Inline flow control valve

[Tmod]

I have a Kioti CK3510 and when I roll the bucket down as in dumping or back dragging it will create a air pocket in the pressure side as the bucket falls faster then the fluid can fill the pressure side.

Are there any dis-advantages of adding a flow control valve inline with the bucket dump line so it restricts the return but still allows full flow on fill when you curl the bucket up?

The valve I have is a Parker F600S which is full flow in one direction and the valve flow in full flow direction flows more then the line will accept so it will not be a restriction on the fill. On return or bucket dump there is an adjustable needle that will restrict how fast the bucket dumps so it will equalize pressures in the cylinder and prevent a floppy bucket. I have already checked the return line pressure with the check valve in place to see if there was any line pressure intensification.

So just checking here with any hydraulic experts to see if there may be something I am overlooking that may cause issues down the road.

Thanks!!

 

[People123]

The F series of hydraulic flow control valves permits free flow in one direction and metered flow in the reverse direction. This flow control valve is used in air and oil applications.

 

[BukitCase]

sounds to me like you may have an AIR leak on the "big end" of the cylinder(s), otherwise the whole thing should only operate as fast as the entire systems's flow capability... Steve

 

[Tmod]

sounds to me like you may have an AIR leak on the "big end" of the cylinder(s), otherwise the whole thing should only operate as fast as the entire systems's flow capability... Steve

According to Kioti this phenomenon is considered normal operation and all the tractors do it according to them anyway.

 

[Tmod]

The F series of hydraulic flow control valves permits free flow in one direction and metered flow in the reverse direction. This flow control valve is used in air and oil applications.

Yes and that is why I had purchased it as it controls the return flow yet allows full flow on the fill. My question is more inline with is there any reason other then intensification of the return pressure that installing this valve would cause issues?

 

[ericm979]

I put a one way needle valve on my Branson to reduce bucket flop. It's not totally effective but it does help some. My loader had 3/8" JIC fittings where the flexible and hard lines meet on the loader arm, so it was easy to do. I can reach the valve from the operators station if I stand up and raise the loader some. If you cranked it down to completely shut off flow and then tried to dump the bucket, you'd trip the relief valve before damaging anything. So it's a safe mod.

Cranking it down far enough to cure flop makes the bucket dump slow. I set it for a compromise, sometimes adjusting it a little depending on what I'm doing and if flop or slowness is bothering me more.

This is the valve I used: 1/4 NPT 5 GPM Prince WFC-4 In-Line Flow Control | Flow Control Valves | Hydraulic Valves | Hydraulics | www.surpluscenter.com

 

[Tx Jim]

IIRC there's a regenerative valve that one can add to FEL hyd circuit to help correct the problem. That hyd problem is not limited to only Kioti FEL but most brands, Hyd pump doesn't have enough GPM to fill butt end of cylinder during loaded bucket dump cycle.

 

[ericm979]

My loader valve has regen. The regen may make the flop better but it's still there.

 

[Tmod]

I put a one way needle valve on my Branson to reduce bucket flop. It's not totally effective but it does help some. My loader had 3/8" JIC fittings where the flexible and hard lines meet on the loader arm, so it was easy to do. I can reach the valve from the operators station if I stand up and raise the loader some. If you cranked it down to completely shut off flow and then tried to dump the bucket, you'd trip the relief valve before damaging anything. So it's a safe mod.

Cranking it down far enough to cure flop makes the bucket dump slow. I set it for a compromise, sometimes adjusting it a little depending on what I'm doing and if flop or slowness is bothering me more.

This is the valve I used: 1/4 NPT 5 GPM Prince WFC-4�� In-Line Flow Control | Flow Control Valves | Hydraulic Valves | Hydraulics | www.surpluscenter.com

Yeah I got a Parker F600S which is pretty much the same valve just in 3/8". Seems to work well just looking for opinion or fact on if there are any negatives to installing it inline.

 

[Tmod]

IIRC there's a regenerative valve that one can add to FEL hyd circuit to help correct the problem. That hyd problem is not limited to only Kioti FEL but most brands, Hyd pump doesn't have enough GPM to fill butt end of cylinder during loaded bucket dump cycle.

Yep I had read about others with the same issue, JD and Kubota dealers offered a work around but nothing from Kioti as had to go out on my own and figure something out. As far as I can tell with the testing I have done there are not any negatives as I checked all pressures and they fall within specs.

 

[oldnslo]

Tmod
Yes the pressure intensification could be a concern especially if you have a condition like forks were the load induced pressure is high. This is rarely a major concern unless you restrict the dump speed to the point you are frequently applying system relief pressure to dump.

Only other issue is your dump speed will vary with load induced pressure which also reduces the effectiveness of the flow control

For majority of people this is a simple cost effective solution.

To be the most effective - size the valve in free flow to barely handle the rated pump flow. This makes it easier to fine adjust the restriction amount.

 

[Tmod]

Tmod
Yes the pressure intensification could be a concern especially if you have a condition like forks were the load induced pressure is high. This is rarely a major concern unless you restrict the dump speed to the point you are frequently applying system relief pressure to dump.

Only other issue is your dump speed will vary with load induced pressure which also reduces the effectiveness of the flow control

For majority of people this is a simple cost effective solution.

To be the most effective - size the valve in free flow to barely handle the rated pump flow. This makes it easier to fine adjust the restriction amount.

Yes the valve is right there with pump flow and I have checked the pressure on the return running at idle which we know will not cause any intensification and again at 2600 rpm where the gauge dropped to zero the minute I started the dump cycle. This is all with an empty bucket as my biggest issue was when back dragging the bucket would roll. With the valve in place I no longer had that issue but as stated I wanted to ask to see if I missed anything on why it would not work correctly or if it would cause any issues.

To me the addition of the valve solved any concerns I was having and yes you are correct it was under $60.00 for both valve and nipple so it was very cost effective.