Do I need a thermal expansion tank? - Let's do an experiment!

let's hope this doesn't fly apart and flood my house I've never done a test like this in Perth I've made kind of a rudimentary clear version of a thermal expansion tank this is where your expansion tank comes in today's video is going to be about thermal expansion tanks [Music] you may be a homeowner and you've got a plumber giving you an estimate for a water heater and they are charging you extra for a thermal expansion tank and you're wondering if you need one or not you may not have had one before you might also be a newer plumber and you are learning about thermal expansion tanks yourself this video is going to work great for both of you we are going to dive into exactly what thermal expansion is what causes it and how to prevent it from causing elevated pressure and excess damage to your water system tune in today's video is going to be an awesome science experiment with real life action and all kinds of fun stats and facts for you we've got some great exercises that are going to show you everything that you need to know about thermal expansion how we're going to use my system to show you exactly what a thermal expansion tank does and is needed we're going to cut into my piping a little bit and I'm going to install a valve right here on the line that feeds this water heater that valve is going to separate this water heater from my current thermal expansion tanks and we're actually going to cut the hot water line out temporarily we've made a clear open top funnel that we are going to actually install on the hot side of the water heater over here we are going to drain the heater and refill it with cold water and then we're going to turn the water heater on what we're going to notice is thermal expansion what thermal expansion is is as water increases in temperature it also increases in volume it takes up more space if we don't give that any room to go any place to go then it turns into enormous pressure and that pressure can damage your plumbing system it can damage your fixtures it can damage your water heater and most commonly it can make this valve on the side of the water heater start to open up and drip water on the floor before we dive into too much about what thermal expansion tanks do we're going to give you a perfect visual representation of just how much expansion happens when we heat water and increase its temperature [Music] busting out a brand new Pro press machine for this one for the plumbers that are watching this video you'll know what I mean the stickers where the pin goes through the end of the the jaw now all the stickers have never been popped on these this is literally the first press for this machine foreign one quick tip if you're a plumber and you've got any kind of battery operated tools you always know keep your tool above the piping so that way when the water comes out of the piping it doesn't run down in your tool and ruin it we are deburring the edging in case you're wondering what I'm doing here this is taking off the sharp corners on the inside and the outside of the copper this way it does not compromise the O-ring that is inside of these Pro press fittings [Music] we are almost ready we've got everything kind of set up for this first little experiment we're going to show you these tanks have been installed in my home for like 11 or 12 years it's been years since I've tested them to see if the bladders inside the tanks are actually intact so I'm going to show you how to do this and I'm going to learn for myself if they are intact or not the way to test the thermal expansion tank is you want to have the water off that's running to the tank and you want to have so so this is the incoming water and that valve is off everything else is open the pressure is off of it that's the only way to test the air bladder you can't test the air bladder when there's water pressure against it because it's going to confuse the results of your test we want to be testing the air bladder when there's no water pressure against it so I'm going to hook it up to my gauge here so it's just a bike pump it should have 60 or 70 pounds in it and it does it has 70 pounds of air pressure in it that's what I aired it up to years ago was 7 70 pounds so we're good while we're here I'm going to go ahead and check the other one the reason I'm doing this is this would be an opportune time to replace these tanks if one of them had a failed bladder inside of it this one's sitting right at about 75 pounds of pressure almost 80. if you want to see that on the gauge here you can so we've got about 75 or 80 pounds of pressure on this one so we're good they will move around slightly we're not looking for an exact science on the number there it doesn't have to be perfect you may be asking yourself what pressure should I be setting these tanks to and we'll actually get to that after we perform a lot of our other tests as far as how to properly install a thermal expansion tank okay so this valve can actually close now and this valve can actually open whenever you're draining a water heater one of the things that you can do or a tip you can do to learn how much farther you have to go is just hold your hose up in the air water seeks its own level so we know that right now we have we have about this much water left in the tank so we're almost drained for the purpose of this test we don't have to drain it all the way what we're looking to do is to get cold water back in the tank just so we can show you what's happening as the water is heating let's go ahead and be done draining the tank and then we're going to fill it back up so that we get water up to the bottom portion of our little catch cup here or our funnel we've closed our drain valve we're going to fill it all the way back up it's going to be much colder water than was in there before while we're doing all of that we're going to be watching this funnel because we want