one pond to a lower pond. I am pretty sure the pump needs a little servicing and adjustment, but I have never worked on one of these before. It pumps around 10,000 gallons/hr. 3" suction, 2" discharge. Powered off a 220v Leeson 5hp electric motor.
The problem I am having is that the amount of water this thing pumps is decreasing. I can tell how much it is pumping by how far out of the discharge hose it sprays. Normally it blows the water out about 6 feet. It will do this on startup, but after running a while (maybe 20-60 min?), it will only shoot water out a foot or so.
There is no obstruction to outflow. There is no blockage on the inflow side and it does not suck any air. Does not make any funny noises to suggest a bad bearing. For what it's worth, I have noticed over the past few years that it has become increasingly difficult to get this pump primed at the beginning of the season.
My best guess is that I need to adjust the impeller. It is adjustable axially, so that it can be moved closer to or farther from the pump face to adjust water output. I am not afraid to tear into anything, but I could get in a mess real quick with this though because many bolts on it are so rusty. I don't want to be screwing around drilling broken bolts and putting in heli-coils only to later discover that I didn't have to remove THAT particular bolt anyways. Before I start messing with this thing, I thought I would consult the experts. Thanks for any help.
-Jay

 

[user.69169]

I sure ain't no pump expert unless carrying them and dragging em and bustin knuckles on pumps in the dark makes you an expert. Went and hunted that pump of yours up on Google, and she sure looks like a pretty basic rotary pump. If I can do this link thing right it'll take you to a picture thing that shows all the innards, and who to call for parts.
http://www.dultmeier.com/pdfs/pw4021.pdf

If I was you before I did any disconnecting I'd look at the packing box on that there pump and ease up on the packing. Course before you go to easing you want to squirt some penetrating oil like Marvel Mystery oil on the bolts, and you dang well only want to go to bringing the gland thing up just a tiny bit at a time and with the pump running and wet. Ya DANG WELL DON'T tighten either bolt more than 1/4 turn without bringing the opposite bolt up the same amount unless you want to saw the dang shaft off!!!

I'd bet on the gland cause you say she's been giving you trouble priming for a while.

 

[Mousefield]

I do the same thing, pump water from our creek into a pond in the backyard as well outside watering. I just use a ｾ hp jet pump as this provides me with enough water and pressure. About every 3-4 years I replace the pumps as they stop working, cost about $300.00 to replace and don稚 think they are worth fixing. The water is fairly dirty water and has a brown color to it, has a lot of fine sand which I think helps to wear it out. You are pumping much more water with yours. Is the manufacturer of your pump still in business? Can you get a kit, bearings or gaskets if needed? Sounds like it has pumped a lot for a number of years, could it be worth looking at just replacing it?
Or the best bet may be if it is pumping now let it run till the fall rains and then pull it apart, that would give you the winter to repair it or replace if needed.

 

[Sandlot]

That looks like an open face impeller type pump. If the output is changing after it has run awhile it is normally a suction problem possibly compounded by a warn impeller. Could your suction hose be collapsing or filling with debris? Or, is the creek level changing in the area where the suction hose is setting? If the impeller is getting worn, just a little change in pumping head can lead to capacity problems.

 

[Egon]

Have you ever applied grease to #243 in the parts diagram?

As per (removed) on adjusting the packing gland bolts! Go easy. If'n you get them to tight expect some smoke.

You might want to consider changing out the packing.:thumbsup::thumbsup:

 

[Kays Supply]

To adjust the impeller , you need to be able to get to items 204 and 229. If you pull the motor off and loosen 204 and 229 you should be able to tap the shaft forward to lessen the gap on the impeller. The packing will only leak while under pressure. With an open dicharge, it would tend to suck air more than show a leak. Impeller wear would be slight if pumping clean clear water. Most of the wear I've seen was on trash pumps or deep well pumps with sand in the water.

 

[jbarker855]

Gentlemen, thanks for all the input so far. To answer some of your questions, I believe the manufacturer still is in business and I am pretty sure I can get parts if needed. I don't want to junk this pump, as it is built like a tank. By looking at it, you can tell this is something that is built "the old way". It's built to be repaired if needed.
The suction hose is rigid and is not collapsing. Suction end is always underwater, even when creek level drops. Yes Egon, I have greased it .
Could someone explain why a bad packing could cause this problem? I simply don't understand. My simple understanding is that the packing is just a way to seal water from leaking around the shaft.
If this means anything, the packing drips briskly and steadily with pump off, and slows to almost a stop with pump running. Do packings get too tight or too loose with age? I should also mention that although I usually pump clean, clear water, I did pump a lot of sand inadvertently about a month ago. The suction end got half buried in a small sandbar after a storm, and I flipped the pump on without realizing this. I noticed what happened when I saw brown water coming out of the discharge. Thanks again.

 

[Egon]

Could someone explain why a bad packing could cause this problem?

I'd bet on the gland cause you say she's been giving you trouble priming for a while.

The pump sucks air through the gland breaking the vacuum required to lift the water to the pump. Air locked pump. This leaking air will also lower the NPSH meaning lower pump flow rates.

