hydraulic flow control

[Stomper]

I am needing to install several smaller screw piles (pylex) for a deck that I am going to build and I have been tossing around the idea for building a simple hyraulic instalation tool to bolt onto the bucket of my tractor and be run off of my third function. I would build a basic frame and just use the hydraulic motor from my capstan winch. The problem is that the motor was sized to give me 60 rpm at idle for the capstan and I would like to have around half of that or less for the screw piles. Can I just add a flow control valve on the unit that I will build (after the third function valve) to slow the rpm down. Will I need to install a line back to tank from the flow control valve for the unused folw? Or would it be best to run hoses from my rear remotes?

 

[wdchyd]

https://www.northerntool.com/shop/t...EJaePXxeA6Be54yq8kZ5JqKxXK8smN4xoChigQAvD_BwE

This type of valve will give you control of speed you desire, they do come in different sizes, with or without relief valve. Yes you will need a third hose back to tank.

 

[ericm979]

Also the normal 3rd function that closes the work ports when the valve is in the closed position will bring the hydraulic motor to a sudden stop. Ideally you'd want a motor spool valve that leaves A and B ports linked in the closed position. It might be ok for a relatively small number of uses.

I have also seen one way flow controls like these
1/4 NPT 5 GPM Prince WFC-4 In-Line Flow Control | Prince Mfg | Brands | www.surpluscenter.com
used to control motor speed. Running a restriction like that would probably heat the oil up over a long run of the motor but it might be ok for short term use.

 

[RickB]

https://www.northerntool.com/shop/t...EJaePXxeA6Be54yq8kZ5JqKxXK8smN4xoChigQAvD_BwE

This type of valve will give you control of speed you desire, they do come in different sizes, with or without relief valve. Yes you will need a third hose back to tank.

Exactly what is needed.

 

[Stomper]

If I used my rear remotes would the internal relief on the remote valve protect the hydraulic system from the extra pressure caused by the restriction of flow control valves.
Or would I even need the flow control valves if I used the rear remotes. Could I not just feather the handle on the remote valve to give me the speed I want.
Sorry for all the questions, Im kinda new to hydraulics

 

[ericm979]

It depends on the quality and size of the remote valves compared to the system flow. If you want a repeatable setting then the real flow control is the way to go. You could try with the remotes and see if that works for you.

The tractor's remote valves are not motor valves. If you shut the valve quickly the motor will slam to a stop.

 

[RNeumann]

If I used my rear remotes would the internal relief on the remote valve protect the hydraulic system from the extra pressure caused by the restriction of flow control valves.
Or would I even need the flow control valves if I used the rear remotes. Could I not just feather the handle on the remote valve to give me the speed I want.
Sorry for all the questions, Im kinda new to hydraulics

I’m curious too. My simple mind would say all you are looking to do is slow the flow a bit- same as just barely moving/opening a hydraulic valve. But to do that simply and repeatedly (to maintain your hydraulic motor RPM) you want something to restrict flow. The simplest would be an orifice fitting that you could drill in steps to get your flow. The next step up in cost and complexity would be and adjustable flow control. Any time you restrict flow for long periods you are going to make heat- maybe that’s what the return line and added complexity is for. But I’m not seeing the need for a lot of complexity- especially given the “home owner” type limited use of the setup- my thinking would be different if you said your new business was drilling these things and you were going to be doing it 8 hours a day for 10 years.

 

[RickB]

An orbit motor that only runs in one direction can be safely controlled with a remote valve for the supply and using a zero pressure return (open return to tank) which eliminates the sudden and damaging instant stop when the return flow to a remote valve is abruptly stopped.

 

[Stomper]

An orbit motor that only runs in one direction can be safely controlled with a remote valve for the supply and using a zero pressure return (open return to tank) which eliminates the sudden and damaging instant stop when the return flow to a remote valve is abruptly stopped.

I don't understand the difference there would be on the hydraulic system between an instant stop of a cylinder and an instant stop of a motor. The motor that I want to use is reversable.

 

[RickB]

I don't understand the difference there would be on the hydraulic system between an instant stop of a cylinder and an instant stop of a motor. The motor that I want to use is reversable.

The damage potential is with the motor, not the supply system.