We're going over seven web design certifications that you can use to increase your hourly rate here on the journey All right now We're going for a ways to increase your hourly rate as a web designer as we know super important We've got to get paid right yeah exactly and most of these certifications They do require at least a little bit of experience or studying But most of them can be completed online and they are relatively affordable and most are even free and to help you out We've compiled this list of seven web design certifications to keep your freelance business competitive now These certifications are not just going to cover web design. They're going to diversify your skill set to really set you apart Yeah, that way you can become a one-stop shop for your clients So rather than just developing their website you can actually offer all of these other you know skills as well Now starting off with our list is Google Analytics IQ IQ this certification is absolutely free and I know what you're thinking Google Analytics That's not really web design or social media But it's definitely a skill that's in high demand and when it comes to analytics Google Analytics is the heavy weight Yeah, basing your web design decisions on data rather than just assumptions is actually going to lead to a lot more results For your clients, right? So you'll be able to tell them. Here's what's working with your site Here's what's not working and maybe even save them money down the road, right? It's definitely a skill set that's going to set you apart from others because yes Many people can throw together a website and make it look pretty But you'll actually be able to use data to drive results for their business The certification is valid for 18 months But you do have to retake it to make sure that you're keeping up with that Yeah What's cool about Google Analytics is they give you a couple of beginner and advanced courses Just brush up on different concepts and make sure that you can ace that exam and most importantly deliver results to your clients Yeah, and then the exam will take about 90 minutes Now next up on our list is Adobe certified expert or ace for short The cost for this is a hundred eighty dollars per product You essentially get certified by the products themselves. Luckily Adobe does offer specials sometimes like buy one get one That's cool. And being that Adobe has just a large suite of products You can get certified with things that can really complement your business like Adobe has a ton of products, right? Adobe for your pro photoshop illustrator all these things So you really pick the ones that make sense for you and your business So Adobe keeps really close control of their testing process and their certification curriculum So this is a really rare certification that can help you actually stand out as an expert for these products And the good news with these certifications is that they don't expire So you get certified once and you're good for life now That doesn't mean that you might want to retake it periodically because as we know Adobe makes tons of updates to their products So check in on every now and then retake that test just to make sure you're up to date Number three is general assembly bootcamp courses. So these typically range anywhere from being free to $4,000. These are the most extensive and really in-depth courses and certifications that you can get it Yeah, what's cool about this they offer in-person sessions or online just depending on whatever is best for you And these courses are taught by industry experts So it's not just someone reigning that picked up the curriculum they're teaching it These are people that are actually walking in the walk not just talking to talk and they do hands-on courses, right? So they're showing you really how to apply these skills into real-life situations topics can range from front-end web design to JavaScript frameworks to mobile app development and even digital marketing and general assembly does offer some free Introductory courses to give you a little taste of the full experience Number four on our list is free code camp and as you can guess the cost is free Free code camp offers web design and development skills for free and their library cannot be beat There's articles video lessons and workshops on all these different things What's even better about it is they offer different study groups in your areas You can get with people there just like you and learn these tactics to and a unique thing that free code camp does is they let you get That hands-on experience if you're just starting out by contributing to these open source software projects for nonprofits Yeah, that's so cool And what's even better about is you can use those projects and put it on your resume and your portfolio as things You've contributed to the fifth certification is Google mobile web specialist So this one costs $99, but that does include a study guide as well as three exam attempts in case You know third dead in such arm. Yeah kiss you fail the first couple But what's cool about is it helps you set you apart from other web developers and show off your skills on mobile We all know mobile is important. It's over half of all internet searches You want to make sure that all sides look great on mobile It's really what your clients are worried about at the end of the day Now this certification will help you test that and really give you hands-on experience with real-world tasks that you may have to face in the future Yeah, it includes topics like progressive web application or performance optimization Yeah, even accessibility or mobile web forms Completing this certification also gives you that really nice digital badge that you can display on your website or your different social media platforms And what's even cooler is Google actually adds you to a directory of all the developers that have passed the exam Which is just another way to really show off your skills and potentially get more leads number six is HubSpot Academy Certification and each course is available for free So what's important is that your clients want a online presence that not only you know looks good But actually sells their products or their services and that's where digital marketing comes in yeah Think about it if you can not only combine your web design skills now with