Air Vents and Air Separators How They Work and How to Apply

the broadcast is now starting all attendees are in listen-only mode hey welcome everybody coffee with kebab hot rod roar today our speaker is Kevin freed he's a product manager for us at Clough ease also worked with technical support very knowledgeable person a heck of a nice guy so he's going to be leading the presentation today I'll be in the background to help also so today will be a lot of the slides that you're gonna see a lot of the information that Kevin's presenting comes from mission number 15 that we did a year or so ago on the separation and in hydronic systems so I hope you'll note that as we go along in some of the slides what do you got here Kevin all right you ready to get going all right take it away okay so we've got Bob this is Kevin and we also have mark Olson on the line too so between the three of us we're going to cover all these topics here a lot of these are based on the questions that came in pre webinar so we want to talk about air how to remove that what type of products we use to do that and we'll talk about vents and air separators and how they work and a little little detail about the difference between some of the separators that are available on the market how many air vents do I need that's a common question that comes in so we'll cover that where do I locate the vents and air separators and chilled water we can't forget about chilled water so we'll cover all these things and remember if you have any questions type them in the comment area and we'll either answer them as we go through here or at the end and if we run out of time we will answer all your questions so you know be sure to enter your comments all right let's get going it's all air to begin with right it's you know air in hydronic systems is a given it's that the challenge is really minimizing the amount that's in the system to begin with and then getting rid of it once the system is up and running and you mean we can't overemphasize the importance of doing a good job and filling and purging because the more we reduce the potential for noise and damage that the air can cause in systems so very important and Bob's for coffee with Coletti webinar is on this topic so the timing is really good it's just perfect so one thing to remember is you need to have enough of a pump you need to have a good fill pump and enough velocity to push all the air through the piping as you do the fill and you need to have at least two feet per second this is a velocity that is sort of the the the key speed at which an air bubble will be able to be pulled through the piping for example in a vertical pipe if you have two feet per second the air bubbles will be pulled along with the water if you have less than that the air bubble buoyancy will actually keep the bubble from being flushed through the piping so so that's something to to be concerned with so and remember too that all the fill water and the makeup water will contain air and that's just just a fact it's it's part of the game and another way that air can get into the systems after we've filled and we're running is in vacuum areas so for example a valve packing if we draw a vacuum where we have a ball valve located like this picture here if the packing is a little bit worn you can pull air into the system through that the same thing for circulator flanges for example if you if they're not quite sealed properly and if you draw a negative pressure at an air vent and you don't have an anti suction cap we'll cover those in a few slides too you can pull air in the system as well and don't forget to that that PEX tubing if you don't have the type of tubing that has the barrier for oxygen you can actually get oxygen in through the system through the tubing so why do we want to remove this air well I think one of the more important reasons is heat transfer air is a really good insulator in fact it impedes the conveyance of heat for example a given volume of water can absorb about 3,500 times more heat than the same volume of air and you can see this thermal diagram here indicates how that air pocket up there is going to be much cooler than then down below where you just have water air airs a problem for more than one reason but primarily it makes noise and can annoy occupants and the important thing to know is that once you get all the air out of a system a good hydronic system that's air free is is silent so speaking of air another source of noise is cavitation and cavitation is generated when dissolved gases are released now this is a topic you know with a training session all by itself but let's touch on it briefly here so this example illustrates how cavitation can occur in a valve just for example so the velocity of the fluid over here on the Left let's say that this velocity right here when it approaches a smaller cross-sectional area as in a valve the the velocity will decrease and the pressure will the velocity will increase and the pressure will decrease for example let's say if this incoming pipe were a one-inch copper pipe with six GPM flow that's about 2.2 feet per second velocity and if this valve opening right here were a half-inch that velocity would increase to seven point six feet per second so this is a pretty big change and pressure is inversely proportional to velocity so as the velocity goes up the pressure goes down and if the pressure at this small cross-sectional area right here falls below the vapor pressure of the fluid then these micro bubbles will form from the dissolved air so we have dissolved air coming in but those micro bubbles will actually form because we're below the vapor pressure the fluid and then when its cross-sectional area increases as we exit the valve these micro bubbles will implode and they'll go back into solution and that's called cavitation so besides causing noise cavitation causes serious damage to the piping walls and to everything else in its path and that's that looks like this on a graph so let's look at this light blue line so here's our velocity as we come through the velocity increases and then it Peaks right here at the smallest cross-sectional area and then that velocity drops again as we exit so here's the inverse proportion the pressure is the pressure this diagram shows the pressure going below the the vapor pressure of that fluid and that's why these bubbles form right here the same thing can happen in the inlet side of a circulator so those dissolved gases can again be released from