Directional Control Valve Basics - Part 1

[@justlucky8254]

Thanks for these videos. I grew up in a farming and logging family so I've learned about the basics of troubleshooting and repairing hydraulics, but not the proper way. By trade, I'm a machinist. Machining jobs are getting harder to find so now I'm working as a millwright. We have a large variety of hydraulic systems in the mill and things have to be repaired as quickly as possible when they break. These videos have been a big help to me. Thanks. At the moment, I'm working on teaching myself how to read the different spool codes and other hydraulic symbols and nomenclature. Thanks again.

[@lunchboxsessions]

Great stuff! Keep on learning.

[@nomercenary5280]

Just learned more about DCV's in 5 mins than i have in the last couple classes, which only repeated the exact same power-point slides, each class... Thanks!

[@blustripes4ever844]

Thanks been watching these for a while. There help refresh my knowledge. Also I've started a new job. Showing your videos to coworkers helps them understand what I'm trying to explain to them. As they don't have a lot of knowledge of how valves woke. Thanks.

[@Tbone6string1]

Thank you. I have risen to a new level of incompetence by being more aware of what I don't know; as opposed to not knowing what I don't know.

[@MinnesotaEric]

Great video. I was just explaining this to somebody asking about feathering a joystick to control two functions at once, and I explained, that they need piloted valves for that. Their system is a utility tractor, so an open-center piloted joystick valve would be needed.

[@TheRepairSpecialist]

Thank you for your time making these videos. Very useful and educational.

[@i.i]

كـــــــــــــــلــــــــــــــــــــــش حــــــــــــــــــــلـــــــــــــــــــــــو تسلم ايدكم شرح روعة

[@kuberansubramaniam1339]

நான் தேடியதை எளிமையாக புரியவைத்தமைக்கு மிக்க நன்றி.

[@masiewpao]

Rather than having the valve system, are there hydraulic gear pumps that can change the direction of rotation? As in, to change the direction of fluid flow, so in the video the fluid flows down into the pump as opposed to up and out of it?

[@lunchboxsessions]

The actuator could in theory be connected to both ports of the pump, and the directional valve removed. The pumping direction can be changed for some models of pumps. However this not typically done with a gear pump. In such a case it is typically a variable displacement piston pump, of the closed loop (hydrostatic - over center) variety. Then keep in mind that if the actuator is a single rod cylinder (as opposed to a motor, or a double rod cyl), there are very different volumes required for extend versus retract. And there we are in the wider world of hydraulic system design with its many possibilities, limitations and design challenges. Thanks for your great question Masiewpao. I hope this answer was helpful.

[@masiewpao]

Thank you very much for the reply mate, it certainly was!

[@andrewhardcastle7982]

Ohhh so simple to understand , thank you !

[@butcher4095]

I don't get it. When you push the lever to the left, why does the intake pilot check valve open so that liquid can flow into the cylinder. I don't get how it is commanded open, since the line which operates it, is not pressurised. From my point of view, only the exhaust pilot check valve would open, and since there is low pressure on the exhaust line, the intake pilot valve wouldn't open, and the pressure would only be modulated by the relief valve. Where am I wrong?

[@ericsaxon1985]

These check valves are directional. Due to the lack of compressibility of hydraulic oil you can effectively prevent movement in the cylinder by preventing oil from escaping until you intend for it to. The check valves prevent flow OUT of the cylinder until the opposite flow IN is engaged (signaling that the out flow needs to open) it does it on a simple system like this by way of pilots. You can see in the animation that once the check valves entered the picture so did the tiny pilot lines connecting the two ports. When one port pressurize it sends a tiny bit of pilot to disengage the opposite port for relief. Hope this helps.

[@slipsonic809]

Im starting a hydraulic-driven 3D printed RC vehicle with 2 hydraulic rams and hydraulic steering. basically a loader. I knew generally how hydraulics worked but not specifics of components. Should be pretty easy to design now. Thanks!