your digital marketing skills You're gonna help your client increase their leads and conversion Not only that you get a charge more for it too because you're adding more value than just a website provides But web designers will most likely find the most value in their inbound certification course Yeah, this course will really take you through understanding inbound marketing and the buyer's journey and more and most these courses only take About two to four hours to complete So it's something that you can spend a weekend on and up your game last but definitely not least is the Facebook blue print certification So each one costs $150, but the certification requires two exams. So that means $300 But this one can really set you apart because Facebook is one of the most powerful Advertising platforms available right now becoming Facebook blueprint certified through that certification process does make you highly valuable to Your clients and businesses alike because it shows that your experience with the platform and you can help them with their marketing goals Exactly a lot of the clients that I work with you know They've tried Facebook boosting in the past and they didn't quite see any results But it's because they didn't quite know how to utilize these tools So if you're the expert then you can show them how to really take better advantage of the money that they're spending and get the Best you know return on investment the certification is administered and proctored by Facebook to Basically test how you do creating ad campaigns measuring results and troubleshooting any issues that do arise and each exam must be retaken once a year to maintain that certification now all this is great and all but landing those great web design clients is Going to require more than being certified with Facebook blueprint or having a HubSpot badge on your website Yeah, ultimately clients care about how you're actually going to help their business grow And they don't want to spend all this time talking to a million different people So if you offer all of these services, you know for them so that it's just one place They have to go one person they have to talk to then think about all the money You could be making from that client exactly or if they just comes to you because you build websites And then you can really show off that hey cool I on not only build websites, but I could also help you convert more leads I can do X Y and Z with all these cool certifications that I have really bringing those big bucks So there are the seven web design certifications you can use to help boost your hourly rate Be sure to like this video and comment down below Hey subscribe to our channel and ring that bell so you get these episodes first. This is the journey. We'll see you next time


Now we have Sankar Arumugam from North Carolina State, and North Carolina State University. Segway in terms of what I want to say. So I think this is the slide that Mike showed in terms of the trends in national water use. So talking to Antar, he mentioned that why don't you talk about the reason paper on the water use, irrigation water use, which is kind of under review. So I thought he's either an associate editor or a reviewer of the paper. So then I thought that I should do a good job in making the case for why water use is important. And one discussion that we had from yesterday as well as today is the importance of looking at the human side and how water use and lack of data on the water use. So what you are seeing here is how the water use has changed over the years from 50 to 2015. This is from the USGS report. And you can see that thermoelectric is the biggest chunk. But of course, it's not significant consumptive use. Most of it returns back. The next to that is the irrigation. And the irrigation is anywhere around, depending on the year, 45% to 50% age. And so if you take out the thermoelectric use out, I think it comes to around 66% age. Public supply is next, which is around anywhere between 12% to 17% age. And so this is over a period of 1952, 2015. And this is at the national level. And USGS puts out this data at the county level. And so when I mention about USGS data, and sometimes there is a lot of gas in the sense that, oh, the data quality is bad. This is one report in which it really digs deep. So if we just go and download the once in five year survey, then this is what we look at. But this report is pretty detailed and very nice in terms of looking at how each state water science centers, they collect the data, what methods they use. And they also provide guidance. I mean, survey is a voluntary effort from the WSE. And what are the sources of uncertainties? And it's a systematic review. And pretty honest and also has a lot of useful recommendations on how we can reduce the uncertainty in this data. So I'm going to now stick to only irrigation withdrawal. So I think some of the key sources of uncertainties, what they report is the acreage irrigated. And then the next one is the application efficiency. That is, what is the efficiency in application? And also heterogeneity in irrigation methods. So they compare in this report very nicely looking at USGS water science centers reports, as well as reports from USDA, as well as FRIIs, Farm Irrigation Survey. And so these are all collected at different years. And at the country level, the acreage irrigated is anywhere within 4% a year. And this is over a period of 2000 to 2010. And the water withdrawal, on the other hand, which is because if the acreage irrigated is really different, it's going to throw into uncertainty in estimating the actual withdrawal data. So they do a systematic study on that one by using a different method as opposed to what water science centers they use for collecting. And so based on that, like, for example, Utah, Arizona, they are within 2% a year. And you can look at the bar chart in the bottom one. And the main differences are primarily for states like Texas, California, and Florida. And I think they also make a point that one of the reasons is these are large states. That is a significant heterogeneity in irrigation methods. And also the other point what they are mentioning in the report is very relevant in the sense of that these states, they have pretty large agricultural surveys. And they do collect extensive data. And