solution and create cavitation rate in in this area of a circulator because of the velocity and the low-pressure now if you have air in a circulator okay that's a problem too because air is compressible when circulators really are designed to convey incompressible fluid so not only does the potential exists for cavitation which will destroy that impeller but also you get that compressibility so the performance is decreased if you have a lot of air in a in a circulator especially a vertical circulator that's especially vulnerable to air air pockets and you can see here there's a in this diagram there's there's a spring-loaded check valve built into the the the downstream side of the pump if you get a lot of air in here that air can build up under that spring-loaded check valve and actually cause a big air pocket in here and that will that will cause that pump to stop turning large air pocket in there were that where the pump is located not only is it just spinning but those bushings will be dry to know and the bushings in circulators need to be wet at least in these this type of circulator for lubrication so that can be a problem and you can cause a lot of damage to the bushings if they're not wetted all right let's move on also air in the system can cause problems with other products like balancing valves in the system for example here's a cutaway if you can imagine that you had air inside of this balancing valve your your pressure caps might not be picking up the fluid directly and that could cause a problem also another big issue this this is a significant problem as corrosion so if you have oxygen in contact with steel and cast iron this is the result corrosion is it causes a lot of damage you can see here this pump volute you can see the corrosion inside of this mixing valve down below obviously that valve isn't going to work very well and you can see corrosion in the pipe and then on this expansion tank because air is about 23 percent oxygen that's what drives this corrosion and you can you know chronic air problems can cause serious damage and eventual failure of components like this another product of corrosion is magnetite now magnetite here are some nice pictures showing that it's a dark gray sludge can cause a lot of damage it's highly magnetic as you can see here and it can be a real problem for ECM pumps we show here to see that pliers hanging from that that that ECM magnet on the right and you can see the collection of that magnetite material on that rotor and that material sometimes also called boiler ink it's it's black and almost looks it sticks to your fingers too so this is a product of corrosion and also caused by air so what we're going to do here is throw out a coal question so in your experience what is the main cause of air related problems in hydronic applications and what he's going to throw up the pole so improper initial filling or flushing leaky gaskets or seals air vents and air separators not properly selected or you don't have any major issues with air so go ahead and make your choice all right so let's look at some forms of air in hydronic systems a stationary pocket the first thing we're going to talk about is an air pocket now this is going to form at any high point in the system here's an example of an air pocket that's on a high section of pipe so you can find these high sections in heat emitters heat exchangers expansion tanks whatever you can form these bubbles and as they join together they'll they'll form these large high pockets okay the other form of air is entrained bubbles so entrained bubbles like this picture shows here can be carried along with the fluid and as long as you have more than 2 feet per second then then those air bubbles will be carried along now some of these are visible like cloudy water like if you take a glass of water out of a faucet that has an aerator on there you can see that cloudy look and those are those are entrained air bubbles and they're really small ones sometimes you can't even see those in the third form is dissolved air now this is air that's actually dissolved in the fluid it's not visible it's called in solution and let's so let's talk about that a little bit ok so here's an example this diagram actually comes from our our disc out literature and let's talk about this a little bit what it is is an example of how dissolved air turns into micro bubbles in a boiler heat exchanger so looking at this red line here let's start at this cold or not cold but cooler temperature in the water in the boiler as that water gets close to the boundary layer of this combustion wall chamber the temperature increases significantly so what happens is these micro bubbles are formed continuously on the surface that separates the water from the combustion chamber due to this high temperature and these bubbles are carried from the boiler to the rest of the system by the flow of the water so these bubbles will appear and disappear with changes in temperature and pressure so they will go you know being from being dissolved to being micro bubbles invisible and back and forth based on the temperature and pressure of the fluid these bubbles can be removed downstream by an air separator before they dissolve back into the fluid so as those bubbles form what we need to do is remove those from the fluid before they then get Reda's all've back into the fluid here's a graph that we like to use this this shows the the water's ability to hold air for example let's let's say that we have a boiler system that's charged up to 15 psi so that's this red line right here and we have cold water 65 degree water coming in to that boiler at 15 psi that water the properties of that water in terms of holding air are about 3.6 percent can be dissolved in other words if you had a hundred gallons of water 3.6 gallons of that would be air now as we heat that water up we come down this red line right here we drop down this red line when that water reaches 172 degrees the property drops to about 1.8 which is half so then in that 100 gallons of water about 1.8 gallons of it our air so what happened to the rest of that air well it went from dissolved into micro bubbles and and then became you know bubbles so we could physically pull those out of the system it makes sense now what about if we have chemicals or additives or glycol what what changes what what things happen here well first of all all the fluid properties change so the density the viscosity the boiling point and these properties change so