to get the water level to where it's pretty neutral in the funnel here then we're going to turn on the heat and watch this water level rise even though we're not adding any water to the tank the only thing that's making this water level rise is heat this Tank's got a lot of hot air in it and as that hot air is coming up out of the top of our funnel you can even hear it whistling slightly as the hot air is coming out of that funnel it's fogging up the inside of it that whistling is kind of funny our water heater is set to Pilot we're not going to turn that up to a heating cycle until after we get this water level up to where we want to see it we're going to have to be fairly careful here because the last thing we want to do is shoot water straight up out the top of it we're going to have to slow down the water and just make sure that we only fill it up to the bottom part of that cup I I've never done a test like this in person like this so much for catching that and slowing it down oh my gosh well we got the water in the bottom of the cup like we wanted it just spit out a bunch of air with it at the same time there's some air bubbles working their way out of the tank as always there's always a little bit of air bubbles in there and another thing to note too you see how dirty the water is we just drained the tank and then filled it very rapidly so any dirt or debris that was on the walls of the tank just got kind of kicked loose and cut loose I know the manufacturers recommend that you drain these tanks once a year I don't recommend that to any of our customers simply because the lateral damage that comes from that you can see it right here all of this debris would normally be going into your system and going into somebody's faucets and all of that kind of stuff in our area we're located in the midwest in our area we don't have a bunch of loose Sandy debris most of the debris that we have in our area it actually forms like a hard cake or scale on the side of the heater and it doesn't come loose let me keep shaking this and see if we can there's a couple more bubbles I put just a little bit more water in here so now we're up onto the flats and I'm going to draw a line right at where the water level is the engineers say that when you heat a 50 gallon body of water and increase its temperature by 70 degrees that 50 gallon body of water expands by one quart well this just happens to be a one quart bottle that we cut the bottom off of and then put on upside down right now our water temperature is a little over 50 degrees mainly because it was coming out of my D superheater tank but we're going to basically get the same rough idea as we turn this water heater on and let it heat tanks back full of water is full all the way up to here we have an open top bottle let's turn the water heater on and actually see thermal expansion happen right in front of our eyes we're going to set the water heater to about 120. the incoming water into the heater is probably a little bit more than 50 degrees so we might not get a full court of increase out of here but we're gonna try it out and see the other thing that I'm going to do is I'm going to get my phone out so long as nobody calls me while I'm doing this and we're going to get a stopwatch and we're going to measure how long it takes for it to actually start Rising remember open body of water just an open tank it's under no pressure we're going to turn it on and we're going to watch the volume of water increase in this tank with nothing other than just temperature increase let's start our stopwatch let's turn our gas valve to hot so we are now heating right now I don't know if you can hear that or not it just turned on and started heating okay 20 seconds into the test I turned the gas valve on reset the stopwatch to zero or 25 almost 30 seconds into the test and if you can see the water level in our one quart jug has already increased by a little over a quarter of an inch it is not going to take long at all for this thing to expand the volume of water enough to fill our quart jug it's possible maybe the engineers might be a little bit off and we might actually be expanding my much more than a quart over a 70 degree temperature rise here we are one minute in and we're a little over a half inch increased into the cup that's pretty cool as we're nearing two minutes here one of the things that I'm going to do is I'm going to draw an indicator line for every two minutes of heating just how how much extra water we're creating 56 7 8 9. so two minutes in and we've already gone up about an inch on our bottle I would assume it's going to continue at that rate the water is still expanding even in a closed system so the thing to keep in mind is where does all of this extra volume of water go well it gets distributed evenly throughout the system but in the form of pressure because it can't go anywhere unless you have drippy or leaky faucets or something like that where it's dripping out those faucets at this rate there's not much other places for it to go and so it just builds enormous enormous water pressure 59 four minutes in we're also actually losing just a tad bit of water out of these connections down here it's kind of hard to get piping to connect to a one liter bottle I did the best I could with some PVC and some garden hose connections and stuff like that it's not a perfect seal so if anything our results are actually going to be Just a Touch under outside of that we are still adding tremendous amounts of water in a very very short time here we are five minutes in and we've already increased by about two and a half inches or so that's pretty amazing considering all of this water right here would have to go somewhere in a closed system a couple of air bubbles working through there so because we drained the heater we have air sitting at the top and that's actually going to distort this next reading a little bit because those air bubbles were taking