Hydraulic Reservoirs

[Foolster]

What makes a good hydraulic reservoir? I have two old small propane tanks that hold 5 gallon each. I was going to mount a 13.5 gpm pump off of the front of my tractor, drive it from the crankshaft, and mount the two propane tanks slightly above it on both sides of it and plumb them in parallel. I have filled the tanks with water. The next step is to turn them upside down and tap a hole to feed oil to the pump.

So is ten gallons enough for a 13.5 pump?

Is there another source of cheap tanks to use for reservoirs?

 

[Tx Jim]

Pump output in GPM doesn't really delegate hyd oil reservoir capacity BUT the larger the reservoir acts as radiator & helps keep hyd oil temperature lower.

The hyd over elect unit that operates 2 hyd cylinders on my rd bale spears on pickup truck flatbed is about 1 gallon capacity. I don't know the GPM of the pump on my truck

 

[J. Schwiebert]

Well you have 2 things in your favor. If you fill them 80% full you will have 8 gallon. Also on the pump if it is a gear pump it will pump a little over 10 gpm if you are operating at the pumps rated rpm so you should be good. More questions.

 

[Steve@Advance]

That's about a cheap as you will find, and it should work!

A couple of considerations, the tank serves as a heat radiator, being 2 tanks they should have plenty of surface area.

It also needs enough capacity to not drop the level so low it can suck air when the cylinders are fully extended or the tractor is bouncing over rough terrain.

If there is any way, a suction strainer would be a big plus. Being a gear pump, or any pump, a stray piece of metal will cause disastrous damage!

 

[matthies]

Breather of some sort?

 

[Pete in Holland MI]

Your reservoir needs to be big enough to hold enough oil to contain the oil from your cylinders all extended, and retracted.
The reservoir also needs a vent to allow the air volume to change as the oil volume changes. That vent should be filtered so
that as the oil level goes down, and air is drawn in, it doesn't draw in dirty air and contaminate the oil. Although many
hydraulic systems are oily & dirty on the outside, they need to be surgically clean on the inside. Any rust & dirt on the
inside of your tanks needs to be cleaned, else problems will arise.

 

[JWA]

I don't think the tank shell will be thick enough to tap threads into. Probably
have to weld in a coupling for the connection, the tanks themselves should
surely serve your needs.

 

[Brendon-KS]

Two main design factors go into hydraulic reservoirs. Fist, as others mentioned, you must hold enough oil to satisfy the demand when cylinders extend. Secondly,
the reservoir must deaerate the oil, either by good design or, lacking that, just a long enough dwell time. You'll need plumbing that maintains a more-or-less
equal level in both tanks and the pump inlet plumbing will need to be designed so you never suck air from one tank or the other. Make sure that the oil return
flow is discharged below the oil surface under all conditions - discharging above the oil level will cause major aeration problems. Position the return so it
isn't pointing directly at the suction port to allow for good circulation and deaeration.