r/Hydraulics

I'm trying to design an irrigation system knowing next to nothing about fluid dynamics. My water sources is a giant reservoir 600' away from the garden with no access to power. I have access to power at the garden but that leads to having a 600' suction line. I've got all the electrical pieced out in my head, and yeah, I know it's not gonna be cheap, but still cheaper than getting power to the reservoir so I can put my big pump nearby.

I remember when I worked in the oil field, the water disposal systems had smaller charge pumps that provided adequate inlet pressure for the big bitch triplex disposal pump to start.

I want to apply that same concept but I have no idea how to size pumps or pipe or have any idea what I'll get at the other end of the hose.

Can anyone recommend an online retailer with a huge selection of seals and hydraulic parts where pricing is visible up front?

I often need to compare different seal types/materials and make economic decisions on whether something is worth rebuilding or just leaving it alone, so being able to quickly toggle between options and prices is important.

Ideally I’m looking for somewhere that also ships internationally (Australia), and has a broad range of hydraulic seals, O-rings, rod seals, wipers, rotary seals, etc.

I’m honestly a bit surprised there doesn’t seem to be a “DigiKey/LCSC” or Chinese equivalent for hydraulic seals and fluid power parts. I’ve searched around but haven’t really found anything that fits -

For some things i have got seals from Alibaba - but because I mostly need small quantities of many different types of seals from different suppliers the cheap parts become expensive due to shipping

Huge thanks for any ideas or input

This was a new cylinder. Was taken apart for modification. This included shortening the cylinder by a few inches, the piston rod, and remachining the threads seen in the photo w/ lathe and manual threading. Gave it new O-rings because it was leaking a little during first test. But other than that, it seemed to have survived…

Until Fluid sprayed everywhere when retracting it for purging air. Extract and Retract was only done a handful of times, less than 5 seconds each. Bolts and pipes were tightened on very well. It is not very usable in the current state.

Cylinder was made to provide 10,000 lbf, maybe the modification affected this? Maybe the Chinese metal was too weak? Would “bottoming” the cylinder out for a second too long have caused this? Any thoughts here?

Figuring this is unfixable, but we are looking to try brazing or maybe even JB Weld for just ONE good run. It’s for a school project, not very high risk

Picked these up today. Cutting power is not what I had hoped for. They work for sure, but is there a way to sharpen these blades or do they have to be replaced? Tried to cut the top off the Passat and just didn’t have the power to close the cutters. It did cut a chunk out of the door pretty easily. Am I doing something wrong?

Hey gang. The above example is specifically from Rexroth A4VG 40 series but I believe 32 series is the same.

So in the above example fluid is being ported from B>A. Say we encounter a pressure spike that exceeds POR and cracks the relief on the B side of the loop.

My understanding has always been that this relieved fluid will go thru the check valve on the A side of the closed loop as that is the low pressure/suction side of the loop and keeps things "closed loop"

The hangup/rub for me here is the charge pressure relief passage being shared with this circuit.

Is my knowledge of the system correct? Or would any pressure higher than charge pressure relief setting (let's call it 400psi in this case) cause the relieved oil from the cross port/high pressure on the B side to flow thru the relief and dump back to tank??

Searching the numbers didn't help.

Is there a way to stop the pump suction from syphoning out in this (poor) design? (Not mine, just my problem now)

Typically the pickup is tubed straight down in these systems.

Can I put a S bend/pee trap type tube arrangement in the tank/oil to stop the pump suction from syphoning out.

Broke steering hydrostatic/ hydraulic line on my FIL tractor...I've tried everything and can not get this end off..bled the system off, torally unhooked the steering piston..am I missing something?!

I got a 'good deal' on a slightly damaged 10-ton electric hydraulic press that I want to use for light forging. It works well enough as is, but it would be more convenient with a foot pedal. So far it looks like my options are to replace the valve with an air actuated one, or rig a pedal to mechanically drive the lever on this model.

There has to be a better way

Could I make a few bucks. Doesn't leak. Could use a new shaft

Sorry I don't have an actual photo; I forgot to take one when I was getting measurements. The overall diameter of this gland is 4.342" diameter. The notches are 0.37" wide, 0.58" long, and 0.22" deep.

Do I just need to find a massive hook spanner for this, or is there a tool that I've never seen that's designed to grab multiple notches at once?

If I knew what type connector these were I could just search for what I want. I need three for the cylinders and one for the pump. Anyone know what these are called?