up volume and so those air bubbles came through six minute reading is now just under what the others had been just because the air had kind of dropped down and worked through I tried to get all the air out before we did this but it's kind of hard to do that and we might get a couple of more air bubbles work through here too the reason the engineers choose that 70 degree temperature rise is that's the most common temperature rise we have in the nation on average across the entire nation the incoming water temperature is about 50 degrees and most water heaters are set to 120. here in the Midwest we might actually I mean we we vary our incoming water in the summertime might be 60 degrees our incoming water in the winter time might be down to 40 degrees it just kind of depends if you live in like Arizona or in a desert climate you don't actually have cold water you have hot and hotter because their cold water is so incredibly warm their water lines aren't buried very deep and their cold water is actually really warm eight minutes right here there's ten we're staying fairly consistent with our levels the only level that's slightly indifferent from all the others is going to be that six minute reading and that's because right at six minutes a couple of air bubbles worked up through the system and kind of dropped the water level a little bit all in all we've only been running for 10 minutes and we've already increased by over half of a quart that's pretty impressive we're going to go ahead and run this all the way up to the top it'll probably take 16 to 18 minutes to fill this thing to the top that's going to be pretty awesome so we got more air bubbles working through a lot of air bubbles coming through right now that's just air that's hanging around at the top of the tank so that's really going to alter our 12 minute reading that water level you can see it it just dropped by over a quarter inch 12 minutes 14 minutes so we just passed 16 minutes and we're getting a lot more air bubbles coming through again so that dropped our it actually dropped our water level under to where it was at 16 minutes so we'll run this to 18 minutes and shut it off typically your water heater is going to run for like 30 or 40 minutes here we are we've demonstrated about half of a heating cycle and you can see just how much expansion we've had here we are at 18 minutes we're going to go ahead and shut the test off now in 18 minutes of heating we have virtually filled a one quart water bottle with nothing more than just heating the water that was inside here so we're going to go ahead and turn things off I'm going to drain this out here and then we're going to talk about what happens when we seal the system up where does all this water go [Music] foreign [Music] test we pulled down our stopwatch I'm going to go ahead and drain out this little bit of water down here we're going to reconnect this piping back to the rest of the house we're going to pressurize everything back up we're going to do the same test again only now we're going to have a pressure gauge on the system and we're going to measure this volume of water in terms of pressure we're going to see what happens when we increase two minutes time this much water what does that equate to in pressure this much water what does that equate to in pressure and so on stay tuned while we pipe all this back together and close the system back up [Music] might be calling in a turkey with that we are all piped back together now we're going to measure the increase in pressure we have gone back and closed our cold inlet valve to this water heater and we have also closed our hot Outlet valve back there so we are back again where a sealed unit right here the only difference between this and the previous test is we've now connected the piping we're not an open system anymore now we're closed so that added volume of water that was rising out of our cup turns into enormous pressure so we've got a gauge on the bottom of the tank and right now the gauge is reading about 60 pounds of pressure I have my house pressure in my house set to about 60 pounds of pressure all we need to do now we're going to turn this on and then we are going to start our stopwatch we're gonna measure how much time it takes for this gauge to start climbing what's going to happen as this gauge gets upwards around 100 to 155 pounds of pressure it's actually going to force the the relief valve on the water heater to open up this valve opens up at 155 PSI or 210 degrees or a combination of the two as we're warming up in the tank and we get close to 150 pounds of pressure we're actually going to see water start dribbling out of the bottom of the relief tube let's get at it we've turned on our heat we'll go ahead and start our stopwatch and right now we are at 60 pounds as this is heating we're going to compare the volume of water that was showing up in our cup to the increase in water pressure so if you'll remember these marks on our gauge here were minutes right so at two minutes we had expanded this much 4 6 8 10 12 14 16 at 18 minutes we hit expanded almost a quart of water at 20 to 24 minutes we would have for sure been an entire court of of water expanded out of our 50 gallon tank we've only been at this for about a minute and 20 seconds and we're already at 75 pounds of pressure we started at 60 pounds of pressure it's going to take no time at all to build enough pressure to relieve that pressure out of our relief tube right there is two minutes and we are just over 80 pounds of pressure packing just this much more water into the tank from the Baseline to the two minute line is enough to build the pressure in the tank from 60 pounds to 80 pounds we're passing 90 pounds already all right we're closing in on four minutes we just passed four minutes and we are 105 PSI now we've at four minutes we've now put this much extra water into the tank it's resulted in a hundred and five PSI so that's