Is it safe to use continuous flow if it's bypassing most of the time?

[kao]

This might be a silly question, but I don't have much experience with attachments outside a bucket and snowblower.
I recently purchased a grader attachment. It has 3 hydraulic rams to move the blade in various directions.
To operate the blade, there are 3 electric solenoids connected to a control box that plugs into the 12v Accessory plug inside the cab.
The control box has 6 buttons.
In order for the control box to function, the grader requires continuous flow.
I have a Bobcat S175 and I am familiar with how the hydraulics work - Maximum and Variable flow on the BICS, Right Trigger to start continuous flow, right thumb toggle to switch flow direction and fine tune variable flow movement.

For constantly moving equipment like the snow blower or brush cutter, it's a no brainer. Trigger the flow on and go.
But with this grader, flow is only needed when I move the blade around... which isn't all that much on flat ground, or small adjustments when grading uneven terrain. So the whole time the flow is activated, it's mostly bypassing the built-up pressure until I move the blade.

My question is - Is this going to harm the machine? The pump? Or anything else if I leave the flow engaged the whole time I'm grading?

Thanks much!

 

[laurencen]

my grader is a Bobcat make but requires the flow to be continuous, when nothing is moving the flow is free and when I move a cylinder it diverst the flow to the required cylinder once switch is released it again free flow

 

[kao]

my grader is a Bobcat make but requires the flow to be continuous, when nothing is moving the flow is free and when I move a cylinder it diverst the flow to the required cylinder once switch is released it again free flow

How is the flow free if nothing is moving?
When I engage the hydraulics, the hoses jitter as the pressure fills them and there is no place for the flow to go. It's just tripping the pressure relief valve. I mean, I guess it's technically flowing then but seems like this might be hard on the pump/valve.

 

[ward]

How is the flow free if nothing is moving?
When I engage the hydraulics, the hoses jitter as the pressure fills them and there is no place for the flow to go. It's just tripping the pressure relief valve. I mean, I guess it's technically flowing then but seems like this might be hard on the pump/valve.

the grader has an open center valve body, when you activate the function it diverts the flow to the function, if it did not do that the system would create a lot of extra heat going over relief, of which it will eventually damage the relief valve and it no longer reaching the desired pressure for the functions of before it goes over relief.

 

[ward]

This might be a silly question, but I don't have much experience with attachments outside a bucket and snowblower.
I recently purchased a grader attachment. It has 3 hydraulic rams to move the blade in various directions.
To operate the blade, there are 3 electric solenoids connected to a control box that plugs into the 12v Accessory plug inside the cab.
The control box has 6 buttons.
In order for the control box to function, the grader requires continuous flow.
I have a Bobcat S175 and I am familiar with how the hydraulics work - Maximum and Variable flow on the BICS, Right Trigger to start continuous flow, right thumb toggle to switch flow direction and fine tune variable flow movement.

For constantly moving equipment like the snow blower or brush cutter, it's a no brainer. Trigger the flow on and go.
But with this grader, flow is only needed when I move the blade around... which isn't all that much on flat ground, or small adjustments when grading uneven terrain. So the whole time the flow is activated, it's mostly bypassing the built-up pressure until I move the blade.

My question is - Is this going to harm the machine? The pump? Or anything else if I leave the flow engaged the whole time I'm grading?

Thanks much!

I would think the attachment would have a open center valve body allowing the flow to go through with out the system going over relief, going over relief will induce a lot of extra heat in the system, if you hear the system going over relief, with out seeing the unit if it was mine I would check the quick connectors to see if one is damaged mainly the return side as the spring can internally break acting as a flow restrictor {while allowing the function to work} and even as a check valve, hydraulic hammers are hard on them and cause quick connector to fail, or maybe you just need to activate it at the time you need the function.

 

[kao]

I would think the attachment would have a open center valve body allowing the flow to go through with out the system going over relief, going over relief will induce a lot of extra heat in the system, if you hear the system going over relief, with out seeing the unit if it was mine I would check the quick connectors to see if one is damaged mainly the return side as the spring can internally break acting as a flow restrictor {while allowing the function to work} and even as a check valve, hydraulic hammers are hard on them and cause quick connector to fail, or maybe you just need to activate it at the time you need the function.

Thank you! That is what I was thinking - there should be an open center valve body allowing flow to go through - and just tap into it when I activate one of the solenoids to adjust the grader blade. But it "feels" like I'm going over the relief until I activate the grader control. For now I'm playing it safe and only activating the hydraulics when I need to adjust the blade. But it's inconvenient because I need to hold the control box button with my left hand, while my right hand engages the hydraulics. I found that using the variable control with the thumb toggle allows for the smoothest operation. Using full speed or the trigger causes very jerky and hard to control motion of the grader blade.

 

[ward]

take off the quick connect for the supplyt line of the grader and add a T between the hose and quick connect and a pressure gauge if you read more then about 200 psi< i would think it would be less, and it is like the relief pressure ie 1500 to 3000 psi then what you could do is add a flow control that lets the system loop back to the tank however when you operate the function it closes to supply flow, what they have is a shuttle valve internally when there if flow the valve shuttles turning off the loop and flow goes to the function valve.