 

[Mousefield]

[QUOTE Do packings get too tight or too loose with age? .[/QUOTE]

Yes, usually they start leaking. I used to use a graphite impregnated string to repack steam valves. Not sure what they have out there now for packing material for a water pump. Going back a just a few years now but if I remember right we used to have a rotary pump that would feed water to the steam boiler, think I used graphite impregnated string as well to pack that if is started to leak.

 

[RalphVa]

I worked with pumps during my 31 years as chemical engineer and have had a swimming pool for almost 30 years. That leaking packing sounds like your culprit because you say it leaks when shut down and almost stops when running. That clues you that it is actually sucking at the packing. This can be air on startup, and it is probably sucking air now while running.

On our swimming pool pump here, I had to take it apart and remove some vegetation that got sucked into the impeller on it. Its impeller has like a screw assembly on its suction side. This wasn't visible from the outside. I just figured that is what it was from its low head symptoms. Fortunately on it, the entire impeller casing splits.

Had to replace it completely about 3 years ago, along with the filter because both the pump seal and filter assembly developed leaks. Found out in my research that the pump we have here is TWICE as efficient as the pump that our pump company was selling. I proven this by measuring its efficiency; yep, about 60-70% vs. about 33% for the other pump from its literature. e.g. HALF the electricity needed by the type of pump we bought. The one we have is a MUCH bigger diameter pump than typical. I know from chem eng experience that small diameter pumps typically have those low, 33%, efficiencies. In refineries, we're generally putting heat energy into what the pump is pumping; so, a little bit of temperature increase due to low efficiency is no big deal and not an energy hog thing. In swimming pools or plain water pumps, it is. It's YOUR energy bill you're paying.

My wife is pretty handy in replacing pumps. Had to talk her through how to do it once with me in Texas and her in NJ.

Ralph

 

[rScotty]

I worked with pumps during my 31 years as chemical engineer and have had a swimming pool for almost 30 years. That leaking packing sounds like your culprit because you say it leaks when shut down and almost stops when running. That clues you that it is actually sucking at the packing. This can be air on startup, and it is probably sucking air now while running.Ralph

I've have experience designing similar centrifugal pumps, and Ralph's idea sounds right to me. It might not be sucking air at the packing - but that is certainly the most likely place and the first place to look if you are happy with the suction hoses and connection. ALWAYS check the suction connection at the pump. Tighten it there or smear the outside of that connection with bathtub caulk. When you take it apart, it's not likely to be worth the hassle of changing any of the adjustments, there isn't much to go wrong or wear in that type of pump that doesn't involve packings and intake. Certainly nothing that would explain how it is running now. Like Ralph says, Id' bet it's heating up and sucking air somewhere. The time and heat heat also suggests the packing. These air leaks can be pinhole small but still cause big losses.
good luck, rScotty

 

[wolc123]

I think the more likely culprit is air building up in you suction piping. You probably have a foot-valve down at the end, in the creek, and you probably fill the pipe between the valve and the pump before startup. This gives you your short time of proper operation. As it runs, air likely begins to accumulate in high spots in the suction piping, reducing your effective suction head. THE SUCTION PIPING SHOULD HAVE A CONSTANT RISE TO THE PUMP, especially when pumping highly-aerated water like that from a running creek. This may mean you have to raise the pump to get it above the bank. Raising the pump will not affect the NPSH because you will still have the same difference between the water level in the creek, from which you draw, and the pond, to which you deliver. NPSH means Net Positive Suction Head and refers to the fact that a pump can not pull liquid, but only push it. Atmospheric pressure (around 34 ft) is what pushes the water into the pump. This means that, in theory at least, a pump may be able to "lift" water about 34 feet, into its suction. If there are any horizontally-installed reducers in the suction piping, they should be of the eccentric type, and installed so that there is no high spots where air can accumulate. The fact that your pump still operates properly for a time after startup is an indication that there is no problem with your impeller, or wear rings. If these components wear out, performance goes away until they are repaired.

 

[user.69169]

.
Could someone explain why a bad packing could cause this problem? I simply don't understand. My simple understanding is that the packing is just a way to seal water from leaking around the shaft.
If this means anything, the packing drips briskly and steadily with pump off, and slows to almost a stop with pump running. Do packings get too tight or too loose with age? I should also mention that although I usually pump clean, clear water, I did pump a lot of sand inadvertently about a month ago. The suction end got half buried in a small sandbar after a storm, and I flipped the pump on without realizing this. I noticed what happened when I saw brown water coming out of the discharge. Thanks again.

Son you just diagnosed your own problem all the way.

Packings require a little attention over their life to keep them working right, that's why pump manufacturers welt to ceramic seals last 50 years. Seems they recognized people's mechanicle ability was falling off before the rest of manufacturing.

If that shaft is leaking the pump is sucking air and loosing ability to pump, ain't no way around that fact. She might have also taken some impeller wear, but looking at the part diagram I posted the link to the impeller is also available, sure hope you don't need that though cause she will cost. Even pumping what looks like clean water impellers do wear, so do the castings around the impeller.