an increase of 45 pounds of pressure just after four minutes of heating this valve connected to this relief pipe opens up at approximately 155 pounds of pressure and here we are closing in on six minutes we've added this much water so probably about a pint of water to the tank so we're now 50 gallons in one pint probably and our pressure gauge is a little over 130 pounds of pressure we're already seeing the indicators that we are not going to be able to make it to the 16 to 18 minute Mark it's understandable this is a steel tank there's no way you're going to get that steel to stretch as far as it would need to to include this much more water and this is why you have a relief valve here when that relief valve opens up it's because we've built so much pressure in there it can't hold anymore we are nearing in on 150 pounds of pressure barely seven minutes in into this it's probably going to open up before the eight minute Mark which would have been about here on our volume gauge just passing 150 right now there it goes so right now our relief valve on the water heater just operated perfectly and it dropped our pressure all the way down which is good that's what we want the reason this relief valve is here is if this relief valve weren't here that pressure would keep building and keep building and keep building and eventually our water heater would explode what are we to do if when we heat water it expands but we don't really have like a movable piece in our plumbing system for that expanding water to go that added volume of water to reside in this is where your expansion tank comes in let's go ahead and turn this off hopefully this guy will stop dripping sometimes they don't sometimes after they've purged like that we have to actually replace those it's possible I end up having to replace that on my heater but let's go ahead and turn this off we will kind of restore this back to normal service and then I'm going to show you one more thing here real quick actually we're gonna bleed that off we are going to refill the system again back to our static pressure We Are One valve turn away from adding a thermal expansion tank to the system when we open this valve our thermal expansion tanks are now in a position where they can work I'm going to go ahead and close my main feed coming into my water heaters here the only thing that happens on the other side of this valve is now the system is connected to these two expansion tanks let me give you a visual real quick on what an expansion tank does and then you'll get to see what it does in relation to pressure as you've seen in this video this is our thermal expansion tank but it's all steel and you don't really know what's going on inside of there I've made kind of a rudimentary clear version of a thermal expansion tank so you can see what's actually going on inside here we've got a big bladder tank big bladder tank it's connected to a water source it's connected to a water source mine's on the bottom that one's on the top on the bottom here you have an air Schrader valve that is connected to a big balloon a big rubber balloon inside this tank inside our tank I actually blew up a balloon there's a red balloon inside there literally about the only difference between this one and that one is with this one I can't really do much for controlling the air pressure in the balloon let's come down here to where I'm can connect to my valve that I'm at as I open this valve we're going to force more water to get into this cavity water does not compress but air does water is is close enough to a solid that it does not compress as we do this test you'll again you'll have to forgive me very difficult to connect garden hoses to bottles I've got it connected the best I can I wrapped a bunch of tape around it but it's going to leak around here a little bit no big deal you'll still get the idea so what's going to happen is as I open this this is going to continue to fill with water and you're actually going to see the balloon inside here shrink because what it's doing is it's increasing the air pressure in that balloon tremendously here we go let's hope this doesn't fly apart and flood my house so we're adding just a little bit of water and that balloon is getting smaller and smaller and now if I were to flip this over you see the balloon is no longer rubbing on the sides of the tank now the balloon is so small it slides up and down the tank I can even add just a little bit more and make the balloon even smaller so the more water I put in there the smaller the balloon has to get well this is exactly what go goes on inside your thermal expansion tank inside your thermal expansion tank as the system increases its pressure and builds volume it crushes the rubber bladder that's inside the expansion tank and that allows the volume to move into the tank temporarily as you go open a faucet or use any water in your home that bladder will immediately expand back to its normal size all of the water will immediately leave the expansion tank and then just go become part of the rest of the system this is a very clear version of what happens inside your expansion tank we can even try to go even a little bit more here and make this balloon even smaller okay that's pretty cool that balloon is very tiny inside there especially compared to the size that it started out at there's a lot of pressure in here I'm afraid it's going to blow off here in a minute so we're going to go ahead and open this back up now what's happening that's going to simulate like turning on a faucet sitting getting rid of all that pressure so watch as I open the hose you're going to watch this balloon rapidly expand real quick it's going to go back to its original size because that air was compressed but now it's going to be allowed to expand back out and all this water that's dripping around everywhere this is all of the extra water that was happening to cause the bladder to crush now that balloon