So we are starting a small bathroom. This is the one that Marie uses. And so many people ask why Marie doesn't stay in this room attached to the bathroom. And that's just because the room that she's in, which is the one that we recently redid on the channel is larger and she just selected that one. But we're the only ones living here. So she uses this bathroom, it's just right through the hallway. And this is a space that we are going to be making over. Now for this project, I was actually asked by Architectural Digest to do kind of a social exclusive with them over on TikTok and Instagram for this bathroom. So I'm actually filming all of this as I'm also creating the content for them. We are changing everything and I'm very excited for this transformation. Leading from the kitchen through the archway is the laundry room, which is right here. And then this is a bathroom we're making over. But something you might be able to tell is this bathroom is extremely small. It's a very, very small bathroom. And it has two doors, which this door here essentially is not necessary. A lot of old houses had a lot of doors because they didn't have air conditioning. So it let the air kind of go through the rooms, which on the other side currently looks something like this. So this is a door that we are going to be walling off and this will all then be one usable wall that we could hopefully then put some storage up here because the only storage in this bathroom for Marie is under the sink. So I'd like to add some sort of wall cabinet storage solution up here. The doorway has been opened completely. We removed the original jam in there or the one that was added and all the plaster and we cleaned it all up. So it's nice and ready to actually be enclosed. Now, what I'm going to be doing down here is just removing these tiles here so that we could add the wall in here and get that all drywalled. Patching a door is actually not as hard as it looks. What you're going to start off by doing is getting it down to the studs as I did here, just removing all the trim. And then I went outside and cut down my two by fours and these are gonna go on the left and right side. We are essentially creating a new frame on the inside of the door frame that we're going to be attaching the drywall to and I'm just using some two inch long screws to attach these to the previous frame. I also cut a two by four for the top and bottom to finish off the frame and then added one to the center for a center support that way we can add the drywall. This is the first time I've ever purchased drywall before and this is what it looks like, a large four by eight sheet of it and this is particularly four bathrooms. It has a moisture barrier on this side so that's why it's purple. To cut drywall, all you're going to do is score it with a blade and it just snaps. I'm gonna start adding this drywall piece with the drywall screws in this. The top center, you can actually see where I drew the two by four on the underside. That's where I knew where to screw it down the middle and then I used some joint compound and mesh taping on either side, just anywhere where the joints needed to be filled and I filled those in. The joint compound is applied and we are gonna let this dry overnight but it's looking so good so far and I'm probably gonna have to do one more layer in the morning once we sand it off. Time to remove everything from the bathroom that is not stained because we're gonna be plastering or concreting this whole bathroom from the shower to the ceiling to the walls. We already sliced the silicone. Is it so heavy? Oh, I mean, it's not particularly heavy. Goodbye. Goodbye. I'm gonna towel it later. Hello.  Let's take off the light as well. The joints need this long. It belongs in what looks like a hospital. In order to move a toilet, you have to get all the water out of it so I did that with this cup and poured it in a mop bucket and then once it was all out, we were able to remove the toilet. Is that the poop hole? That was sick. I've never seen a toilet hole. Can you put your hand in? Yeah. Oh. That is so hard. Since I'm not gonna be demoing this bathroom tile at all on the walls, I have to create the same projection on the door that we enclosed that the tile has created.  That way the tile in our enclosed door area is flush and it looks seamless. And then I also added a small piece of wood trim to the top there to connect up the chair rail on the tile. I forgot to share that section, but I did add that. So as you can see here, I have done a little bit of joint compounding at the top of the shower because up here is where the tile kind of juts off and off the side. Around the edge we have the chair rail molding. So what I did was I actually used some joint compound to essentially build up the wall a little bit and then smooth it into the current wall. And again, this is just so I did not have to rip out all the tile in this bathroom. That would have literally required me to rip out all the tile, redo all of the drywall throw, everything have the entire shower re-hot mopped. Everything would have been kind of a big, big project and undertaking. So I really wanted to do the most I could in the preparation steps, which are these ones. So I added the joint compound there to kind of meet up with the tile because we are gonna be putting a waterproof concrete over the top of all of this, multiple coats of it that's going to create a waterproof sealed barrier and we're gonna get to that in just a minute. And I tried to do that around the top of the cove as well, including the corners, but I think this will give us a little bit more of a seamless look once we apply the concrete over top, which will be multiple coats and hopefully it'll just even itself out and look nice and seamless with the wall. This is a part that we're using to concrete and plaster the entire walls. It's a mixture of concrete and plaster by a brand called Neoded, it's called Concretta and I used this only once in the past on some countertops.  Yes, like I mentioned, this is a waterproof shower plaster that you could put essentially over anything. Now, if you have large scale tiles, I do suggest you put down the special tape first when you do it, but you have to mix it up with a drill and kind of a drill mixer attachment and then they add the pigment, they give you a little pigment cup for whatever you do. I chose this color called Westwood Beige. Out of the two trowels, I'm going to pick up with one and then kind of scoop it off and plaster it on the wall with the other. So let's add a little on. This process is just like, I mean guys, it is messy, I'm not gonna lie. Not going to make this look like a glamorous process because it is not. However, I enjoy things like this. Like I really do enjoy plastering. It's something that is satisfying. Like I can listen to music and do it. And I worked on this over a couple of days. I'm not going to lie. Now for your last coat of plaster, you do want to do it all in one day. I only did two coats, but I did cover the entire bathroom including the ceiling, the walls, everything because there are coved ceilings in this bathroom and