as a result the air vents and separators will still work but the efficiency can change in other words it might be harder to remove that air because we have different properties of the fluid and because there's oxygen and air in the system we know who that that degrades glycol in other words it breaks down the glycol so it's even more important to make sure that we have effective air removal when we when we have additives and chemicals let's talk about devices that are used to remove the air so high point air vents are one and you can see a bunch of pictures here that show where air vents are located for example at any high point in the piping as shown here on the top of the solar collector array on the top of a hydraulic separator manifolds and and other locations so again here's here's the high points that we were talking about the other device used to remove air our central air separators and we'll we'll talk about those two both in heating and chilled water systems all right let's start off talking about air vents so manual air vents like shown here they're usually small they come in 1/8 or quarter inch sizes and here are a couple of pictures this is a little cutaway of our 337 and here's an example of that installed on the side of a radiator so what you do basically is just open it until water flows and then you close it it's just a little manual valve there are a couple of other illustrations that show it being mounted on the side of a radiator and actually on the top of a baseboard tee okay hygroscopic now this is a really cool product it's an air vent that is manual but it's also automatic let's talk about that a little bit what it has inside are these natural cellulose fiber washers that will expand when they get wet so if you look at this cutaway if you unscrew this top you can actually open the open this inside here to do a manual vent but normally you keep these closed and when this is screwed closed those o-rings form a seal right here so this air is allowed to escape up through these fibers and then out the vent underneath the cap up here so if they get wet what happens you can see here on the right the certain thickness of the disk when it's dry and as soon as it wets it it just within a few seconds it expands and what that does is it closes off that air that that air escape and prevents water from getting out past your vent and dripping on a ceiling tile or something else that might be sensitive and here's a picture of our 5080 that's a chrome plated hygroscopic air vent to collect cells okay let's talk about an automatic air vent here's a cutaway which is really nice it shows the float inside and you can I don't know if you can see the water level here but what happens is as air builds up inside of the the body of the vent this air gap on the top increases in size and so the float will drop and at some point it's going to drop enough so that this little linkage right here is going to pull down on this needle valve to let the air vent out through the vent cap so this float just moves up and down to open and close this little tiny needle valve right here and let the air out that's the fundamental function of an automatic float type air vent here's a cap now the air vents that we sell are available with the hygroscopic cap that I just talked about so those are options you can if you get an air vent that just has a plastic cap like this you can put a hygroscopic cap on there if you want to and then down below we have something called a service check valve now we offer models that have this or you can buy it separately and what that device is is it screws on the bottom of the air vent and it allows you to remove the air vent if you have to service it for some reason and that little spring-loaded stop on the bottom closes so you don't have to you know open a valve in the system or anything that's like a little um it's like a Schrader valve type of spring-loaded valve that will close if you need to remove the this cap right here is called an anti suction vent cap so you can replace the vent with this device and what it will do is let air out but not allow air in so if you have an installation where you're having problems with pulling a vacuum at the location where the vent is you can put that cap on there and that will solve that problem for you here's another version of our vent this is called a disc al air and this one's a little fancier it has a pinned float so functionality is very similar to the one on the left but this one has a pinned float which guides that float and keeps it from maybe rubbing up against the sides of the inside of the vent if your vent isn't perfectly vertical and that's a stainless steel pin a little higher capacity a little more like I said of sort of a fancy event that's called the disc el air and then we have our big commercial models here that's what the cutaway looks like it has a large stainless steel float and excuse me and similar functionality it's a little more complex inside it has a very high capacity to relieve air but functionally it's very similar and here's what the family look like that little one on the left is a tall tower compact air vent that's got one eighth inch connections and then we have the the next group our mini Cal you can see the one on the top has the black plastic cap and the one on the bottom there's that hygroscopic cap that's what that looks like and then we move into some larger sizes again the disc el air and then on the far right that big commercial high volume vent moving on let's look at this is a great picture I like this for a couple of different reasons here are three boilers installed now up above look I know it's hard to see but you can see the air vents in these little red circles but what's on top of those is a piece of copper tubing now with this what this contractor is done is put a discharge tube on top of these air vents and we make a little adapter that you can screw on where the the vent cap goes and it takes you two a quarter inch npt so from there you can put you know compression fitting or some kind of a discharge tube that's in case these valves excuse me these these air vents do get a little debris or get clogged up for any reason and they start to spit water then you won't drip on top of the boiler and cause any damage so just want everybody to know that that's pretty common practice especially when you're located somewhere like this right on top of the boiler and then over here on the right there's a little hard to see I know but