WWJ (Six reasons Submersibles Fail)
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Boycedrilling
In the Trades
Yup that's exactly what happened. Swung the valve shut and instant water hammer. The fire Dept told me if any leaks showed up, is was my resposibility to repair them.
Water hammer is all about the velocity or speed of the water moving in the pipe. That's why the CSV eliminates water hammer from the pump, it slows the water down gradually before shutting the pump off. Think about water moving at 10 or 20 gallons per minute in a pipe, compared to water moving in the pipe at 1 gallon per minute.
Water hammer is all about the velocity or speed of the water moving in the pipe. That's why the CSV eliminates water hammer from the pump, it slows the water down gradually before shutting the pump off. Think about water moving at 10 or 20 gallons per minute in a pipe, compared to water moving in the pipe at 1 gallon per minute.
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Ballvalve
General Engineering Contractor
You could use the ball valve if you could trust someone to take 30 seconds to close it in increments. That's why those 6" plus high peressure butterfly valves need a gear drive, to slow you down. Funny, but I have a brass 8" ballvalve in my yard from a govt. auction - came with test docs and resealed for some outrageous pressure. The handle is about 4' long. Imagine the explosion if someone shut that off quick.
Any buyers?
Ballvalve
General Engineering Contractor
Same as a check valve - that's like the fastest closing ball valve in the world. Water hammer can produce pressures enough to break any pipe. That is how hydraulic water ram pumps work. https://en.wikipedia.org/wiki/Hydraulic_ram -with controlled hammer.
I have a well where I laid 1 mile of pipe uphill to service 4 homes. Static pressure at the well is 170 PSI, so that eliminates all normal pressure tanks as a buffer. I put in a top end ball cone check valve at the well head and a few adjustable pressure relief valves before it to kill the hammer by spilling a bit of water at shut off. Before the adjustable pressure relief valves were in, would blow the back right out of a pressure gauge! This is the sort of run of pipe where multiple check might be in order. Only one house is in and how to automate this system in the future is a good question for me.
The biggest problem we have with water hammer is on concrete batch plants. They use an air operated valve to fill the trucks. They weigh the water and when it gets to the right amount, the air operated valve slams shut so they don't get 1 ounce more than the recipe requires. Those fill stations are usually 500-1000' away from the pump and CSV. So stopping 1000' of water in a fraction of a second causes major water hammer. We suggest using a riser pipe just before the air operated valve. The tee and riser pipe need to be the same size as the pipe line. And we use a foot of riser sticking up for every inch of pipe size. 3" pipe uses 3' riser sticking up with a cap on top. 4" pipe uses a 4' riser and so on. This stops the water hammer from the air operated valve closing.
The CSV can stop any water hammer from the pump starting and stopping as in the following video. This was a big resort in Can Cun. And the water hammer was seen and felt throughout the entire property. They were very glad to have that problem solved so easily.
http://www.cyclestopvalves.com/video/waterhammer-dsl.wmv
The CSV can stop any water hammer from the pump starting and stopping as in the following video. This was a big resort in Can Cun. And the water hammer was seen and felt throughout the entire property. They were very glad to have that problem solved so easily.
http://www.cyclestopvalves.com/video/waterhammer-dsl.wmv
Boycedrilling
In the Trades
Had an interesting service call yesterday. Farmer called me, "We had really good pressure on the house well yesterday, but nothing today. and the pumps only 3 or 4 years old." Now I've never worked on his system, but I go out. He's got the cover off the control box and pressure switch and the fuse box open. It's a Franklin 3 hp standard control box 1994 date code. The pump is being directly controlled by a standard duty square D pressure switch with the low pressure cutout lever. Only line one is being switched. Of course the points are burned. He has two 80 gallon pressure tanks, WITH a CSV! he tells me the pump is set 625 ft deep, so I know it's a 10 gpm pump if it's a 3 hp.
I close the points with the lever, nothing. So I grab the fluke meter and test the voltage at the fuses. 209 volts leg to leg. Line one is 73 volts, line 2 measures 123 volts. Open the breaker panel next to the pump fuse box, same thing. Call the utility company, I know it's a fault in between the power pole and the meter. So I go ahead and put the meggometer on the motor leads, it tests OK. replace his pressure switch. Talk him into a deluxe control box with a contactor. Because the pressure switch is only rated for 2 hp. I'm thinking we might also need to put a cycle sensor on it to replace the low pressure cutout on the old pressure switch. I get a call about 7:30 last night, the PUD fixed the underground fault. His wife has water again. Happy, happy, happy.
I close the points with the lever, nothing. So I grab the fluke meter and test the voltage at the fuses. 209 volts leg to leg. Line one is 73 volts, line 2 measures 123 volts. Open the breaker panel next to the pump fuse box, same thing. Call the utility company, I know it's a fault in between the power pole and the meter. So I go ahead and put the meggometer on the motor leads, it tests OK. replace his pressure switch. Talk him into a deluxe control box with a contactor. Because the pressure switch is only rated for 2 hp. I'm thinking we might also need to put a cycle sensor on it to replace the low pressure cutout on the old pressure switch. I get a call about 7:30 last night, the PUD fixed the underground fault. His wife has water again. Happy, happy, happy.
Boycedrilling
In the Trades
I'm thinking the last guy to work on this system didn't have a clue what the CSV was, and added the second pressure tank.
Probably right. But there really is no problem with 2 pressure tanks with a CSV, as long as the CSV setting is just a pound or two below the pressure switch off setting. You can still make it have a 2-3 minute run time in this way, no matter how big or how many tanks there are.
