Stemmed vs Stemless Check Valve

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ACWxRADR

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Lead free, eh?

As a baby, I chewed on paint tainted with lead. I ate dirt tainted with lead and other chemicals out of the yard. As an older child, I went on family vacations in the back of a green, Chevrolet station wagon over thousands of miles with no seat belts and no child restraints. They didn't exist then. As a young pre-teen hooligan, I jumped upon passing railroad freight trains for a ride to the local lakes and I rode them back home at the end of the day! I jumped off of 50 foot bridges into rivers of murk and I slept in a cabin all through my high school years without running water and only an outhouse for a place to poop. When I was younger, I navigated the river in a flat bottomed boat down the Platte River in Nebraska for several weeks alone, living on berries and catfish and rabbits and squirrels and fresh water clams and crayfish.

I have been hit by a Union Pacific train, shot at six or seven times, hit once, run over by a semi-tractor trailer, nearly drowned by a native girl from Nairobi because she freaked out in the Platte River on an inner tube trip, I was electrocuted, fell down a 60 foot ravine and got my ass kicked by people I never knew.

So don't get this wrong! The lead contained in any plumbing product manufactured today is immaterial. Except in the state of California, (where everything causes cancer and birth defects in lab rats) and the EPA won't allow you to harvest rain water.

Hee Hee!

Gordy (RADAR)
 

Ballvalve

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Maybe there is something to be said for all the pump MFG's and water system handbooks calling for check valves every 200' or so. Spread the load, extend the life.

While the concept of the csv is without question, it's application to small residential systems is in some doubt in my mind. It is without doubt ideal on large pumps and most irrigation schemes, especially residential, that a homeowner is not bright enough to zone or set the shut off pressure on the pump high enough for. But I have a LOT of pumps in place in the old standard mode, and never saw one die in less than 20 or 30 years unless the pump was sized wrong. I have a Grunfos at least 32 years old on 3 grungy plain tanks with all kinds of lag bolts in the holes. Recently found them all waterlogged, and the pump doing the death shuffle every 10 seconds. Perhaps going on for 1 or more months.

Got it on a cscr box and I plan on changing that out soon, just for the capacitor and switch life issues, no matter the cycling. OK, you'll say the csv takes the guess out of it all, and who needs 3 big tanks. Correct. But the fact that the csv won't help with waterlogged tanks, makes me step back again. It seems to all boil down to pressure tank maintenance, CORRECT pump sizing, and last, a top quality check valve. In that valve I don't want to see any plastic cages or O rings. And if a spring, one that allows the valve to continue working when it fails. A good check valve will take a lot more abuse than a pressure switch contact, a start cap, or the start switch.
 

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ACWxRADR, post: 470070, member: 72019"]Lead free, eh?

As a baby, I chewed on paint tainted with lead. I ate dirt tainted with lead and other chemicals out of the yard. As an older child, I went on family vacations in the back of a green, Chevrolet station wagon over thousands of miles with no seat belts and no child restraints. They didn't exist then.

....But you didn't step out in front of moving cars and expect it was your right to live.

Today, I am on a small northern California coastal town. Everyone seems to be the type that lives on kale, never shaved any body part, and love those little overly cute trendy restaurants where a glass of crappy wine costs $18. All the trendy eateries have big glass windows and dining patios, with the local artwork on the walls and the manifesto posted about how they only serve "sustainable" organic meat products and local, tenderly harvested vegetables. [Don't want them damn onions to feel any pain when they get their roots ripped out!]

Point being, driving slowly on the trendy boulevard, dark night, no street lights, I watched one dumb broad step out in front of the car in front of me, who had to slam their brakes on - this POS, looked up in anger at them and just continued to strut slowly as if she owned the earth. Then a few moments later, 2 more of these 30ish, carefully dressed fu--tards, stepped in front of my car - dressed in dark clothes, mid road, and just sure that it was my responsibility to see them, to stop, and to wait for them to stroll by. I wish I had paused to give them some information on their ignorance and arrogance. But they would have called the police and filed verbal assault charges.

