Pipes Hammer when pump cuts out

[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.