With an open center hydraulic system on a front end loader. Say i have a 2 spool hydraulic valve(lift & tilt) and want to add a 3rd function(grapple or hammer). Is it as simple as it seems to be to connect them together in series? Taking into consideration similar flow ratings of the valves and such. Specifically, I am wondering on the return portion of the 1st 2 section valve. Normally it only sees a low pressure, but with another valve installed "downstream" between it and the tank/cooler, it will see full system pressure depending on the usage of the 3rd valve. I tend to think it would not cause any issues. Thanks
See if your valve has “power beyond” or carry over option, usual it is sleeve that you screw in to return port or plug next to return port. You can connect to return port also, but risking damaging seals with pressure they not designed to withstand.
Also your using function of valve downstream at the same time with using one upstream is seriously hindered, and in case of using single action cylinder upstream is impossible!
Correct, given similar high gpm ratings. But, I wonder if I had a 12gpm main valve, and a 12 gpm 3rd section valve with a 25gpm pump. I suppose a flow meter on the return would be needed for sure, but it seems that situation may allow both sections to operate at full flow rate. However, if I had a 25gpm main valve and the same 25gpm pump, nothing would be left for the 2nd valve to operate with when the main valve was in use. Yes, I see some valves list the power beyond option. how does that differ from the ones without the sleeve?
A little research is in order. https://www.hydraulicspneumatics.com/blog/how-power-beyond-works-video And... I initially thought the power beyond sleeve might just convert the 1st valve to closed center, and leave the 2nd as open, but maybe that is not completely true.
It’s just difference in design. Main thing to separate your drain passeges from pressurized return gallery.
If you have 25gpm fixed displacement pump, you cannot use control valves with less GPMs rating in series, because you will create restriction. For that you will have to use either priority valve or flow divider and create parallel circuits.
By blocking power beyond sleeve you blocking return passage to tank, hence “closed center” it will not work with fixed displacement pump.
You wanna have a good head scratcher?! Look up HAWE PSV, PSL, or Sauer Danfoss PVG!
You seem to have problem with understanding that “ open center” refers to open to tank in neutral position only. If you move any of the spools you effectively partially or fully blocking the return, or PB port depending on configuration.
What brand of wheel loader are you talking about? What kind of implement are you thinking of adding? Are you talking about adding a mono block valve down stream of the regular loader valve. Usually loader valves are stack valves where you can just buy the third valve, unbolt the end plate and install the new valve section. As far as adding another valve down stream it won't make any difference as long as it is the same type of valve as those preceding it and has the same gallonage rating. Wheel loaders typically don't have much provision for running two implements at a time anyway.
If it's the same loader as the one you repaired the lift arm on, it's more of a compact wheel loader. First thing to do is see what valve it currently has on it. Some machines actually come with an (unused) 3rd valve that could be hooked up for optional accessories. If it's a mono block valve you'd need a power beyond adaptor and you could just add another valve. If it's a sectional valve, then maybe an extra section could be added. Don't try to over think it. Show and/or us or tell us what you have and someone will be able to help as this is basic compared to a system like on a modern excavator.
I think it’s FEL on the tractor, maybe even home made one, Ive seen those a lot. Usually controlled by a cheap Prince valve. But you never know.
Sorry if wasn't clear. But i understand at least that much. Perhaps my last quote is the source of the confusion? Here is where I got it. https://crossmfg.com/parts/valves/ba-bc-series-valves/power-beyond-option Brand of loader doesn't really matter, as I am looking at new "generic" valves for budgetary reasons. My oem valve is long gone. I am, currently operating the loader with a valve body from a Yale foklift, but it isn't working very well. Implement wise, just a small cylinder for a grapple initially, but potentially something with a hydraulic motor like a post driver, maybe even a hydraulic breaker or trencher even. I do realize those are very different applications and may not work(trencher). But I am keeping in mind to target larger GPM rated valves to keep my options open.
It wasn’t clear if you do understand open center, that’s why I said it, sorry if I offended you! Surplus center, Baylee’s, Northern tools - check them out. But the biggest flow in the in series circuit will be your smallest GPM rated component.
Maybe stack valve is an option?
Another thing to pay attention to if you want to do combined operations is load check! Without it the cylinder that require more pressure will be dropping when you operate cylinder which requires less pressure, as a fluid will go through the pass of less resistance. So if you still looking for DCV I would suggest stack valve with load check, if combined operation is important to you.
No offence. I was editing as you where replying, I think. As you guys mention, a stack valve may be my best bet as I can build my own so to speak. And yes, it is the same loader.
Not saying i need it, but one advantage to seperate valves would be the ability to have different relief valve pressures.
You will need to define just what you are wanting to do with your machine as you stated some very different uses for the extra valve. In one sentence you talk about a grapple and then you talk about operating a motor. These are very different purposes with very different valve operating characteristics. Once you nail down what you want to do you can take that to a supplier who can then recommend which of their products will fit your needs without causing operational and internal problems.