everything connects up beautifully. So there's no kind of sharp edges where you could start and stop. So I actually kind of had to do it all in one go. I'm gonna do the shower floor now. All the walls in here have a first coat and I let them dry for a bit. And now we're going to do the floor. I'm gonna see how I'll scoop a hole in here. My favorite part of plastering is connecting the edges. I don't know why, it's so satisfying. I wanna show you how the first coat of plaster looks. Here's me just kind of walking in and this is what it's looking like so far. So as you can see, starting to even out a little bit, you could still see some of the tile kind of grout lines here, but with the second coat, I'm hoping that we're not gonna be able to see any of those. And as you can see over here, this is starting to blend really nicely. It's not looking super harsh. And even over on this side, it's like blended pretty great. I think once we add another coat on top, the reason there's this like crazy color variation is we started and stopped on the first coat because you can only do it on the first but on your final, you have to do the entire coat at once. So that is what we are gonna start doing right now. So for the second coat, I actually had Justin help me with this. That way we can get the entire coat done in one day. This is a small bathroom and we were able to do it in probably like six hours or so. So we spread it all of the Concretta on, mixed it up to start, and then went all the way around everything. As you can see, I haven't even removed that shower head yet. I am going to swap that. But the great thing is I have an access panel from the backside of the bathroom because this is an old house. So that's where all of the kind of access is. And I used a damp sponge just to smooth out any of the graininess as it started to dry down. Hello, I'm doing a little bathroom check-in. It is looking so, so good in here. And I don't know. I think I probably already didn't mention that this is being filmed for architectural digest which is really exciting. So I've been filming a lot of the process on my phone and kind of forgetting something for the YouTube. So the floor's now laid, but I'm gonna give you guys like an overview of what happened. In order to create these floors, I ended up using some pantry pavers that I get from Clay Tile. And I love these because they give you the look of kind of like an old Travertine paver or cobblestone kind of effect, but they're not insanely expensive. So they kind of give you that reclaimed feel, but they're not overly priced and they're not super thick either. So they're not hard to cut or work with. I really enjoy them. I'll link them below for you guys. I use them throughout my entire kitchen, laundry room, everywhere. And in the actual bathroom, we just laid them in kind of your traditional brick pattern, mixed up some mortar and then you can kind of see them going down here. Justin actually laid them because I was on a flight when we were working on this bathroom and he laid them really, really beautifully. It looks so good. And he said it only took him about two hours to do. This bathroom is literally like a five by five foot square. So not too large. Look how good it looks. I'm so happy with how the floor looks. Now these are tumbled Travertine like pavers. And I used these in my kitchen as you guys know, but I ended up using the square shape. It was a different style. These are the squares that I was mentioning, but I did use some of the bricks on the threshold here to create this kind of like striped detail, which I absolutely love. As you know, there used to be a door here and I was always going to have the same tile transition from here into the laundry room and then back into the kitchen. So I wanted to just do various shapes, but just look how good the plaster looks like the concrete plaster looks absolutely incredible. On camera, it kind of shows a little bit more contrasty and also keep in mind, vanity is going to be here, toilet is going to be right there, mirror. So we are going to have some items in here of course, but the actual plaster treatment is just stunning. It was definitely a labor of love. I've just been doing a lot of plaster lately in this house. I feel like Spanish homes and plaster just pair so nicely. And I love how this is looking. The color is so pretty and the light in this bathroom is really just so stunning. You can see kind of a few, just feel so completely different than as you can see like what's out here. This is a grow up bag I'm using. I got this at floor and decor, but I'll link some below for you. On the bottom, I actually ended up using the tile to create a baseboard. And I love the way that this looked and felt because I didn't want to add wood in between the plaster and the stone. It just felt like the stone and the plaster were one and I wanted them to stay connected. So for the grout, I just thinned that out, added it into a grout bag and grouted it just as I do traditionally with any of these masonry projects, like when I've shared my kitchen or the laundry room, you just grout it and you essentially over grout it and let it dry down. And once it starts to dry down, you could knock the top off with a trowel. So you let this dry for probably about 45 minutes to an hour or so and go all the way through piping through all your different lines, but also making sure you leave yourself an area to exit. You want to start at one side and then kind of work your way out. So as you can see here, once this area dried went through with my trowel and scraped off any excess grout and you can fill in and smash any of that grout into any areas that isn't fully filled. Hello and welcome to my vanity that I found on Facebook Marketplace. As many of you know, I tend to buy a lot on there. Actually I found this one on OfferUp. Same place that I found the box tape along. So OfferUp has been doing me well lately and I got this vanity for $275 on OfferUp. It was new in box, but from like a warehouse or something that got a liquidation of vanities. I loved kind of these little accents as well. And then also it has a really pretty marble top and the sink already integrated into it. So I already went ahead and used this product right here. This is crud cutter gloss off. So I used this and it just wiped it across the entire piece and got all of the gloss. I've just let it sit now for about 10 minutes. So I'm opting for Farron Ball. I'm gonna be using the estate egg shell finish in the color Sardine, which is one of the new colors from the Christopher John Rogers line. And we're gonna be doing two coats of this and then adding on some new hardware, which we're gonna go shopping for in just a bit right after adding on the paint. Whenever I'm painting any cabinetry, I always use a cabinet and door roller. It's like a velvety one and it just makes it so much easier. So pretty. Oh my gosh, it reminds me of my breakfast snuck, the old breakfast snuck. This is exactly the color. My little tip for painting furniture is to always make sure that you're finishing off with the roller. So I start off with the brush and I go through and I