two stage hydraulic pump adjustment in stock

I got the same pump as yours on my wood splitter, except mine is a John"s Barns but it is the same thing. Theses pumps give you 11 or 16 gpm under 700 psi and over 700 psi 6 to 8 gpm up to 3000 psi.

First, you must check your engine, if it will be able to handle this rise of pressure. Usually the factory setting for the first stage is 700 psi. If you got a 8 or 9 hp on a 11 gpm pumps, just forget it, the engine will dies on the effort. But if you got a 13 hp, it will works just fine.

Two-stage hydraulic pumps are used in hydraulic systems, and allow for the passage of a substance through the pump and to other devices installed in the system. You can adjust the various working aspects of the pump, including pressure settings and accuracy of the valve, by making minor adjustments with common household tools.

Adjust the hydraulic gauge by locating the adjustment screw on the back of the gauge. Use a flathead screwdriver to turn the screw. Turning the screw allows you to adjust the screw needle, turning it to zero when needed.

Adjust the pressure switch, located behind the hydraulic gauge, by using a wrench to loosen the lock-nut on the switch, then turning the adjusting screw. This switch can be adjusted to stop the pump when it reaches a given pressure setting. Turning the screw counterclockwise will decrease the pressure switch setting.

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http://www.energymfg.com/pdf/16445x.pdfGood catch, I should have seen that. Now the interesting part is that the relief is preset 2000psi from factory and a max range of 2500psi. His engine should pull that without any serious bogging. Rereading the first post, he says it boggs out and stalls. I am now wondering if its the engine that is stalling, ( which is what I thought he was saying),or the cylinder that is stalling. I think that issue needs to be clarified before going any further. If the cylinder is what is stalling, and the engine continues to run, it could just be a matter of the relief being set to low, or to small a cylinder for the wood being split. If it is indeed not shifting into lowflow/high pressure, then he might need to adjust the pump to the the 650psi high flow/ low pressure. Remove the cap on the inlet side of the pump. Under the cap is a slotted screw. Turn clockwise to increase pressure. Turn the screw all the way clockwise to the stop and see if the engine can handle it. If not then back it out a little and try again. Run the engine full throttle and plan to play with the setting until you find the limit for your engine. You will find that the higher you can run the pressure on high flow side, the less the pump will kick down into low flow/high pressure and the faster your splitter will work. If you engine is actually already what is bogging, you may have to turn the screw counter clockwise to lower the unloader pressure.. It is best to use a pressure gauge, but you can do this by ear. If its killing the engine, just turn the screw out until it no longer kills the engine. You should adjust the relief setting on the control valvle first before trying to adjust the unloader valve on the pump. The load is what will cause the pressure to build, you can simulate a full load by fully extending or retracting the cyl, and the relief valve on the valve will activate. If it will not get to 2500 psi, then the valve pressure relief (on control valve) is not set, or you don"t have a load equivalent to 2500 psi. With a gauge installed, pressure will be at a minimum until you activate the lever on the control valve, Once lever is activated, pressure should climb on the gauge until the cyl is fully extended or retracted, at which point the pressure will climb rapidly to the relief setting. Watch the gauge, it should jump from the settings on the pump unloader valve (650psi), to the setting on the relief (2500psi). You may need to split a round or two to actually see the pressure spike as the spike can be pretty fast

I will just add, that I have never had to adjust the relief on the control valve or unloader relief on a pump that was new out of the box. Usually if the reliefs need adjusting, its because someone has already been messing with them. Usually the factory guys have it pretty close, not saying mess ups dont happen, just that it is unusual when it does. I also usually use large bore cyls and bigger hp engines than the minimums required. If you have the hp to pull the pumps and cyls that create more than enough force, the factory relief setting will usually take care of themselfs.

A two-stage hydraulic pump is two gear pumps that combine flow at low pressures and only use one pump at high pressures.  This allows for high flow rates at low pressures or high pressures at low flow rates.  As a result, total horsepower required is limited.

Pumps are rated at their maximum displacement.  This is the maximum amount of oil that is produced in a single rotation.  This is usually specified in cubic inches per revolution (cipr) or cubic centimeters per revolution (ccpr).  Flow is simply the pump displacement multiplied by the rotation speed (usually RPM) and then converted to gallons or liters.  For example, a 0.19 cipr pump will produce 1.48 gallons per minute (gpm) at 1800 rpm.

Simply put, gear pumps are positive displacement pumps and are the simplest type you can purchase. Positive displacement means that every time I rotate the shaft there is a fixed amount of oil coming out.  In the diagram shown here, oil comes in the bottom and is pressurized by the gears and then moves out the top.  The blue gear will spin clockwise. These pumps are small, inexpensive and will handle dirty oil well.  As a result, they are the most common pump type on the market.

