Pipes Hammer when pump cuts out

[jodan]

I just recently bought the house. House sat empty for a while before i moved in. From day one the pipes have hammered. The well is 398' pump is at 265'. Cut in pressure is at 40, cut out is 60. At least that is what i have witnessed. So far i have been told that the check valve at the pump is bad. But there is no delay of pressure build up at cut in. Next one is that i have a bad pressure tank. But tank bladder holds pressure and does not quick cycle. i have drained and checked the pressure. i checked again today but noticed that with a drained tank and valve shut to the house that the tank built up 25# of pressure. Any suggestions?

[jadnashua]

I don't think you can get a valid reading on the tank if the valve is closed. When the pump turns off after it cycles, the air pressure in the tank will equal the water pressure. If it is 25# higher than expected, you may have a defective water pressure gauge and that would also mean that the pressure switch is set wrong as a result.

You could get a little pressure increase when your water heater turns on, but I don't think you'd get 25# unless the bladder was shot.

[speedbump]

Is there a check valve in the house near the tank?

bob...

[jodan]

There is no check valve in the house. i started to put one in and then realized that the hydrant out side by the well head would only run until the water in the pipe was gone. Because if it does not drop the pressure tank the pump will not get tripped on. Does that make sense? i am debating weather or not to make an expansion tank in the pipe.

[speedbump]

If you put one in the house, the pipe underground feeding the hydrant would be at or close to zero pressure. You couldn't get a drop from the hydrant unless the pump was running.

Do you mean one of those inwell tanks?

bob...

[sammyhydro11]

See the reason why you are getting water hammer is because there is only one check valve inline. The reason why there is no check valve at the tank is because the person that set up that hydrant decided that he was going to run the hydrant off the main line coming from the well. He should have ran two lines in the same trench one for the supply for your home and one running off the tank in the house back to the hydrant. I had a customer w/the same issue. I replace his pump and tank. The next day he callse me back and told me he had no water coming from his hydrant. Come to find out by putting in my check valve it cut off the water going to the hydrant. When the hydrant was turned on there was no water pressure drop to kick on the pressure switch. Needles to say i removed the check valve and everything worked.

SAM

[speedbump]

I tend to think there is something else causing the hammer. There are too many systems out there with only the check valve in the pump and none at the tank. They don't have water hammer problems. In fact, it's the check valve up top that causes a lot of water hammer. With a little leak in the droppipe, the water can settle back away from the upper valve. When the pump kicks on, the water will travel back up toward that check valves poppet. When it hits it, there will be a water hammer.

Since he doesn't have an upper check valve, I'm not sure what is causing the noise.

Can you tell us, when you hear it? Is it when the pump turns off? Is it the instant the pump turns on? Or somewhere in between?

bob...

[sammyhydro11]

It could be something else but if the check valve at his pump isn't closing fast enough i would suspect it. Also with all that water wanting to get back down that well it only makes sense. But i had a customer that experienced a loud chatter noise every once in a while and the problem was at the toilet. I'm wondering if when he put that check valve in the problem went away. I think he stopped midway realizing it would cut off water to the hydrant.

Jodan i would put that check valve in at the tank and see what happens? I replaced a foot valve in a guys well that was having the same problem and his problem was cause by a slow closing foot valve. I know it will cut off the use of your hydrant but atleast do it just to eliminate a check valve problem at the pump. You can always take it out when you are done.

SAM

[valveman]

I agree with Speedbump. I have better luck eliminating water hammer by using only the check valve at the pump. In some states like Michigan, it is illegal to have a check above ground. If you have a leak in the drop pipe or a the lower check is leaking, it can create a vacuum which can draw in contamination. The vacuum also causes water hammer when the pump starts. If check in the well is leaking, it needs to be fixed anyway. If check is working and tank is OK and there is still water hammer the instant the pump starts or stops, the CSV will help. It makes the pump start and stop at 1 GPM, so checks don't slam from wide open or fly wide open on start up.

[jodan]

The hammer starts soon as the pump shuts off. The pressure guage jumps but luckly at this point it does not quick cycle the pump. As far as a leak in the line is concerned, i do not believe there is one because the tank holds pressure. I can put the check valve in. I understand the theory. But what i might do instead is put and expansion pipe in first in the spot that i started to install the check valve. That way if that eliminates the hammer i can leave it in and still have the hydrant. Unless you guys agree that it would not help. The pipe that is hammering is the inlet pipe from the well. The tank is not right next to the wall where the pipe enters. It rises about 6' runs 15' along the floor joist and then drops down to the tank. So there is plenty of length in the house for the water to move once the valve closes. But the hammering is the same rythem each time, and seems to fast for water slosh. I may be on the wrong path with that idea.

[sammyhydro11]

I don't think you have a leak in your line either. I think the check valve at the pump isn't closing fast enough and some of that water is working its way back down the well. Its seems like the same thing that my customer was experiencing when he had a slow closing foot valve.