True. But those are common applications that are frequently handled on skid steers and tractors. I don't really see my desires as unique. I admit that currently I dont know the flow requirements of a typical rental breaker. But a smallish hyd motor should certainly be possible.
In this case just plumb in PB, return and case drain. Install gate valves. If you’ll be using implements with piston motors case drain is a must, gerotors and vane - highly recommended! On many applications you need to have “motor spool” or tandem center to not to ruin the motor or something else.the best scenario is to buy four sections valve with PB option. You can use additional sections as remotes and PB with motors with external controls.
Driving a motor usually requires a motor spool in the valve. Driving a cylinder requires it to hold position when the valve is in neutral. A breaker usually requires and drain directly to tank. The answers to these questions will be provided by a supplier. You can get some general knowledge here maybe as a check against what you are told by a supplier but since we don't have any idea of what you are working with or your future intensions, most of the information will likely just confuse you and all of us.
Yea, You might be right about the confusion thing but... Perhaps the simplest example of something similar... On most compact excavator 3rd valves. There are only 2 lines. No quick return. The same valve would operate most commonly a thumb, breaker or an auger. Those are 3 fairly different functions to accomplish with the same valve. Only difference is most of them are electric over hydraulic these days. Most "regular flow" skid steers do have the 3rd line for quick drain back. Other than that, they are very similar. As far as oil requirements go... pavement planers and trenchers require the most flow, the breakers and augers need 20 gpm or less. Thumbs and grapples, hardly any oil at all in relation.
Excavators with an auxiliary valve need a three way valve installed to run a breaker or an auger to shift the return flow to the reservoir or the cooler circuit. Regular flow skid steers have a case drain line to prevent oil pressure from blowing out a shaft seal. You need to do some home work and a supplier can fill you in plus provide free catalogs that contain more information than you are likely to use.
Nearly all valves return to the tank on the line not getting the pressure. Not sure why a 3 way valve would be required there. I might have hit a mini jackpot. At my local rental place and talking to my buddies about my loader and attachments. They remembered a valve they removed from a machine when it was fairly new. They think it was a Gehl 4640 skid steer which is a 19 gpm machine. So much closer to my loader than the fork lift valve i am using now. Bonus is they gave me a hard copy parts manual with it. And access to online service manual. There's a strong chance i can make it work. However it will be without float. But I can't beat the price. . No $. I just fix golf carts for them when they can't figure them out, or get backed up. The valve is definitely more complex. One function has seperate relief for each direction, while the center section has only one relief. 3rd section has none, other than the main relief. So the piggy back option might be on hold.
Why do your inquiries always seem to make things 1000 times more complicated than they need to be. You seem to be ashamed of your loader as it's a big mystery what brand it is and then when people try to help you, you go way off in a different direction asking a bunch of irrelevant questions. Knowing the make and model someone might be able to tell you what valve it uses and the pressure and flow. I'm no hydraulics expert but I think you're trying turn your loader into the same type of set up like a standard flow skid steer. Had you mentioned from the outset that the original valve was missing and you wanted an aux. valve would have saved a whole lot time. Just get a 3 spool open center valve with float on one section and maybe detent on the aux. spool. I'd guess your running 2200-2500 PSI max. I'd be surprised if the valve from the skid steer doesn't have float for the boom circuit. 90% of skid steer have float. If it doesn't it can probably be added if it's commercially available valve. Standard flow skid steer aux. valves don't have a case drain line. High flow usually do though. Trying to compare to an excavator just confuses the issue more.
No shame here - Waldon 7000. Heck, I am saving this heap from the scrap pile and making it serviceable and useful. The only thing OEM left on the hydraulics is the pump and cooler. The OEM joystic controlled valve was replaced long ago with a 3 section generic monoblock valve that had already outlived it's lifespan when I got the loader. That's why it wasn't mentioned. Simple as that. The fork lift valve in it now is not working out. So I wanted to keep the discussion as generic as possible. I did mention in my 2nd post the 25 gpm as a ballpark for the discussion of the system. And you are correct about my desire to get it close to a skid steer in operation. Most skid steers have a similarly rated pump. Why would that be a bad thing for maximizing the utility of this loader? My situation is somewhat like this example. Say I have 67 nova that needs an engine. OEM was a little inline 6, but I am exploring other/higher horsepower V8 options. But you seem to be brow beating me for not going back to the OEM V6. I am just trying to explore options with others that have relevant experience. Also, doing things "off the book" can help hone troubleshooting skills. Lots of people can troubleshoot using a book line by line. But throw away the book and let's have some fun. If I wanted to dump lots of $$$ into it, it would also be more simple perhaps to return it to OEM. But that would be $2k or more to replace what has already been changed. I am attempting to use the resources at hand, and/or the cheapest ones that would accomplish my needs. Sure, I know I could get a 3 section valve like you describe, but I have more time than $$$ presently. Looking at my options when I created this thread, it looked like I could get a 2 section and 1 section monoblock valves for around 1/2 of what a complete 3 section that fit my description. That is why I wanted to explore the possibility of the two seperate valves. Purely to potentially save $$ I only mention an excavator as an illustration of the universality of my desire for a 3rd valve section, after it was implied that I was trying to do something strange and way out in left field. Furthermore, some of the responses provided didn't make sense with existing equipment I am familiar with or have access to. If we limit our excavator discussion to compact models, I don't think the valves are not all that different from a skid steer. That is the reason for my further questions. I suppose the line between back and forth discussion and being argumentative is a fine one. I don't mean to be the latter. You are probably correct about the float. But after looking through the parts and service manuals, I think on this model, the float is accomplished with a separate solenoid valve that also keeps the bucket level when lifting, I think. Not part of the valve I have.
