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  1. #1
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    Default Video of odd water pressure readings.

    Recent inspection of a new-build vacant home. Owners had not moved in as yet so house was completely empty with nobody at the house but me.

    When I checked water pressure at front corner spigot, the reading on the gauge changed depending on how far i opened up the spigot handle. I did this a couple of times and then used a different gauge with the same result. I then took both gauges and went to the back yard spigot and got the same result, which was water pressure reading changing depending on how far the spigot tap was opened. These were not 1/4 turn type handles. Also the liquid you see inside the gauges is they are liquid-glycerin-filled gauges. That is not water inside the gauge. (there is a little water on the outside of the gauge)

    You have to see the video to get an idea of what I am referring to. Don't recall seeing this type of water pressure reading behavior before. Click on link below to watch 2 minute video of this water pressure reading.

    https://www.youtube.com/watch?v=Gr_jB86Yhi8

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    Default Re: Video of odd water pressure readings.

    Gene,

    That is weird. I have not seen that before. It looks like the first gauge has water in it, but the second one did not appear to have water in the gauge.

    Did you try turning on the hose bibb without the gauge on?

    Did you try the gauge at a hose bibb at your house?

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    Default Re: Video of odd water pressure readings.

    Hi Gunnar:

    Both gauges are liquid-glycerin filled gauges. That is not water in the gauges. The video shows a little water dripping on the outside of gauge but that is not water inside the gauge.

    Yes, I checked them at my house later that evening and gauges were normal.

    Gene



    Quote Originally Posted by Gunnar Alquist View Post
    Gene,

    That is weird. I have not seen that before. It looks like the first gauge has water in it, but the second one did not appear to have water in the gauge.

    Did you try turning on the hose bibb without the gauge on?

    Did you try the gauge at a hose bibb at your house?



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    Default Re: Video of odd water pressure readings.

    Quote Originally Posted by Gene South View Post
    Hi Gunnar:

    Both gauges are liquid-glycerin filled gauges. That is not water in the gauges. The video shows a little water dripping on the outside of gauge but that is not water inside the gauge.

    Yes, I checked them at my house later that evening and gauges were normal.

    Gene
    Glycerin-filled? Ooooo fancy!

    That type of hose bibb is not familiar to me. Is it typical for your area? Just wondering if it is some kind of weird pressure-regulating hose bibb of some kind that I have never heard of.
    We just have the old, boring type hose bibbs around here.

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    Default Re: Video of odd water pressure readings.

    Gene,

    Agree on the weird part, did you put the gauges on the clothes washer hose bibb inside? Just curious if that was the same.

    Have you tried you gauges on another house since then and verified that the gauges are reading 'normally'?

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    Default Re: Video of odd water pressure readings.

    Hi Jerry: I did not put the gauges on the washing machine valve, just on both outside spigots. Yes, I confirmed the gauges were acting normally.

    I realize this is such a weird problem that we want to make sure the gauges are okay. The gauges are fine. that is why I use two gauges on each house.


    Quote Originally Posted by Jerry Peck View Post
    Gene,

    Agree on the weird part, did you put the gauges on the clothes washer hose bibb inside? Just curious if that was the same.

    Have you tried you gauges on another house since then and verified that the gauges are reading 'normally'?



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    Default Re: Video of odd water pressure readings.

    My thought when I first read it and watched the video was 'I wonder if freeze resistant hose bibbs do that?'.

    The valve in freeze resistant hose bibbs is back inside with a water way to the hose connection thread. When opened, could water trap an air pocket up inside the water way section, and would it be enough to reduce the pressure until the valve was fully open?

    I doubt they use freeze resistant hose bibbs where you are, but I wonder if any of our northern inspectors have seen this with freeze resistant hose bibbs?

    Just a WAG of a thought.

    That's why I asked about the clothes washer hose bibb.

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    Default Re: Video of odd water pressure readings.

    You need to know the flow characteristics to properly access that pressure demonstration.


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    Default Re: Video of odd water pressure readings.

