Water Hammer - Well pump to storage tank to Shallow well booster pump

[Valveman]

Well I think you just got lucky that the water hammer stopped. Nothing you did should have solved the hammer problem. First, plastic check valves suck. I doubt it will work for very long. Second, the main problem is the pressure switch is too far from the pressure tank. You have enough friction loss in the pipe going to the pressure tank that the pressure in the pump case will be higher that tank pressure. So when the pressure switch on the pump case says 60 and shuts the pump off, the tank only has maybe 55 PSI. So as soon as the pump shuts off the pressure drops and bounces the pressure switch. I would have used a brass or SS spring loaded check valve right on the suction of the pump and moved my pressure switch to within a few inches of the pressure tank.

A CSV would certainly have helped stop water hammer on pump stop. The CSV reduces the flow to fill the tank to 1 GPM, so there is no friction loss in the pipe going to the tank and both the pump and tank see 60 PSI at the same time. Plus you only have water hammer when the pump starts and/or stops, which wouldn't happen but once per water use with a CSV. Without a CSV the pump may come on and off (causing water hammer) several times during a shower or long term use of water. Pumps like to run. What they hate is cycling on and off. Also you may be used to the pressure continually rising and falling between 40 and 60, but constant pressure would be so much better. Many people don't even realize how bad the 40/60 pressure swing is until they get a CSV and experience a constant 50 PSI for the first time. Then they tell me the pressure seems so much stronger they no longer need soap in the shower. That little 20-30 gallon size tank only holds 5-7 gallons of water. So the pump has to come on for every 5 gallons of water used and the pressure drops from 60 to 40 as that happens.

Glad you got it working but I bet is starts again soon. A metal check valve (where it is is OK) and moving the pressure switch closer to the tank will permanently solve the water hammer problem. And a CSV would permanently solve the cycling and pressure fluctuation problems.

 

[JohnnyAirtime]

Cary...

I was hoping you'd have seen my post, and replied. So thank you.

As I know, and have heard... that plastic bodied flapper check valves are no good. And I understood the spring loaded check valves to be better. Which is what I installed. But you simply state "plastic" check valves suck. Then later talk about brass or Stainless spring check valves. I thought my plastic bodied spring check valve is just what your explaining to use, yes? If so, that's what was also used at the suction side of the Jet pump originally. So, rather then me guessing at exactly which check valve I should be using, do you have a brand or model I should be using? Maybe a web link to one, so I can see... order... etc?

About the pressure switch...
It's been like that since I moved into this house a year ago. However, on a flotec pump.

(like so)



I had the flotec switched to a new Goulds under our home warranty. I'll use the flotec as backup (was the idea). The local "pump guy" and well and septic guru, left it as is - and on the pump itself as you see it. I assumed it was proper due to it being there since day one and the local guru not changing it when having his minions swapping pumps.

I also pinged on him to ask about my water hammer, and he had nothing to offer. Not sure if he's not interested in helping, or if he's only motivated by money. We all live very rural, and he's 20-30min away... but a few minutes of his expertise over the phone didn't help. I was a bit surprised, as his business name is all over my equipment (via a sticker) down at my well (and neighbor's too).

I'll also say that the reading on the gauge at the pump is 55psi when the gauge downstream (no more then a few feet) at my sediment filters is 60psi. I know no gauge is perfect, but a 5psi difference is quite a bit. I don't think the sediment filter is so dirty to add the pressure reading. Either way, I don't worry about it as it's enough pressure for me and my wife and I'm not going to chase down the reason for a 5psi difference.

Moving the pressure switch closer to the pressure tank will be what I do if we get hammer back. I kind of like the check valve where it is now, as like I said... I get pressure at places I didn't have it before, and only had storage tank head pressure. Key place, is near the storage tank where I'll eventually put a shop bathroom/washroom. I don't see any issue with it there just yet... and hope that devil doesn't rear it's head when I least expect it.

About the CSV...
Not sure I'd like one. Sure, people like constant pressure. Sure, it's better on the pump to not cycle on/off so frequently. BUT... I don't like to hear the pump run, and I do... from within my house since the pump is directly below in the basement. Also, the electricity used to run the pump hasn't been factored into the equation. The more the pump runs, the more costly it becomes. I'm sure there's some math to do to see just how much more costly, if at all... due to the startup energy needed for the pump compared to 'run time' cost. Just not sure I'm sold on the CSV concept and if it's better for us, in our situation. I do know, that it's great for those on a well pump and no storage tank... but, that's not how our setup operates.