I really hope that natural selection gets them and they die of chrome grille poisoning soon. These are likely the same imbecile college grads that wrote the laws about a check valve causing brain damage. These morons must have seasoned their sushi with lead dust since birth.

May they and all the 'get the lead out' politicians feel the sting of the lash across their pitiful shoulders.
 
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Valveman

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Maybe there is something to be said for all the pump MFG's and water system handbooks calling for check valves every 200' or so. Spread the load, extend the life.

While the concept of the csv is without question, it's application to small residential systems is in some doubt in my mind. It is without doubt ideal on large pumps and most irrigation schemes, especially residential, that a homeowner is not bright enough to zone or set the shut off pressure on the pump high enough for. But I have a LOT of pumps in place in the old standard mode, and never saw one die in less than 20 or 30 years unless the pump was sized wrong. I have a Grunfos at least 32 years old on 3 grungy plain tanks with all kinds of lag bolts in the holes. Recently found them all waterlogged, and the pump doing the death shuffle every 10 seconds. Perhaps going on for 1 or more months.

Got it on a cscr box and I plan on changing that out soon, just for the capacitor and switch life issues, no matter the cycling. OK, you'll say the csv takes the guess out of it all, and who needs 3 big tanks. Correct. But the fact that the csv won't help with waterlogged tanks, makes me step back again. It seems to all boil down to pressure tank maintenance, CORRECT pump sizing, and last, a top quality check valve. In that valve I don't want to see any plastic cages or O rings. And if a spring, one that allows the valve to continue working when it fails. A good check valve will take a lot more abuse than a pressure switch contact, a start cap, or the start switch.

If you don't have a CSV and your pump is contually cycling on and off and the check valve is continually slamming shut and flying open, you can't add enough check valves to be sure you don't get a reversal of flow. But multiple check valves cause negative pressures between them which greatly accentuates water hammer from each start of the pump.

The CSV is not as beneficial for residential systems that don't have any irrigation, pool filling, or other long term uses of water. But it does eliminate the need for a large pressure tank and still protects the pump if you develope a leak that would normally cycle the pump to death before you discovered the leak. The CSV is more advantagous on larger systems, but it has many benefits for small systems as well.

With 3 big tanks working properly most of the time you reduced cycling so much that the pump is able to survive a waterlogged tank event or two. But I wouldn't want to test it a couple more times.

The CSV does help with a waterlogged tank. If you have a diaphragm tank the CSV reduces cycling so much that you don't wear out the diaphragm and therefore don't have waterlogged conditions. And if you do have a waterlogged tank the CSV still makes the pump stay on while taking a shower instead of pounding on/off like a slow firing machine gun, which WILL quickly destroy a pump.
 

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ACWxRADR, post: 470070, member: 72019"]Lead free, eh?

As a baby, I chewed on paint tainted with lead. I ate dirt tainted with lead and other chemicals out of the yard. As an older child, I went on family vacations in the back of a green, Chevrolet station wagon over thousands of miles with no seat belts and no child restraints. They didn't exist then.

....But you didn't step out in front of moving cars and expect it was your right to live.

Today, I am on a small northern California coastal town. Everyone seems to be the type that lives on kale, never shaved any body part, and love those little overly cute trendy restaurants where a glass of crappy wine costs $18. All the trendy eateries have big glass windows and dining patios, with the local artwork on the walls and the manifesto posted about how they only serve "sustainable" organic meat products and local, tenderly harvested vegetables. [Don't want them damn onions to feel any pain when they get their roots ripped out!]

Point being, driving slowly on the trendy boulevard, dark night, no street lights, I watched one dumb broad step out in front of the car in front of me, who had to slam their brakes on - this POS, looked up in anger at them and just continued to strut slowly as if she owned the earth. Then a few moments later, 2 more of these 30ish, carefully dressed fu--tards, stepped in front of my car - dressed in dark clothes, mid road, and just sure that it was my responsibility to see them, to stop, and to wait for them to stroll by. I wish I had paused to give them some information on their ignorance and arrogance. But they would have called the police and filed verbal assault charges.