    I ran across this exact same thing a few weeks ago and it was on a hose bib exactly like the one you have in the video. That being said, I tried it on another hose bib, that looked the same design as the first and got a normal reading and pressure. This was also on a new home. I'm thinking it must have something to do with the design of the no freeze/anti-backflow set-up OR another theory I had (after leaving the home); since it was a new build, I'm wondering if maybe it had no water in the line and it acted this way for some 'Weird' reason. I think I did turn on the water to check for flow but can't remember if I tried checking the pressure at this hose bib after running water. Would love to see the design of the hose bib to see if we could figure this out.

    Last edited by Larry Morrison; 08-07-2019 at 05:04 AM.

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    Default Re: Video of odd water pressure readings.

    I inspect houses with these faucets all the time and I do not get this fluctuation in pressure. My gut feeling is that there is air in the lines (new build) and all faucets and toilets should be run for a while. Here is cut away of freeze-proof faucet.

    https://www.familyhandyman.com/plumb...-from-leaking/

    Last edited by Tom Rees; 08-07-2019 at 05:56 AM.
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    Default Re: Video of odd water pressure readings.

    I just had another thought. I'm wondering if this might be a blocked or stuck PRV?? During the construction process you can get a lot of debris in lines and this may be affecting the function of the PRV. Just throwing it out there??

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    Default Re: Video of odd water pressure readings.

    Quote Originally Posted by Tom Rees View Post
    My gut feeling is that there is air in the lines (new build) and all faucets and toilets should be run for a while.
    Tom,

    That was second thought, but I figured that by the time Gene (and you) get there, water has likely been run through all lines from use be the trades and the cleaners, but ... That could be a wrong presumption to make.

    As you said, always run water first (you don't want empty water heaters for one thing).

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    Default Re: Video of odd water pressure readings.

    So here is what is going on - Valves have two seats - one that closes off the flow and the second is to seal the back side of the valve stem packing. So when you crack the valve (1/4 turn for argument) you let water flow into the space (I am also guessing there is some air trapped) because the valve is not back seated (against the valve stem packing) there is some flow of air / water flowing when the valve is fully opened (back seated) there is no more loss giving a total rise in pressure , this is why it acted that way as you closed it. If I didn't know any better I would say it was diaphragm control valve but that's not the case here - also the vacuum breaker might be leaking slightly as well.

    May I suggest if you see this - run the valve full open - close it connect the gauge (not tight yet) crack the valve and let some water flow - then tighten the gauge and open the valve fully. Now if it is a freeze prevention valve (seat is 3-12 inches in - then you will almost always have some air when you hook up a gauge.


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    Default Re: Video of odd water pressure readings.

    Quote Originally Posted by Dwight Doane View Post
    So here is what is going on - Valves have two seats - one that closes off the flow and the second is to seal the back side of the valve stem packing. So when you crack the valve (1/4 turn for argument) you let water flow into the space (I am also guessing there is some air trapped) because the valve is not back seated (against the valve stem packing) there is some flow of air / water flowing when the valve is fully opened (back seated) there is no more loss giving a total rise in pressure , this is why it acted that way as you closed it. If I didn't know any better I would say it was diaphragm control valve but that's not the case here - also the vacuum breaker might be leaking slightly as well.

    May I suggest if you see this - run the valve full open - close it connect the gauge (not tight yet) crack the valve and let some water flow - then tighten the gauge and open the valve fully. Now if it is a freeze prevention valve (seat is 3-12 inches in - then you will almost always have some air when you hook up a gauge.
    That make sense Dwight. However, I do not see this fluctuation in pressure that is in the video and almost every house I inspect has these valves. By the way, I am going to start connecting my gauge as you suggested. 18 years and I'm still learning every day.

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    Default Re: Video of odd water pressure readings.

    Quote Originally Posted by Dwight Doane View Post
    So here is what is going on - Valves have two seats - one that closes off the flow and the second is to seal the back side of the valve stem packing. So when you crack the valve (1/4 turn for argument) you let water flow into the space (I am also guessing there is some air trapped) because the valve is not back seated (against the valve stem packing) there is some flow of air / water flowing when the valve is fully opened (back seated) there is no more loss giving a total rise in pressure , this is why it acted that way as you closed it. If I didn't know any better I would say it was diaphragm control valve but that's not the case here - also the vacuum breaker might be leaking slightly as well.