It is good that you suggested a Deluxe box, because as you said the FSG switch is only good to 2 HP. But also with the 3-15 HP single phase Cycle Sensor you need the relay in the Deluxe box to wire into.
Boycedrilling
In the Trades
It's suprizing how many 5 hp pumps I come across that use the standard control box and just the fsg pressure switch. Talk about burning points. But hey, they saved a couple hundred bucks.
Big problem if the points weld them selves closed and the pump doesn't shut off.
Of course you could just file them and be good to go again, right? NOT!!!!
Big problem if the points weld them selves closed and the pump doesn't shut off.
Of course you could just file them and be good to go again, right? NOT!!!!
A lot of people use the GHG2 switch on 5HP pumps because it says they are good to 5HP. But if you look closer it says 5HP at 480V or three phase and only 3HP on single phase. Of course with a three phase starter you could use even the FSG for a 500HP if you wanted.
That is a good video. You don't even need the gauge to see the water hammer on pump start. The water just shotgunned out the faucet for a second on pump start. And if you had not been releasing water just prior to the pressure gauge, the gauge needle may have broken off from bouncing so hard. You can leave the gauge on that faucet and let water out to start the pump from a different hydrant farther down and the gauge reading will be more violent.
That gauge bouncing back and forth on pump stop also shows a big water hammer from having too many check valves. You just don't know what you are looking at. Can you imagine how bad the water hammer is down by the check valve that is causing it?
I would love to see that same test on a pump system with only the one check valve on the pump. The extra check valve is causing a lot of that hammer. So the gauge should be much smother in a system with only one check. However, it will still hammer some on pump shut off, as the check valve slams from the wide open position when the pump shuts off.
I would also like to see that test on a system with one check and a CSV. You would not even see the needle bounce the slightest on pump stop when using a CSV. When using a CSV to reduce the flow to 1 GPM before the pump shuts off, the check valve only closes from a distance the thickness of a piece of paper, and there is absolutely no water hammer.
Can you imagine how bad the water hammer would be on a larger pump and/or with steel pipe?
That gauge bouncing back and forth on pump stop also shows a big water hammer from having too many check valves. You just don't know what you are looking at. Can you imagine how bad the water hammer is down by the check valve that is causing it?
I would love to see that same test on a pump system with only the one check valve on the pump. The extra check valve is causing a lot of that hammer. So the gauge should be much smother in a system with only one check. However, it will still hammer some on pump shut off, as the check valve slams from the wide open position when the pump shuts off.
I would also like to see that test on a system with one check and a CSV. You would not even see the needle bounce the slightest on pump stop when using a CSV. When using a CSV to reduce the flow to 1 GPM before the pump shuts off, the check valve only closes from a distance the thickness of a piece of paper, and there is absolutely no water hammer.
Can you imagine how bad the water hammer would be on a larger pump and/or with steel pipe?
Do your videos. You will find that multiple check valves are causing the water hammer we see in the video. The short life of any check valve is caused from slamming shut from the wide open position, which doesn't happen with a CSV. But as you can see from your video, that extra check valves causes quite a water hammer and a big pulse of water from the hydrant. People who use multiple check valves do so to spread the damage around to try and make the check valves last longer from all the slamming from cycling. What you are seeing on the gauge is just a fraction of the pressure the check valve has to live with.
The engineers at Franklin even said to use a Schrader below each check to eliminate the vacuum and let air in to cushion the next start. So engineers know that multiple check valves cause water hammer. They just don't know how to make the velocity really slow before the pump shuts off so you don't have water hammer. Well they do know, but they are not going to suggest using a Cycle Stop Valve because that would solve too many problems and you would no longer need an engineer.
Quite the gauge needle jumping action at 1:13 and at the end. Pressure tank is in the house.
No needle jumping.
Well your video in post #73 at about 1:13 shows what I would call "bad water hammer". The needle on the 100# gauge pegs out completely and violently at 1:13 when the pump starts, and the gauge bounces like crazy at 2:32 when the pump shuts off. When water hammer pegs a 100# gauge so violently, there is really a pressure spike of about 500 PSI. It just happens so fast you couldn't see it if you had a 500# gauge. I don't see how anyone could think this is a good thing. This is why you have to use multiple check valves. One check valve can only handle that kind of abuse for a short time. Two check valve will last a little longer. But if you didn't have the water hammer, the check valve would not see those tremendous pressure spikes, and neither would any of the other components in the pump system.
The video of the CSV system in your post #74 shows absolutely no water hammer or spike when the pump starts or stops. That is what a pressure gauge should look like when a pump starts and stops.
The video of the CSV system in your post #74 shows absolutely no water hammer or spike when the pump starts or stops. That is what a pressure gauge should look like when a pump starts and stops.
I had trouble reading the Franklin Aid June 1984 scan initially. It was easier this way:
What I particularly found interesting was the wording "check valve manufacturers often recommend that . . . ." rather than saying that was a Franklin Electric recommendation.
I also looked at the 2015 Franklin AIM manual, and I did not see recommendations for multiple check valves. I was thinking I had seen that in an earlier version a multiple checkvalve recommendation. Maybe I was thinking of something else.
Boycedrilling
In the Trades
I've got one pump guy in my area that really likes check valves. He says well the manufacturers recommend them every 200 ft, so I double that and put them every 100 ft. I think he just likes to sell extra check valves.
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