they do make valuable information out of it. So the independent assessment method even could be wrong. I'm not going into the details of the method. So I think, and also there are guidance in terms of rating. If you're going to use the state data, whether it is good or bad, you can use this report nicely to assess. So there is quite a bit valuable information that exists beyond just that five-year water use. So we have to dig a little bit deeper. I also want to make one point that is on the slide. There is no data, to my knowledge, that exists publicly, either with USDA or with USGS, on area irrigated under surface water and ground water separately across the entire country. So you have it's lumped, area irrigated for flood irrigation, sprinkler irrigation, micro irrigation, but you don't have anything available. So this is the paper under review. So you have two plots here. One is the surface water irrigation withdrawal on the top. And the second one is the ground water irrigation withdrawal on the bottom. And you see the numbers on it, which primarily shows whether it is increasing over the five-year. That is all the way from 1985 to 2015. And these are all in 1,000 meter cube per day. So basically divided by 1,000, and you are looking at million meter cube per day in terms of withdrawal. And you can see that the surface water withdrawal in general has been increasing. But on the other hand, ground water irrigation withdrawals has been, surface water withdrawal in the West has been decreasing. But ground water irrigation withdrawals over the country, it is increasing. It's not just whether it is blue, it is decreased. But also you want to have zero on your state, which means the temporal aspect of how it has been changing over the years. And we show that, as I mentioned earlier, the acreage irrigated and also the heterogeneity in the irrigation methods, they are much more important. In fact, in the WRR paper, we show that the climate comes later because at the climate division level, it doesn't really matter because most of the irrigation withdrawals, they heavily depend on other aspects, like surface water storage as well as ground water storage. So given that, I think there is plenty of useful information that one can draw from on the management aspect of the story. Just to switch gears, this is a project that we have started in China. And in the case of China, they have water use data primarily available every year collected. And the North China Plain is one place where the withdrawal is pretty significant. And in fact, most of the river, they don't see any water primarily because of the pumping. I mean, Beijing is one. You can see that this is anywhere around 70 feet deep. And some other provinces around Beijing, like Tianjin and all, is much more than that. And significant extraction of ground water. I mean, I was fortunate to get the data here primarily because I had the faculty from China Institute of Water Resources and Hydropower. So I think there's some other key points that I want to mention here. The bullets are in there just to do these are all collected. The irrigation efficiency has significantly over the time, primarily thanks to drip irrigation and sprinkler irrigation. And what is the space that we want to look at? And that's the question. I mean, if you look at, I mean, in our WRR paper, too, we show that at the county level, there is nothing there we can model. But at the climate division and beyond, we can talk something meaning. So this is a nice article in New York Times on water is broken, data can fix it, and it kind of complains about water use data. But it says glowing things about the energy and the power use data. But if you really go and look into what's how the power data is estimated at the monthly level for each day, it's some survey, and then autoregressive model. So I think when we look into the social and economic aspects or the human side of the aspect, some level of surrogates and some level of approximation is needed so that we capture the key variables in terms of mapping up what the management is. So this is, I mean, we have discussed quite a bit about the lack of data on groundwater, water quality, and the water use. And I also want to mention one more thing. Most of the dams and other things, surface water, this is a workshop on groundwater. But most of the, for example, details on, like, for example, inflow releases and other things from the reservoirs is not available. And if you look at, for example, interbasin transfer, most of them are like anywhere in the 80s. And I think the key point here is these data are going to control how we are going to appropriate on the surface water, how much is left is going to basically determine how much groundwater we are going to withdraw. So I think you cannot look at these two as two separate entities, issues such as water law, water appropriation, they are heavily interlinked and it should be looked together rather than in a separate way. So just to wrap up here my thoughts, I mean, data issues and uncertainties exist in all aspects. I mean, including geophysical data, like, for example, precipitation in early regions, is a big challenge and the same thing exists with model two, process representation and coupling. So what we need to look at is, my last point is, how the data, additional data of what we collect, how it will translate to decision making. And also it's important maybe identifying the right spatiotemporal scale in decision making, the decision making is important. So it starts with maybe conflict resolution or water sharing. Maybe you don't need like a how early model at a fine grain to run the model. Maybe annual is good enough or if good data is available, monthly is good enough, then goes the information on monthly if it is like a actual allocation and the extreme conditions like forecasting, remote sensing is extremely useful and like anywhere between how early to weekly, site specific. So I think the question is, what is the decision, what is the problem and how do we look at it and what is the spatiotemporal scale of the problem and map that one to the data rather than the other way around. I have a model that runs at this time scale and spatial scale and I want to fix it to the problem. It doesn't work that way in a management aspect. A little bit more.