    May I suggest if you see this - run the valve full open - close it connect the gauge (not tight yet) crack the valve and let some water flow - then tighten the gauge and open the valve fully. Now if it is a freeze prevention valve (seat is 3-12 inches in - then you will almost always have some air when you hook up a gauge.
    Having served as a Firefighter for 45 years I have done a fair number of flow tests. Those tests are done at both the normal service pressure; that is the pressure at the test point under the influence of the domestic water usage at the time; and at the fire flow test of calibrated nozzles. It is the difference in those pressures that shows us what that hydrant is likely to be able to deliver under the conditions arising from a fire in a single structure. Here I am talking about a fairly homogeneous residential neighborhood. If there were some large building such as an enclosed shopping mall nearby we would take a group flow from several hydrants simultaneously to see what the water system could deliver to suppress a fire of extensive involvement in those larger structures. Ignore that later case for your purposes.

    Is there a standard for how much water should be available to the home at a minimum pressure?

    Let me take a guess at what may be happening here. I only know of two basic designs of freeze proof hose bibs or wall hydrants or sill cocks. The name seems to vary by region of the country. The first uses a spring loaded check valve mechanism to close the drain which is outside the hose. That operates as soon as the valve is opened and the exterior portion of the hose bib up to the nozzle is filled with water. There is usually sufficient pressure drop in the valve mechanism to keep that check valve closed even if there is nothing attached to the bib's nozzle threads. In that type of frost proof design I would think it unlikely that the pressure would increase after the valve was opened under any condition of operation which I can imagine. Some areas require a mechanically opened drain valve when the valve is closed That means that it opens mechanically even though the back pressure will have closed it initially. If you have a moving valve stem on the outside of the building with such a small amount of water being affected by it's movement as you finish opening the valve stem at the inside end of the valve I can imagine that it could raise the pressure between the combination back flow preventer and drain valve. The reason for the two designs is simple the first is to open and close the drain only. Those will not open to drain the bib as long as there is pressure on the inside of the hose bib such as a hose left connected with it's nozzle shut off closed. The elasticity of the hose itself maintains that pressure for days if none of the couplings nor the nozzle is leaking. In the second type, which is meant to function as a Back flow preventer as well as a freeze avoidance drain for the bib, there is a need to prevent water from flowing back into the home even while the bib's shut off valve is open. I do not know how that is accomplished mechanically but those are laboratory listed valves. The reason that some water utilities require back flow prevention to be built into exterior hose bibs or irreversibly added to existing exterior valves is that there have been several group poisonings caused by the back flow of chemicals, such as fertilizers, into domestic water systems. In an incident in the county just north of mine several people died and others ended up on dialysis for life because the end of a hose was in a tub of fertilizer and siphon effect caused it to back flow into the house and public water lines when everyone came home from work and began using a lot of water and the system pressure dropped sharply due to inadequately sized water mains. Please remember that I said I was guessing. If you need a hydraulic engineer I'm a pretty good electrician.

    Sorry about the image. I was experimenting with that feature of the interface and now I don't know how to successfully remove it.

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    Last edited by THOMAS HORNE; 08-07-2019 at 01:31 PM.

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    Default Re: Video of odd water pressure readings.

    Interesting...I use a glycerin filled gauge and most of our bibs around here are frost-proof. I see those type of changes as I open the bib so often that I long ago quit wondering why and just use the fully open reading as my final.

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    Default Re: Video of odd water pressure readings.

    Quote Originally Posted by Lon Henderson View Post
    Interesting...I use a glycerin filled gauge and most of our bibs around here are frost-proof. I see those type of changes as I open the bib so often that I long ago quit wondering why and just use the fully open reading as my final.
    I think what we are seeing is what was expressed above the double seats can cause an increase of pressure inside the tube and we are reading that pressure. which will change as you open or close the valve (move the piston, stem) Actually the high pressure was noted when you fully open the valve. Normal pressure when you first crack it open. I think it is associated with how the Anti-Backflow is reacting (closing) when there is No Flow or give, when a gauge is attached (abrupt hydraulic lock) rather than a hose which would give it some volume/flow or room for expansion and allow anti-backflow to work normally. (not sure if my words are translating to how my brain is picturing this)


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    Default Re: Video of odd water pressure readings.