that's our commercial air vent and the customer's done the same thing here he's attached to discharge tube to the top of it so great installation up and surrey from Rocky Point engineering all right let's summarize air vents okay there are a few things really to take away from this make sure you design your systems so that you always have at least 5 psi at the highest point of the system we want to make sure that the vents will always expel air we don't want to draw a vacuum up there or anywhere where you locate a vent we want to make sure that the discharge pressure rating now this is a spec item make sure that the vent you're picking or selecting has a rating discharge pressure rating greater than what you will see in your system because if the system pressure is higher than the discharge pressure rating what happens is the little needle valve will be held closed so that that that no air will escape from the system so just just make sure you check that again avoid a vacuum we've been talking about this but if you put the expansion tank in the wrong location relative to the circulator you can draw a vacuum now I would suggest if anybody wants to see how this works look at I'd Ronix pages 35 and 36 there's a really good explanation there in our IDE Ronix journal on on what that looks like so you want to make sure and locate the tank near the circulator Inlet install the vent as vertical as possible again like the reasons we talked about if it's off a little bit that float might ride up and down on the side the inside wall of the vent and over time that can stick or maybe not work as well as it should and again locate the vents at all your high points you may need four or five six vents depending on your piping we get that question a lot how many events do I need well how many high points do you have that's that's the point and be sure to locate them for serviceability it's it's very possible that over time you can get some debris or build up up in that little needle valve it's a small orifice and you may have to take it apart and clean it and by the way the vents are easily cleaned you can unscrew the top take them apart clean them out put them back together they'll be as good as new so if one starts to weep or drip that doesn't mean you have to replace it it probably just needs a good cleaning okay let's move to air separators aperture is a type of central air separator that's semi effective in removing larger bubbles only at low velocities though and it does not remove micro bubbles so it relies on the the buoyancy of the bubbles to actually remove the air and what did you say Bob it's like the rotary phone of central air separators it's kind of outdated but we still see them out there yeah the the main thing on that when Kevin is that you know the intention of that device is they make a big wide spot in the road so the fluid comes into that it slows down for a second as it goes through there reduces the velocity trying to encourage those bubbles to go up to the top and find their way out of that little typically eighth inch air vent on the top but yeah those little micro bubbles entrained air it just doesn't have any mechanism which Evans going to explain on the next slide - to grab those and capture them float them up and release himself and it's they it had a place but there's there's a better way to do this now especially with high efficiency equipment both boilers and heat emitters all right so central air separators they have a coalescing element that captures micro bubbles so here's a here's a graphic that sort of illustrates that as the flow comes in through that pipe you can see at the bottom these are really small bubbles and what those little bubbles will cling to the sharp edges of a coalescing and the bubbles will join together and rise up as their buoyancy increases and eventually become large large enough bubbles that they'll they'll go up to the top and then they'll build up in the top of the air vent and be expelled out of the system so again the key is this coalescing element down here now the the what helps this this whole process is that when you come into an air separator you have basically a large barrel okay it creates a low-pressure low velocity zone and that that zone where the water slows down promotes the you know the coalescing of the bubbles on the on the element and the buoyancy so again an air separator is not a filter so they they're they don't have much of a pressure drop I'm going to talk about that in a minute if at all and so they don't typically require service they just do their job if we look at a cutaway here's what that might look like because your flow comes in with the entrained air the coalescing element is in that flow path you can see the increase in cross sectional area there where the water slows down and those bubbles coalesce and then bubble up into the air vent and then get discharge out of the cap so that's a nice cutaway that illustrates how that works we get the question on what size of an air separator to pick I think this is one of the pre submitted questions actually what we suggest is that four feet per second or less is ideal and you can go up to 10 feet per second and velocity especially in your larger flanged units because those are those are big pipes and you know even in chilled water systems for example we tend to have higher velocities so up to 10 feet per second is still okay you'll still get air removal than the coalescing elements will still scrub out that air at that velocity at least in our products that's what we say now I mentioned low pressure drop typically that's a negligible thing so when you're doing your head loss calculations in your piping you don't need to count these you don't need to count an air separator if you want to you can look in the literature that we offer there is a flow versus pressure loss graph in our literature but it's a really really small number so check that out if you want to let's again typically we say you don't have to worry about it another question that has come in as are their requirements for straight pipe lengths you know upstream or downstream of an air separator and the answer is no they don't they don't require that straight pipe lengths are typically applied when you are measuring flow like in a flow meter or a differential pressure sensor of some type but this device doesn't need that here's a nice cutaway of our commercial model now you can see the coalescing element in there and what you'll notice too is on