Cloquet Girls basketball hosting Grand Rapids tonight. Right after the tip off, a pass up to Grand Rapids senior Hannah DeMars makes her 1,000th career point on the first basket of the game. They honor her as they take a time out. Here, Lema Jack. Fitby Barry collects the pass, tossed one in from the side. Later, Ali Wotisciak sinks the rebound as Kendra Kelly misses the initial shot. But DeMars was on fire all night long. Charges the net to sink another. She scored 23 points throughout the game. Grand Rapids wins 60 to 51. If you enjoyed this segment of Lakeland News, please consider making a tax deductible contribution to Lakeland PBS.


Welcome to lecture 7 on different types of valves, features and operations part 1. This is under module 3, hydraulic valves and these valves are of general category. Devices which are used to regulate and control the flow and pressure in any assigned manner are called control valves or simply valves. Actually we should call it control valves, but normally we omit this control part and we call only valve. With the tremendous advancement in machineries involving fluid power, the various sophisticated valves are developed to match with exact requirements. However, in this section we shall discuss only the basic features and operative principles of few ordinary and general purpose valves. In fact, if we would like to know the how the valves works and what are their constructional features, I think this is not possible to learn not only within this scope of class work, even it may take few years and also day by day with the modernization this valve configurations are changing. Manufacturers they change their valve very often particularly the engineering features of the valves. Anyway basic principles remain same, so we shall look into that. Special valves such as electro-hydraulic servo valves, proportional valves will be discussed in section, the next section in module 4. Now what are the basic considerations? First both the flow and pressure are controlled by using the principle of orifice flow that which I have discussed in lecture 4. The major factors that affect the valve performances are number 1, rate of opening the orifice, size of the orifice, here size includes the shape also. Third design characteristics orifice that also dependent on the shape of the orifice. Direction of opening, sequence of opening the orifices in a multi orifice valve. Now first of all we shall consider pressure operated valves. Now in the last slide what I have discussed, what are the orifices that we shall come later about the different shapes of the orifices. But in this lecture we shall only discuss how these valves are working and what are their features. There are several pressure operated valves. Pressure relief valve which is most commonly called as PRV being the most common and an essential one in all hydraulic circuits. Others are pressure reducing valve, pressure control valves etcetera. Now pressure relief valve, a PRV is incorporated in all hydraulic systems to operate by that is bypass the valve when the pressure in supply line reaches a predetermined or set value. Thus protecting components in particular the pump from being overloaded. PRV may be of two basic types, one direct acting spring operated relief valve or balance piston type pilot operated valve. Adding other features to PRV mainly on second one other variety of PRVs are made. Now we shall consider direct acting pressure relief valve cone or puppet type. Now look at this, this is the system line. If you remember the our earlier figure where we developed that how the fluid power circuit is made basic circuit. We connected this pressure relief valve in the supply line from pump outlet to the valve. Usually this is put just after the pump and it is connected to the system supply line. Now in this construction the this is the valve body. Now here we find a orifice on which a cone or puppet is placed and this puppet is supported by another spring where this spring can be compressed or expanded by tightening this or loosening this hand wheel. And what we find there is a hole through the body connected to the tank. Now how it operates when oil pressure increases or so to say say this oil pressure creates a thrust on this cone. So, this cone will experience a force. Now when this force exceeds the force given by this spring then there will be a opening. So, oil will directly come and go to the tank. This means suppose we are having a set pressure of 10 mega Pascal. So, when this exceeds 10 mega Pascal then this will open. This means that the pressure into that area whatever force is given to this spring that is balanced by tightening this hand wheel. Now when the pressure will slightly exceed that this will open and flow will begin. So, this means that at pressure flow should go out. But the problem is that of this type of valve that when flow begins. So, there will be opening. Now due to this opening if we use this orifice equations we will find that inside the pressure will drop. In this system line pressure will drop once the flow begins then what will happen to this? This poppet force on this poppet or cone will reduce and again it will be closed. But once it is closed again the pressure will rise again this one will open. This means that if in the system the pressure rises above the set pressure this poppet will open and close open and close until the pressure is reduced. That means until the load is reduced. Now this valve definitely is not suitable for a continuous system. It is only suitable where this is only for a safety valve and this set pressure is rarely reached. What will happen due to this cone sitting and opening sitting and opening a chattering sound will be there and this will be very noisy. However for the very simple system still we use the direct acting valve. But always we should remember there is a rare case when we reach the set pressure. Usually working