    Quote Originally Posted by THOMAS HORNE View Post
    Sorry about the image. I was experimenting with that feature of the interface and now I don't know how to successfully remove it.
    Tom,

    Using your 'edit' button, I think you can scroll down to the photos shown attached and remove/delete/etc a selected photo.

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    Default Re: Video of odd water pressure readings.

    Quote Originally Posted by Gene South View Post
    Recent inspection of a new-build vacant home. Owners had not moved in as yet so house was completely empty with nobody at the house but me.

    When I checked water pressure at front corner spigot, the reading on the gauge changed depending on how far i opened up the spigot handle. I did this a couple of times and then used a different gauge with the same result. I then took both gauges and went to the back yard spigot and got the same result, which was water pressure reading changing depending on how far the spigot tap was opened. These were not 1/4 turn type handles. Also the liquid you see inside the gauges is they are liquid-glycerin-filled gauges. That is not water inside the gauge. (there is a little water on the outside of the gauge)

    You have to see the video to get an idea of what I am referring to. Don't recall seeing this type of water pressure reading behavior before. Click on link below to watch 2 minute video of this water pressure reading.

    https://www.youtube.com/watch?v=Gr_jB86Yhi8
    looks like woodford f/p faucet from the land of gar
    did you contact them

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    Default Re: Video of odd water pressure readings.

    Quote Originally Posted by Larry Morrison View Post
    Actually the high pressure was noted when you fully open the valve. Normal pressure when you first crack it open.
    Maybe, but how can the pressure increase beyond whatever the water pressure to the house is. I can't think of a way on a house system that pressure could compound. If the city is delivering 60psi (the target pressure by most of the muni's around here), I don't think there is any mechanism for a bib to show 100psi.
    So, I think the accurate measurement is with the valve fully open.
    As for a bubble or air pocket in the valve causing the variation, maybe....but once again, I don't think it can cause a compounding affect on the pressure. When the valve is fully open, the trapped air bubble should be the same pressure as the water in the house. An air bubble can create a surge in a moving stream through a pipe or hose as the water in front of the bubble nears the nozzle, but once water in the pipe to the valve is no longer moving, the pressure will stabilize throughout and should be whatever the city is delivering.

    However, this conversation has triggered my curiosity, and next time I see this, I'll further investigate.

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    Default Re: Video of odd water pressure readings.

    Quote Originally Posted by Lon Henderson View Post
    Maybe, but how can the pressure increase beyond whatever the water pressure to the house is. I can't think of a way on a house system that pressure could compound. If the city is delivering 60psi (the target pressure by most of the muni's around here), I don't think there is any mechanism for a bib to show 100psi.
    So, I think the accurate measurement is with the valve fully open.
    Correct as far as I can think of too - there is no mechanism in the system which would 'pressurize' the system above street pressure ... unless ... there was a thermal expansion tank at the water heater and it was pressurized to 100 psi ... that would put that 100 psi pressure into the cold water line at the water heater, which is a direct connection to the cold water supply, which is the street pressure.

    If the pressure is above 85 psi, then a pressure reducing regulator would be needed.

    Was there a thermal expansion tank? Would it withstand 100 psi anyway?

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    Default Re: Video of odd water pressure readings.

    I think what is happening is the anti backflow is abruptly closing . Think of it how the safety valve works on some propane grills will shut down the full flow of it senses a break in the line. I think something similar is happening with the anti backflow . It is somehow locking up and the pressure is just that that is inside the tube . When you screw it out it, it is acting as a piston and is pressurizing just what is inside the enclosed pipe. More you screw out the valve the more pressure smaller space of that enclosed portion of pipe. I think a picture would help showing a hydrolic lock and what happens inside an enclosed cylinder when a piston moves in and out.


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    Default Re: Video of odd water pressure readings.

    Gene, you really have the brain trust here going! I can't explain why this happens but I have seen it before but since I regularly get abnormally high pressure readings when checking frost proof hose bibs, I always loosen the gauge a little to bleed off excess pressure.

    When pressure is acting like this I always ascribe it to a conflict between back flow preventer and the tiny amount of space inside the valve and the turning of the valve acts like a piston increasing pressure or decreasing depending on the position of the stem inside the valve.

    I also get the rapid flutter of the gauge sometimes which goes away most of the time (not always) when you bleed a little pressure at the gauge connection.