Please get a bit more specific on what check valve you recommend.

John

 

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[LLigetfa]

Pressure switches when factory mounted on pumps are for convenience since they cannot do it any other way. It does not make it ideal.

Electricity consumption is measured mostly by the volume of water used, not the minutes the pump runs. While the difference between the two vary by pump design, it generally holds true that you pay per gallon not per minute.

 

[JohnnyAirtime]

Pressure switches when factory mounted on pumps are for convenience since they cannot do it any other way. It does not make it ideal.

Electricity consumption is measured mostly by the volume of water used, not the minutes the pump runs. While the difference between the two vary by pump design, it generally holds true that you pay per gallon not per minute.

If that's the 'measure' of electrical consumption, then how does one factor in the 'startup' of the motor? I know the startup is the most demanding, but if you simply measure volume of water then it can't be accurate when considering my question/issue.

... I know we're getting a bit side tracked with talking "electrical consumption", but I'm more curious at this point.

 

[Valveman]

Just because that line is pressurized to the check valve when the pump is off doesn't mean you can tee off that line to use water. It is still a suction line when the pump is running. Having any lines tee off the suction is just another place for a possible suction leak. A faucet or anything on that line can let air in the pump and it will lose prime. If someone opens a faucet on the suction line while the pump is running, it will lose prime in a couple seconds. You need to run a line back to that point from the discharge side of the pump.

All jet pumps are noisy. The back pressure from a CSV usually makes the pump run more quite. But it will run longer, that is how a CSV stops the cycling on/off. It takes 6-9 times running amps to start a pump. Those starting amps are only there for a fraction of a second, but they add up over multiple cycles. Then the back pressure from a CSV will make the pump/motor draw lower amps. A jet pump will usually drop 20-40% in amps when using a CSV. So when using a CSV the pump is loping along at 20-40% less amps and not seeing any of those excessive starting currents because the pump is not cycling on and off. Even though the electric bill for a house pump is generally only about 5 bucks a month, most of the time a CSV will reduce the electric bill. In the rare circumstances where the pumps amps don't drop much and extra run time from a CSV has caused an increase in power consumption, it has only been about a nickle per day. Even then a nickle per day is not bad for getting constant pressure in the house, making the pump last longer, eliminating water hammer, and being able to use a much smaller and less expensive pressure tank.

BTW, if you want quiet and efficient, installing a submersible inside the storage tank is the way to go. Submersibles are considerably more efficient than jet pumps and you can't hear them in the least.

 

[JohnnyAirtime]

Just because that line is pressurized to the check valve when the pump is off doesn't mean you can tee off that line to use water. It is still a suction line when the pump is running. Having any lines tee off the suction is just another place for a possible suction leak. A faucet or anything on that line can let air in the pump and it will lose prime. If someone opens a faucet on the suction line while the pump is running, it will lose prime in a couple seconds. You need to run a line back to that point from the discharge side of the pump.

All jet pumps are noisy. The back pressure from a CSV usually makes the pump run more quite. But it will run longer, that is how a CSV stops the cycling on/off. It takes 6-9 times running amps to start a pump. Those starting amps are only there for a fraction of a second, but they add up over multiple cycles. Then the back pressure from a CSV will make the pump/motor draw lower amps. A jet pump will usually drop 20-40% in amps when using a CSV. So when using a CSV the pump is loping along at 20-40% less amps and not seeing any of those excessive starting currents because the pump is not cycling on and off. Even though the electric bill for a house pump is generally only about 5 bucks a month, most of the time a CSV will reduce the electric bill. In the rare circumstances where the pumps amps don't drop much and extra run time from a CSV has caused an increase in power consumption, it has only been about a nickle per day. Even then a nickle per day is not bad for getting constant pressure in the house, making the pump last longer, eliminating water hammer, and being able to use a much smaller and less expensive pressure tank.

BTW, if you want quiet and efficient, installing a submersible inside the storage tank is the way to go. Submersibles are considerably more efficient than jet pumps and you can't hear them in the least.

Thanks for the detailed and informative reply.

It's not an option to backfeed the shop with a water supply AFTER the pump, and pressure tank. It could be, but would be super costly at this point. What would be more of an option, is to move the pressure tank and pump to the storage tank area... as many do, when I see small pump houses or them out in the open near a well or storage tank. I could power the pump off the shop. But then I again run into other issues in the basement and tying it all back together. Either way... I'm willing to see just how it works (or doesn't) as it is now.