https://waldonequipment.com/wp-content/uploads/2017/09/7000.pdf That's why make and model matters. I found this in 3 seconds. Give as much information as possible the first time and you'll have a lot better success. Don't waste people's time giving generic info and other stuff that is not relevant in the least. Otherwise when you really need help people will ignore you because they don't want to go through 4 pages of back and forth to finally get the info they need to help you. If that valve isn't rated for 25 GPM it's going to cause problems that could cost you a lot more in the long run.
Yea, that's my loader. I have had that exact pdf printed out since the week that i got the loader home. Now that I look at it again, it does mention "power beyond" as an option to the original hydraulics. But i am not sure what answers it provides to my questions. But maybe i am overlooking something... Look at all the attachments it shows possible. See, I am not crazy.
Crazy isn't the word. You had that PDF since day 1 and deliberately neglected to make any mention of it??? What your overlooking is people trying to help you don't like their valuable time wasted unnecessarily.
Yeah, well, you know, that's just, like, your opinion, man. ... Nothing deliberate about it. It's a sales brochure, not a technical document. I already said oem is out. Why can't YOU understand that? I am attempting to discuss series connection of "generic", open center mono block valves.
Welder Dave, I think you need to go easier on this guy. He started this thread not talking about specific machine and specific problem. Guy is a tinkerer, and wants to learn something to see if he can improve his machine I understood this right away. If someone doesn’t want to waste time he can just go to other threads.
Steve, you also have a solenoid without coil on the left coil on The left section.
Yeah, that missing coil could be the main problem with this valve. The reason is valve was removed originally was due to that faulty coil. A replacent was ordered under warranty but they were shipped the complete valve rather than just the coil. They asked about returning the whole valve but we're told just to keep it. It has been sitting on their shelf for a few years. That solenoid is on the auxiliary circuit and serves to lock out that function when the handlebar is up. I think I should be able to find a coil to put on the stem. Definitely not planning on spending the $600 it would take to replace just that solenoid. Surprisingly the parts manual does not break down the valve assembly very much.
Try just putting a plug in it, select ORB plug same size as the solenoid valve. But it all depends on what kind of solenoid is NC or NO
The manual says that the spool lock activates when the operator raises the restraint bar or leaves his seat, locking the auxiliary hydraulics. Based on that description it may not need power for normal operation. We shall see. Back to the original question. I wonder if multiple mono block valves in series would work if the 1st one does not have the power beyond spool option. Say 2 log splitter valves
I am actually try to help Steve. He's like the boy who cried wolf too many times and then when he really needs help (and he will) nobody responds because he doesn't listen. He does have a specific machine with a specific problem. This isn't the first topic he's started where he's been really vague, withholds information, questions all the responses, changes the subject and just wastes everyone's time. You notice everyone else is long gone. Here's a response on his" What engine is this thread". 5 PAGES of d!ckin around when it all could have been sorted out on pg.2 post #27.. Like I don't have anything better to do.?? Lol..
Lighten up, Francis.
Steve, you are your own worst enemy. I'm just telling it like it is.
Well, you know me better than anybody. Thanks for the encouragement.
Pretty sad actually that anyone else would come to same conclusion after only 3 topics (that you started). You need to spend more time comprehending what people are saying instead of being so bull headed. Your generator thread is a classic example of this and who knew it was just a precursor of what was to come. Read more and type less and you'll get a lot more support. Not everybody can be a rocket scientist and not everybody can be a mechanic. When you can't see the forest for the trees maybe you need to step back and take a better look. Knowing your limits can be humbling. I've reached mine so good luck.
And yet, he continues. Amazing.
Besides berating me, what have you accomplished today? Me, installed some glass and single handedly drug a backrest assembly out of a junk yard, loaded it, brought it home and stripped and prepped it in preperations of welding it into my quick attach back plate. I suppose you would have me go buy a new loader and attachment and quit wasting everyone's time. How about you give me a cookie? That's why I did it.
For now, i am no longer going to pursue the daisy chained valves, but I am glad that I asked and learned a little about doing so. It will probably become relevant at some point for me. I am committed to the skid steer valve I was given. Since it is far from the same topic as this thread, I have posted information about it here - for those interested. HeavyEquipmentForums