I really hope that natural selection gets them and they die of chrome grille poisoning soon. These are likely the same imbecile college grads that wrote the laws about a check valve causing brain damage. These morons must have seasoned their sushi with lead dust since birth.

May they and all the 'get the lead out' politicians feel the sting of the lash across their pitiful shoulders.

Lead regulations ate like global warming. They are solutions to problems that don't exist. Nobody was being killed from lead in plumbing fixtures. If they had the manufacturers would have been sued out of business long ago. It just ceated more government agencies that want you to believe they are trying to save you from the evil capatilistic corporations, when in reality these goverment agencies are the ones capatilizing on peoples fear and ignorance.

Yeah trying to give our children a better life than we had, we raised a couple of generations of spoiled rotten brats. When the government runs out of other people's money and just printing more makes money worthless, the long depression that we just keep postponing will be more than these milenialss can survive. But I don't know if that is going to happen before we let in enough illegals and terriosts to destroy us first.

From either thing or both, there will be a thinning of the heard, and those left won't be the kind that think they are entitled to other people's money or to step in front of your car.
 

ACWxRADR

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This is a very good discussion thread. I will interject a couple of comments.

First of all, regarding lead: What most uneducated, anti-GMO, "mowing grass" is cruelty, NIMBY (Not In My Back Yard) people do not realize is that even a solid lead pipe for water conveyance probably would never harm you. Now, I wouldn't take this statement too literally! However, there is proof to this. Lead exposed to normal atmospheric conditions combines with oxygen and readily forms a protective "skin" which resists absorption of the elemental lead into water. This is dependent upon the acidity of the water, however. Low pH water will eat away at this protection layer and dissolve elemental lead into the water, which could be consumed and would be bad. So the problem is greatly dependent on the properties of the water source.

In the times of the Roman empire, it has been speculated that because the Romans manufactured their water pipes from lead, that this resulted in lead poisoning and hastened the decline of the Roman empire.. The real story behind this notion is that many of the upper class drank their wine, an acidic drink, from chalices or goblets made from pure lead. The reason why they did so was because the lead would mix with the wine and impart a unique and different flavor that they liked. As well, an immediate euphoric effect produced from the toxic brew made them feel even more "drunk" than a straight wine high. This social habit or practice did lead to mental illnesses, blood disorders, pure lead poisoning and shortened life spans.

Regarding pump cycling and wear and life span. As in all things, MODERATION is the key. Obviously, a pump running dead head without any pressure tank at all would kill it in short order. But running a pump continuously without EVER shutting off would not be good either. A pump running hard against a blocked screen or foot valve or running dry would be bad too. So, if we have a clear inlet, no blockage, and we are not dead heading the pump, then we have a system where a pressure tank and a CSV will offer advantages. Using both together should be the best strategy by simple laws of physics and mechanics and electrical power consumption.

However, a HUGE pressure tank or one that is oversized for the delivery demand is a detraction to the efficiency of the pump in an economical sense. There is a point at which the size of the tank offers no positive return and begins to detract from the economy or efficiency of the pump. Besides, the size of the tank begins to take up too much space, cost too much money to purchase and the water stored inside may become "stagnant" or become a breeding ground for bacteria. Better to leave the water in the ground until you need it.

Size the pressure tank appropriately for the maximum efficiency for the household water usage demand and then add a CSV set to the appropriate pressure versus the pressure switch setting. That should be about mid range between the cut-in and cut-out pressure of the switch.

RADAR
 

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This is a very good discussion thread. I will interject a couple of comments.

First of all, regarding lead: What most uneducated, anti-GMO, "mowing grass" is cruelty, NIMBY (Not In My Back Yard) people do not realize is that even a solid lead pipe for water conveyance probably would never harm you. Now, I wouldn't take this statement too literally! However, there is proof to this. Lead exposed to normal atmospheric conditions combines with oxygen and readily forms a protective "skin" which resists absorption of the elemental lead into water. This is dependent upon the acidity of the water, however. Low pH water will eat away at this protection layer and dissolve elemental lead into the water, which could be consumed and would be bad. So the problem is greatly dependent on the properties of the water source.