brush just all of the details, many areas that have like kind of ridges that need to really get that paint inside of them. And then I go back through with the roller and the roller is what smooths everything out. And I try to go over the top of everything I've painted with the brush as well to give it that nice clean finish that the roller gives it. So we have made some progress and check out how it's looking. Lore is currently wet. That's why it's looking a little crazy at the moment. Has to dry down. I just cleaned it with the grout haze tile remover or like the grout remover. It looks like this gonna dry down quite a bit lighter but I love the way the tile looks so much. The vanity I actually ended up changing the color of. So as you can see, I put the blue one in this morning and with the brass hardware and with this kind of very clean marble top, it just felt very pretty. It almost felt like a little bit childlike. I think the blue next to the very stark white kind of leaned a little bit of like turquoise and white. So I ended up swapping it for this color and I just love it. Now it looks so pretty in this bathroom and the color is Aurora Brown from Sherman Williams. I just picked from their historic colors and now I wanna actually get the mirror and light up in here because I want it to start actually looking like a bathroom again. We also got the glass in yesterday which looks so good. This is the original glass and everything still functions just as before which is great, really nice. I still need to bring that out. I need to get a handle for this too. I don't know what I wanna do yet but it definitely looks so much better. Like look how good that looks. So pretty. I have to do all the new hardware in here. I have a very special light that I've been saving for probably the past like three or four months. Now I found this at a shop in Los Angeles called Panopoli shop. It is so cute. You have the opportunity to go there. Gotta check it out. It's a really cute curated vintage store and it's really hard to find sconces one-off. Normally they're sold in pairs because they're meant to go on either side of something but the owner actually had a single of this sconce that I've been wanting for a long time. I've seen some of my favorite designers use these sconces in the past and she had a solo. So I was like, oh, this would be great for the bathroom and I picked this one up. It has the gold backing on it. It's gonna be going up here and I just think it's gonna be so beautiful. To add the toilet. And I got a new toilet for this room because the previous one was so modern and just not cute. And I didn't realize toilets are really not that expensive. The two I was going between at Lowe's were between 149 and 199. So I ended up getting the one for 199 and we were going to put this in the bathroom now. I am going to hire a plumber to come attach all the fixtures properly but I'm just placing them for the time. Toilet is actually so cute. I love it. Oil painting, I got for $10 from an estate sale and it was in the damage area because it had a rip in the back of it but look how old it is. And you can't even tell the rip at all. Like, I mean, of course you can but it's pretty well-masked and I love the colors and the frame. I thought was so nice. I was thinking of maybe hanging it here. I bought all of this Unlackered Brass hardware for my bathroom. However, it's far too shiny so I want to share with you how to age it in just a few hours. You'll also just need some vinegar and some salt and you're going to need a large tub that has a lid on it and then a smaller tub that could fit on the inside.  You're only going to want about an inch or so just enough if you feel like is enough for the project you're working on. Then I also added the salt on the inside there and placed my smaller tub in the inside. So what actually ages the metal is not the vinegar and salt itself. It's actually the fumes from the vinegar and salt that creates a reaction that then ages the Unlackered Brass. You're going to put that lid on, close it nice and tight and then check back every couple hours. I just took the lid off and this is after about 45 minutes. As you can see, it's starting to get nice and aged. This is after about two and a half hours sitting in here and it's starting to really get aged and looking so, so pretty. I left mine in for about five hours and just loved the way that it ended up looking. It was nighttime at this point so I pulled them out but hopefully you can see some of that distressing on the surface of the brass. The bathroom is officially complete and I think it is time to share with you the reveal of this bathroom makeover because this is probably the most intense bathroom makeover I have done in terms of just kind of transforming a space. I adore the way that it turned out. Now I will say architectural digest has already gone live with this content and a lot of people had so many questions about it so if anyone has questions just leave them in the comments below and I'll try to answer them for you. However, keep in mind, this product is meant for the walls. Like they're supposed to get wet. It's like used at water parks. It's used for this purpose and I just used it in the bathroom. Maria's already been using the shower behind me as well for about a month now. This was filmed quite a while back so I'm just kind of filming this little outro for the reveal and I cannot wait to share it with you guys. So let me share it in three, two...


Good evening everybody, today lecture is hydraulic circuits and valves and this is under module 3 hydraulic valve in general. Now, today I shall discuss that how the circuit is designed using pressure control and flow control valve or using a set of valves, how we can make various possible hydraulic circuits. Some exemplary circuits also will be discussed next. Actually, we can make various circuits, in fact whatever work we like to do, we have to select the valves and we have to place that valve at proper location to achieve the performance. Now, first I shall discuss a venting system. This is with mostly pressure control valve, why I should say mostly it is with the pressure control valve. Apparently, it will look like a pressure relief valve, but we will find there is some constructional difference with a ordinary pressure relief valve and these valves what I am going to show in this lecture. Now, we know the meaning of venting, venting means we should bypass oil or in case of gas due to some reason. In this case, venting is done usually when we are not operating the load. How it is done? What I have shown here? A circuit here as if this is a from the symbols as we know this is a pressure relief valve. Now, this pressure relief valve can be operated from the remote by allowing a flow through this valve and then the flow to the main system will bypass to the tank. In more details, the inner construction of this valve which is being used for venting which is a pressure control valve almost the function is like a pressure relief valve looks like this. Now, here first of all if I compare with the circuit, then in this valve usually instead of connecting