this one the air vent has a really long float chamber and what that does is it prevents debris from getting into the vent mechanism and the picture on the left shows you how you can pull the whole thing out and clean it if you do need to clean it for some reason if you have really bad water the whole thing comes apart so you can get in there and service it and this thing right here on the side is called a side drain vent and what that is for is you can open that to release large amounts of air when you're filling the system so you don't have to wait for the little air vent to purge out the air when you're doing your fill just open that valve and let that air come out quickly during the fill also you can use that and open that during the life of the system to skim off any impurities that might be floating at the top of the water level so that's another purpose for that side drain vent here's a graph that comes up a lot okay we we get a lot of questions what's the efficiency or you know what is the what is the specification for your your air separators and this is an actual test graph this is based on empirical data from testing we did at one of our labs and what we did this blue line here you can see we introduced a certain amount of air within 10 seconds okay on the bottom here or is that seven and a half that's 10 seconds so we introduced some air and then we measured with a mass flow meter the air being removed as as it was introduced and you can see immediately it starts to remove the air and then over time the x-axis down here is time so after about one minute we're already at what 96 percent of the air removed and as time goes on that red line just continues to get more and more close to 100 so the point of this graph is that you know air separators are multipass devices and they take time so this this illustrates that pretty clearly I think in this testing we did we compared a lot of different products on the market and here are some images of the five brands that we tested and you know it really comes down to all the popular air separators that are available and they're successful on the market have some type of coalescing media that you can see here and they all will allow bubbles to cling to the edges of that media and over time and over a number of passes that air is removed now depending on the the coalescing element you know some may be faster than others some may be more you know stand up to chemicals and and impurities better than others that that top one in the center is is ours it's a type of nonmetallic product and that really holds up to two chemicals if there's you know chemicals in in the water and another thing to mention here too is there's no standard for air removal performance so we we do get the question you know what about your efficiency whose is better whose is faster whose does a better job well you know that's honestly me honestly it's it's a lot of specs Manship because if there's no standard you know anybody can make a test that you know has results that may be favorable so the point here is that they all remove air over time and and you know we know that ours gets up to that hundred percent mark over time as well and I should also mention there's another type of technology called a tangential or a vortex air separator out there and now call efi doesn't make these so i don't have a lot of detail about them I'm not an expert but I do know that they're based on a cyclone principle and at the center of that cyclone is a low-pressure zone so what happens is those bubbles will rise at the center of that product as the cyclone or the vortex forms and this is a simple sort of an older design it's been around for a long time but something to think about or to know is that these are dependent on pressure and velocity so if you have for example a very low velocity you may not get a very good vortex and if you don't have a good vortex then you're not going to have very effective air removal hey Kevin these can you hear me this is Mark yeah on this type of separator it's important on that velocity as you've mentioned because you want to basically you're you're basically relying on the velocity to send air bubbles towards the middle and then up out the vent and a problem with these is basically sizing these based on pipe size so what that means is that if your pipe is been sized to deliver four feet per second and you basically size your separator to be equivalent to that I mean to match that pipe size it might be in insufficient velocity going around that vortex to create that action needed to get rid of the air bubbles so that's one of the issues with this type of product right and what if you put in a variable speed pump and this pump slows down then you're gonna be looking at the same potential problem right correct right so like I said we don't make those but we make these so here is the family of our air separators starting from that small compact unit you can see there by the way I show also that service valve down here that same service valve is can be used on the bottom of an air separator and a lot of installations use that bottom connection on our air separator for their fill and flush connection and also for they expand tank very common use so that compact one we have the disk gal shown with the press connections up to two inch and brass and then we go into the larger steel ones and you can see the steel ones have again they have that side side vent tube okay these steel products have ANSI 150 flanges all of our steel vessels have ANSI 150 flanges flanges and we have a SME and CRN for our Canadian friends all the way up to eight inch and we can go larger it's just a matter of money and paperwork right mark so to speak okay let's talk about where they are placed okay because of what we talked about with pressure and temperature and removing micro bubbles we want to locate an air separator where the temperature is high and the pressure is low so here are a couple of pictures of our schematics showing a horizontal and a vertical air separator located in the hot supply line from Ahmad Khan boiler and you saw this before two on a chiller we're going to put that in the the warmest pipe which is leading back to the chiller hey Kevin going back up to that last one a question came in is the is the air separator placed directly after a boiler always the best location and as you you show it here directly after the boiler and in many cases that's true but we have to remember the pressure effect on air