In the times of the Roman empire, it has been speculated that because the Romans manufactured their water pipes from lead, that this resulted in lead poisoning and hastened the decline of the Roman empire.. The real story behind this notion is that many of the upper class drank their wine, an acidic drink, from chalices or goblets made from pure lead. The reason why they did so was because the lead would mix with the wine and impart a unique and different flavor that they liked. As well, an immediate euphoric effect produced from the toxic brew made them feel even more "drunk" than a straight wine high. This social habit or practice did lead to mental illnesses, blood disorders, pure lead poisoning and shortened life spans.

Regarding pump cycling and wear and life span. As in all things, MODERATION is the key. Obviously, a pump running dead head without any pressure tank at all would kill it in short order. But running a pump continuously without EVER shutting off would not be good either. A pump running hard against a blocked screen or foot valve or running dry would be bad too. So, if we have a clear inlet, no blockage, and we are not dead heading the pump, then we have a system where a pressure tank and a CSV will offer advantages. Using both together should be the best strategy by simple laws of physics and mechanics and electrical power consumption.

However, a HUGE pressure tank or one that is oversized for the delivery demand is a detraction to the efficiency of the pump in an economical sense. There is a point at which the size of the tank offers no positive return and begins to detract from the economy or efficiency of the pump. Besides, the size of the tank begins to take up too much space, cost too much money to purchase and the water stored inside may become "stagnant" or become a breeding ground for bacteria. Better to leave the water in the ground until you need it.

Size the pressure tank appropriately for the maximum efficiency for the household water usage demand and then add a CSV set to the appropriate pressure versus the pressure switch setting. That should be about mid range between the cut-in and cut-out pressure of the switch.

RADAR

You are exactly right about lead in plumbing not being a problem unless you have acidic or hot water. Then again it is the acidic or hot water that is the problem, not lead in the plumbing. It would have made much more sense to outlaw acidic water than lead plumbing. Drinking acidic wine from lead goblets was not good for the Romans. They even added lead to the wine as a preservitive. But the solid lead fresh water pipes were never the problem.

I must disagree with you however about it not being good to run a pump 24/7 or that a pressure tank can be too large as far as the pump is concerned. You are right that a large tank takes up too much space, cost too much, and can cause problems with water quality. But the larger the tank, the longer the pump runs, which is almost as good for the pump as running continuously. Because running continuously is the best thing for a pump. This is one of the biggest misconception about pumps, but pumps are made for continuous duty. Bearings in pumps are completely frictionless when running. Pumps only wear during startup when the bearings are dry. So pumps last longer running 24/7 than if they cycle on and off even a few times.

Yes CSVs will work with large pressure tanks. But once you understand how CSVs function you will realize that even a so called properly sized tank is a waste of money and space when using a CSV.

And when used with a large tank you don't want the CSV setting in the middle of the pressure switch setting. It won't hurt anything but it will take longer than needed to fill the tank, which will waste some electricity. The larger the pressure tank, the closer the CSV setting should be the the pressure switch off setting.
 

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Hey Valveman,

I understand your notion, regarding continuous pump operation being beneficial, but only in theory. I must disagree with you because it is first and most, impractical and uneconomical. Unless you do not have to pay for the electricity or other power to operate the pump. Secondly, I disagree because no matter how you look at it, it is still a mechanical system and subject to physical stress and mechanical wear. Too many frequent start and stop cycles are bad, very bad for any mechanical system. But continuous operation also means wear and mechanical stress, period. Strange things happen to metal and lubricants, even the non-moving components like the pump housing or the bearing races or the bearings themselves if they were subjected to continuous operation. There are certain vibrations which are induced simply because of the time factor which set up harmonic frequencies and forces of stress that eventually tear any system apart. The human body cannot withstand running a marathon forever, rowing a boat forever, lifting weights forever. This is not just because the human body needs time to replenish the energy source and expel waste products from the burning of sugars during the exercise process, swivel bone joints and cartilage require time to repair and relax. Metal bearings and motor shafts and wiring need time to rest and relax, too. Not because they are the same as a biological organism that needs to rest or sleep and time to repair itself between workouts, but because metal fatigues. All material fatigues with constant use.

