hydraulic manifold material

[CORBIN92087]

what kind of aluminum is used for hydraulic manifolds?

[Geof]

Aluminum??? For hydraulic manifolds, isn't steel the better choice?

[Al_The_Man]

6061 up to 3000lbs/sq" according to the catalogue I have.
Al.

[thebodger@roger]

You didn't state what size bores it will have , or the working pressures.

But consider this. The area through the bore is subjected to stresses equal to pi*radius*legnth*pressure. As you can see the stress can be enormous with large size pipe. Then there is an often over looked factor, this is when valves rapidly shift the fluid, the sudden surge can cause some very large shocks ( look at hoses when valves operate, you can see them jump).
And another thing is the threads to which you couple the fittings. there is a lot of force trying to rip the fittings out of the mating material. a shallow thread in aluminium, it doesn't take much to rip them out.

[Geof]

Originally Posted by Al_The_Man 6061 up to 3000lbs/sq" according to the catalogue I have. Al.

Come to think of it I have seen an aluminum manifold on the hydraulic system on my Haas lathes, but these max out at 500 psi. I would be very nervous using aluminum at 3000 no matter what any catalogue says, it is pretty easy to get pulses peaking at twice the working pressure and I like to think my material has a many many fold excess strength.

Anyway my way of using hydraulics is take no prisoners; which is why I pushed the rear cross member out of a hydraulic tipping trailer I have, but at least it wasn't the hydraulics that failed.

[Al_The_Man]

On one retrofit I did on a 30ft bed 4 head planer, I powered the (very large) servo's up and was using the jog to test the motion, I overlooked the fact that the heads vertical hydraulic counterbalance had to be picked up, failing to do this meant the solenoid valve at centre blocked both side of the hydraulic cylinder.
The motor did not seem to mind, a few seconds later a five feet length of steel tube to the cylinder let go and opened up along the full length.
Since then I have had great respect for the power of Hydraulics.
Al.