SAM

[sammyhydro11]

Another reason why people install check valves at there tank is that it actualy does prevent contamination. If you have a bad leak in your waterline and that line is under pressure water is going to spray and not leak from the break.That break can cause pooling around that broken fitting. As soon as that pump kicks on all that water that has pooled around that broken fitting alot of times gets sucked into the line drawing in contamination.Alot of times with systems set up like this,with a bad leak,my customers have noticed turbid water and sand as well. With a checkvalve at that tank my customers have noticed leaks right away because where that leak is it creates a gap of air in that line. As soon as that pump kicks on all that air gets pushed into the system and unless they have an air release tank they get a blast of air into the plumbing. They usualy notice it first thing in the morning after the fitting has been leaking all night. So people can argue either but hey,i do what works.

SAM

[Ddanrr]

I am having the same problem. New tank, new pressure switch, new two wire pump, no check valves in the house, and the water hammers the pipes bad when the pump shuts off (no problems when turning on though). Can someone explain better how a "CSV" could help this problem? I think my next house is going to have city water.

[sammyhydro11]

You need a check valve at that tank or valveman could help you out w/ a CSV.

SAM

[valveman]

Water hammer happens when a pump shuts off because the pump is pumping 10 or 20 gallons per minute, depending on the size of the pump, so the check valve is wide open. Wide open for this size check is only about an inch. Water flowing through the check valve is filling the pressure tank at 10 or 20 GPM until the pressure reaches 60 PSI and the pressure switch shuts off the pump. Water in the pipe is flowing several feet per second into the tank when the pump shuts off. Then the 60 PSI of air in the tank acts like a spring and reverses the direction of the flow in the pipe. The water can only move backwards for one inch before the check valve closes, unless the check valve is worn out and slow to operate. The water can be moving very fast even if it only moves an inch but, the further backwards it goes before the check closes, the faster it closes the check valve. The check valve slamming closed causes the water hammer, which is actually a shock wave bouncing off the closed check valve and rippling through the entire system at 3,000 to 8,000 feet per second. This shock wave can also happen from the starting of the pump, as it instantly starts cramming 10 or 20 GPM into the system before the water in the pipe has time to start moving. The larger the water system, longer the pipe, the further this shock wave can travel, and the more places it can cause damage. This is why a single house system does usually not have as much problem with water hammer as larger systems like city water supplies. However even the smallest system can have these problems. The Cycle Stop Valve eliminates water hammer in a couple of ways. First the pump usually only causes water hammer when it is started or stopped. The CSV keeps the pump running continuously as long as at least 1 GPM is being used. So in systems like one I am discussing with a home owner who has a heat pump causing his pump to cycle on and off 19 times per hour, keeping the pump running continuously doesn’t let that check valve close and open 19 times per hour. This not only keeps the check valve from wearing out but, also eliminates 38 water hammer events per hour. The second way a Cycle Stop Valve eliminates water hammer is by restricting the flow from the pump to only 1 GPM when filling the pressure tank When the heat pump does shut off and no one is using water anywhere in the system, the CSV allows the tank to fill at 1 GPM until the pressure switch shuts off the pump. While only pumping 1 GPM, the flow is so low that the check valve is only open the width of a piece of paper when the pump shuts off. Again the flow reverses and comes back from the pressure tank but, is only able to move as far as the width of a piece of paper before the check valve is closed. The reversed flow cannot build up any speed and the check valve closes as light as a feather. The CSV can also eliminate water hammer when the pump starts. As long as the check valve on the pump is the only check valve in the system, the flow from the pump starting will be held back to 1 GPM because the CSV is still closed to the 1 GPM position. The check valve lightly opens as the flow starts gently moving at 1 GPM. Within a second of the pump starting, the CSV senses that more water is required and quickly opens enough to supply as much water as is needed The CSV starts the system at 1 GPM instead of 10 or 20, then rapidly opens up to keep up with the amount of water being used. This eliminates the pressure surge that causes water hammer as the pump starts. A second check valve before the pressure tank, with or without a CSV, can cause the drop pipe to be at zero or even a negative pressure like holding your finger over a straw of water. Then when the pump starts it sees no pressure in the lines which allows it to start flow wide open at 10 or 20 GPM. The water may only move up an inch before it hits the second check valve that is still closed. Even in an inch the water gets to moving so fast that it pops the second check valve open causing a shock wave that we hear as water hammer. Using only one check valve right at the pump, makes sure that the pump starts with pressure already against it.

[jodan]

If i am following correctly the CSV will in a sense have the pump running longer. Will that cause the pump to have an shorter than normal life expectency? Since my problem is when the pump shuts down would a CSV work? To me it fixes hammer at the start of the cycle. Unless 1GPM is sufficient to run a house hold, when it senses more water need and ramps up to 10 - 20 GPM it will hammer again at shut down, unless it ramps down before shut down. That is the way i am following at the moment. Where does this CSV go in the line? Do i need to pull the pump to install? Where are they sold? i have not come across them previously, but have not specifically looked either. Could my idea of an expansion pipe work. What i am thinking at the moment is to T into the vertical run where the line enters the house. Add a 4" piece of pipe to another T. Run a 2' piece of pipe parallel to the inlet pipe either the ame size pipe or slightly larger with a cap on it. Out the bottom i run a short piece of pipe with a screw cap. That way if the expansion pipe would happen to fill up over time i could drain it and reintroduce air to the expansion pipe. What i don't know is will it work on a vertical pipe or would it need to be on a horizontal run. Last question for the moment, can a check valve actually wear out. To my thinking the spring does not do much, back flow closes the valve. Guess some wear could occur but not enough to ruin it in a short period of time. Merry Christmas to all, gotta go.