If you stop your pump and allow it to set idle for a time, the internal structure of the metals have an opportunity to relax and change. They can revert to their more natural state of elasticity. Too much exercise on such a device can eventually lead to such anomalies as crystalline formation, especially if there is heat buildup in the process. All this wear and tear is happening on a molecular level, due to vibrations and heat stress and centrifugal forces and many other forces that we are not even aware of as a general consumer or user Properties of physics are not well understood by laymen, but they exist. The biggest culprit for wear in any mechanical system is component fatigue. We call it that, fatigue, because it emulates the very same stressors which wear down the human body with continuous use.

This is most important for a car engine, for example, because of the heat build up from the burning of fuels, but it occurs in any mechanical system, even water pumps which are naturally cooled by the fluid they pump. Keeping the device cool is a great advantage, but there are still other stress factors working against us that you need to take into account.

Allowing any pump or mechanical device to run continuously " forever" is NOT a good thing. All things need to rest, not just a biological entity like the human body.

A BALANCE between WORK and IDLE time is a must for everything in the universe.

RADAR
 

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And when used with a large tank you don't want the CSV setting in the middle of the pressure switch setting. It won't hurt anything but it will take longer than needed to fill the tank, which will waste some electricity. The larger the pressure tank, the closer the CSV setting should be the the pressure switch off setting.

I have read that it should be near the mid point between cut-in and cut-off pressure. But. my own logic has to agree with you on this. ZI would want it (the CS) setting to be near 80-90% of the top pressure setting of the switch. For example, with a 40-60 switch setting, the CSV should be set at 55 psi to 50 psi.
\
RADAER
 

Valveman

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I understand your notion.

A BALANCE between WORK and IDLE time is a must for everything in the universe.

RADAR

It is not just my notion. It is a difficult concept to understand, but still a well proven fact. Pumps do not need to rest.

As long as the pump is running over 1800 rpm the Kingsbury thrust bearing in the motor has a film of water between the moving parts and it is completely frictionless. Cutless ruber bushings in the liquid end do the same thing. The ONLY time a pump sees any wear is when it is started. From 1 to 1799 rpm the hydroplaning effect hasn't started yet and the bearings are running dry. Once it is up to 1800 of its 3450 rpms there is a film of water between the bearings and there is no more friction that a car tire skidding in a half inch of water.

The motor is also sitting in very cold water and when off, all of it's components have restricted to there smallest form. When running the motor heats up to as much as it will when being cooled by flowing water, but it is still enough to expand all components to there largest form. It is the continued contracting and expanding from starting and stopping that causes stress. A motor running continously stays at a constant temp and there is no contracting and expanding.

Remember we are also pumping cool, clean water which is the perfect lubricant and coolant. The pump doesn't wear when pumping nice cool lubricant.

If we were talking about pumping concrete, sand, etc. then I would agree with you. But when pumping cool, clean water a pump will always last longer running 24/7 than if it has to continually restart, which is what causes wear.
 

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My uncle (We call him Uncle Hoagie, but his name is Glenn Verne) has had his well running for toilet water, watering his garden and watering his grass and cleaning off the tractor for decades. The same well point, the same check valve and the same pump and the same pipes down the same hole since the early 1970's.

This installation is an above ground centrifugal pump with a 1/2 HP motor and a 26 foot deep sand point driven well.

If there were such a thing as a poster child for well longevity, this would be one to include. How many years has this system been running without a hitch? 2015 (almost 2016) minus 1972 would be 43 or 44 years on the same pump, same well screen.

There is no simulation of well life expectancy here, this is the real deal. He has no CSV and only a 2-3 gallon pressure tank.