When you tighten the packing gland a bit the problem of the leak might go away. Bring it up just a wee bit at a time or you'll ruin something for sure.

After you bring the packing up and shut the pump down it'll be a real good idea in the future to pop the endcap off the back end of the motor bearing and eyeball the back of the shaft. Generally the shaft has a screwdriver slot on a little pump like that you got, and you will want to use a screwdriver to turn it over before putting the power to the motor to be sure the packing ain't overtight. That packing also acts like a bearing right up close to the impeller in that pump.

Back when I went to driving truck we had little grease cups on the water pumps of the truck engine, and every day you'd give that greasecup a bit of a turn to keep the pump lubricated. Fellow told me one time a pump is a whole lot like a woman, you keep her maintained and she keeps you happy. You don't take care of either one and you got a big problem.

 

[jbarker855]

Well fellas, I have to say that the depth and breadth of knowledge here at TBN never fails to amaze me. I believe you guys are right-on about the bad/loose packing. It makes perfect sense. Difficult priming. Pumps good at first and then falls off as packing heats up and starts sucking air. Also, the packing leaks when the pump is off, further suggesting the packing is too loose. Thanks for the help here. It's a little embarrassing I didn't see how bad packing could cause air leak and poor output.
The bolts holding the packing in are completely shot. No getting them off without cutting them. But they will be easy to replace, as they will just fall right out when I cut them. I will get new bolts, tighten them up slowly and gently, making sure not to over-tighten. If that doesn't work, I will try getting new packing, as I suspect this packing hasn't been replaced in many years. I'll let you know how things work out. Thanks so much.
-Jay

 

[Egon]

Consider installing new packing right away. Gives you a look at the shaft condition and will be easier on the shaft if some sand got stuck in the old packing.:thumbsup:

Some packing comes in rolls, others is precut and the joints are staggered when installing. It also comes in many different types for different usage.

A little tool with a hook on the end, another with a corkscrew type end and needle nosed pliers are usually the type of tools required for packing removal.

Flashlight and mirror may also help for inspecting the shaft.

Course, considering the number of years since I've repacked a gland ever thing about doing it may be different!

 

[jbarker855]

Well I decided to just replace the packing. Bought a little packing puller to help with the job. Unfortunately, I destroyed the lantern ring in the process. To be honest, I knew it was in there and I reallly wasn't too careful with it. Figured I'd just buy a new one. Well before you read farther, guess how much a new lantern ring from Crane-Deming is.....10? I thought maybe $20 at the high end. Nope. New lantern ring- $100. I was shocked but felt I didn't really have a choice. So now it is all back together and working great. I still have a concern though. Instructions from pump owner's manual said after putting packing in, tighten up gland bolts to cinch it all in there, and then back off them. This is what I did, but even with bolts backed all the way off now, I don't get much of a drip at the gland with pump running. Manual states it should drip slowly while running so as to keep packing cooled. Maybe as it wears in, it will start dripping a bit, but the no-drip makes me a little concerned. The shaft turns easily by hand. I have run it for about 10 minutes, and the shaft gets warm, but not hot. I have not run it for a prolonged period of time yet. By the way, it pumps better than it has in years. Thanks again guys.
-Jay

 

[Egon]

The shaft turns easily by hand. I have run it for about 10 minutes, and the shaft gets warm, but not hot.

That sounds like it's working OK and the shaft is good.:thumbsup::thumbsup:

 

[jbooth]

I'm a bit late with this info. Unless your lantern ring is piped back to the suction, discharge, or poses as a leak off port, you could probably have eliminated it.

It is possible to help cool new packing on the breakin period with an external source of water placed on the external parts of the stuffing box and pump shaft. We used this method in some of the old fossil power plants that still used packing. Even the newer seals had built in coolers on them.

Another thing that might be beneficial as your new packing wears is to apply a small amount of water pump grease through the lantern ring leakoff ports.

If your pump has a tubing on the leak-off port piped to the suction it will reduce the pressure your packing is exposed to. If the port is connected to the discharge it is for water lubricating the packing.

I worked power plants for 40 years prior to retiring and had a lot of expierence with pumps. I thought you were getting good advice. Hope my tardiness didn't cause you to spend the $100 for a needless lantern ring.

 

[jbarker855]

A little update-
I tried running the pump a little longer, and the shaft got too hot to touch. Now I don't really have any idea how warm it used to get when it was running fine, but I was still concerned about the fact no water was dripping from the packing. So I took the darn packing out again and repacked it, but looser this time. Still no drip. Then it finally hit me. I sucked a bunch of sand in one day. The lantern ring is plumbed to the pump discharge as a water source by a small copper line. The line must have got plugged with debris, the packing overheated, and then started sucking air and failing to pump. I took the line off that was feeding the lantern ring, and EUREKA! The line was plugged with sand. I cleaned it all out, put it back together, and the pump ran great for over 6 hours today, and the shaft was barely warm. I get the nice slow steady drip from the gland that the manual insisted I should have. Now the pump is back in action!.......though I noticed the bearing housing on the motor side of the pump is quite warm to touch. Certainly unrelated problem, but I will have to look into it soon. Thanks again all.
-Jay