pressure will be below that. Now one important thing look at the symbol. What are the symbol we have learnt in the second lecture? This is different from that. You see as it is a direct one there is no pilot line. And in that case if you remember I think in the next slide we will come to that. But there was a straight line and this can come to the line of flow. In this case apparently say this means that it is drained. When the pressure again will be reduced then this will be straight and oil will not be drained. This symbol means that very often we use this some symbol. This may not be ISO symbols but this is very common for the relief valve. Even if it is balanced type by mistake we use this type of symbol. If you study a hydraulic circuit, industrial hydraulic circuit very often you will find this symbol is used. Now next one is the direct acting pressure relief valve piston type. Again this is also direct acting. But instead of poppet or cone what we have used here we have used a piston. And if you look into this part there is an orifice and which is giving a pressure to this piston which is a cap type. That means you may consider this is a piston and this is a cap and then what will happen when the pressure rises there will be thrust. But this gradually move outside and then the flow through this there is a hole on this cap and through this hole the oil will come and it will go to the tank. Other mechanism is more or less same as in the poppet type valve. Now what is the advantage of this? This is also direct acting. So, the theory is same that when this opens then pressure reduces here and again it will be closed. But due to this piston and a cylinder sort of things what will happen? This will take some time to close and open and it is better from the chattering point of view. In case of the cone that was directly heating the cone sheet. In this case this piston is moving. So, sound will be less. So, it is slightly better than the other one and the same symbol is used. From the symbol you cannot understand whether it is piston type or poppet type. But alternative symbols what we have learnt we can use this symbol also. This line this arrow means we can regulate it. Here it is not given but that does not means we cannot regulate it. We can regulate this also. So, this arrow is given to indicate that we can adjust the spring. Although here it is not given but still we should say that this can be adjusted. There are only a rare case where fixed type spring is used, fixed compressed spring is used and that is a set relief valve. Usually inside some system a set relief valve is used. It is also possible that we can prefixed and it is a fixed one. That means set pressure is always same. Now if I look into this colored figure. Now when the pressure below the set value then as you can see that this is the piston type and this is another orifice. This orifice is put here and then this is the piston and when there will be rise in pressure then it will open and oil will flow through this and it will go to the tank. Now we consider balanced piston type relief valve or pilot control relief valve. Now in fact the pilot control relief valve is nothing but one relief valve inside the other or a direct relief valve inside another bigger relief valve. How it is working? So, this is the flow path. This can be put. Usually you will find this body of this valve is having one port here another port here which are normally threaded and you can connect one pipe here another kind here pipe here which is directly connected to the system line. That means system line is passing through inside the valve. It is not that we are externally fitting to the system line. It is directly put inside the system line. Now what is there? This is the main piston type and this is the main stage orifice passage. Now this is imagine this is a circular and from this diameter it is a step down here and this is a cone and then this diameter is increased to this and here on this puppet there is a hole. There is a orifice. Now how it is being operated? The oil is going through this. It might be from this side or from the other side. That does not matter. Now when this oil going through this orifice it will come inside. Now this one we may call this is a direct relief valve. But in fact this direct relief valve is called the pilot stage. Now here as you see this is a RC that is the external control. We can control from externally but this is normally remain closed unless we would like to operate externally. Then oil is coming over here. Now if we consider here is a very small area. So with a small thrust I mean the force is not very high. So this is a finer spring with a small force and when it exceed the set pressure then it opens. Then oil come over here. Now if the pressure is below set pressure then there is no flow. Remember there is no flow. No flow means the pressure the thrust this side and thrust this side remains same. So this is in a position and it is sitting on that. Now when this opens then flow is coming through this. What will happen there will be pressure drop. Due to this pressure drop there will be reduction in the force this side. Remember this side force is high. This side force is less. So this one will move inside. Now once it moves inside then this will open and oil will go through this. Now here the question is that when the oil is going through this pressure here will reduce. So if the pressure reduces then there will be again change in flow but there will be imbalance here again and it will try to close. But the thing is that this now works on a differential pressure. That means the reduction of pressure here is not very high or in other words pressure here and pressure this side with a small difference. With that difference this piston remains at it position for much longer time than the direct acting valve. So if we develop the equations fully from there we can understand