A piston pump is a variable displacement pump and will produce full flow to no flow depending on a variety of conditions.  There is no direct link between shaft rotation and flow output.  In the diagram below, there are eight pistons (mini cylinders) arranged in a circle.  The movable end is attached to a swashplate which pushes and pulls the pistons in and out of the cylinder.  The pistons are all attached to the rotating shaft while the swashplate stays fixed.  Oil from the inlet flows into the cylinders as the swashplate is extending the pistons.  When the swashplate starts to push the pistons back in, this oil is expelled to the outlet.

So, we don’t actually turn one of the pumps off.  It is very difficult to mechanically disconnect the pump, but we do the next best thing.  So earlier in the article I mentioned that pumps move oil they don’t create pressure.  Keeping this in mind, we can simply recirculate the oil from the pressure side back to the tank side.  Simple.   So, let’s look at this as a schematic.

Luckily, turning off the pump is quite simple and only involves two components: a check valve and an unloader valve.  The check valve is there to keep the higher-pressure oil from the low flow pump separate from the oil in the high flow pump.  The higher-pressure oil from the low flow pump will shift the unloader valve by compressing the spring.  This allows flow from the high flow pump to return to the suction line of the pump.  Many pumps have this return line internal to the pump, so there is no additional plumbing needed.  At this point, the high flow pump uses little to no power to perform this action.  You will notice that the cylinder speed slows dramatically.  As the log splits apart, the pressure may drop causing the unloader valve to close again.  At this point, the flows will combine again.  This process may repeat several times during a single split.

The graph above shows the overlay of a performance curve of a piston pump and two stage gear pumps.  As you can see, the piston pump between 700 psi and 3000 psi will deliver the maximum HP that our engine can produce and as a result, it will have maximum speed.  Unfortunately, it will also have maximum cost.  If we are willing to sacrifice a little performance, the two-stage pump will work very well.  Most of our work is done under 500 psi where the two pumps have identical performance.  As pressure builds, the gear pump will be at a slight disadvantage, but with good performance.  The amount of time we spend in this region of the curve is very little and it would be hard to calculate the time wasted.

After the pump on my log splitter died, I replaced it with a two-stage pump.   While I was missing out on the full benefits of the piston pump, there was a tremendous increase in my output (logs/hr.).  I noticed that instead of me waiting on the cylinder to be in the right position, I was now the hold up.  I couldn’t get the logs in and positioned fast enough.  What a difference!

As you go from a standard two-stage pump to your own custom design, you will find that you will need to add the check valve and unloader separately.  However, there are many available cartridges manifold out there already that make this simple.  Some even have relief valves built in!

Two stage pumps are wonderful creations!  They allow for better utilization of pressure, flow and power by giving you two performance curve areas.  They also show their versatility in conserving power which leads to energy savings while remaining inexpensive.  A lot of these pumps come pre-made and preset, but you can make your own!  See if your next project can get a boost from one of these wonderful devices.

Have any of you threw a pressure gauge on your hose between the pump and control valve to see what pressure the relief valve is set at? I"ve read in numerous forums that most relief valves are set around the 2,500psi area. Assuming this is correct then most splitters are grossly over-rated in tonnage. I have a CountyLine 40 ton and it has a 5 1/8" cylinder. This means I would have to see 3,880psi in order for it to apply 40 tons of force. Manual states max PSI is 3,800 psi which would make 39.2 tons. I thought they were out of their minds.........

Anyway, I am assuming, based on everything I have read, I wouldn"t be seeing anywhere near those pressures. It has both an adjustable relief and detent. I already adjusted the detent and I installed a 3,000 psi gauge. I was completely surprised as to what I saw when I went to test what the relief was set to. I still don"t know because it maxed out the 3,000 psi gauge before I left off. I remember the ram slowing down as the pump hit the second stage and the engine digging in and next thing I know the pressure went pretty rapidly to burying the 3,000psi gauge before I lifted. It was probably around 3,200psi when I said that"s enough.

This 2-Stage pump fits a wide variety of log splitters and outdoor power equipment and works in both horizontal and vertical orientations. The included inlet nipple requires a 1" inner diameter suction hose.

Rated for up to 3,000 PSI at 3,600 RPM, this pump can power log splitters from 5 to 35 tons, depending on the inner diameter of the hydraulic cylinder. It features a fast cycle time by moving quickly when unloaded. It automatically shifts to low-flow/high-pressure mode at 500 PSI.

Be sure to use AW-32 10-Weight (ISO 32) or AW-46 20-Weight (ISO 46) light hydraulic fluid or Dexron III automatic transmission fluid. This pump is not designed for use with “universal” or "tractor" transmission oil, such as "303". The use of incorrect fluid may damage the pump and void the warranty.

Make sure the hydraulic fluid reservoir is not below the pump to ensure a sufficient flow of fluid to the pump. Suction-side filtration should be no finer than 150 microns. The use of a 10-25 micron filter on the suction side of the pump is too restrictive and will cause failure.

We recommend using an L-style jaw coupling to connect the pump to an engine. Couplings and mounting brackets are available. You should use at least a 5hp 163cc engine to maintain 3,600 RPM under load.