I understand that using the suction line can cause other issues, but I don't think the amount of times I wash my hands or flush a toilet will cause an issue in the house. Why? Well... I've never had my pump "lose prime" no matter how many times I've messed with the pump and plumbing. Never had I had to let any air out of the prime hole, or heard it cavitate during operation. In fact, I've never primed the pump after a replumb. I've read where it's mandatory to make sure all air is out of the line... yet, never had I done so. And... I'm not the lucky type, so I'm not sure why it's always worked as it should without taking extra pre-caution to air being induced (even during a replumb).

... But, to test your theory as I'm sure your dead on for most all applications. I'll connect a garden hose to my spigot (on the suction line at the check valve), and turn it on full blast. I'll then make sure to drop the pressure on the house side (flushing all 3 toilets for example) to allow the pump to turn on. Once pump is on, I'll stand AT the pump to see if it actually loses prime or cavitates. If not... and it continues to operate as it should, I'll then still plan to use that suction side as my shop bathroom supply (knowing it's not recommended). If it ever becomes a problem or does exactly as you mention, I'll then install a small booster pump at the shop bathroom and make a mini-system at that location (removing it from the house system all-together). In fact, I might just plan on the latter to save me any grief down the road. Yet, I'll still test and see what happens. I'm curious. ... or in a worse case scenario, move the jet pump and pressure tank to the shop's bathroom, tying it all in as one (house and shop). I've got options!

I understand the CSV, and appreciate the more detailed response. All good info. Just not sure I'm ready to hear our pump run constantly when water is bypassing the pressure tank. And yes, I know I can drop in a submersible into the storage tank... or (as I mentioned) plumb the jet pump and pressure tank just outside the storage tank and never hear any of it. But, I also like to know it's working as it should by hearing it every now and again. If it was outside, and I had a leak... and it ran constantly, I'd never know it until it was major catastrophe. Or, hearing it run (if I had a CSV installed) more often would make me think I had a leak... just not the "norm" for me. "Norm" being... my RV does the same. Pump runs when it needs to boost pressure for the accumulator. If it was constantly running for water pressure, I'd think we had a leak or problem. ... I know it's backasswards thinking, and somewhat old school of me. It's just how I operate.

 

[Valveman]

I guess it is possible that your storage tank is tall enough to deliver enough pressure to the suction line that you can open a suction line tap while the pump is on and not lose prime. But it is still not a good idea to use a suction line as a supply line. You know what they say about continuing to do stuff the old way over and over and expecting a different outcome? You are never too old to learn something new!

 

[Reach4]

I guess it is possible that your storage tank is tall enough to deliver enough pressure to the suction line that you can open a suction line tap while the pump is on and not lose prime.

Would a "self priming" pump save him from having to actuall prime if he just closes the tap for a while? I expect his ability to use that intake water would be better if he tops up the cistern first.

 

[Valveman]

A self priming pump won't help, for the same reason he has never had to prime the pump. The storage tank is so tall it provides a flooded suction or positive pressure to the pump. If it is tall enough it will even let you use a little water out of the suction line without losing prime on the pump.

 

[JohnnyAirtime]

I do believe the head pressure, from the storage tank is quite a bit more then you all anticipate... the tank is 28-30ft tall (at least) and we often keep it more then half full. It's base is about 12ft in diameter. That's a lot of water... and, if I open the 2" line that feeds the fire hose... It's a fire hose! I had to use it to put out a small fire... however, its not enough head pressure to push past a kink in 2" the line. But it'll squirt 20-25ft from that line. That should give you a calculated idea. (haha - "calculated")

... the jet pump DEFINITELY doesn't need to suck water from the tank. At one time, I lost the 1-1/4" PVC mpt fitting off the old pump due to heat. It flooded my basement, and a river ran from the basement through the garage in a matter of a minute. The storage tank being 200ft away, and water going down hill along with the head pressure... it flows pretty darn good through that 1-1/2" line. So much so, I put another ball valve on the line (50ft upstream) in case it ever happens again.

Storage tank is the greenish color in the two pictures. Hard to tell it's size, but the shop is directly in front of the tank and it's peak is 15ft tall. In the second picture, the block wall around a portion of the tank's base is 6ft tall at it's highest. That should give you a better perspective of "tank height" and size.