how it is working. But that is for some valve definitely we will do that. But difference between this balance type pilot operated pressure relief valve and direct valve is there. There it is direct pressure is opening the puppet. Here the differential pressure is opening the this puppet. Now if I say suppose if I tighten this then what will happen this head pressure will change. This means that here the pressure it can it will be able to work at a much higher pressure than this because we have tightened this one we have changed the head pressure. But at that pressure also when this will open you will find that differential pressure will remain more or less same. And for that differential pressure this puppet will remain open. Now this is again we are not regulating this much only thing one is open and another is closed. Normally you will find this opening is very large definitely by controlling this size another we can have the valve of different flow rate. This means that suppose this flow rate is very small then you will find for that a small area of this or if you will be suitable. And for large flow you will find this area is larger whereas this portion remains more or less same except the spring will be different spring strength will be different. Now you can see this it is written here the pilot stage drain or if it is to pilot pilot stage main stage spring and this is the pilot stage spring sorry this arrow is not given. And this is this one is the external drain port in many cases there will be an external drain port through which the oil will go out it is better if we can take this oil out here separately it is from cooling point of view. But in most of the cases you will find this is closed and this oil is internally going through this one through this single outlet. However if we would like to control with external signal then we open this one this means that in that case if we do not send any signal to this this will work as it is what I have explained. But with the external signal signal also we can open this one and then there will be bypass flow drain flow it is sometimes it is required that with an external signal we should open this relief valve. Now looking into the symbols we also use this simplified symbol for this one only thing here we have shown the pilot lines as you see. There is an alternative also simplified one which you have seen which I will show but here if you look into the this is a ASA symbols if you look into this you will find that this is the main relief valve whereas this is the directly relief valve. So this is basically combination of one directly relief valve and another is the balance piston relief valve. Now alternative symbol which is shown here this these are also used and then if you look into this you can see this normal operation is like that the oil is going through this and this is closed depending on the pressure here it is below the set pressure so no flow is there no difference is pressure. So definitely this is being closed because in this side there is the pressure force which is equal to the pressure force here plus the spring force. Now when this pressure is above this pressure this has opened the oil has started flowing through this there will be imbalance in the force that gradually the force is being reduced here or in other words pressure force is being reduced and pressure force here remain the same. So difference between these two pressure force at one point will higher than this spring force and this will open. So ultimately this poppet will open and the flow will go through this drain line to the tank. Now we shall consider the sequence valve the sequence valve is in we can call it is also pressure relief valve but better we should call pressure control valve. Now this sequential valve sequence valve is having different applications it ordinarily it looks like in a relief valve the only differences we can we can understand from their function. Now in this case here what we have shown that is without check valve without non-return valve. Now here the flow is going in to this and flow is going out to this one. Now then at that point you can see that one external signal port for external signal and this is internal port this is optional we can make it we can keep it open or we can keep it closed. Now this is the pilot pistons. Now what happens this depending on the set pressure this will have a limited amount of flow but if the flow wants to come from this side it will always remain closed. So this valve you can say that it is after controlling the pressure it is allowing some flow. Now the actually the purpose of this valve is not discussed here we will show that by using this valve which is some sort of pressure relief valve we can conduct a different operations.  Now this variety is having another option to have a check valve what is the check valve we have a check valve like this. Now this check valve due to introduction of this check valve this allows flow from the other side also. In this case flow is only from one directions may be regulated pressure may be regulated flow. In this case if the flow is coming from other side then this will operate this check valve and flow can go out. Now this is again in both cases this is for external drain and this is for internal drain. If we use this external drain then the oil will go out because this is a more resistive path. In some cases instead of closing this there is also a check valve is there. So, when the pressure inside increases automatically it comes out of that and it go in the direction of flow. In this case it may go this direction or that direction in this case it will go only in this directions. Next sequence valve with check valve and auxiliary pilot. In this case as you if you look into this check valve is there which I have described earlier. But instead of this is being closed there it is connected. Now due to this we have an