like this usually there will be through passage. That means, we can directly put one end of this line here and other end on the other sides. Now, I have written here from pump. So, oil is coming from pump and it is going through the main system. Now, what I find inside there a stem or a cylindrical body is there. In that cylindrical body what we find there is a piston. In that piston there is another hole which is like an orifice and at the bottom what we find that this passage is connected to another path in which there is this stem is extended this piston is extended and apparently it is closing this valve. What else we look into this stem that there is a hole also inside and as if some sort of light spring is there. This one is a light spring and there is a hole. That means, this is directly connected to end of this. Now, ordinarily this will work as a pressure relief valve as long as this is closed. Now, we should call venting along with this valve, but basically you can say this is working for the venting process. This is again with a nonwritten valve with a check valve. So, that no back flow is possible to this side. Now, what happens let us consider it is initially closed then the oil is flowing through this oil is also coming this side. This point is closed that means, it cannot go oil cannot go this side. There is no flow there is a setting pressure this is pressure relief setting pressure say 10 megapascals. So, first thing what will happen when the pressure in the system exceeds 10 megapascals then this will open. Once this opens then there will be flow will begin as there is a flow in this side then there is a pressure drop here. So, this piston which is having exposing equal areas from both the sides will have a thrust upward. So, with this upward thrust this will move and oil will go to the sorry this oil from here it will go to the tank. So, this is actually you can call pilot operated pressure relief valve ok. Now, with that how we are doing the venting while we want a venting then a remote control actuates this one then this is this opens. So, venting position opens. Now, this venting position opens means the oil start flowing there, but this is not open once oil start flowing there again this will open again this will open and this oil will go to the tank. That means, at that time it is pressure may not be the set pressure it is may be below set pressure usually it is the ideal conditions when we need to vent the oil this is used with the fixed displacement pump. Why we need fixed displacement pump this to keep the circuit always ready with high pressure oil and frequent operation is there, but when we due to some reason we want that to vent the oil and we keep on running the pump, but we would like to vent the oil at low pressure then we operate remotely operate this one and then oil is passing through the tank through this valve. Now, here another note I have written float piston allow flow to tank only at 0.137 it will be megapascal sorry this 0.137 megapascal difference this is or in other words it is 1.37 bar 1.37 kg per centimeter square. So, I have forgotten to indicate that pressure unit. So, is that clear to you that how it is venting system is working now usually you will find that in pressure relief valve the construction is almost same only there will be a drain passage or so this internal reading is also there in PRV, but sometimes external and reading will be there. However, another important thing is that whatever may be the pressure this side that will try to pull this one because if you think of the load balance this side load and this side load that is a differential load which balancing the piston in or normal case when there is a no flow equal pressure, but there will be pressure from this side to balance this there is a hole and other side also same pressure is there this area and this area is same. So, this will at the condition when there is a no flow it will be in its position steady state position equal force from both the side with the light spring it is closed and oil is not going through this passage. Now, we will come to the next operation that is called sequence circuit. Now, here I have drawn a circuit you can understand that there is a cylinder A there is a cylinder B and from 4 by 3 DC valve this is 4 by 3 DC valve and x y are the solenoids we have solenoids both side and both side we are having the spring then that means it is a spring centered. Now, this straight connection that means when we will be in the right side then this is connected to both the cylinder rod end side whereas for the cross connection this pump will be connected to other side that means the piston side. Now, cylinder A and B are operated in sequence we need to operate this in sequence either cylinder A first or cylinder B in this case actually cylinder A first and then cylinder B. This means that if they are of equal size there will be definitely there will be some pressure difference for operations. So, what we do we use a sequence valve here again it is the basically the principle wise more or less same as that of the pressure relief valve. Now, in this case first of all let me explain the valve if we consider that the flow say first of all what we at what time the flow will start the initially there is no flow because this is a closed center. Now, what we do we say we have connected the x the x solenoid is operated piston of cylinder A moves to right to its full extent. Now, this oil is going like this cross connection is there. So, oil is going through this it is going through this valve it is trying to go here it also trying to go here. Now, at this position what is there there is some setting is there the setting is there. So, unless we reach that setting this oil will not go through this point then pressure is build up further to set pressure of sequence valve. We have set a pressure setting is there. So, oil is now we will try to pass through this, but it cannot it will move the cylinder A to its extreme positions and now pressure is building up. Once the pressure is build up then oil will go through this then it will operate the B. Piston of cylinder B moves to right to its full extent. Now, then when solenoid Y is operated that means we are allowing oil in the opposite side then the both cylinder A and B retract to left at a time or one after another depending on resistance. It might be some residual load is there if they are perfectly alright they can return at a time or depending on the resistance one will return to the other. In that case say this we have connected now this the oil is going back through this one which is almost no resistance is there. Now, this means that this return flow is shown here oil is returning here, but to go the oil to this side what will happen due to this pressure balance there it is like a relief valve this will open this path will be closed and then oil will go to this side that path is not shown of course, but this oil no through this path through this path it will go this will go this will open and it will go apparently this position is shown this oil is passing through it is bypassing not to this