Check valve leakage

Users who are viewing this thread

southcppaw

New Member
Messages
16
Reaction score
1
Points
3
Location
Saskatchewan
Hi all,

I've researched a few things on this site before and it seems like there are a lot of knowledgeable people on this site. I've a got a question so I went ahead and signed up.

This weekend I re-did the plumbing in the house we bought and our sytem is as follows: pipeline water fills a tank in the basement and is controlled by a float valve. A jet pump is connected to the tank, goes through a Cycle Stop then into the pressure tanks/pressure switch across the room. I installed a check valve on the suction side between the tank and the pump.

The first night after the install I noticed the pump ran at 3am when no water was being used. Wondering how that could be I conducted a test today: in 7 hours of not being home, the system leaked down from 55 psi to 50 psi at the pressure tank (48 to 43 at the pump). I am 99% percent sure that I do not have any leaking faucets or fixtures. I'm not sure how the pressure tanks play into it but I seem to be get a decent amount of drawdown so I'm wondering if this is just a normal amount of leakage for a spring-loaded, Lowes/Home Depot quality check valve? Should I have sought out a better quality valve? Could something else be going on?

Thanks in advance for your replies.
IMG_20180729_200507647.jpg
 

Reach4

Well-Known Member
Messages
38,798
Reaction score
4,412
Points
113
Location
IL
Wondering how that could be I conducted a test today: in 7 hours of not being home, the system leaked down from 55 psi to 50 psi at the pressure tank (48 to 43 at the pump).
  1. how much drop do you get in the first 10 minutes? I think there is some pressure drop as the diaphragm relaxes, but that is over a shorter time.
  2. I see that you have two check valves. I think that having one is normal.
  3. Do both pressure gauges read zero when the water pressure is zero? I am wondering why the pressure gauge at the pressure tank reads 7 psi less. There may be a calibration difference.
 

Valveman

Cary Austin
Staff member
Messages
14,599
Reaction score
1,296
Points
113
Location
Lubbock, Texas
Website
cyclestopvalves.com
If you have a ball valve after the pressure tank, close it and see if you still have a leak. If you don't have a ball valve after the pressure tank, turn off the pump, close the ball valve in the picture, then see if you have a leak.
 

southcppaw

New Member
Messages
16
Reaction score
1
Points
3
Location
Saskatchewan
I had only watched the gauge for a couple mins before leaving yesterday and it hadn't dropped but I can try watching a little longer. I will also try shutting the valve in the picture and watching the gauges as I do not currently have a valve after the tanks.

Reach4, I'm not sure what you mean about having two check valves. Where is the second one?

About the difference in gauge readings.. when the pump is running the gauge on the pump reads about 10 psi higher than the one on the tanks/switch. I think this makes sense since the tanks are about 25ft of pipe away with several elbows. In the split second the pump shuts off, the gauge on the pump drops to some amount below the switch cut out pressure. I just chalked it up to that gauge experiencing some weird effect from being in between the check valve and the CSV.
 

Valveman

Cary Austin
Staff member
Messages
14,599
Reaction score
1,296
Points
113
Location
Lubbock, Texas
Website
cyclestopvalves.com
You should have higher pressure before the CSV when the pump is running. The pressure before and after the CSV will equalize as soon as the pump shuts off. Don't close that ball valve without turning power off to the pump first.
 

Reach4

Well-Known Member
Messages
38,798
Reaction score
4,412
Points
113
Location
IL
Reach4, I'm not sure what you mean about having two check valves. Where is the second one?
C and F.

img_6.jpg


I presume arrow N was already on the wood, and you did not draw that for this use.
 

southcppaw

New Member
Messages
16
Reaction score
1
Points
3
Location
Saskatchewan
Any idea why I'm not seeing the pressure equalize across the CSV, even over 7 hours?

I should probably have a relief valve plumbed in. Didn't think of that when I put the valve there.
 

southcppaw

New Member
Messages
16
Reaction score
1
Points
3
Location
Saskatchewan
Ok, I found out a couple things: First, I put in two new gauges and they now read within 1 psi of each other. The one on the pump was probably fine but the older one on the tanks was off a good 4-5psi high. Bit of an eye opener for me... Anyways, the mystery is solved.

Also, I found out there is a valve on the water softener, after the pressure tanks. I closed that valve and I also closed the one in the picture (I also installed a relief valve for peace of mind) when there was 50 psi on both gauges. Again about 7 hours later, the pressure tanks are still 50 psi, and the pump was down to 45 psi.. So to me either the plumbing in the pictures is leaking or the check valve is letting it back into the tank. I confirmed there is no leakage within the first 10 minutes and there were no visible drips on the plumbing. My question is, Is this a normal amount of leakage for a check valve if you guys agree thats what's going on? I'm I chasing my tail trying to get another one in there that doesn't leak? Not sure if I'd be able to return this one...
 

Reach4

Well-Known Member
Messages
38,798
Reaction score
4,412
Points
113
Location
IL
Also, I found out there is a valve on the water softener, after the pressure tanks. I closed that valve and I also closed the one in the picture (I also installed a relief valve for peace of mind) when there was 50 psi on both gauges. Again about 7 hours later, the pressure tanks are still 50 psi, and the pump was down to 45 psi.. So to me either the plumbing in the pictures is leaking or the check valve is letting it back into the tank.
I am not sure what your system is. Does your jet pump suck from the big green storage tank in the background of your photo? That is what I am thinking. Some other pump fills the storage tank.

Your picture shows two valves: A and L.