[speedbump]

I just read through this again. Valveman says the water is moving through the pipe at 10 to 20 gpm. This is correct depending on size of submersible pump. Sam says the check valve at the top can cause water to be sucked into the suction line. True, but this would only happen with a jet pump. Jodan's pump is at 265', so we know it's a submersible pump.

So to fix this man's problem as per Ranchers request, I recommend pulling the pump and replacing the check valve. I have seen a lot of check vavles over the years go bad. Not because of the poppit so much, but because of the SS spring that slowly closes off the poppit when the volume drops as pressure rises (this spring is used to prevent hammer). I think this spring is broken and the poppit is staying close to wide open. When the pump stops, bang it closes hard, when the pump starts, bang all the way to the nut that prevents it from getting pumped into the tank. Since Jodan didn't answer my question of when he heard this noise, I will assume it is both when the pump starts and stops. This would indicate the bad spring theory.

bob...

[sammyhydro11]

I suggested that the check valve was clsoing slowly as well. And i disagree with the jet pump and check valve. Its the same principal as a chemical feed unit on some pressure washers. The high flow passing by the reservoir creates a vacume on the container drawing in the chemical.

SAM

[speedbump]

On a pressure washer Sam, they would have an ejector that will draw the bleach. That's why the nozzle is much larger than the high pressure nozzles. Ejectors will only operate between a narrow pressure range. In the case of the hole in the submersible feed line to the house, the entrie pipe will be under pressure and water will be flowing outward all the time the pump is running. There is no ejector to create a vacuum, so the only time that hole will take in water is when the submersible is turned off. Are we both on the same page, or am I misinterpreting what your saying?

bob...

[sammyhydro11]

Bob,
i'm not going to argue with you about injectors and how they work. I will say that i have seen fittings break in positions that cause water that has pooled around fittings to be sucked into water lines. If you take a peice of pipe and drill a hole into it on an angle and then send a good amount of water through it, at a good amount of speed,you will create a vacume. I have seen it happen too many times. This can happen w/water lines and broken fittings. So are we on the same page? Maybe,maybe not. Hopefuly we can get there.

SAM

[speedbump]

I never wanted to argue Sam, I just haven't seen what your describing happen before. I can see the pool that you mention being sucked back into the pipe after a sub shut off. It would only take a small leak below that spot to cause that vacuum. This is the reason a lot of say not to install a check valve at the tank or anywhere in the feed line. Without one the feed line stays pressurized all the time.

I think we are on the same page, it's just that we are describing it differently. In reality, the same thing happens, it just has a different movie title.

bob...

[Ddanrr]

So it sounds like a CSV is going to partially close, to slow down the flow rate against my pump trying to run at full speed? It doesn't sound like it would be very good for the pump. I also considered a whole house filter between the pump and the tank, to slow the water down a bit and prevent the hammer, but then the pump wants to pump at 10 gpm, and the filter 5 gpm, the pump would be fighting it. Makes me wonder if there would be an electrical way to ramp the pump down slowly, so it doesn't bang the pipes shutting off.

There have been a lot of posts here, but I'm still trying to understand why the water will hammer when the pump shuts off in a normal, small system. Because the check valve at the pump is worn and closing too slow? Would another check valve installed in the house where the pipe comes in the wall help? Or a water hammer arrestor? In other threads I understood that a bladder tank was supposed to act as a water hammer arrestor, but now it sounds like it helps cause the problem? One thing I noticed in common with the original poster is that my tank is not close to where the pipe comes in from the wall, but is across the basement on the other side. I wonder if this is a factor at all.

[speedbump]

I think what you are saying is the inline filter is a poor mans CSV. I don't think so. If you put that inline filter between the pump and tank, watch for some major problems down the line.

Is your pressure switch at this tank that is across the room or is it somewhere else?

bob...

[sammyhydro11]

If you want to stop that hammer put in that check valve at the tank. How difficult is that?? People can go back and forth on this all they want but your check valve at your pump is closing too slow. Pull it out,replace it,put a check valve at your tank,or do the csv along with the check valve at the pump.

SAM

[sammyhydro11]

Speedbump is right,that filter is a bad move. I still don't understand why you haven't tryed any of these solutions. I would say the easiest and cheapest way for now would to try that cycle stop valve or slap in a check valve at the tank. But that will be my last reply on this subject because i feel like were going in circles. SPEND SOME MONEY AND GET IT DONE

SAM

[vaplumber]

There is no check valve in the house. i started to put one in and then realized that the hydrant out side by the well head would only run until the water in the pipe was gone. Because if it does not drop the pressure tank the pump will not get tripped on. Does that make sense? i am debating weather or not to make an expansion tank in the pipe.