passage it is going through this check valve. This is not very understandable with comparison to this, but actually for operating cylinder B this pull has to open and then oil will go like this and what the path is shown this is return path. In case of this forward flow to cylinder B this will be opened which also can be actuated by a remote control here this is there. Say sometimes we may need to operate cylinder B out of sequence in that case this path is connected. Now, flow from piston ends of both cylinders go back to tank in cylinder of B via check valve. So, this is for the return path I have written this note. Now, we are coming to the sequence circuit valve actually now this valve already we have studied that this valve may be without check valve the sequence valve may be without check valve that is for only one side flow of course, that we have to see that is when is oil is coming back in that case we have to find out some other path. Here what we have done in this case we have used a check valve which is apparently integral part of sequence circuits the earlier which I have shown. If we would like to use only I mean this valve only sequence circuits with non-return without non-return valve in that case we have to use a separate path for return oil from the cylinder B that might be low pressure pressure relief valve that is possible or separately we can connect the check valve there it is possible. Now, this function already we have learnt this is nothing, but just like a pressure relief valve the flow is coming in. Now, referring to this figure the sequence valve can be externally piloted we can externally operate this one this means that when we are pressure giving the signal here this is moving and oil is going out. Now, basic principle is that here the connection this in case of external operation we have to first of all we have to plug this one then oil is coming here and this side and this side pressure are same. So, it is not moving. Now, if I excite externally then this will move and oil will go at what pressure it will work depending on the setting we have done here it will work. Now, there is an external drain also this oil is always will go through the external drain passage. In some cases this external drain is not preferred and in that case we put the internal leakage path internal leakage path then oil will go through this. Now, this is only in one direction without check valve if we look into this it will operate only in one direction. Now, if I want to operate this with the internal piloting in that case we have to plug this one and we have to open this one. Then oil will come here again we will find this side balance and the there is a very small passage and here is also this is not very clear, but again if we allow the oil from this side also this will be balanced it will not move, but when certain pressure will increase that means here this pressure differential will be such that it is able to move this one then again it will open. So, in this case what we find both internal and external piloting is possible. Now, external draining is must to avoid back pressure. Now, here I have shown a little detail that if we look into this valve this is closed. So, in flow is coming in we are we look here the flow is coming in from this side. Now, then this is internal piloting it has come over here this is being balanced it is not very clear from this, but it is being balanced by the pressure here and here and also here and here look into this pressure is going through this oil is going through this it is coming over here. So, this side and this side is balanced and oil pressure is here and here this side is also balanced unless there is a flow. Now, how the flow will begin when this pressure reach a certain level so that it can it can move through this there will be a little opening and external drain will start flow will begin pressure will drop here then this will open. So, this is the open position when this is opening then oil is going to this side it might be secondary circuit. Again here I would like to say that this valve is constructed in that way instead of side fitting or tap fitting we can directly fit one side input side here and output side to the system here. And you can have a look into the symbol how the symbol is is it clear somewhat I will give you this picture and you can study this. So, system is like that here it is not shown, but here it is shown clearly that there will be a passage in fact there is also a passage. So, oil is going like this oil is going this side. So, initial condition we should draw that everything is red here, but anyway they have used this two colors. So, this means that all side pressure are equal it is in balance when only this pressure exceed to move there will be a this this pin is there it will move and then for oil will start flowing through this and then it will go to this path. And this is for external draining in anyway it is shown here closed. In a carefully designed valve internal draining is also possible by removing internal D plug while XD is plugged we can this is plugged and we can internal drain that means we can have this passage connected it is not shown here. Now, this the same valve if you look into this construction what we find here only a check valve is used there otherwise construction wise it is same as before. Now, this check valve once we use this check valve what you find that the flow in from both the sides and out from both the sides. This means that with this check valve we can allow the flow from this side to this side. Now, this check valve is operated with the external force we externally operate this check valve to flow through flow to both the directions. So, oil is going from this side to this side as well oil can come from this side to this side. So, this is the sequence valve which we can use the circuit already we have shown. Now, in this valve what this check valve is there as well as there is auxiliary external pilot. In this case what we find they this valve is normally with internal piloting normally with internal piloting, but as well there is also external piloting. This means that we can change the sequence norms that means whenever we need we can externally operate that and we can also operate the cylinder B not in sequence or according to our desire, but according to our desire a significant difference in the valve as shown in this figure which as the auxiliary external pilot is directly exposed to the bottom of the larger section of main valve. According to other two this gives dual control we get dual control one is that the sequence what for we are using this valve as well as external control. Now, there is also a two stage sequence valve now in that two stage sequence valve it is also named as Y type. Now, here if we look into that venting system if you remember that venting system what is the difference between that venting system and this valve. Can you say the basic difference is that we do not have connection here we have an external drain in this case we have external drain not it is connected to there venting system this was connected to there in pressure