Hydraulic top link issues

[olPete]

I'm doing my shopping for restrictor orifices and i saw the mini ball valve and was wondering if this could achieve the same purpose as the flow control valve? The restrictors are only $5 each and the flow controls are $50 each and the mini ball valves are $10 each.

I'd place a vote for the ball valves. Then you can completely turn it off, if need be, and lock it solid. And then it's easy to unplug, even if you have pressure in the line.
I sometimes restrict flow with mine as it's a lot faster to reach out the back window and bump it nearly shut, than to wind the knob in on my flow adjusters. Just my opinion, which is worth what I'm charging for it if you don't need to adjust it then you can always take the handle off once set to your liking.

 

[Kodiak45]

I ordered the restrictor ports and the ball valves and we'll give it a shot. I'll try the ball valves first and see how that goes. The ball valves should be within reach from the seat. I don't care to fool with hydraulics as I always seem to get oil all over me somehow and eternally stain my pants like I've pissed myself, but I'm becoming obsessed lately and I have visions of adding some extra valves in the future.

 

[olPete]

Good work. I hope the restrictors will fix your top link issues, I'd put a ball valve in the return/rod end hose at least, that's what I'm doing tonight to my new one. Handy if you need your rear remotes for something else, there was another thread with a guy using a 3pt woodsplitter having trouble connecting/disconnecting his toplink to run the splitter under pressure, for example. You never know what the future holds for you and your tractor. Just be careful if you use Teflon thread tape, that you don't get it in the hydraulic system as it can be a bit of a showstopper. Jams valves etc, if you have little bits get in there.

 

[npalen]

I'm doing my shopping for restrictor orifices and i saw the mini ball valve and was wondering if this could achieve the same purpose as the flow control valve? The restrictors are only $5 each and the flow controls are $50 each and the mini ball valves are $10 each.

Would you mind sharing your source for the mini ball valves at $10 each? Is it rated for hydraulic pressures? Thanks.

 

[Rich B1]

I'm doing my shopping for restrictor orifices and i saw the mini ball valve and was wondering if this could achieve the same purpose as the flow control valve? The restrictors are only $5 each and the flow controls are $50 each and the mini ball valves are $10 each.

The Parker type restrictions are more expensive, but they will give you precise, repeatable control, the ball valves, not so much.

The flow restrictions are also free flow in one direction, restricted opposite. The ball valves are going to be restricted in both directions which is going to be a bit difficult to get good metering.

Yes the flow restrictions are more money, but they do the job.

I would install so the flow out of the cylinder is restricted. That is called exhaust metering. The backpressure created on the cylinder outlet slows cylinder movement. Other people prefer to restrict on inlet. Just a personal preference

 

[olPete]

I would install so the flow out of the cylinder is restricted. That is called exhaust metering. The backpressure created on the cylinder outlet slows cylinder movement. Other people prefer to restrict on inlet. Just a personal preference

Excellent advice!
The OP mentioned that he has two restrictors coming.
Given the problem that's given rise to this thread (possibly getting air in the cylinder due to fast flow?), would you suggest he puts one in each port or just the exhaust side? IF- it somehow is still getting air in there, would the restrictors hinder the bleeding of the cylinder?
As far as my assumption goes, one restrictor or two won't alter the flow rate

 

[Kodiak45]

Would you mind sharing your source for the mini ball valves at $10 each? Is it rated for hydraulic pressures? Thanks.

Product Index | Trausch Dynamics[catalog]=1&data[parent]=200102

 

[Kodiak45]

The Parker type restrictions are more expensive, but they will give you precise, repeatable control, the ball valves, not so much.

The flow restrictions are also free flow in one direction, restricted opposite. The ball valves are going to be restricted in both directions which is going to be a bit difficult to get good metering.

Yes the flow restrictions are more money, but they do the job.

I would install so the flow out of the cylinder is restricted. That is called exhaust metering. The backpressure created on the cylinder outlet slows cylinder movement. Other people prefer to restrict on inlet. Just a personal preference

I look forward to hopefully getting this resolved this weekend. This has been a big hydraulic learning experience. Thank you all for sharing your knowledge and advice.

 

[olPete]

Product Index | Trausch Dynamics[catalog]=1&data[parent]=200102

^^^^ some nice kit in there! I really hope it solves your problem.

 

[teg]

Product Index | Trausch Dynamics[catalog]=1&data[parent]=200102

Item was not found... Cheapest one I could find that was over 2500 psi was $25...

ITEM # 7005122 BALL VALVE, HIGH PRESSURE

 

[Kodiak45]

Item was not found... Cheapest one I could find that was over 2500 psi was $25...

ITEM # 7005122 BALL VALVE, HIGH PRESSURE

Yes, the mini ball valves I was referring to are only 400psi, which are only $10. My mistake and thanks for catching it.