I believe that the pump and motor design from years ago coupled with a free flowing well point is the key. Keep the sand out of the impeller, don't stress the motor of the pump by drawing water from a plugged well, don't allow the pump to cycle on and off too often and don't let it run continuously. BALANCE!

RADAR
 

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Yeah everybody has an uncle or a friend with a pump that lasted 40 years. But that is not the norm. When you work with tens of thousands of pump systems like I do, you will find most pumps are cycled to death in a short period of time.

Little 1/2 or 3/4 hp pumps last longer than larger pumps. That is because those little pumps don't pump much volume or build much pressure. They are down to an output of 2-3 gpm before they reach the pressure swith shut off. So they have longer run times and don't cycle, which is very similar to a system with a CSV.

A 1 or 2hp pump would cycle a lot and only last a fraction of that time.

Jet pumps have ball bearings that are made for a certain number of hours. And you can bet that a pump made today would have a much cheaper and shorter lived bearing than one made 40 years ago. But still even jet pumps are made for continous duty.

Submersibles have Kingsbury type bearings that last longer if they run 24/7. Pumps don't need to rest, they don't need BALANCE. They like to run and only wear during starts. Understanding this is a requirement to being able to understand anything else about pumps. Until you understand this there is no sense in asking any other questions about pumps. Nothing else about pumps will even make sense until you first understand that pumps are MADE FOR CONTINUOUS DUTY.

When I discuss pump systems with engineers or installers, my first question is, you do know that pumps are made for continuous duty and will last longer if they run 24/7? If they answer, "of course', then we can discus how to solve this problem and make pumps last longer. If they say, "that's wrong, pumps need to rest", then there is no reason discussing anything else with them until they do some studying and finnaly get a clue how pumps really work.
 

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I guess there is a "balance" between running a pump continuously and "letting it rest". But it is just the opposite of what you might think. It is a balance of how much the pump runs continuously which causes no wear, and how many times the pump cycles as starts are what actually causes wear.

So the longer the run times (larger tank or CSV even better) the fewer times the pump has to cycle (start), and the less wear on the pump. Now if you are not using the pump a well is a good place to store it while it is resting. But if you are using water the pump will experience less wear running 24 hours straight than if it only runs 12 and rest 12 if it had to cycle multiple times to do that.

But yes as I explained many times, if tank drawdown is your only concern, then use a large pressure tank WITH a CSV instesd of a small tank. The CSV will keep the pump running continuously when using water for extended periods of time. It will even keep the pump running steady as long as a shower is on instead of letting the pump cycle a half dozen times. And the large pressure tank will let you flush a toilet half a dozen times when the pump is not already running for showers and other stuff.

However, this is not a "balance". The CSV with a large tank actually throws the balance way off to the side of being really good for the pump. No cycling AND a large drawdown.

Using a CSV with a small tank actually utilizes more of a "balance". Now you are balancing the CSVs ability to keep the pump running continuously while you are using water anywhere in or out of the house (which is good for the pump), with the number of cycles needed for a few random toilet flushes with a pressure tank that only holds 1 gallon.

The CSV with a large tank shifts the balance so much more towards standard pump longevity that using a small tank with a CSV only shifts the balance back closer to the normal 20-30 year pump life.
 

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Hey Valveman,

I understand your notion, regarding continuous pump operation being beneficial, but only in theory. I must disagree with you because it is first and most, impractical and uneconomical. Unless you do not have to pay for the electricity or other power to operate the pump. Secondly, I disagree because no matter how you look at it, it is still a mechanical system and subject to physical stress and mechanical wear. Too many frequent start and stop cycles are bad, very bad for any mechanical system. But continuous operation also means wear and mechanical stress, period. Strange things happen to metal and lubricants, even the non-moving components like the pump housing or the bearing races or the bearings themselves if they were subjected to continuous operation. There are certain vibrations which are induced simply because of the time factor which set up harmonic frequencies and forces of stress that eventually tear any system apart. The human body cannot withstand running a marathon forever, rowing a boat forever, lifting weights forever. This is not just because the human body needs time to replenish the energy source and expel waste products from the burning of sugars during the exercise process, swivel bone joints and cartilage require time to repair and relax. Metal bearings and motor shafts and wiring need time to rest and relax, too. Not because they are the same as a biological organism that needs to rest or sleep and time to repair itself between workouts, but because metal fatigues. All material fatigues with constant use.