    And yes Jerry, it does freeze here and frost proof hose bibs are the standard. Single digit temps are pretty common here at least a few nights every few years and sub freezing is a regular occurrence until you get much further south. One reason I check every outdoor hose bib is to check for freeze damage when people leave hoses attached during extreme cold.

    Jim Luttrall
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    Default Re: Video of odd water pressure readings.

    I think I've got it!
    Thanks to Barry for providing the brand name and Google for the expanded parts diagram.
    This valve has an integral check valve that travels with the stem as it moves in and out making a perfect piston inside the valve housing cylinder. The pressure varies in proportion to the position of the valve stem and that check valve.

    https://www.plumbingsupply.com/woodf...-model-17.html

    https://www.woodfordmfg.com/woodford...ech%20Note.pdf


    See part number 7 on the diagram on the Woodford site if you care.
    Point is it is part of the design of that valve and is normal.
    Just bleed a bit of water from the hose bib spout when checking pressure and all is well.

    Last edited by Jim Luttrall; 08-08-2019 at 10:24 PM.
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    Default Re: Video of odd water pressure readings.

    Quote Originally Posted by Jim Luttrall View Post
    This valve has an integral check valve that travels with the stem as it moves in and out making a perfect piston inside the valve housing cylinder.
    Jim,

    I looked at the drawing and it shows arrows indicating the direction of water flow, and shows the check valve in the same position (not moving).

    The rubber check valve cup lips 'fold in' as water flows when the valve is open, and 'unfold out' when the water flow stops, thus preventing back flow/siphonage when the valve is closed.

    Did I miss where it shows the check valve moves? Or maybe they just didn't draw the check valve having moved?

    I see where the design would allow it to move, maybe they just didn't show the valve moved?

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    Default Re: Video of odd water pressure readings.

    If you look at the indoor end of the valve stem, in the photograph at the top of Table A in the first linked page, you can make out that it has female threads. Then when you see the cut away drawing in the PDF at the second link it shows that female thread engaged over an internal nipple which is also the valve seat of the assembly. The drawing in the PDF is not complete enough to show either thread but it appears to me that the female thread on the end of the stem is going in or out on the threads which must be on the outside of the valve seat nipple. If that is not true then there is no mechanism to move valve stem at all.

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    Default Re: Video of odd water pressure readings.

    Quote Originally Posted by Jerry Peck View Post
    Jim,

    I looked at the drawing and it shows arrows indicating the direction of water flow, and shows the check valve in the same position (not moving).

    The rubber check valve cup lips 'fold in' as water flows when the valve is open, and 'unfold out' when the water flow stops, thus preventing back flow/siphonage when the valve is closed.

    Did I miss where it shows the check valve moves? Or maybe they just didn't draw the check valve having moved?

    I see where the design would allow it to move, maybe they just didn't show the valve moved?
    From the drawing, the check valve rides on the stem which will move in and out as it is operated. I have this type of valve in my house and the stem moves in and out even if it is not visible on the diagram.

    Jim Luttrall
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    Default Re: Video of odd water pressure readings.

    I had these same types on the home yesterday (1 year old home) and today 6 year old home). Did the same as in the video and I actually took a video of it "Acting Weird" (might post it later).

    What I found is you can get an accurate reading by screwing on your gauge. Turn the valve all the way on (the pressure did (may) rise). Then loosen your gauge enough to bleed of the pressure till it drops then tighten the gauge. This should give you the correct pressure. I confirmed at both houses by installing the gauge at the water heater drain. Showed the same pressure as my corrected pressure.


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    Default Re: Video of odd water pressure readings.

    You are imparting water pressure on a column of trapped air (inside the length of the valve). The greater the exposure to water the rise in pressure.more akin to an air spring. Loosen the gauge connection and attempt to purge the air then see the change.


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    Default Re: Video of odd water pressure readings.

    Quote Originally Posted by Phil brody View Post
    You are imparting water pressure on a column of trapped air (inside the length of the valve). The greater the exposure to water the rise in pressure.more akin to an air spring. Loosen the gauge connection and attempt to purge the air then see the change.
    I concur.
    Likely, the anti-siphon valve requires maintenance or replacement.
    An anti-siphon valve consists of a port that's open and a disk called a poppet that completely covers it. A spring keeps the poppet separated from the port when the water is off. When you turn the faucet, water pressure pushes the poppet against the port to seal the valve. The spring once again pulls the poppet away from the opening when you turn the water off, 'allowing air' to come in and equalize the pressure in the pipe.