is back darn near to full size this is also kind of funny it's actually sucking the bladder tank in the main reason why is we went from tremendous positive pressure to actually negative pressure gravity is forcing all of the water out of the hose and everything when I peel it off of here and when I unscrew it from here all the water is able to drain out of my hose our tank is still kind of deformed so our tank is back to its original size the balloon is back to its original size but this was a quick demonstration of how you can control thermal expansion put a balloon inside of a sealed chamber pressurize that balloon to match what the house water pressure is going to be and then as the water heater expands and and all that water and that extra volume of water is created it now has a movable piece in the plumbing system for that extra volume of water to go to one final demonstration to do for you and that is to turn all of this on and build up some serious pressure but then with the opening of a valve we are going to be able to instantly bring our expansion tank into the picture we're back at our resting 60 pounds of pressure now everything is balanced out and neutral I'm going to turn the water heater on and after a few minutes we're going to get to about a hundred pounds of pressure and ride it when we get to about a hundred pounds of pressure I'm gonna open this one by ball valve here and when we open this valve all that's going to happen is that extra volume of water is now going to be able to move into this expansion tank and our pressure will go right back down to about 60 or 70 pounds we've turned our heater back on this gauge will start climbing while that gauge is climbing I don't want to talk about something here real quick and that is these expansion tanks come out of the factory with a pre-charge of air it is the installer's job to add air to them the air that we're adding to them we want to at least be whatever the house water pressure is the maximum allowable water pressure by code in a home is 80 pounds of pressure I have my pressure reduced down all the way to 60 pounds just to make everything last a little bit longer with that said as we checked earlier my expansion tanks might have just a little bit more than that in them they might have 65 or 70 pounds of pressure in them they started out with like 45 pounds of pressure so anytime we're installing a thermal expansion tank we want to hook it up to an air compressor or a bike pump or anything like that and we want to make sure that we're putting air pressure in there to match our house water pressure the maximum amount of air pressure you can put in an expansion tank is 80 pounds because of the maximum amount of water pressure you're supposed to have is 80 pounds the reason for that is you want that bladder to be neutrally buoyant if we have 60 pounds of air pressure in the bladder and we put 60 pounds of water pressure into the tank that bladder is under zero stress like we mentioned earlier in the video my expansion tanks are 11 years old and the bladders are still perfectly fine because I aired them up properly from day one right here we're requesting 90 pounds we're getting close to 90 pounds anyway as we hit that hundred pound Mark I'll open this valve that way our added volume of water now has access to our thermal expansion tank and you're going to watch that pressure gauge drop to a about 70 pounds or so and then it's going to stay there and even though this water heater stays Heating and heating and heating you're not going to see any change in water pressure because now we have a movable piece in the system that's accepting that extra volume we've just crossed about a hundred pounds of pressure so now we are going to open this valve and simultaneously you're going to be able to watch this gauge drop back to a safe level just by adding a thermal expansion tank so here we go valve open in three two one all I did was open that valve gave the system access to the thermal expansion tank and now our pressure just went right back down to between 60 and 70 pounds which is perfect also note that water heater is still going and that needle will not move at all you may see it bump around like one or two pounds go up and down just minor little adjustments but it will not be on a steady climb like it was before we added a thermal expansion tank so that completes today's video on everything related to thermal expansion tanks hopefully we've done a really good job of showing you why thermal expansion tanks are so important and why you need them if you've recently installed your heater and this valve is dripping now you know why it's all of this extra water in here if you've ever wondered what goes on in an expansion tank now you've seen it because you've seen exactly what happens with the bladder inside there and if you've ever been wondering what happens with the pressures and what pressure as it takes to make things you know function and everything else you've seen that too so do us a favor and throw a thumbs up on this video if you liked it share this amongst your colleagues if you're a plumber and you think this was a really good informational video and if you're a homeowner and you want to learn more about all things Plumbing within your home go ahead and subscribe to the channel because that's the whole purpose of this channel is to show you everything we can do with plumbing and just how fun it is to start and run a small plumbing company in the middle of America

Channel: Smedley Plumbing

Views: 514,759

Keywords: plumbing, plumber, mitch smedley, smedley plumbing, plummer, smedley plumming, plumming, diy, self employed, business owner, start my own company, ceo, president, the void, the void podcast, how do I start my own company, find the need fill the void, #findtheneedfillthevoid, #familyfirst, community involvement

Id: S2HVSogYELM

Length: 31min 45sec (1905 seconds)

Published: Sat Jan 07 2023