I'm buying a bh92 today if it will handle lifting and placing 1200
to 1500 pound pipes. Can this backhoe handle that kind of weight?
Wow, that's a lot of weight to be lifting with a hoe attachment.
The answer is not simple. You can lift 3 ways: with the boom, dipper, or bucket cylinders.
The first is the weakest and the last is the strongest. Your tractor puts out 2500psi, and
that's good. The Kubota specs hopefully use that # and set the relief at 2500 on the
hoe.
The greatest digging force the hoe can produce is with the bkt cyl at max mechanical
advantage. In lifting with the bkt cyl only (pulling instead of pushing), your force
is substantially less than this so-called "breakout" force. That's due to the rod
taking up space in your cylinder. You can calculate the reduced lifting force of
your bkt cyl, knowing what the breakout force is. Of course, you can't lift very high
with just the bkt cyl.
The dipper cyl can lift, too, but substantially less than the bkt cyl. A similar calc
can be used to estimate this so-called "craning force".
I think you are asking an awful lot here, and all this lifting can over-pressure the
boom cylinder, depending on how far out you are doing the lifting.