relief valve also this connection will be there. Let us read it what it is there pilot operated sequence valve differs from pilot operated PRV. The drain passage is external instead of through stem of balance piston this is called balance piston. The primary system flow passes through below the piston land that means this is the primary system this is going to the system. We I have already explained this these are available in the valve system that we can can connectly direct to the system with secondary system connected to the bottom port. Sequency occurs at about a pressure of 0.137 mega Pascal that is 1.37 bar over the setting pressures. Now, in this case what is happening that we are keeping it close now only when the pressure setting pressure reaches here in that case this piston moves and the flow begins to allow to the secondary circuit. And here also as I have explained to keep this stem in balance there is a small hole. So, that pressure this side and pressure that side remains same as well there is also spring because this is actually this will be a balance piston. Now, ordinarily when there is no flow this is completely balanced there is no force acting on that except that spring force that is just allowing this to sit on this positions. So, when this flow is there the seat is like that ordinarily it will not leakage with a small force it will remain closed and there will be no leakage. Only if there is a flow then this will move and this will be operated. And for operating this only we need a very small pressure difference and as we need small pressure difference only then it remains balanced for longer time. Otherwise as we know that once this flow begins this gradually this pressure will also drop. You see in a system once you say in a tank there is a pressure. Now, if you make a hole there immediately inside pressure also will drop. Now, secondary system pressure below the piston is sensed at the top of this stem here secondary system pressure has no effect on piston movement which I have discussed. Thus piston remains at position until the pilot needle cracks at set pressure and pressure drops at upper chamber and the piston is lifted allowing secondary flow. This flow we call secondary flow that is to the cylinder B. Now, we shall study some circuit with pressure valve. This is counter balance valve and counter balance circuit what I have shown this is the counter balance circuit and system. Now, this is also we can call this is somewhat sequencing and called as counter balance system. This system is called counter balance valve, but the valve principle as you see there is a pressure I mean non written valve and the same as pressure valve. So, this also some sort of sequencing valve, but here the purpose is different. In that case it maintains resistance against flow in one direction whereas, allows free flow in other directions. It is usually placed at the rod end side of double acting actuator. This is an double acting actuator and the cylinder we have placed in vertical directions. It can be upside down also, but this is not for horizontal work normally where we are lifting load there this counter balance is used. Why the counter balance is used? This prevents the free fall of load that is uncontrolled movement of load towards the gravity. What will happen? You know that if you have must have seen in a crane. Suppose, when we release the break of the load lifting hook or the drum then it will start falling and as you know due to the gravity it will start accelerating and when it will touch the gown it there will be severe impact to prevent that we must control the load. In that case in case of crane mechanical system we use the break it is there is a break that when it start falling at a higher speed automatically that break will be engaged. Once this is engaged then again the force will act on that to release that one and the load will fall and by that they it will balance it will control the movement. Now, this circuit is shown here it is something like that. So, when it is lowering load let me explain what it is there. First of all we have used a DC valve direction control valve which is fully open and again it might be solenoid I have not shown here it might be manual or it might be hydraulic that does not matter, but what we have used here this is a open center valve. Now, this flow is normal conditions when we will not operate this valve then this will oil will go to this. Now, this is again we do not need very fast response here we can gradually we can slowly leave the load and lower the load this purpose is main purpose is that handle this load not very fast operations. So, we can go for open center to save the energy right. Now, we have now think of lowering load because that is the main purpose. So, while we are lowering load we allow this to tank that means we will go to the left hand side. So, it is connected to there I mean this side is connected to the tank and the pump side or pressure side is connected to the other way. Now, while this load is being lowered how much pressure we need practically we do not need the pressure what we need we need the flow because this is to be filled otherwise it will not move. On the other hand to prevent the load free falling this oil will try to come this way, but it will not be able to go because this is a non written valve then oil has to go through this pressure relief valve and the setting is such that depending on this load this setting is there. So, this might be again control from the remotely control and the load will come down by blowing this valve that means there will be restricted flow. Now, if there is a suppose it if it wants to speed up then there will be due to this flow we need to have pressure increase in that again this will be closed. Now, here we have seen the we have shown this valve this is the direction control valve here and this is the counter balance valve this one is the counter valve valve. Now, what is happening that what I have explained if you look into this then oil is through this valve is going to this side where there is oil coming through this and through this restriction it is going to the back to the tank. This is tank path is not shown, but if you look if you study this this is nothing, but some sort of a sequence valve operation principle is same and here as well you can see that external draining and internal draining is shown. If you external drain for external draining we have to open this we have to close this path is there and as well as also internal piloting and external piloting is also possible. So, this is basically a sequencing valve, but application is different. Now, also it is possible that while we are using this valve we can use another valve which is called slow down valve the, but the feature is not shown in that slow down valve it is the there is a spool that with the increase in velocity that spool will experience a load and that will close the path. Once it closes the path they again the velocity of fluid will decrease again the force will reduce and that will open that is a very simple in comparison to that, but this is having the external control, but