Dont ever put a check valve at the tank. Weve worked on many set up this way over the years. When the valve at the submersible pump starts to get weak and close slower, the valve you put at the tank will cause water hammer. Also if the check valve on the pump is weak, it can cause hammer even if you dont have any other check valves in the system. The inspectors here will fail a system if you have a check installed any where out side of the well casing. There reason being as stated earlier. If there is a leak in a pipe between the well and the tank and you put a check valve at the tank to cover a bad pump check, when the water in the drop pipe and the buried pipe to the tank falls back to the well, you build a vacuum in the line behind that new check valve, and that can cause contamination.

[jodan]

As in my reply on the 22nd the hammer occurs only when the pump turns off. As for Ranchers questions for the pressure build up. I turned the pump off, then drained the tank by opening the cold water in a tub. That did put the guage to zero. At that point i turned the ball valve to the house supply off. Why, i do not have an answer. But when i did, the pressure guage slowly rose to 25#. That is all the higher it ever went. So at that point i opened the house back up and you could hear the air enter the pipes, and the guage did go back to zero. I then turned the house back off and the pressure on the guage rose to about 25# again. At that point i cut the 1 1/4 pvc supply line where i intended on putting the check valve. Which is above the tank in a horizontal line. By all rights the water should have been gone. There was still about a gallon in that line. It did stop running, which tells me the line probably was pitched just enough away from the tank to hold the water. Yes pressure on the guage went to zero. As we all know from there i did not put the valve in, glued my pipe back in, turned on the pump, opened most all of the faucets to purge the air that was introduced. I havn't messed with anything since. Night time and holiday water repairs in the country is something i try not to do unless absolutly needed.

After todays posting it would appear that i need to pull the pump and change the check valve. I have access to cranes. Could i pull the well on my own with out alot of issues. The reason i ask is, out of six, only one well man has returned my call and his diagnosis was a bad pressure tank.

[vaplumber]

drained the tank by opening the cold water in a tub. That did put the guage to zero. At that point i turned the ball valve to the house supply off. Why, i do not have an answer. But when i did, the pressure guage slowly rose to 25#. That is all the higher it ever went. So at that point i opened the house back up and you could hear the air enter the pipes, and the guage did go back to zero. I then turned the house back off and the pressure on the guage rose to about 25# again.

This diagnosis tells me that the bladder in your tank is shot. The pressure is rising because the air that is suppose to be above the bladder is entering the water side of the tank via a small leak. This will also cause hammer as it causes the tank to become unstable and loose air. Replace the pressure tank and leave the pump alone. Also do not allow the well man to install a check valve at the tank. Trust me at this. Ive been at this since 1954, and a second check valve will only lead to trouble. Good luck.

[Rancher]

Sounds like the well man was correct in his diagnosis. I agree with Vaplumber, a small pin hole in the bladder would cause the pressure to rise, it would also account for that gallon of water you found after draining.

Rancher

[jodan]

I will get a tank, its cheaper than pulling the well. The only thing that puzzles me is that when i and the well man checked the bladder pressure it read 40#. Correct me if i am wrong but wouldn't the pressure in the bladder go down and also introduce air into the pipes in the house?

[speedbump]

The air mixes with the water and you wouldn't notice it.

bob...

[jodan]

i suspected that. What about pressure drop in the bladder.

[Rancher]

i suspected that. What about pressure drop in the bladder.Did you measure the air pressure in the bladder when you emptyed the tank, it should have been around 25# if it was leaking like we suspect. If so that was probably the source of your water hammer. It should have been 2psi less than the cut in of your pressure switch... 40psi?

Rancher

[jodan]

I have installed the new tank.
It did not fix the hammer.
I did check the old tank before i removed it. Confirmed bad.
I did check the new tank pressure, i had to had air to get it to the 38#. I did all of that before install. I then ran the pump and filled the system. I then ran every faucet in the house and outside to purge the air. I have drained the system down a second time and and rechecked the tank bladder pressure. I did add about a 2 pounds which brought it back up to 38#. I did notice that the pressure guage does not drop all the way to zero, it stops at about 5#. But on the same note it does note build pressure either. I have opened every faucet again to purge air. I have also cycled the pump by running water. Pump starts at 40# and stops at 60#. But i still have hammer when the pump stops, same as before no change.

[sammyhydro11]

Wow,
i guess i would be a very angry customer if someone told me that replacing my tank would fix my water hammer propblem.......and it didn't. Come to new england fellas and every well system has a check valve right at the holding tank. I guess they should all be removed. And i wonder why they say you should have a check valve every 250'. It couldn't have anything to do with water hammer.....could it??

Jodan,
I know with putting a check valve at your tank would prevent you from using your hydrant but i was looking to prove a point. You need to pull that pump and replace that check valve like i first stated.

SAM

[vaplumber]

Wow,
i guess i would be a very angry customer if someone told me that replacing my tank would fix my water hammer propblem.......and it didn't. Come to new england fellas and every well system has a check valve right at the holding tank. I guess they should all be removed. And i wonder why they say you should have a check valve every 250'. It couldn't have anything to do with water hammer.....could it??

Jodan,
I know with putting a check valve at your tank would prevent you from using your hydrant but i was looking to prove a point. You need to pull that pump and replace that check valve like i first stated.