 

[teg]

...My mistake and thanks for catching it.

We're trying to help... don't worry about it. Personally, I like needle valves since they are so adjustable from zero to 8 gpm. It's very slow to cut it off.... dial, dial, dial it down. What I like is once you find the sweet spot, you can see where that mark is so you can dial back to it.

3/8 NPT 8 GPM PRINCE WFC-6 IN-LINE FLOW CONTROL

 

[Kodiak45]

That's the ticket at roughly $30 each. Cancelling the original and going to get this.

 

[Rich B1]

Excellent advice!
The OP mentioned that he has two restrictors coming.
Given the problem that's given rise to this thread (possibly getting air in the cylinder due to fast flow?), would you suggest he puts one in each port or just the exhaust side? IF- it somehow is still getting air in there, would the restrictors hinder the bleeding of the cylinder?
As far as my assumption goes, one restrictor or two won't alter the flow rate

Since gravity or working forces can act in both directions on a top link cylinder, I would do double Parker type restrictor valves. You also are dealing with rod and barrel flow differences so you can adjust flow for same speed in both directions.

If you over run a cylinder, you can introduce air from mild cavitation. That is why I prefer restricting the exhaust side. The restrictor functions as a dynamic brake in effect.

The flow rate to the cylinder won't change, but the cylinder speed can be restricted using the restrictors.

 

[Rich B1]

We're trying to help... don't worry about it. Personally, I like needle valves since they are so adjustable from zero to 8 gpm. It's very slow to cut it off.... dial, dial, dial it down. What I like is once you find the sweet spot, you can see where that mark is so you can dial back to it.

3/8 NPT 8 GPM PRINCE WFC-6 IN-LINE FLOW CONTROL

That's the ticket. Those work really well.

 

[olPete]

Very interesting, thanks Teg and Rich. One of my spools has a sticky flow rate adjuster so the toplink is usually plumbed into that bank.. I'm considering getting what you advised the OP for my mower, it has a single acting lift cylinder and my ears pricked up when you said it free flows one way. I don't like to adjust it too slow on the drop, as it's then too slow coming up. Sounds just like the answer to our problems.
Pete

 

[Luke'sScreenName]

Since gravity or working forces can act in both directions on a top link cylinder, I would do double Parker type restrictor valves. You also are dealing with rod and barrel flow differences so you can adjust flow for same speed in both directions.

If you over run a cylinder, you can introduce air from mild cavitation. That is why I prefer restricting the exhaust side. The restrictor functions as a dynamic brake in effect.

The flow rate to the cylinder won't change, but the cylinder speed can be restricted using the restrictors.

Does anyone know how much vacuum (negative pressure) is needed to cavitate hydraulic fluid?

 

[Kodiak45]

I plan on using the flow control valves when they arrive rather than the restrictor ports. So correctly me if I'm wrong, but I am going to put both of these controlling the exhaust flow on each port...right? I took the cylinder off tonight and brought it home so when I install the valves I can make sure all the air is out and hopefully my problems will be solved. The knowledge on here is amazing.

 

[olPete]

I plan on using the flow control valves when they arrive rather than the restrictor ports. So correctly me if I'm wrong, but I am going to put both of these controlling the exhaust flow on each port...right? I took the cylinder off tonight and brought it home so when I install the valves I can make sure all the air is out and hopefully my problems will be solved. The knowledge on here is amazing.

Yep that's the one! So the flow in is restricted but the flow out is not, as I understand it at least.
I'd maybe clamp it in a vise with the ports at TDC so the oil inside stays in, and you won't introduce any air that way, or have too much mess to contend with.. I'm nervous actually.. really hoping you get the results we're all after.. and it's not even my $$
( don't worry I've learned a lot on this thread myself, I'm just a farmer on the other side of the world.. I've always liked to see things as solutions yet to be discovered, rather than problems! )

 

[npalen]

I plan on using the flow control valves when they arrive rather than the restrictor ports. So correctly me if I'm wrong, but I am going to put both of these controlling the exhaust flow on each port...right? I took the cylinder off tonight and brought it home so when I install the valves I can make sure all the air is out and hopefully my problems will be solved. The knowledge on here is amazing.

I believe you should put restrictors of any type on the port where the fluid is coming out of the cylinder. This would be the port at the rod end in the case of a top link cylinder which would normally be in tension from the weight of the implement.
Putting the restriction on the base end of the cylinder only would tend to create a vacuum if the tractor pump wasn't able to keep up with the "free fall" of the cylinder when lowering.

Edit: Might be more accurate to say: With the restriction on the base port of the cylinder, the oil would flow out of the rod end of the cylinder faster that it could enter thru the base port restriction thus creating a vacuum.