If you stop your pump and allow it to set idle for a time, the internal structure of the metals have an opportunity to relax and change. They can revert to their more natural state of elasticity. Too much exercise on such a device can eventually lead to such anomalies as crystalline formation, especially if there is heat buildup in the process. All this wear and tear is happening on a molecular level, due to vibrations and heat stress and centrifugal forces and many other forces that we are not even aware of as a general consumer or user Properties of physics are not well understood by laymen, but they exist. The biggest culprit for wear in any mechanical system is component fatigue. We call it that, fatigue, because it emulates the very same stressors which wear down the human body with continuous use.

This is most important for a car engine, for example, because of the heat build up from the burning of fuels, but it occurs in any mechanical system, even water pumps which are naturally cooled by the fluid they pump. Keeping the device cool is a great advantage, but there are still other stress factors working against us that you need to take into account.

Allowing any pump or mechanical device to run continuously " forever" is NOT a good thing. All things need to rest, not just a biological entity like the human body.

A BALANCE between WORK and IDLE time is a must for everything in the universe.

RADAR

Interesting thread here. I agree the body needs time to replace its worn items in rest periods. I am even discovering that as the body ages, those rest periods need be longer and do not always succeed in the proper rejuvenation. Dad told me that as a kid, but I thought I was superman and would always be. I had a CSV in my back and legs, but now I am paying the price.

But for machinery, there are no bio-chemical needs to be refreshed on a week at the beach. Indeed, quite the opposite is true. If memory serves, some of the turbines and generating units in large dams such as Hoover have run for 30 to 50 years at a stretch before a shutdown for inspection, mainly for cavitation on the runners. As long as the massive generators are turning - perhaps 20' + in diameter - they are frictionless on their kingsbury type bearings, and as long as you can balance that dime on edge on the casing, there is no molecular changes or fatigue. Just from memory, there was such a turbine that was shut down, and it was determined that after 50 years of constant use, it still had another 200 years left in the bearings. But we don't want to let our cars idle all night in the driveway, nor do we want our tiny water pumps to run for 1 hour when 15 minutes will suffice.

As for component fatigue, you are correct for mechanisms in extreme states of use, such as a jet engine, or an Apollo rocket motor. Harmonic vibration will end any mechanisms funcionality very quickly. When I see helicopters over my house, and my teeth are rattling, I hope that the machine will not self destruct at that moment, as destruct it must one day. But that is not a 3 gorges dam generator turning at perhaps 40 rpm [43 foot diameter +/-] or a well balanced 4" pump motor turning at 3500 rpm. - both can run near forever until the weakest link fails.

How about the diesel engines in large ships? Cylinders the size of water tanks, and running for decades. No need for a rest there.
 

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As long as there is enough lift from the static level and/or enough backpressure still in the system for the pump to be working left of its max safe flow line the pump should not upthrust.

But if there is more than the one check valve on the pump, the extra check valve can let the pump start while seeing a negative pressure and upthrust will occur.

When that happens the pump will instantly go from upthrust to slamming down thrust, which can shatter a Kingsbury thrust bearing.
 

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Interesting thread here. I agree the body needs time to replace its worn items in rest periods. I am even discovering that as the body ages, those rest periods need be longer and do not always succeed in the proper rejuvenation. Dad told me that as a kid, but I thought I was superman and would always be. I had a CSV in my back and legs, but now I am paying the price.