[@user-ch5zj2uf4v]

Would love to see the results and a video of the process if you have it 😁

[@MR-nl8xr]

Wtf.

[@sarahjoy143]

Excuse me Sir, may I ask what the colors indicated? I can't see clearly your legend. thanks!

[@lunchboxsessions]

Violet = Partial Vacuum Pressure, Blue = Drain Pressure, Yellow = Low Pressure, Orange = Medium Pressure, Red = High Pressure. Thanks for your question.

[@sarahjoy143]

+LunchBox Sessions thank you answering sir

[@larrypalanuk3460]

It would be very interesting to know applications for each of these scenarios. And why you would choose one over the other.Wood splitter? Up lift only? I have the 3rd one on my excavator thumb and I would like to know why that one was chosen.

[@lunchboxsessions]

Great suggestion Larry, thank you. The third one on your excavator thumb attachment is a float center valve (A, B, and T connected at center)? Yes this is quite comment. Starting at about 4:15 in the video, we install a pair of pilot operated check valves. Nothing beats these check valves for positive locking of a cylinder. But,...in order to make sure that they lock, when you let go of the valve lever, the pilot lines to the checks (those angled, dashed lines in the schematic, and the narrow cross-over lines in the cutaway) have to be depressurized for sure, otherwise the pilot piston may not come to rest, which might leave the ball in the check valve, slightly off the seat (leaking internally - thumb drifting). I hope that helps a little. Thanks for writing. - Carl

[@Ajaxaxxess]

Have a 3 position valve stuck. This clears up the internal workings prior tome ripping it apart. Thanks for the video.

[@newdays9040]

thank you, your explanation is very good, can you tell us , what is the name of this software? thanks

[@athulmuttissery7530]

Could you post material on hydraulic motor control.

[@cantoexato9361]

Very good class, thanks.

[@DhrubaBubu]

great tutorials...

[@danowens5397]

very nice. only thing you should add is unloaded hyd pressure returning to tank. the way the schematic is now, its just blowing the gear pump pressure thru the relief valve which will cause the power plant to bog, excessive heat, and probably burn up the relief valve.

[@danowens5397]

as seen in part 2

[@danowens5397]

woops

[@lunchboxsessions]

You've got a good eye for hydraulics systems Dan. We build all of these animations and their various modes to teach one or two simple concepts at a time. Every time I teach a hydraulics class with this set of working animations, we discuss that very point that you have brought up. - Carl

[@samuelmoore4765]

Dan Owens and

[@wafi-11]

Great What is name of software?

[@addy3896]

Is the working of DCVs same for hydraulics and pneumatics? Or are they totally different ? Also, are other control valves (such as Relief valves, Flow control valves, etc) same for hydraulic and Pneumatic systems?

[@MuhammadYusuf-fo6lc]

great work.. thank you..but what's is the software or the simulator do use in the video please? i wanna try it my self

[@lunchboxsessions]

Hi Muhammad. Our team of programmers and artists make all the software and graphics from scratch. You can read more about our Live Schematics here: www.cdiginc.com/live-schematic

[@guangdewang1032]

Thank you for making such good quality video, it's very helpful.

[@jorgeduarte2438]

Hello there! Could you please tell me what kind of “Directional control valve” do I need to do an excavator's arm? Thank you

[@sagayaraja7789]

Excellent presentation and explained the concept in very easy manner with help of this animation. great!

[@martinbernal5693]

I just found your videos today. I drive a flat bed tow truck. The controls are on both sides of the truck. When I push up on the lever the lever on the other side goes up. Where can I find a videos about systems like this?

[@johnynassif]

Hello. Thanks for sharing. I have a log splitter and the pressure is not ramping up unless the piston is fully opened. If there is a wood mid way the pressure is not ramping up. Would it be the valve?

[@99MikeHamilton]

I think I am in the same boat, I have found that for a log splitter you need a "2 stage Pump" the High Pressure 2nd stage is controlled within the 2 stage pump itself....