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    Default Re: Video of odd water pressure readings.

    Okay, I just did an inspection in Rockwall Tx (or as Barry would say in the wall of Rock) and it did just what Gene's did. The home is 11 months old, occupied, has no PRV, no expansion tank, 2 tankless water heaters and I used two Watts gauges, bled the connections, removed it and ran water for 20 seconds and it still did the same thing. Got 90 psi on one hose bibb and 100 psi on another. Couldn't get to washer connection as a big ol machine was installed. I reported high presssure but if I didn't open it up all the way I could stop at any pressure I wanted. I can understand volume but not pressure........something's up!


  32. #32
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    Ormond Beach, Florida
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    Default Re: Video of odd water pressure readings.

    Here would be my test on those hose bibbs (still have one someplace, but the glass in one meter smashed years ago when I dropped it into my tool bag and the wrong thing (the glass) hit the wrong thing (something hard).

    It is essentially this: https://www.plumbersstock.com/toro-9...low-gauge.html

    Easy enough to make one must for much less, but I bought mine from Professional Equipment (remember them, from way back when?).

    Connect to the hose bibb, turn the hose bibb valve open, turn the valve on the tester open (which checks flow rate), now you have 'primed' those hose bibbs so that their anti-freeze system is fully open and the air has been pushed out by the water (also gives you a nice number to write down for flow rate) - now close the valve on the tester and you will get the pressure reading ... a real reading of what the water pressure is, not something which "might" be affected by the anti-freeze design of the hose bibb.

    Parts needed to make one:
    (starting at the hose bibb connection)
    - a) female 3/4 hose bibb x male 3/4 IP adapter
    - b) 3/4 IP x 3/4 IP x 1/4 IP tee (the 1/4 IP thread is off the tee for the next item)
    - c) 1/4 IP male thread on pressure gauge (likely the most common size at the pressure gauge)
    - d) 3/4 IP x closed nipple
    - e) 3/4 IP x 3/4 IP valve (I prefer 1//4 turn valves as they only take 1/4 turn to operate)
    - f) 3/4 IP x closed nipple
    - (stop here if you are only interested in 'priming' those hose bibbs)
    - (continue if you want to measure water flow also)
    - g) 3/4 IP x 3/4 IP x 1/4 IP tee (the 1/4 IP thread is off the tee for the next item)
    - h) 1/4 IP male thread on flow gauge
    - i) 3/4 IP x closed nipple (or however long you want so water does not just spray out of the tee and get all over you, a short nipple should help reduce the wide spray you would get from just coming right out of the valve)

    Find out what the parts cost, add in some pipe thread tape, factor in your labor (unless you want to just do it for the fun of it) ... and you may just order one. While I frequently made my own tools and devices - for 'the fun of it' and because I 'couldn't find what I wanted, so I made it', but ... I 'just ordered one' of those.

    Jerry Peck, Construction / Litigation Consultant
    Construction Litigation Consultants, LLC ( www.ConstructionLitigationConsultants.com )
    www.AskCodeMan.com

  33. #33
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    Jul 2019
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    Default Re: Video of odd water pressure readings.

    Quote Originally Posted by ROBERT YOUNG View Post
    I concur.
    Likely, the anti-siphon valve requires maintenance or replacement.
    An anti-siphon valve consists of a port that's open and a disk called a poppet that completely covers it. A spring keeps the poppet separated from the port when the water is off. When you turn the faucet, water pressure pushes the poppet against the port to seal the valve. The spring once again pulls the poppet away from the opening when you turn the water off, 'allowing air' to come in and equalize the pressure in the pipe.
    Did you read that other posts before making that comment. The anti-siphon valve is mounted on the stem that opens the valve seat in some designs. Photographs and line drawings were provided. As you open the valve the one way anti siphon valve is moved as well. Since it pushes all of the water that is between it and the gauge as it moves the washer which is attached to it's end out away from the valve seat it is further compressing the water so that the gauge reads higher than the water pressure actually is. The movement of the anti siphon check valve toward the gauge is like a single stroke of a piston pump creating more pressure by forcing the water into a smaller space. The valve is operating exactly as it was manufactured to operate. The only negative effect that is having is to make it less convenient to use that particular design of frost proof sill valve to take pressure readings on the pressure which is actually in the building water piping system.