coming out of solution so let's say for example take that boiler in the middle let's say we're running let's say our zones are a couple stories up two or three stories up for example before we start zoning branching it off now as that water has traveled up I'll be it at pretty much the same temperature as coming off the boiler that reduce pressure as you go up up the building is going to release more air that you otherwise wouldn't have captured with the separator place exactly there so so it's a it's the answer is dependent on your application and so by way of what I just mentioned by placing it up close to where you're starting to zone off then that would give you the advantage of both a high temperature and B low pressure which is the place you're trying to look for when putting the proper placement for an air separator or I should say optimal yep exactly good point and remember it's it's you know if it's really difficult to locate it in one place you can locate it in another place just try and follow the high temperature low pressure rule as best you can and remember there multipass devices right so maybe it take a little longer if it's not in the absolutely perfect location you'll still get effective air removal hey Kevin another question came in here on this particular slide before he leaves sorry about that and on a chiller application there we don't show an expansion tank now ideally you're gonna have to have an expansion take on a chilled water system just as you would a heating system and as you would any heating system you always have your expansion take place upstream from your pump you want to pump away from your expansion take no matter what so you would put it on the suction side as you would on the heating side okay good great questions okay another schematic just a variation here this is a geothermal heat pump so right in the middle here we can see a good location for an air separator right coming out of them the buffer tank also in the same supply line here this one's perfect because it's on the suction side of the pump so that's a great location for this one and then of course as we have heating zones if we have any high high points out in that piping you want to put air vents out there too another picture just just for variety here's a conventional boiler so we show the air separator right on the outlet and this is a boiler protection valve so that's that's that's for here but we're the one that show two is remember here's some high points out here so our manifolds will want to have air vents out any any high point location out there to and Ahmad Khan this is a this is a nice picture I like it because here's a vertical air separator we have closely spaced T's which is really common and we have a primary circulator here so this circulator is is pumping water in this loop right here and we show a dirt separator down here a magnetic dirt separator that's that's another webinar but again we have air separation here and then we're gonna have air venting out here and any other high points so I'm thinking of getting the message by now here's a couple of projects the pictures that came in by the way we love pictures please send pictures here's an illustration of closely spaced T's and a nice discount location right here great job here's a picture of a discount that has the installation jacket now we make these preformed insulation jackets like we show here and this one even has as I mentioned earlier the bottom connection you can see this small tube it's coming out here and this is a fill valve so here's a backflow preventer and an auto fill valve then when the system gets finished that will be the location of the fill for that thanks for that picture Ashley here's another picture I like here is a discount again with the now here's here's the expansion tank and valve hooked right to the bottom so here's the filling location again another magnetic dirt separator and a good picture of some air vents upon on a manifold assembly I like this commercial example here from M Co up and up in Quebec here's a flanged version and again look at the bottom connection here this hooked to a fill valve now this is a 3/4 inch it's a slightly larger commercial size fill valve with the backflow preventer here as well this job isn't finished but nice shot of a flange disc al-kafi also makes air and dirt separators so this is a combo unit the picture we're showing here is called a discount dirt mag and if you look at the upper half this this top half of the the discal dirt it's an air separator everything is the same from here up and what we've done is added dirt separation in the same housing so this is a two in one this particular one has magnetic dirt removal and dirt removal down here and and the purge valve on the bottom so where do we locate that well we're showing it in this schematic again in in the hot pipe right here now we get that question well if I have a combo unit do I put it here where the temperature is the highest or maybe I should put it back here on the return to the boiler so I eliminate the dirt before it gets into the boiler well it's our general opinion that air excuse me that the temperature Trump's the dirt removal why the air it's extremely important to get the air out for reasons of corrosion and everything else that happens downstream now we'll pull the dirt out right here that's true but that dirt has already passed through here but if it were me if I had to make the call I would say that you know put it on the high temperature pipe here's what the the air plus dirt separators look like on the inside on the commercial models so here again we have the lower housing right doing the dirt removal and the upper section with the long-stroke air vent and the side port in this coalesce coalescing media you know filling up the whole entire section of the body this one on the right just happens to be an image of the magnetic the N a 5 4 6 M with magnet so this this has magnetic air removal and dirt removal all in one device here a couple of installed shots the one on the right is really nice picture you can see how its installed with the flanges the mating flanges in and here's the flush valve down here got a nice valve garden hose type connection on the bottom this one over here has the magnet if you look close you can see this magnetic handle that screws in and the magnet is up in side the body in a dry well that's a nice shot from Abby from hey cow take yes you wanna go back up to that one so questions have come