[@filmaker256]

how many different machines can this operate?

[@pw1045]

Wow thank you for the free information, much appreciated!

[@joshualeonard1900]

Hi, This is a great video, what software do you use to make the diagrams?

[@JoseMariSoto]

I'm looking for this one as well

[@MrChaiyapongwongluan]

In 1st case 4/2 valve, why pressure is vacuum pressure when retract sir?

[@michaelgeorge3092]

the way im looking at this, is when the pressure is released (blue) the weight of the block of steel is so heavy that it pretty much unloads the pump as the piston comes down. it creates a vacuum or sucks the fluid down faster than the pump can push it down. thus a vacuum of sorts. if the weight came down slowly it might allow the pump pressure to build up instead. :)

[@keithshreve6736]

Thank you for this great video !

[@tuanohuu3996]

Thank so much! Which software do you use to make valve animation?

[@lunchboxsessions]

See here: www.lunchboxsessions.com/help/what-software-do-you-use-to-make-the-simulations

[@jimmycantago1250]

Sir i am new here and i am encouraged by your channel. Learn a lot's, Thank you

[@quocphanvan5243]

can I ask you a question. Which software you used to simulate for this video?

[@lunchboxsessions]

We've got some information about how we make these simulations here on our website: www.lunchboxsessions.com/help/what-software-do-you-use-to-make-the-simulations

[@cursor3186]

Hola tengan un gran saludo, me gustaría saber si tienen los videos en español, gracias feliz día¡

[@ricardobernalc6170]

Great video, really well explained sir.

[@kaushikiyer9445]

why is 4/2 and 4/3 valves used only for hydraulics and not for pneumatics?

[@ishwerpoonia]

How can I design these type ok circuit in animated video..which software u r using ...

[@lunchboxsessions]

Hi Ishwer. We do not use any software program. Our team of developers and artists build these working animations entirely from scratch. I hope that answers your question.

[@ishwerpoonia]

Oohh....I was thinking it's an software. ..anyway thanks for ur valuable reply..

[@parthvaria4361]

Plz explain working of cartridge in counter balance valve with float centre operated with pilot line pressure

[@huylehuy4166]

thank you for a funny video can you tell me what is the simulation software?

[@lunchboxsessions]

See here: www.lunchboxsessions.com/help/what-software-do-you-use-to-make-the-simulations

[@adelsobenitez214]

La mejor explication de videos que he visto

[@arslanahmad7000]

For last two hours i was looking for it Thank you

[@registromalplena2514]

During the mid-1970s it was popular to make your own wood splitter my grandfather a long time farmer who had lots of experience with hydraulics built one of these from plans he bought out of some magazine. Plans for the wood splitter were simple problem was that when the Piston reach the end of stroke, the control everwood snapback and it broke his wrist he went into the doctor to find out that this was now a common injury in his area. It seems a bunch of farmers and people in that area had bought or built similar wood splitters and had similar injuries I'm wondering what caused the control lever to build up so much pressure can snapback and break somebody's wrist? My grandfather has passed away many many years ago as I am now grandfather so I don't know and I'm not able to ask him whether this had a pressure release valve and what kind of control ever he used.

[@michaelzajac5284]

How to Pascal's Principle and Hydraulics formula?

[@lunchboxsessions]

Thanks for those suggestions Michael. Those might indeed be good topics for future videos.

[@michaelzajac5284]

I must be learned my lesson, next levels. Thank you for message.

[@michaelzajac5284]

When you're ready How to Pascal's Principle and Hydraulics formula, show me.

[@alesko89]

Can i ask you what is the software you have made this simulation ? thanks for replied :D

[@yodayodi]

What's with the background music?

[@lunchboxsessions]

We think the videos are more enjoyable with a subtle background sound. When the only audio in a video is the recorded voice, it feels a bit empty. On the other hand, a lot of the royalty free rock & roll and electronic music used in educational videos is just awful. So, we decided to go a different direction. If you'd like, you can think of it as "the hum of simulated machinery". Thanks for your question!