But for machinery, there are no bio-chemical needs to be refreshed on a week at the beach. Indeed, quite the opposite is true. If memory serves, some of the turbines and generating units in large dams such as Hoover have run for 30 to 50 years at a stretch before a shutdown for inspection, mainly for cavitation on the runners. As long as the massive generators are turning - perhaps 20' + in diameter - they are frictionless on their kingsbury type bearings, and as long as you can balance that dime on edge on the casing, there is no molecular changes or fatigue. Just from memory, there was such a turbine that was shut down, and it was determined that after 50 years of constant use, it still had another 200 years left in the bearings. But we don't want to let our cars idle all night in the driveway, nor do we want our tiny water pumps to run for 1 hour when 15 minutes will suffice.

As for component fatigue, you are correct for mechanisms in extreme states of use, such as a jet engine, or an Apollo rocket motor. Harmonic vibration will end any mechanisms funcionality very quickly. When I see helicopters over my house, and my teeth are rattling, I hope that the machine will not self destruct at that moment, as destruct it must one day. But that is not a 3 gorges dam generator turning at perhaps 40 rpm [43 foot diameter +/-] or a well balanced 4" pump motor turning at 3500 rpm. - both can run near forever until the weakest link fails.

How about the diesel engines in large ships? Cylinders the size of water tanks, and running for decades. No need for a rest there.

Thanks for mentioning those turbine generators that have Kingsbury bearings. I was going to go there next. Yeah 50 years easy and 200 years left as long as they keep running continuously. Multiple starts would destroy those bearings quickly.

And because subs have the same type of Kingsbury bearing, even your little water pump will last longer running for an hour continuously verses just running 15 minutes and having to cycle 10-15 times to do that.
 

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The water level dropping after the pump starts is not important. It is the static plus line pressure that must be high enough to prevent upthrust on pump start.

And the backpressure from a CSV is good for the pump. Add that to the reduction of cycling and the CSV will always make pumps last longer than so called "traditional" systems. If your CSV systems are not lasting longer than other systems then you are doing something wrong. Short lived pumps have more to do with installers who think pumps need to rest, uses more than one check valve, doesn't pay attention to upthrust from high static, or some other reason. If they don't understand these things then they certainly don't understand CSVs. But the CSV always gets the blame when an installer doesn't understand what he is doing.
 

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Valveman,

I have gone through this thread and re-read all the posts. I am now certainly understanding the theory of continuous pump operation as you are teaching. I needed the education in this regard, so I thank you for persisting.

The only problems I have with this is that most home residential water consumers wouldn't want to pay the electric bill to run their pump continuously. Secondly, would you really desire to pump water out of your well continuously if you are not using it? That could possibly create two problems. First, you would be draining the water from the well, sucking it out of the ground for no other purpose than to keep the pump running continuously. That is unless you can set it up to return the water back, in some sort of a loop system. Secondly, wouldn't you be drawing minerals and fines through the water bearing substrate towards the well screen and causing the area near the screen to plug sooner?

With the knowledge that starting and stopping is hardest on the pump and check valves, I understand that continuous operation means less wear on the components of these systems, but I still have to state that continuous operation is not practical in residential water systems. Would you tend to agree with this?

Obviously, the reason that CSV's and pressure tanks exist in the first place is because of this very same logic.

Going back to my original topic, the check valves. I ordered a stem-less model from Simmons. It is a brass or bronze, 1-1/4" valve without any ports. Just their plain Jane version. I will mount it vertically and above ground in use with a Gould's JTRS7 shallow well jet pump. I also ordered an eight-slot, 36", SS Vee-wire sand point manufactured by Johnson.

This system will be for my cabin.

RADAR
 

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The pump does not run unless you are using water. The CSV makes the pump run continuously WHILE you are using water. Like the pump runs for 20 minutes continuously while taking a 20 minute shower instead of cycling on and off 10 times. But the CSV doesnt use any extra water it just makes the pump deliver exactly as much water as you are using.

To do that it makes the pump run longer to deliver the same amount of water. Extending the time the pump runs is good for everything. And because restricting the flow from a pump decresses the amp draw, it adds very little to the electric bill. It could add a dollar or two a month to a 5 to 7 dollar normal electric bill for a pump used for the home only.
 
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