in relative to we've been talking about air separators but should a dirt separator be used also where you have an air separator in a system I mean when do you you use a dirt separator and do you want to take a shot at that or you want me to respond or sure well you know maybe from a purist standpoint you'd want to put an air separator up on the hot supply pipe and put a dirt separator on the return to the boiler especially you know if you have a high-efficiency boiler that's very sensitive to dirt that might be you know the the ultimate way to go because then you're scrubbing out that dirt before it gets into the the small passages and sensitive areas and a high-efficiency boiler but a lot of times it's just that that's inconvenient it cost a little more to have two devices and so often you need using a two in one like we show here of course it's gonna reduce labor it's only two connections instead of four and maybe the project just doesn't have the room or the budget for separate devices so that's my take on it I don't know if you were Bob have any other comments yeah I got a couple thoughts that since we got it looks like we got a little bit of time here I can see where you're at in your slide one thing I was thinking about if you're doing a brand new system and it's got all brand-new copper pipe maybe PEX to being brand new boy they're brand new pumps and stuff like that I think the more critical application is to get the air at the hottest point in the system which would obviously be the supply right out of the boiler now keep in mind if a boy who's running it at 20 or 15 degree delta-t you don't have a huge temperature difference between your supply and return now the other school of thought is if you're connecting a new boiler to an old system that's got maybe iron pipe or caster and radiators in it or steel piping that has rust and debris in it that is going to continue to flake off as that system goes on with the new boiler installed in there maybe the better position is on the return because I'm concerned about you know catching that well that sentiment and dirt that to come out of that system for probably the rest of its life so that might be one way that you look at it you know if you've got a two and one device here what's gonna be the best bang for the buck on the particular application that you're putting into it because again the temperature coming back to that system if it's running the 15 or 20 degree Delta T isn't that much cooler than it is right at the outlet of the boiler so that might be something else that helps helps guide you in decision but we offer all the options you know if you want to put an air separator on the hottest point third separator certainly the magnetic device I would encourage everybody to consider the magnetic device if you're using the ECM technology which I think Kevin's get in the next I think that's coming up but that might be another determination on which device to use and also where to put it yeah so we're going to go from air plus dirt now to what we call our SEP 4 this is air plus dirt plus hydraulic and it has magnetic separation so this device is is a four in one and what it's doing is is separating the primary circuit here with our mod con boiler from the secondary circuit serving serving our zones now what we have here is this upper section again there there is our air separator the coalescing media right inside here is scrubbing out the air and the air vent is releasing it to atmosphere down below we have the dirt separation we have a coalescing element down here as well I'll show you what that looks like that's scrubbing out the dirt so we have the magnet on this small one the magnet is a collar it's a snap-on collar and we have the cold dirt coalescing going on down here and the air coalescing going on up here so again a very very you know efficient product right with four connections you get everything you need with hydraulic air and dirt plus the added benefit of magnetic and again well you know we still have our vents right we always have our high point vents sorry Bob what was that yeah one other point on this to the dotted line on the top of the SEP four there is what we're cylinders we also give you a little convenience well there or convenience part that you can put a sensor well in there and so what a lot of installers will do is they'll take the operating sensor out of the boiler and stick it the hydraulic separator so now look what you're doing there is you're turning that boiler and that separator into a minute miniature buffer tank for your system so in in addition to the fluid volume in the boiler let's say that boiler holds two gallons of water my separator maybe you know one point eight two gallons of water in there plus all the piping so now that entire circuit there from the boiler through the separator back up to the boiler is now additional fluid capacity for a miniature buffer thing and also what that will do is when you do have a call for heat on that ECM pump that we're showing off to the right there that whole circuit is already warm because the boiler is keeping itself warmed keeping the separator and the pipe excuse me to and from the separator warm and so we see a lot of installers like to use that part that we give you there and we also have a well that you can screw right in that part that'll take a typical six millimeter sensor that most of the boilers are using on their control so that could yet I guess you could call it Step five if you consider that as a another function of that device I like that so these products again we have a full range so that one we showed on the earlier slide was this small one on the left with the Union connections and that comes in Sweatt threaded or pressed so the tail pieces you have good flexibility there it comes with that insulation jacket with the with the top and bottom piece and the front piece to cover it all up and then the one in the middle the two-inch to 4-inch those also come with pre pre molded insulation jackets and you can see a picture here this one shows the the magnet is the insertion type so this has the drywall that goes up in the return flow path in this part of the device where we're scrubbing out the dirt and that has a commercial size air vent on the top of it as well and then these great big ones on up to 14 inches they have legs and this this picture actually shows one magnet but there's actually three that these these really large ones have three insertion magnets on the bottom and