[@carbon273]

Is there a book where I can learn this stuff?

[@fastestmanon3legs454]

Modern Diesel Technology:Heavy Equipment Systems.......I'm currently taking advanced hydraulics (this book is what we use for both basic & advanced courses-it has all this info^^) but the video is also very helpful for visuals

[@lunchboxsessions]

Our website is a bit like a textbook, to help you learn about hydraulics, electrical, and machinery: lunchboxsessions.com

[@pcgamer_buds8814]

The best hydraulics book is the one from Rexroth Hydraulics. I have all volumes up to 6 or 7 if I remember correctly. There is one American Rexroth book that is really enough to read/know most complex and almost complete systems. I’ve had vickers and Parker but they are not as detailed and complex as Rexroth v

[@qwezxc23456]

Amazing teaching, thank you

[@masroorahemad99]

thank you for this great video

[@ajaykumarsharma7942]

i need this part so how can i find please

[@brandonsimmons552]

Great Video. Really helps to get the image in your mind on how these valves work. I had one question. When the lever is pulled to the right, it shows that there is vacuum pressure on both sides of the positive displacement pump. But I was under the understanding that a positive displacement pump always has a vacuum on one side and pressure on the other. Wouldn't the pump just supply pressure to the B port and since the A port is now connected to the drain, the pressure pushes the actuator back?

[@brandonsimmons552]

At 2:44 in the video

[@lunchboxsessions]

Keep in mind that these are very simplistic teaching animations. But if the Acme block on top of the cylinder is heavy enough, the cylinder will be in a runaway condition when the lever is pulled. A runaway, or negative load as engineers call it, moves under its own weight or under some external force, thus the cylinder is creating suction at that top A port.

[@mikehawk4517]

On most hydraulic system I know of that is controlling a piston they can always be "lowered" without the pump running. In the last example with the check valves that seems to me like that wouldn't be possible? What is commonly used in those cases?

[@MR-nl8xr]

It is possible, rewatch the video.

[@mikehawk4517]

@@MR-nl8xr Yeah, if the pump wasn't running the pressure would just be released to the tank, lowering it. Not sure what I was thinking when I wrote this comment, sorry.

[@MR-nl8xr]

@@mikehawk4517 It is a little hard to read your original comment, as I reread it. But in the last example, with the check valve configuration in place; if the directional valve is in the float position(middle), and the Piston is mid stroke. It will not lower, and the hydraulic oil will only go back to tank, if pump is on, via relief valve.

[@johnbradshaw7000]

Wile E. Coyote approves of your cylinder load.

[@marius86ar]

What software do u use for the animation?

[@lunchboxsessions]

We've got some information about how we make these simulations here on our website: www.lunchboxsessions.com/help/what-software-do-you-use-to-make-the-simulations

[@omerongor4637]

which program do you use to make these animations? thanks for your answer

[@aayogiiskandar6049]

tell me please to create your vidio bacause my project in my campus to made simulation vidio.

[@abhitrivedi6861]

Which software do you use ?

[@kooroshaieneh9681]

that was great . what is your software that use in your videos ?

[@lunchboxsessions]

See here: www.lunchboxsessions.com/help/what-software-do-you-use-to-make-the-simulations

[@saikrishna2094]

any one explain to me....if flot centre DC valve using with meter-out circuit on both working ports.... what is the condition of cylinder when DC valve in neutral position?

[@lunchboxsessions]

SAI KRISHNA the cylinder would be floating freely under the conditions you described. The meter-out is of no particular consequence unless the orifice openings are extremely small.

[@boxingfan5742]

So, the check valves always need to be oriented to stop exhaust from each side of the actuator and you need to feed (signal) the pilot check valve intake to open the check valve on the opposite side of the side you are pushing. I had to write that out because I initially didn't see your parallel actuation of the opposite side's check valve and I was wondering how the heck it knew to stay open to exhaust. (Old eyes) Wonderful video. Thank you!