SAM

Sammy, I didnt mean to insult your intelligence here. I posted that based on my own experiences and what has worked for me. A check valve every 250 feet, some thing that I have been taught here in pump seminars is that the 250 foot rule applies to well depth and water level specs, and no it doesnt relate to hammer. It's simply to reduce the workload on the valve down in the well. There are several wells here that are over 800 feet, and my own experience shows me that they will work great for many years with only the check on the pump, and to forget the 250 foot depth rule. Some thing else that time has taught me is the diagnosis of a bladder tank. A very small leak in the bladder will allow the air pressure to drop without water showing up above the bladder. If the bladder becomes unstable, ie air pressure drops during drawdown, then rises during a pump cycle, when the pump kicks, you'll get a hammer. The pressure rising with pump off and valve closed tells me that air from the bladder is entering the water side of the system. The extra gallon of water that he drained after draining the tank, which shouldnt have been there after the bladder bottomed, tells me he has a bad tank. The water entered the air side through the small leak, and when he drained the tank, the air pressure forced the water back out of the bladder. I dont know about new england, but here any check valve installed has to be inside of the well casing and below the pitless adapter, and that even includes the foot valve for jet pumps. Yea a check valve at the tank would probably resolve the hammer caused by a slow leak, but thats like using a band aid for a gunshot wound. You might stop the bleeding, but wait until time lets the infection and lead poison set in. Once again, I didnt mean it as an insult. I have learned a great deal from this forum, and hopefuly I can learn a lot more, plus I hope to pass at least one thing along to some one else as well. Maybe youre right, and Im wrong, but if thats the case, I wont take it as an isult. Just some thing that a universal friend taught to me.

[speedbump]

Having lived and worked in Michigan since they introduced licensing back in the 60's them moving to Florida 25 years ago, I see two different mentalities. In Michigan just like where VAPlumber lives, a check valve above ground is illegal. The reason is the vacuum that can be put on the suction/pressure line from home to well. Here in Florida, or at least in my county of Hillsborough, we have been regulated first by the health department, then the building department and now the plumbing department. The Chief Inspector (yes about as smart as Inspector Cluso) decided to take it upon himself to add a check valve in the pipe between the well and tank. He doesn't know why, he just thinks it is a good idea. I argued with him about it to no avail.

I don't think any of us argue that a check valve won't stop the water from running back down the well, it's just that after the fact it's a big band aid masking a larger problem.

bob...

[jodan]

It appears i have two issues. But i do know the tank was bad. Sam i know you want a check valve at the tank. But i still want my hydrant to work and it is to cold to run the second line to the hydrant, at least for me to want to do right now with frost. How difficult is the pulling of the pump? As stated before, i have cranes. Can it be accomplished that way? My quote to pull the pump was around $500. I'll battle that for a $20 valve.

[jodan]

I found out the well information from a well drilling company off of his platte map. He quoted me the names dates and address, so it should be good info. As for teh man that put the well in, i have left another of many messages on his phone with no response yet.

[Gary Slusser]

Franklin Electric makes pump motors, not pumps. Some (wet end) pump manufacturers also suggest a check valve every 250'. In both cases they are trying to protect their product, not solve other issues and probably don't care much if their fix causes other problems.

One check at or in the submersible pump is the best choice. That's for a number of reasons and all are good but the best is because a second check anywhere very successfully hides leaks.

I say your problem may be caused by the length of pipe from the wall to the pressure tank and its anchoring/stabilization. If it moves and the movement causes a noise, you'll call it water hammer. If it moves or doesn't and you are hearing a bang/boom type noise, then you have real water hammer and I say the cause is a leaking check valve in or on the outlet of your submersible pump. It needs to be replaced.

Pulling a 300' deep pump on PE pipe is difficult to impossible to do by hand. It is easier with a leaking check dumping the water in the pipe as you pull it though. On galvanized pipe you need a derrick truck or pump pulling machine. A crane/backhoe etc. ... how you change the grip on the drop pipe would be a problem, you need to hold the pipe and pump from falling down the well as you undo 10-20' sections of pipe. With PE you don't take it apart but you still have to hold it as you change the grip or rest.

That $500 charge to pull your pump, it's well worth it; especially when you've never seen it done or done it before. You may not believe me until after attempting it on your own to "save" $300; or doing it on your own, but you'll more than likely say never again; especially if you do something wrong.

Here's what I would do if I were there... Shut off the power to the pump. Shut off the water to the house PAST the pressure tank. Drain all water out of the pressure tank. Check the air pressure to be 39-38 psi. Turn on the power to the pump and watch the gauge and note the cut-out setting psi. Watch the gauge for the next 10 minutes looking for a loss of pressure. If the pressure holds, there is no leak from the tank to the check/pump. If you don't shut off the water to the house past the tank, you get to measure the weight of water above the tank...

I would not install any type of hammer arrestor(or anything that can block up as a filter can) between a pump and pressure tank. The arrestors eventually fill with water due to the trapped air being absorbed into the water. Anything that can block up can cause major damage. That can take only a few weeks. You need to fix the cause of the problem rather than silence the symptom. Water hammer is very destructive, so not removing the cause allows pipe and pump etc. to be damaged and cause other problems later.