that valve is not having external control usually that slow down valve is used where the loads are limited say in case of what lift truck when the load is being lifted there we can use that slow down valve, but that feature is not shown, but basically that is also called counterbalance valve. So, at least you can understand what is counterbalance valve what is their applications. Now, if I hear perhaps it is wise to discuss that in your question what will be there say probably you have to what is a short note or maybe a part of the question is that what is counterbalance valve explained with a circuit. You can draw a circuit and you can explain this few words that you have to first of all you have to understand how it is working internal feature of this valve and how it is working. Now, we will go for unloading that was a counterbalance now we will go for a unloading valve what is unloading. Now, usually in any fluid power system we need to go for energy saving process. Now, in many operations you will find that there is sometimes we need to actuate more load and other time may be lower load. Once there is a low load I mean low capacity load then we can increase the speed we can have this because we have a fixed motor that motor full energy we can use for that purpose. If it is allowed that we can move the load at higher speed then in that case there should have some system that we can either control the flow or we can have system when there is a high pressure only certain amount of flow when there is a low pressure we can increase the flow that is possible variable displacement pump but variable displacement and pump is costly expensive as well as that control is also difficult in comparison to this system where there is a high pressure pump and there is a low pressure pump. Idea is that when there is a load is more then full power of this will be utilized full or the maximum power will be extracted from this motor to run the HP motor and that will work and load will move at slow speed and then but this is connected to low pressure pump also this low pressure pump oil has to go somewhere what it would do it should bypass the oil it should drain the oil at a very low pressure relief but if we use that very low pressure relief here then again it will not be work when we will need this flow. Suppose the load has decreased in that case it should automatically work such that both this flow and this flow should mixed up and should operate that one the load now let us see what is there this is called unloading valve. Now what I have shown here say this unloading valve this is the symbol and we can see this whole unit is called unloading valve it is also a pressure relief valve but it looks like this. Now primary port from LP pump basically here what we are doing this unloading means we are unloading the flow of low pressure pump to the tank this is the purpose of unloading it is no connection with the high pressure pumps. Now how it is working now you have to compare this with this figure this is the check valve and this is the connection to this to operate this one this is the pilot connection. Now this primary port from LP pump is connected to here so ordinarily when this is a high pressure this is blocked the no oil is coming to this side but only it is remotely trying to control this valve. Now again this pressure is not sufficient to open this one if it is not sufficient to open this one then this will remain closed but if there is a high pressure this will be this will open and then oil will go to this isn't it. Say let us consider that this pressure setting here is 10 megapascals and system pressure is more than that then this is not being operated sorry I have many mistakes this is 10 megapascal it is working at a high pressure. Now this same pressure is coming over here and then at that conditions this is being opened rather this is being opened do you understand pressure here more than here the setting is 10 pressure pressure here more than 10 megapascals so this is being opened 11 megapascal so it will open so flow is going to this and so this is unloading this coming from here to here. Now this is secondary port to tank now this is the main system I have already discussed now main system pressure is higher than set pressure only HP pump flow is being used. So no flow through this check valve and this is being operated I have discussed already now we will come to the other positions. Now suppose this pressure has come down below this set pressure say it has become 9 megapascals once it is 9 megapascals then this cannot open this valve then this flow can go through here it will be mix up. Now it should be it is interesting that this is a basically low pressure pump and usually this is a high flow and this is a low flow but it is like that when this will operate and this will operate at pressure say setting pressure below 10 then total power of this will be equal to the motor power. So this is by this way we use the I mean optimize the energy co-injumptions. So this means that unloading valve is to unload a usually a low pressure pump when there is a high pressure and load is being used only from the high pressure side. Now this is one application there might have some other applications also. Now in brief we can say that an unloading valve is also another version of sequence valve what we have studied earlier it allows the pressure to build up to a value determined by a pressure setting then it is to a valve generally used to bypass part of this circuit back to tank at very low pressure. So to a means that we have shown that there is a passage is interconnected and it is also connected to the high pressure side and low pressure side. So construction wise it will be slightly different from the sequence valve or pressure relief valve. The internal draining occurs the internal draining of draining occurs and double pump system as shown in figure is an example of unloading valve this is one example using the same power two outs food are mixed up at low pressures and at high pressure only the flow of one pump is used by the system where as the flow of other pump is diverted to tank at a nominal pressures. Now again I would mention here that what might be the type of questions you have to draw a circuit like this you have to write this few words and if it is additionally mentioned you have to draw the internal features of that valve. Now usually if the internal features of the valve are asked to draw that is usually a full question but this might be a part question or short night short mode type questions. So again I suggest you to read it thoroughly look into the construction of the valve so that if you ask to write that you have to you can write these words and as well as you can show this figure. Now next circuits using flow control valve. So far I have used the pressure control valve so now we will come to flow control valve. Flow control valves are used in three basic ways in circuit designs one is that meter in control if understand from the words that meter in control that means while we are allowing the flow inside the system it will be metered then meter out