[@mickcope8751]

grate video makes it much easier to understand

[@woodsplitter]

Great explanation as always!

[@ericmedgardbemezui3482]

So quickly explications

[@ianmangham4570]

Excellent, I couldn't of explained it better myself 😎👍😴

[@KrazyKajun602]

you not showing a tandam center config

[@markgray8707]

go watch part 2

[@sounderrajan131]

excellent for students

[@jayatissapeiris6781]

Excellent easy to understand. 👍

[@artemiasalina1860]

I hate it when my P port gets blocked.

[@dianat.9400]

hello, thanks a lot for great animation videos, but i want to ask you to add english subtitles because my english is not so good and i cannot understand a lot of words, and i will work using a translator. thanks a lot

[@chonle9931]

Great tutorial, the gears rotation is reverse relative to the flow 😩 !

[@Damie236]

I thought so at first too but it’s correct

[@thoroughbred1444]

@@Damie236 cuz it creates vaccum at the center right.

[@ramus157]

My tractor tantum pump 36 lpm I modify double acting sigle cylinder but two control valve use can ?

[@ramus157]

Am expect valuable comments on any body

[@solovssquadsgamer5445]

great tutorial,( it is very small thing but need correction if i am right i.e. the rotation of pump is in wrong direction if i am wrong please right me)

[@lunchboxsessions]

The direction of rotation is correct. In a gear pump, the fluid travels through the pump in the spaces between the gear teeth, around the outside of the gears. Where the two gears mesh, in the middle, there are no spaces. The mesh is actually a very important area of sealing, in order to maintain positive displacement. Does that make sense?

[@solovssquadsgamer5445]

thank u sir

[@djaberkharoubi3825]

This is very great :)

[@CommentsReading077]

thank you 1like is less for u nice work

[@douggiedevil]

Great visuals an easy to follow subscribe and will be checking out your other videos

[@nguyencanh8369]

thank you for your help

[@michaelcostello6991]

Excellent. thanks

[@FirstName-nf4fx]

So good. Thanks!

[@reliancepacking2553]

great video :)

[@JKTCGMV13]

beautiful

[@asheshshrestha]

really loved it..

[@rahuldhayal436]

Very nice

[@md.toriqulislamtutul2246]

excellent

[@petermutahi1637]

this it help a lot

[@baekyeonultraprecisionnkl9574]

We are ultra precision company BAEK YEON thanks..

[@themysteriousexp]

Thank you sir..

[@a.f.mforeromecon3559]

Bueno

[@medmeed5047]

Mercie bien

[@aarongettingup]

excellent thank you :)

[@RippedZock]

Yep I got lost mid way

[@RippedZock]

Ok after going through your solenoid valve basic video I now get it

[@robaiha9204]

hi

[@lunchboxsessions]

hi

[@Santoshsamrat02]

Pampers hydraulic GS 310 part phitig

[@EmeraldLavigne]

If you've got a blocked P port, you should probably see a doctor.

[@EmeraldLavigne]

Tho I am a big fan of P to A, generally speaking.

[@marioukoc]

What exactly do you mean? Is it bad to block P port?

[@NoxUmbrae]

@@marioukoc It's a joke. The letter "P" is homophonous with the word "pee", as in urine. They took it out of context and transformed it into an innuendo.

[@veritenishimwe6296]

Very well

[@DisabledTeamYT]

I don't get any of it was I suppose to learn something? I'm new at all this and didn't learn anything

[@lunchboxsessions]

Please don't be discouraged. Some of us in our company have several decades of hydraulics experience and find that there are often new challenges and that there is always more to learn. On our eLearning site LunchBoxSessions.com you can take lessons starting with the very basics. Many other videos and books can also help. Perhaps look for a introductory hydraulics course at a nearby college. Wishing you well with your learning!

[@yogeshmani2356]

Super

[@nedalhachmi297]

Great 🖒

[@shijiazhuanghanjiutechnolo3997]

Hydraulic valve @t