[sammyhydro11]

Well thank god for Republicans!

[jodan]

I just did a stupid stunt. I cut the power to the pump while it was on. When i turned it back on it didn't start back up. I have a franklin electric control box teh two reset buttons have been push. no luck. Any guesses

[speedbump]

Cutting the power to a pump while it is running would be no different than the pressure switch cutting it off.

Do you have an volt/ohm meter?

bob...

[Randyj]

This is getting to be a pretty long thread...I am stupid about wells...but just thinking about a logical explanation...and have not read all of the posts... if the well is 398'..that means you got a heck of alot of pressure going toward the well when the pump shuts off...which tells me that a check valve is slamming shut and probablly need some kind of a heck of a muffler or shock absorber to lessen that hammer effect. May the force be with you....

[jodan]

Yes i have a meter

[Randyj]

Is this hammering a "rat-a-tat-tat" or just a "thud"?

[speedbump]

This is getting to be a pretty long thread...I am stupid about wells...but just thinking about a logical explanation...and have not read all of the posts... if the well is 398'..that means you got a heck of alot of pressure going toward the well when the pump shuts off...which tells me that a check valve is slamming shut and probablly need some kind of a heck of a muffler or shock absorber to lessen that hammer effect. May the force be with you....
Contrary to popular belief, most if not all submersible pumps below 1.5hp come with either a built in or external check valve. All are spring loaded to prevent water hammer. Otherwise you had might just as well install a swing check that could hammer your pipes to death. The idea of the spring is to keep the valve as near to close as possible. As a submersible pump builds pressure, it's volume decreases which let's the spring close the poppet in the valve more. Once the pump shuts off, the valve is nearly closed and closes the rest of the way quietly. Water hammer in submersible pump systems is a rare thing and in most instances is caused by other things rather than the check valve. And like someone mentioned earlier, this noise could be a pipe rattling that is not properly fastened.

The 398 feet would be 172 lbs. if the water level were at that depth, but would not be a cause for hammer.


bob...

[jodan]

Okay, Speedbump got me thinking. The pressure was at 50 and was not calling for the pump. I drained it down and it kicked back on. Randy the sound is similar to the rat a tat tat. Its like a diaphram pump and hits between 4 and 5 times

[speedbump]

Yes i have a meter

Do you know how to test the relay, or the capacitor? The meter has to be analog to check the start capacitor. Use the X1K scale and after shorting the two leads on the cap, touch one lead to one terminal then the other lead to the other terminal. The meter should swing hard right then drift back near infinity. Reverse leads and try again. The same thing should happen, if not the cap is bad. There are different types of relays. If you have a blue one, they can be checked, but the test is not definate. There is a black square relay than can be checked with a meter also, but that test isn't definate either. You may just want to replace it. If you have a run capacitor, you can check it the same way as the start cap, the deflection of the meter will not be as severe.

bob...

[speedbump]

This rat tat thing, are the points on the switch opening and closing with the tats or the rats???

bob...

[jodan]

i do not here anything at the control box. The hammering is the pipe i have the spot pin pointed. i have secured it, it is at a free standing setion of pipe 6'' from the concrete wall. i have built brackets and drilled them into the concrete and fastened the pipe. it did quiet the hammer some, but it still occurs, The main item i watch during the cut off is the pressure guage which jumps. Which to me confirms the movement of air or water in the line. I was in the process of checking the leak possibility of the check valve with the process earlier mentioned when i had the brain fart. I'll finish that when i get a chance.

[Rancher]

If you perform the water -back- down- the well test as earlier described and the pump checkvalve is not leaking, then do not pull the pump. The problem with the water-back-down the well test, is if there is a check valve at the pump, and a second further up the shaft, then if you believe Franklin who is providing the information to save their motors, if the botton one leaks, it will put a vaccuum that will cause the hammer at start up.


Jordon, this does only happen at start up, correct?

rancher

[speedbump]

I want you to take the cover off the pressure switch and see if the points open and close in conjunction with the hammering.

bob...

[Raucina]

I will second and third that idea....

[sammyhydro11]

Hmmmmm..........i wonder when he is going to pull the pump and replace that check valve.

SAM

[Rancher]

Only when he checks the pressure switch to see if that is causing the water hammer.

Rancher

[sammyhydro11]

Hmmmmm......it only happens when the pressure shuts off,hmmmmmmmm....

SAM

[sammyhydro11]

I like the idea of hooking up with a couple of guerillas and and yanking that sucker!

SAM

[Randyj]

After all this discussion I'd be broken hearted if it is only a pipe moving causing the noise when it is bumping up against something...... or something as goofy as a bad toilet valve bumping open and close.

[Gary Slusser]

He probably has a busted spring in the check valve in the pump. It hesitates in closing and allows the water to stop and reverse direction and move slighty down the well pushed by the pressure tank pressure before the check closes, and when it does, the shock wave expands his PE tubing moving it in the basement making a noise.

[sammyhydro11]

Thank you gary,i totally agree.

SAM

[Randyj]

I kinda sorta think you guys got this thing whittled down to a nub. (big problem...lots of debate/discussion...and probably a fifty cent solution).