again here's here's a location for a sensor and our commercial size air vent up on top so that's that sums up the set for so let's let's wrap it up let's kind of bring it all together here course a fact of air removal is critical I think we've pretty much driven that home right it's very important for a number of reasons it all starts with proper filling and flushing and purging and we need to minimize that air at the beginning if we don't we have more problems down the road so let's let's get that filling and flushing done properly to begin with locate the air vents at high points and locate your microbubble air separators where you can based on everything we've talked about with pressure and temperature and remember their multipath devices so they will they will get rid of the air and if you do all these things you'll maximize system efficiency your customers will be happy and you'll extend the longevity of your equipment of course that's the goal so if you get the air out this all can be achieved and I hope we hope we got all that information across and that's about it I think you know we have a couple of minutes if we have any questions mark we can answer a few questions but again everybody make sure that if you do have a question send it in I will personally respond to it Bob Bob or or me and we'll get back to you but if you have any right now mark do we have anything that we can talk about before we let everybody go yeah okay a couple of questions a lot of questions but we've been answering as we go here one of the things that is sometimes done Kevin that on air vents if you if you look into the top of an air vent sometimes you'll see what looks like a Schrader valve or basically a little needle you can depress there and by doing that what happens is that if the air vent is under pressure it releases all of the air that's underneath that air vent and providing a kind of a cushion from any debris from getting up into the needle valve that is crucial for preventing any type of weeping so unless you absolutely have to we don't recommend taking an air vent when a when a system is in service and depressing that valve there really is little need to do so and it just increases the chances that a little bit of debris can get in there and cause a weeping alright and that and that's you know some folks just in general like to run a a pipe as you showed in one of those earlier slides from the top of the air vent over to someplace in case there is a little bit of weeping so that the moisture gets drained off somewhere it's meant to be and another question consider some questions on glycol again concerning glycol and air separation yes you anytime you put glycol in a system what it's going to do is it's going to cause your the the efficiency of removing air out of the system lowered and the reason for that is glycol has a higher boiling temperature than water glycol BoBoiBoy lat I guess 380 and water about 212 atmosphere and so if you have a 50-50 mixture of AB glycol which is not uncommon and Canada and parts of the United States your boiling temperature is going to be somewhere 290 degrees Fahrenheit and you showed that chart of the boiler wall with the flame temperature and water temperature and you can see that just just looking at that when you have a glycol system all things being the same it's more difficult to cause air to come out of solution so that you can grab it and for the air separator do its job coalesce and get rid of the air it wants if it does boil it wants to go back into solution quick so as a result it's very important to have a high efficiency air separator which means if you have a glycol system you should be looking at coalescing for sure and make sure you have optimal placement of that separator so that you can quickly get as much oxygen air out as out of out of solution also glycol is very viscous compared to water and it prevents the bubbles from one honey to migrate up as quickly as it would they would in air and as a result they have a higher tendency to carry through a separator and resulting ly it's they spend more time oxygen will spend more time in a glycol system and of course glycol does that his scavenges oxygen and as a result that's why glycol manufacturers will typically include an inhibitor with glycol so probably more than was needed to know but I would just wanted to explain that because there was three or four questions that came in on that I think a good bottom line to that market and everything you said was excellent it's just it takes more time to get air out of glycol I mean a disco you put it on the system and by the end of the job at the end of the day you've got all the air out it's a hundred percent air free and quiet it could take a couple days to get it out of the glycol certainly raising the temperature and that fluids just a tricky fluid for a lot of different reasons number one get glycol tends to leak out of a lot of threaded connections and stuff it's a you know it's the only good thing about it this doesn't freeze I suppose now another question came in it was an expansion tanks Kevin I guess we were trying to chime in there but expansion tanks we had a listener that has expansion tanks that corrode out and I think you should have an example of one of the ones that we had in our lab that were that corroded and when it's especially important some some contractors will take an expansion tank and mount them upside down with the expansion tank above the pipe and um if you think about how an expansion tank is design air can get trapped up underneath the bladder there and and come in contact with the inside of that expansion tank which in many cases is just steel and and unlike a riser a top of a riser where air also can get trapped but where you can easily put an air vent and expel any air that gets trapped you can't do that with an expansion tank and as a result it's a good place for air to want to get trapped and stayed trapped and only to react with its surroundings being the expansion tank and the telltale sign is that blister on the paint that tells you that your expansion tanks just about ready to corrode out so proper orientation of the expansion tank is for good design is important as well okay well if that's it I want to thank everybody for listening and hanging in there we've still got a lot of people hanging in but again send your questions in we're here for you let us know if you have any questions and that's a wrap thanks very much Bob thanks mark goodbye everybody