    All that is needed to overcome this problem is a hose Y valve screwed on to the outlet under test. To avoid damaging the gauge with the added pressure leave the ball valve on the outlet that you have connected your gauge to closed. Once you have opened the frost proof valve all the way you can open the ball valve on the other outlet of the Y so that water is flowing. You may find it handy to bring along a length of hose to take the test flow to a place were it will not be a nuisance. Once the water is flowing through the fully opened sill valve slowly open the Y outlet to which the gauge is connected and slowly close the valve on the other Y outlet to stop the flow of water and obtain the static pressure reading.

    --
    Tom Horne


  34. #34
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    Mar 2007
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    Plano, Texas
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    Default Re: Video of odd water pressure readings.

    Quote Originally Posted by Gary Burnett View Post
    Okay, I just did an inspection in Rockwall Tx (or as Barry would say in the wall of Rock) and it did just what Gene's did. The home is 11 months old, occupied, has no PRV, no expansion tank, 2 tankless water heaters and I used two Watts gauges, bled the connections, removed it and ran water for 20 seconds and it still did the same thing. Got 90 psi on one hose bibb and 100 psi on another. Couldn't get to washer connection as a big ol machine was installed. I reported high presssure but if I didn't open it up all the way I could stop at any pressure I wanted. I can understand volume but not pressure........something's up!
    Unscrew the gauge enough to get leakage after you turn the water on. The idea is to bleed PRESSURE, not air, off of the valve assembly. The valve assembly itself creates the pressure since the gauge creates a closed system. Tighten the gauge without messing with the valve handle to get the true reading.

    Jim Luttrall
    www.MrInspector.net
    Plano, Texas

  35. #35
    Join Date
    Mar 2007
    Location
    Plano, Texas
    Posts
    177

    Default Re: Video of odd water pressure readings.

    Quote Originally Posted by Jim Luttrall View Post
    Unscrew the gauge enough to get leakage after you turn the water on. The idea is to bleed PRESSURE, not air, off of the valve assembly. The valve assembly itself creates the pressure since the gauge creates a closed system. Tighten the gauge without messing with the valve handle to get the true reading.

    Exactly what I did twice on two different hose bibbs with two different guages. Didn't want to spend all morning just testing water pressure .


  36. #36
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    Mar 2007
    Location
    Plano, Texas
    Posts
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    Default Re: Video of odd water pressure readings.

    Quote Originally Posted by Gary Burnett View Post
    Exactly what I did twice on two different hose bibbs with two different guages. Didn't want to spend all morning just testing water pressure .
    Not according to what you posted previously. The key is to NOT adjust the valve stem while the gauge is attached, just bleed off excess pressure, retighten the gauge enough to stop leakage and you have the pressure of the system without the interference of the defacto "piston" of the valve.

    Jim Luttrall
    www.MrInspector.net
    Plano, Texas

  37. #37
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    Default Re: Video of odd water pressure readings.

    Seems to me that instead of playing around with tightening, then loosening, then tightening the pressure gauge onto the hose bibb, it would be far simpler to use what I described which has a valve built into it and a known discharge going in a known direction.

    Sure, the wye fitting with a valve in each take off of the wye would work, with the pressure gauge screwed onto one of the wye fittings (with that valve open, of course), but does one want to be a professional and use professional tools (and be able to also get a water flow reading) or does one want to look otherwise? And in some instances that I've seen (maybe even many instances on older homes) - trying to screw a wye onto a hose bibb which was partially buried in the wall isn't going to happen as the wye would hit the wall (hard enough to turn the handle on some of those installation, why make it even more difficult on yourselves).

    That said, though, either would solve the issue of checking pressure with those anti-freeze types of hose bibbs.

    Jerry Peck, Construction / Litigation Consultant
    Construction Litigation Consultants, LLC ( www.ConstructionLitigationConsultants.com )
    www.AskCodeMan.com

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