[sammyhydro11]

Randy,
just curious,what is the 50 cent solution?? We could become millionaires!!I'm pretty good at marketing,you have the idea,and rancher could probably fetch us coffee while we come up with a plan to sell this product! What do you think??

SAM

[Rancher]

Sammy, Randy said probably a 50 cent solution, but probably not if you have pull the pump and either replace it or add another checkvalve on top of it. Brass spring loaded checks are 5-10 bucks around here. And since you're the newbie with all the correct answers you buy the coffee.

Rancher

[valveman]

Wow! Gone a few days and have to read a book to catch up. To summerize, replaced tank, which I agree was bad, but did not fix problem. Second check at tank would probably stop water hammer on pump shut down but, hydrant would not work, and can cause a vacuum when pump is off. Second check valves usually cause water hammer on pump start up, not pump shut down. Conclusion; Check valve at pump is probably bad, replacing should fix the problem. The draw back is that you have to pull the pump. By the way, what caused the check valve to fail in the first place? Even with a good spring in a good check valve, the valve will only be open according to how much flow is moving through it. The closer the check valve is to the closed position when the pump shuts off, the less water hammer happens. Restricting the flow before the pressure tank with a valve, puts higher back pressure on the pump. Higher back pressure on the pump does not hurt anything. When the pump sees higher back pressure it just thinks it is in a deeper well. Your pipe just has to be strong enough to handle the pressure, the same as it would for a pump in a deeper well. Just check your pumps max pressure to see if your pipe is OK. As the tank is filling at 1 GPM through a CSV, the flow through the check valve is also 1 GPM. At 1 GPM the check valve is only open the width of a piece of paper, regardless of spring in the check being good or bad. When the pressure reaches 60 and the pump shuts off, you will not hear the check valve close or any subsequent water hammer. I suggest installing a CSV before the yard hydrant. If the CSV does not fix the problem, return it for a full refund. However, if the CSV does not stop the water hammer, then your bottom check is really, really bad. The check would have to have loose, broken, or missing parts. Remember when I ask what causes this problem? Like most other items in a pump system, the check valve and the bladder in the tank, where destroyed by repetitive cycling on and off of the pump. This causes the check valve to basically slam itself to death, and the tank bladder to break like repeatedly bending a wire. If it is already too late for the CSV to salvage the last remaining life left in the check valve, it will certainly keep this problem from happening again to a new check valve. The CSV will fix the root of the problem which is cycling. Anything else, including just replacing the check valve, is just a band aid.

[Randyj]

Aw heck man... if I knew the answer I'd be in the well business rather than a lowly plumber.

[sammyhydro11]

You know that vacume issue w/ a check valve at the tank. Wouldn't a csv act the same as a check valve when it closes???

SAM

[sammyhydro11]

I still dont get the fifty cent solution rancher. Check valves for 5 to 10 bucks?? That doesn't sound like 50 cents to me. Rancher needs 2nd grade math. I'll take a small regular old man and i want my change.

SAM

[valveman]

The CSV can never completely close. That's what makes it a CSV.

[sammyhydro11]

Thanks valveman,
i'm still learning about that valve i guess.

SAM

[vaplumber]

I still dont get the fifty cent solution rancher. Check valves for 5 to 10 bucks?? That doesn't sound like 50 cents to me. Rancher needs 2nd grade math. I'll take a small regular old man and i want my change.

SAM

Come on guys! Sam, learn some common english figures of speach! The "50 cent solution" is just a figure of speach for when you spend a fortune in labor to replace a part that costs only a few bucks, and for the new guys, stop taking every thing as an insult. Ive learned a lot from the people on here even after many years in the profession, and I hope to learn a lot more. Many times Ive been wrong, and yes even a little hard headed, but I have learned. Jordan, if nothing else cures the problem check out that check valve. Another suggestion I have recieved, with the pump at that depth, you may not be able to cure the hammer if the pump is hung on poly pipe. Uncap the well, turn on the water and watch to see if the pipes down the well move when the pump stops. Ive always been split half way between using a torque arrestor and not using one, but farther advice from another source tells me that if the well has poly pipe (the black flex pipe) and either no torque arrestor, or improperly installed torque arrestor, and your hammer is a "tink, tink, tink type noise, it could be cause by the torque arrestor issue, and will cause no harm other than the annoying noise.

[Gary Slusser]

May I suggest that those PMing you be told to post instead? No one else can learn from their wealth of knowledge when they send private messages. Anyway, that's what I tell anyone that PMs me.

In 18 years as a local well pump and water treatment dealer, I worked on many wells but only one with drop pipe of another kind than PE. Additionally, I've installed thousands of pieces of water treatment equipment on many more well water systems than those where I worked on the well pump; 99% of all my water treatment work was on wells. I've been posting about wells and pumps and water treatment in Usenet newsgroups and forums for 10 years tomorrow and no one has ever blamed PE for water hammer before!

If you think about PE pipe, it is semi flexible and expands when frozen (not as much as PEX), so it will expand during a water hammer incident which would minimize the effect and sound. So.... how could it (or any type of pipe) cause water hammer!!!

