Richard Smith writes:

Richard Smith writes:

"Jim Wilkins" writes:

"Richard Smith" wrote in message ...

Hello again all

I need to get advice.
I need a portable hydraulic pump & cylinder combination
- hand pump
- oil pressure gauge
- hydraulic cylinder(s)

because

* blowing someone else's hydraulic seals makes you "persona less
grata"

* the fillet weld tests break abruptly, which is cruel to repeatedly
do to someone's "shop" press

so, as I can see a lot more tests to do - plus other applications for
a hydraulic jack - I need to get my own kit.

The oil pressure gauge is to give a "Force=pressure*area" estimate of
Force being applied in the tests.
Plus other uses. eg. you could be tensioning bolts.

I've done calculations, and in view of experience I have, this is the
"bottom line" - the biggest cylinder needed
v
50Tonne cylinder with 50mm stroke.

Any good advice?

Rich Smith

=======================================
I think the best answer is to acquaint yourself with local small
hydraulics shops and ask them. Several of the owners were happy to
find another creative tinkerer and showed me all the stuff they'd
designed and built.

A hydraulic press is a particularly easy machine to build or modify if
you have the means to cut and drill structural steel. I'd record the
dimensions of the channels and bolts of the 50 ton press you used and
look for cutoffs from a steel fabricator.

Hand pumps can be found in real or fake Porta-Power kits and Greenlee
punches, however I haven't seen 2-speed hand pumps except on 50 ton
presses and manual log splitters. Powered log splitters do have
2-speed gear pumps, actually separate wide and narrow gear pairs. A
valve bypasses the wide pair at high pressure.

Do you have British suppliers like these where much of my hydraulic
kit came from?
https://www.northerntool.com/

https://www.baileyhydraulics.com/

I haven't tried it yet, but I wouldn't use a press.
Would get a beam about 3m long and use that as the "base" / "frame" /
"chassis"

Either add a "bridge" / "hoop" transversely in the middle to put the
cylinder under it, with the sample on bearers
- or fasten down the beam ends and put the cylinder directly on the
beam pushing up on the sample.

Advantage is, as welds get bigger, eg 12mm (1/2inch) leg-length with
over 80 tonnes-force breaking, can keep forces down by having longer
sample.

Here's what I've got

http://www.weldsmith.co.uk/tech/tech...gaugecyl_1.jpg
http://www.weldsmith.co.uk/tech/tech...gaugecyl_2.jpg

Hydraulics:
* single-stage 700Bar pump
* 4inch/100mm gauge to 700Bar
* 3m hose
* 20Tonne cylinder with 44mm stroke

I worked-out 20 Tonnes-force would be "the Goldilocks quantity" (just
right) with this for-purpose testing rig
http://www.weldsmith.co.uk/tech/stru...t_testrig.html
"Tensile-test rig for beam-configuration fillet-weld samples"

I went to a local supplier.

They also got me a piston seal for the Co.'s 10T cylinder which
started leaking when I was using it, and it works perfectly again when
I fitted it - "persona grata" and it's seen in the test rig pic.

I've been using Co's cylinders and pump for a number of steel
fabricating jobs - got going on this as a line of knowledge.