The question I was asked by a customer (and which I couldn't really answer), was 'knowing Q, h and the fluid viscosity, what's the minimum size of pipe that would be required to ensure zero back pressure at P ?'
If I want to know the pressure at P, can I simply determine the pressure drop along the pipe, assuming it's horizontal (and knowing Q, d and fluid viscosity), then subtract from that 0.4 psi per foot difference in height ?
Is there a simple way of calculating the pressure drop of fluid (hydraulic oil) flowing down a vertical pipe ?
Or should I be asking this on the Pipelines Forum ?
It's unlikely that the Rexroth card will be able to provide the correct control function to the Eaton proportional directional valve. You really need the Eaton ER 9.3 card which closes the swashplate position loop via the yoke angle sensor. Maximum displacement is normally set by spacers in the...
Looks like it could be part of a pump control (possibly torque limiter).
The directional spool is mechanically operated inside a sleeve which is pilot pressure positioned between two adjustable maximum stops.
Agree that the rest of the circuitry is required to see the context.
In a dusty old bookshop in a back street of Cambridge (UK), an old manuscript has just come to light which is believed to be a previously unknown work of Sir Isaac Newton and entitled Principia Mathematica Part 2.
In it appears a corollary to his first law of motion which states:
‘Non quiescit...
Do the pneumatic people also say that 'flow makes it go' ?
If so I'd better make sure my bike is chained down the next time I pump up its tyres (sorry, tires).
I wasn't around here then but yes, it is amazing. Not to mention all the other myths, fallacies and inexactitudes put about by our industry's educators. It's not only Sir Isaac who must be turning in his grave !
It's not quite a chicken and egg situation since, (assuming the egg has been fertilised), both chicken and egg are active components.
It's true that a pump on its own won't create pressure. It's also true that there won't be pressure in the system if the pump is removed. However, in this case...
Your valve started life as a spring-offset two-stage solenoid operated valve. The little valve circled in red is the solenoid pilot valve which has had its solenoid removed. It then looks like one end cap has been modified to convert the main stage of the valve to manual operation. However, the...
Sounds like an issue with excessive flow forces acting on the spool due to flow intensification.
Would need to know pump flow, cylinder bore & rod dimensions & valve size/flow rating to confirm.
That's right it's a KFDG5V 7 proportional directional valve. Better performance than the non-feedback KDG5V version but not as good as the double feedback KHDG5V.
http://www.eaton.com/ecm/groups/public/@pub/@eaton/@hyd/documents/content/pll_2112.pdf
I can't provide an answer but:
1) Generally speaking the disc valve motors are better (smoother) at low speeds than the spool valve motors. However, at such a low torque requirement there may not be too much difference.
2) At such a low pressure, leakage shouldn't be an issue with either...
Those are the case drain lines ie. they drain the internal leakage that takes place within the pump back to the reservoir.
It's not always recommended to put a filter in case drain lines but in a multi-pump system such as this if one pump destroys itself it stops all the debris being blown back...
"There is no valve that can differentiate between air and liquid to the point where it can let one pass, but not the other".
Other than an automatic air-bleed valve of course, but that's not what the OP is looking for.
As 3DDave says, it's basically a check valve but you may struggle to find...
Your best bet would be the DRL (parallel) control (as mentioned by Jacc) but I don't think you can combine that with the power limiter on the A11V.
When you say 'electronic control' are you talking about electronic pressure control or electronic displacement control? If it's the latter I don't...
Agreed, some pumps are more susceptible to this phenomenon than others so you need to tell us which pumps you are using.
There are two schools of thought on staggering the compensator settings. Some say it's best to set them at the same pressure and even out the work load whereas others say...
Jacc's got it just about right. Those may be the damping orifices just to the left of the left-hand compensator but the resolution of the diagram isn't really good enough to say.
But in reply to HPost's comments:
The main pressure relief valve is a belt & braces requirement since pump...