I am thinking the pressure tanks (more than one??) are not in the picture. How about a picture that shows the inputs to the pressure tanks and the other pressure gauge.

While I don't follow your symptoms totally, you said that shutting off the water to the softener made some change. One thing to check is whether the drain line from the softener is dripping water. It should not be dripping water except during regeneration.

I am not understanding how your new pressure gauges differ much when there is no water flowing.
 

southcppaw

New Member
Messages
16
Reaction score
1
Points
3
Location
Saskatchewan
The softener has a valve on it with three positions: ON, OFF, BYPASS. The pipeline water is soft enough in our opinion so it has always been on BYPASS.

I don't have any more pictures right now but this is how the system is laid out:

- Pipeline water enters the basement > fills the green tank > controlled by a float valve
- Jet pump sucks out of the green tank > sucks through check valve F
- Water is pumped into 3 small, ganged pressure tanks across the room > pressure switch and a gauge are on a tee cross on one of the tanks
- The tanks push water through the softener valve, into the house

Last night I shut off the softener valve and also valve A in the picture. I then had water trapped in 2 zones, both starting at 50 psi.

- Zone 1 is from the check valve F to the ball valve A.
- Zone 2 is from the ball valve A to the softener valve. The pressure tanks/switch are included in Zone 2.
- Valve L was open the whole time.

After 7 hrs of sleeping, Zone 2 was still at 50 psi, Zone 1 was down to 45 psi.
 

southcppaw

New Member
Messages
16
Reaction score
1
Points
3
Location
Saskatchewan
Fair enough. It matches up with the first test I did with all valves open though. The leak down was also 5psi over 7 hours then.

Maybe it's a waste of time going any further?
 

Reach4

Well-Known Member
Messages
38,798
Reaction score
4,412
Points
113
Location
IL
After 7 hrs of sleeping, Zone 2 was still at 50 psi, Zone 1 was down to 45 psi.
Got it. Since there is no storage in zone 1 in your description, a tiny amount of water change could result in a pressure change. A tiny tiny amount of leakage through the ball valve could explain it. A drop in temperature in that area could explain it. IMO that pressure drop in that isolated section is nothing to worry about.

It is not normal to have a valve between a pump and the pressure switch. There is always the danger that the pump would turn on for long periods.
 

southcppaw

New Member
Messages
16
Reaction score
1
Points
3
Location
Saskatchewan
It is not normal to have a valve between a pump and the pressure switch. There is always the danger that the pump would turn on for long periods.

How does the valve relate to the pump turning on for long periods? I did install a relief valve in case I ever forgot the valve was closed and the pump was on. I wanted it there so I could work on anything pump or tank related without draining the whole house.

I understand that the volume was very small in the second test but what's bugging me is that the leakage matches up so perfectly with the first test I did when all the valves were open.
 

Reach4

Well-Known Member
Messages
38,798
Reaction score
4,412
Points
113
Location
IL
How does the valve relate to the pump turning on for long periods?
Valve is closed. Pressure at the pressure switch turns on due to water use. Pump drives pressure but the pressure is not felt at the pressure switch. Pump never turns off. Pump has no flow to cool the motor.

I understand that the volume was very small in the second test but what's bugging me is that the leakage matches up so perfectly with the first test I did when all the valves were open.
So what happens when that valve is open? It seems to me that your previous description had the two gauges differing from each other a lot. What do you get now with the new gauges?

Note you can close your valves that are before the pressure switch for testing only if the pump is turned off.
 
Last edited:

southcppaw

New Member
Messages
16
Reaction score
1
Points
3
Location
Saskatchewan
Previously, the gauge on the pump and the gauge on the tank were showing different values but the pressure drop over the test was the same. I.e, both gauges dropped 5 psi over 7hrs, but the nominal values were different. That was the first test with all valves open.

Now with new gauges, they both read within 1psi of each other when the system is in normal use.
 

Reach4

Well-Known Member
Messages
38,798
Reaction score
4,412
Points
113
Location
IL
Previously, the gauge on the pump and the gauge on the tank were showing different values but the pressure drop over the test was the same. I.e, both gauges dropped 5 psi over 7hrs, but the nominal values were different. That was the first test with all valves open.

Now with new gauges, they both read within 1psi of each other when the system is in normal use.
Good. Is there a remaining symptom? If so, describe it.
 

southcppaw

New Member
Messages
16
Reaction score
1
Points
3
Location
Saskatchewan
Good. Is there a remaining symptom? If so, describe it.

- 1st night after pump install: pump ran at 3am when no water was being used

- Test 1: All valves open, water trapped between the check valve and my house fixtures - 5 psi drop in 7hrs at both the pump gauge and the tank gauge (nominal gauge values were different due to a bad gauge, but the drop was the same)

Test 2: This was the Zone 1&2 test with the softener valve and ball valve A closed (and pump off). This time only the pressure between the check valve and the ball valve A was down 5psi in 7hrs. New gauges were installed for this test so the nominal values started off the same.

I understand that the second test had a very small volume that lost pressure but it is bugging me that the leakage result was exactly the same (down 5psi in 7hrs) as the first test when the volume was my entire water system.
 
Top
Hey, wait a minute.

This is awkward, but...

It looks like you're using an ad blocker. We get it, but (1) terrylove.com can't live without ads, and (2) ad blockers can cause issues with videos and comments. If you'd like to support the site, please allow ads.

If any particular ad is your REASON for blocking ads, please let us know. We might be able to do something about it. Thanks.
I've Disabled AdBlock    No Thanks