Use of a torque arrestor or not is not going to cause or prevent water hammer. Torque arrestors usually cause more problems than they prevent but, water hammer happens when the water movement is stopped suddenly; and here the hammer happens at shut off of the pump, not a fixture etc.

A torque arrestor prevents rotation of the pipe and/or rubbing the pipe/pump/cable on the inside of the well rock or casing by centering the pump/cable and drop pipe in the hole.

[sammyhydro11]

Well put Gary.

Vaplumber,
you're right.I do need to cool it a bit. That rancher guy just gets me riled up.

SAM

[Rancher]

That rancher guy just gets me riled up.

Sammy, I apologize, it was not my intention to get you riled up.

Rancher

[Randyj]

Just think... if I can learn 50 cents worth of good info I can use it to make millions of dollars fixing wells......

[vaplumber]

Sammy, I owe you a apology as well. I need to learn not to get so defensive myself. Im sorry.

Gary, I agree with you about the poly pipe. Have never seen a problem in all of my years working with it. My suggestion came from another well man, and at this point, Im sure the man with the problem is at the point of trying anything. The well man that offered this idea says that the tink, tink, tink noise might not be water hammer, and especially if the noise has been there from day one. If it's a really quiet noise, and not a loud BANG!!, his idea is that the components in the well are moving from torque when the pump stops. He says that they would move when the pump starts too, but you wouldnt be able to hear it because of the operating pressure on the pipe down the well. Ive never heard of this, and am curious myself if it could be. Might be worth un capping that well and have a look down the hole as the pump starts and stops.

[valveman]

The strength of the pipe determines how fast the water hammer shock wave travels. Softer pipe like poly, bounce the shock wave off at about 3,000 feet per second. Stronger wall pipe like steel, bounce off the shock wave at about 8,000 feet per second. I agree that the softer wall poly should even absorb some of the pulse but, can’t cause water hammer. Water in motion wants to stay in motion. Water at rest wants to stay at rest. Water hammer happens when you start moving water that was at rest, or when you stop water that was moving. The slower the velocity of water when the pump shuts off, the less the check valve will slam and the less water hammer you have. Same thing is true of starting a pump. When you have tried everything and you still have a hydraulic phenomenon that causes a water hammer, try restricting the flow to 1 GPM before shutting on or off the pump. I guarantee you will not see the pipe move or hear the tink or thud when the pump is only pumping 1 GPM at time of shut off.

[sammyhydro11]

Yeah Rancher,
maybe we should just bury the hatchet and move on. If we don't agree on one anothers opinions,then i guess it can make for good debate as long as it doesn't get out of hand. If we could only figure out a way to make a reality show of it,then we could make some money badgering each other but until then we will play it cool.

I just hope this guy gets someone out there to fix his well problem because it sounds to me like its beyond anything he can fix himself.

SAM

[Randyj]

Aw shucks man... ain't nobody gonna give me an apology? GEE WHIZ... I apololgize for all the bad info I give and to everyone I pee in their cornflakes.

[sammyhydro11]

OK Randy,
ummmm.....i apologize to you too,ok? Dont piss in my corn flakes they taste bad enough!!!!

SAM

[jodan]

I did the back down test. Pump cut out at 60, 61#'s. House off it dropped 2#'s in about the 10 min. I let it set for 30, and still was at 2#'s loss. I did watch the points and they did not move at all once they cut out. Looks like two options left. Dump some cash on a pump pull and hope it works or dig through the frost for a CSV install. Neither going to happen today.

[vaplumber]

Im still curious about the pipes and pump twisting down the well causing your noise. I have never heard of this, but would like to see if it could be true. Have you had a chance to un cap the well and observe this phenomenon yet? Well man Ive spoken to says if this is the cause of your noise, it's no relation to hammer at all, simply torque moving the components resulting in water slosh, and will cause no harm what so ever.

[valveman]

If there is no air in the pipe, water can't slosh around. I have heard the noise made from the pipe or wire slapping against each other or the casing. This sounds much different than water hammer and usually happens on pump start up not shut down. The check valve is holding but, it is dragging. Probably worn out enough to be sticking in the wide open position. After the pump shuts off, the flow must reverse for a second before there is sufficient force to close the check valve, which causes the water hammer "thunk". If this is the case the only thing that will fix the problem is replacing the check with one that does not stick. Even the CSV won't help if the spring in the check is broken and the valve sticks wide open. The CSV would have kept this problem from happening in the first place as check valves are just one of many items in a pump system that is destroyed from cycling on and off repeatedly. I don't see how anyone can read a few lines from this forum and decide that you don't have a problem at all. So I guess you are being told that the problem must all be in your head. So I would certainly listen to this person when they tell you not to use a CSV. The CSV is one thing that might fix the problem without having to pull the pump. The CSV is the only thing that would have kept this from happening in the first place and will keep it from happening again. If you install the CSV in the well, you won't have to do any digging. You will however, need to pull the pump up far enough to install the CSV just under the pitless adapter. You would need to use a CSC1 coupling to make the CSV strong enough to hold the weight of the pump. Replacing the down hole check valve and installing the CSV would stop the water hammer and keep it from happening again.