control and then bleed of control these have specific and specific applications. Now let us consider the meter in control in that case what we find what is this valve this valve is 4 by 2 valve 4 by 2 valve it is just operating this double heating cylinders but we have put a flow control valve in line. Now the flow of the fluid can be controlled as it enters the cylinder or motor making it a meter in applications. For example operation of a grinding table or a welding table that means when we are grinding we need to control the speed while the grinding operation is being done whereas for the of the other hand on the other hand it can move faster in that case although there is the control I mean it is a this control in both directions but at that time there will be low pressures so and also as well as the area is less in that case it will return very fast so while it is grinding or welding that will operate at slow speed and with a controlled flow. Now this is a picture as you can see this the high pressure while is going and then it is being controlled always you should remember that when this is control means this side pressure becomes equal to the pressure of this relief valve set pressure say if it is a 10 mega Pascal this side 10 mega Pascal whereas this side it will be less pressure will be less. Now meter out control as you see that we have used the control flow control valve in the other side. Now meter in control that fluid leaves the cylinder with a control flow is meter out. Now it is widely used in machines tools often as a quick return mechanism because we can control this and we can vary this return time also it is commonly used on drills when the drill point is about to break through it tends to drag but metering the flow out of the cylinder prevents the drill from a fast break through of the material being drilled. This sentence it might be difficult to understand but I am explaining that this is like that while this is being operated this side pressure and this side pressure will balance this force that means this is not for the rotation of the drill rather the feeding of the drill. Now this is controlling the force but still it is moving in the forward directions not applying much force only it is applying the required force. Suppose there is it requires more force then this will be controlled in such a way that there will be pressure difference and force will drive the drill through pass through that. So usually this is again we should have better knowledge of cutting material removing process by drill in that case what happens when it gets stuck then there is a back force on the drill. So this can be controlled better way by meter out. Now this is again a meter out circuit you can see this how this is a pressure this side there is a low pressure this side because of this flow pressure will be but still pressure will be generated. If we do not use this one no pressure will be there but if we use this flow control there will be pressure as well as the motion will also be controlled. Now here I have shown you can see this figure I will give you the note from there you will have a better understanding but if you look here that it is 1000 psi this pressure level set here it is a 10 gallon 37.85 liter per minute flow is there and here pressure is 1000 psi setting pressure. So as this is a flow control valve it will normally go to the set pressure and there will be some flow from this side because this is being controlled position is being controlled. So some flow has to go this side and it is at full pressure. Now here the 2 inch pistons therefore force is 2000 pound. Now this side in normal course it can go up to 2000. That means here pressure if you look into this this will be very high pressure this side because there is a only 1 inch piston this rod area will be subtracted from the pistons. So what will happen in normal course when the drill is moving we do not we if you have operated a drill if the material is good you will find and drill is properly sharpened you may not apply much forces but whenever a due to some reason or you have given a more feed by hand you will feel that it needs more force once it is there then there will be force balance and this motion will be restricted it will not be moved further as well as this pressure difference will be there. So automatically again it will try to give more force but it will not allow much movement. So it is the meter out is used in this way. Now we will come to a bleed of control in bleed of control what we find that this is externally we have used a flow control valve. Now if we operate this one then flow will pass through this valve and this can be used for both directions while that means this is a combination of meter in or meter out. What we can do in that instead of allowing control flow we are controlling the drain flow here. Now diverting the flow of fluid to the tank is known as bleed of functions used in planar table or broaching. Broaching machines and planing table you would have seen in case of planing machine or broaching machines what moves in case of broaching machine or of course the broach moves in case of planar table the table moves not the job and if we in brief if we study say this is a bleed of circuit is shown here. If we in summary we can say the meter in and meter out circuits are not very efficient although accurate. These are not efficient not energy efficient I must say but these are accurate operations both meter in and meter out. On the other hand bleed of circuit is efficient those are efficient but not very accurate. We cannot have accurate control over there. So we must think of specific applications the meter in circuit can control over running only this meter in circuit that can over running say in case of drill what we need and can oppose loads as I explain little bit and in other 2 cases that means meter in and bleed of they cannot handle opposing load I mean if the load is there then they cannot make much control over that. Only they can control the flow the choice of location of flow control valve is important. We have to put this valve in proper positions to make it meter out make it meter in or make it bleed of. So may be the same flow control valve you are using and the same circuit same cylinder but using this flow control valve at 3 different positions you can make meter in meter out and bleed of and you can handle the load in different ways depending on the purpose. If you look into the planar machines there is purpose is different if you look into saving machines where the tool head is moving there is it is different and load is also will be different in case of drilling as you know that if you allow the feed is increases the more load will be experienced and particularly at the time of break through means when the drill is being finished suppose you are making a through hole. You may not get problem when while it is a mid positions but when it is just finishing the hole that time you will find that it is require extra load and thrust. So, and it is going for over running and at that time meter out flow will be the best. So, thank you here we end today's lecture.