auxiliary pilot or wherever this pilot is there whether it is a pressure relief valve or any pressure regulating valve. This means that this works on the principle of differential pressure. Differential pressure means it better balance is possible of this spool main spool and this will remain stable for longer time. But definitely to make this valve will be expensive and as well as you see there is an external pilot of course it was there in earlier one also. Now if we would like to operate from the outside we can operate this. Now remember in that case we are forcefully moving this spool. So, this may be anything any situations you can see this if you if possible you can remember this symbol or else just for your knowledge this is the symbol of the sequence valve with check valve and auxiliary pilot. Now counter balance valve and unloading valve. In fact the sequence valve depending on the applications they are given different name. Normally we do not call that we need a sequence valve for this circuit rather we call we need a counter balance valve basically which is a sequence valve we call a unloading valve we call a venting valve etcetera. Now the sequence valve also can be used to maintain a resistance against flow in one direction. The sequence valve if used for this purpose or is made only for serving such purposes it is then known as either a counter balance valve or an unloading valve depending on the purpose and circuit. Now one if we do not come to the circuit design we will not be able to understand the purpose of counter balance valve and unloading valve which are sequence valve. So, that we will learn may be in next lecture it is actually in lecture 9 in module 3. Now we will come to the pressure reducing valve. What is pressure relief valve and what is pressure reducing valve? Pressure relief valve is the valve where we relief the flow if it is above the safe pressure whereas in case of pressure reducing valve from a system flow we can reduce the pressure we cannot increase we can reduce the pressure to a desired pressure. Of course depending on the amount we would like to reduce we have to select the spring and other features size of the puppet and etcetera. Now how it is working? First let us examine this is the main puppet and flow is coming through this. Now what is there? There is also this orifice but this orifice on the reduced flow side not on the main flow side. So, this is the flow coming into the valve and here is the main puppet and here is the main orifice variable orifice means when this will move this way or that way this orifice will open. So, this is the main orifice. Now the orifice to this pilot stage is on the reduced pressure side the outlet side not in the inlet side. Now what will happen? Now when the oil is coming in suppose consider that this is in a closed position but it is not actually with the spring force and here the stop of this puppet it will remain open. Now so this means that depending on the size automatically there will be some reduction in that. Now let us consider that pressure this side has increased then this flow will come over here and also this will come to this. Now in that case if this pressure has increased above this head pressure then the flow will enter to this passage also flow will begin and there will be a pressure drop. This pressure drop and there is also a thrust from this side this will move in this directions this will be closed. This orifice is being closed means less area and through this less area same flow means we need to have a pressure drop here. So, that pressure drop we will again set to the desired pressure what it means this valve we can control again by using this one. Suppose if we open fully then almost this pressure will be equal to this outlet pressure but gradually if we close this one always we will get some reduction pressure and that will be utilized in the circuits. But there is one question say if we are reducing the pressure from this side to this side suppose here we are we have set at a 10 megapascals by using this one then this side definitely there is a pressure on the system line pressure is more than the system pressure set pressure is there 10 megapascals. Now what will happen that if this total flow is not utilized in this side this will increase this pressure will increase to the set pressure here. In fact in most of the time the pressure here will be just above the system pressure supplied by the system line that means in this line there is a pressure relief valve you will find the whatever flow is not being utilized it is going through this relief valve. This means that we can regulate this pressure but in this side the pressure will remain the set pressure of the main system relief valve that you should remember. In our laboratory we have this type of valve and when the experiment will be there or some other time I can show you. Now operating principle which I have already described but quickly we will go through this inlet flow goes out through the outlet port via an orifice the area of which is regulated by the mains pool loaded by the mains spring mains pool loaded by the mains spring. Then when the inlet pressure varies the pilot stage receives signal through the orifice and the mains pool is reset in such a way causing the change in pressure drop across the mains pool orifice to maintain a constant pressure at outlet. This means when here this opens then this will reset to the controlled pressure. Obviously the outlet pressure is always less than the inlet pressure which is varied within a limit for which the valve is designed depending of amount of flow and the pressure drop this orifice size pool size spring etcetera all are determined. That means this valve will have a range only you will find say suppose if you want to control very small level say 1 mega Pascal pressure probably you have to go for a smaller valve. Now the magnitude of reduced pressure can be set adjusting the pilot knob we can adjust this one. It is to be noted that flow rate remains unchanged. The flow rate normally will remain unchanged within this range. If this is an excess flow system that means this flow will always go through the pressure relief valve. XD is the optional external drain port. So, here I have shown another pressure reducing pilot operated valve now look at this. This symbol is very complicated as you see there is a pressure relief valve. This is the symbol of pressure relief valve but as well there is a flow control valve added to that and then there is another valve with a check valve which is added to that. Actually this is you can say the way the flow is going from this side then it can go through this. So, this valve is not the symbol of this one. This is some other valve added to this system and this is the pressure reducing valve. Now how it operates in this case as we see that this is inlet and this is the reduced outlet and this oil is going through this and also from the inlet side going to this pilot stage which is controlled by this knob and then this area here this area varies to give this outlet flow. This is just to understand because I shall not ask you to remember this and to produce in the answer script. Now this is another pressure reducing valve which is called cartridge stripe. As you see here you can study this part. This is the pressure line oil is coming over here and this is the mains pole which moves depending on the regulation here and then flow goes to the tank through this part. So, this means that it is having one flow in and then regulated pressure flow out and then this is to the tank. Now this whole thing can be mounted on a manifold. Simply this is threaded to there and there are cavities. As you see this groove there will be an orifice. So, this is one chamber and there will be another chamber where the where the oil can go to the tank and then this is directly connected to the regulated flow side. So, this is a cartridge type, but as you see this is a fixed one. This cannot be regulated. This is a fixed one. Now again there is a direct acting pressure reducing valve. In that case what is there this is a very simple mechanism. This oil is in normal course it is going like this. Now we can regulate this one that means here we can increase the thrust or decrease the thrust. Now what happens if there is. So, when this pressure will come then this will go through this orifice and it will go outside. Now in case this pressure increases then there will be more thrust and when there is a more thrust then this will be closed and there will be a pressure drop. Now the question is that will it remain in that stable conditions. The answer is yes because of the reason that this pressure reduction will be there only when this pressure exceeds the pressure we need here. Suppose this pressure is less than the regulated pressure say for example the regulated pressure is 10 megapascals and here the pressure say 12 megapascals, but we need the pressure here only 7 megapascals for the operation. In that case the situation will be like this to understand my point say regulated pressure we need 10 megapascals and utilize pressure is less than 10 megapascals then this is the situation. But when the utilize pressure is 10 megapascals and here the pressure is more in the system only then this will operate and it will work like this. So, this is called direct active. Now here are we are discussing some other valve also this is constructional and operational feature of shuttle valve. If you remember this is the shuttle valve what is shuttle valve in that case there are two inlet one inlet here and another inlet here. Now whatever may be the inlet outlet is always through this. Now suppose there is a flow then simply this ball will go here and oil will go through this and it will go to the main system or may be to the drain. Suppose oil is coming through this point then this will be closed and oil will go out through this one. Now question is that if the oil in from both the side then what will happen then probably depending on the flow this ball may not sit on any side and all the oil will go out. So, depending on the applications this shuttle valve is used in the circuit. Now check valve already I have described now here a simple mechanism is there this is the main puppet of the check valve. Now when the flow so flow can go like this means if the flow is going like this then oil will go it will not be able to go in any directions whereas if the oil is going from this then it will it can blow this one and this oil will go out. Now check valve is also called non-return valve allows the flow in only one directions it might also be pilot operated by an external signal XP for flow in both directions. Now suppose if we use a signal like this then we can allow the flow from this side also this is completely from external operations here the symbol is this one. So, if the flow is from this side then this will be operated then flow can go from either side otherwise flow only can go from this to this side and when the flow is coming from this side it will remain closed. Now this is construction operational feature of a pilot operated check valve. Now in the case this is which I have described the same thing in a colored figure as you see that oil is going through this and it can when it is going through this it can blow and it can go to the tank. But if the oil is coming from this side it cannot go to the other side the symbol is like this. Now more features of pressure control valves will be discussed in hydraulic circuit and valve section only with the applications we will be able to understand the working principle of valves and that will be discussed with the different circuit. Now this portion I have taken mainly from a book named hydrostatic transmission system and this is edited by J. Korn. So, thank you.