This 2-Stage pump fits a wide variety of log splitters and outdoor power equipment and works in both horizontal and vertical orientations. The included inlet nipple requires a 1" inner diameter suction hose.

Rated for up to 3,000 PSI at 3,600 RPM, this pump can power log splitters from 5 to 35 tons, depending on the inner diameter of the hydraulic cylinder. It features a fast cycle time by moving quickly when unloaded. It automatically shifts to low-flow/high-pressure mode at 500 PSI.

Be sure to use AW-32 10-Weight (ISO 32) or AW-46 20-Weight (ISO 46) light hydraulic fluid or Dexron III automatic transmission fluid. This pump is not designed for use with “universal” or "tractor" transmission oil, such as "303". The use of incorrect fluid may damage the pump and void the warranty.

Make sure the hydraulic fluid reservoir is not below the pump to ensure a sufficient flow of fluid to the pump. Suction-side filtration should be no finer than 150 microns. The use of a 10-25 micron filter on the suction side of the pump is too restrictive and will cause failure.

The mounting flange on this pump has a 4-bolt, 2 inches on center, mounting pattern. The bolt circle is 2.85" and the bolt hole diameter is M8 (.344").

2-stage hydraulic pumps are used in motor-driven operations wherein a low-pressure, high rate inlet must be transferred to high pressure, low flow-rate outlet. Single-stage pumps are rated to a static max pressure level and have a limited recycle rate.

To achieve high pressure without a 2-stage unit, the drive engine would require significantly higher horsepower and torque capacity but still lack an effective cycle rate. Other hydraulic pump variants exist – such as piston pumps – but are expensive, making 2-stage units more feasible.

For example, a single gear hydraulic pump might be designed to generate a high-pressure output. Still, it will be unable to repeat a cycle rapidly due to a necessarily low flow rate at the intake. A 2-stage unit ensures consistent flow to increase cycle turnover.

Compactors utilize a similar 2-stage process. High-pressure flow drives the compacting rod, while the low-pressure flow retracts the mechanism and feeds the high-pressure chamber for repeated impacts.

2. Once the first-stage pressure meets a certain pressure threshold, a combiner check valve will open and feed into the second-stage, small-gear unit – joining flows at relatively low pressure.

A piston pump operates according to variable displacement. Flow is determined by the angle of an internal slant disk attached to the pump shaft. Pump adjustments – like torque or horsepower limiters – allow piston pumps to emit a max flow rate regardless of pressure level.

In most cases, hydraulic piston pumps are an order of magnitude more expensive than gear-based pumps. Potential downtime and part replacement in high volume work conditions exacerbate price disparities further.

Chiefly: fuel and power consumption. A piston pump operating in high-pressure ranges will regularly demand the full horsepower capabilities of its associated drive engine – increasing the power utilization of the system.

Opportunity cost may also be considered when using a piston pump. Depending on the application (e.g., log splitting), work output can be heavily impacted by the cycle speed of the pump. Not only is a piston pump more expensive to peruse, it is also slower than 2-stage pumps.

Panagon Systems has specialized in manufacturing industry-standard and custom hydraulic assemblies for 25 years. Reach out to our team for a consultation on your specific operational and equipment needs.

Just doing a short video today to demonstrate how to adjust the pressure on the Eaton pressure compensating piston pumps. These are on the 12, 16, and 20 gallon a minute HydraBoost systems. To adjust it, you need to break this plastic cap that has an Allen screw fitting underneath of it. So you basically pop it off. It’s plastic with some aluminum tabs. As you can see, you’re gonna wreck the cap doing it. Then you have this piece here come off next.

Then to change the pressure setting, you’ll need to loosen the jam nut here against the body of the pump. To adjust the pressure on the high-pressure screw here, you need to loosen the jam nut while holding this with your Allen wrench.Break that loose. If you give this a quarter of a turn clockwise, that increases the pressure, counter clockwise of course decreases. Do this a quarter of a turn at a time, you will get a substantial jump. Do not have the pump turning; have your tractor PTO off. Do it a quarter turn at a time should give you 100-150 psi increase going this way. And then restart it, check your system pressure and repeat as needed. And that’s it.

The HP-700 is a portable|tough|hydraulic steel pump that has two speed pumping pistons for rapid advance and an external adjustable pressure setting from 4,000 to 10,000 psi output. An internal oil bladder allows the tool to be used in any position. Our exclusive replaceable|by-pass cartridge is standard in the HP-700. Field repairs and pressure adjustments can be made in minutes. Use our PG-1 gauge for pressure adjustments.; NOTE: When using any of these high pressure tools|always use 10,000 psi rated non-conductive hose (NC-16 series).

Northern Hydraulics offers a full line of two stage Hi-Lo hydraulic gear pumps for your log splitters, compactors, and press type applications. Haldex/Concentric pumps have a cast iron gear housing and are available in flows ranging from 9 GPM to 28 GPM. These hydraulic two stage pumps are designed for heavy duty use and long cycle times. The Haldex brand assures you are getting top quality, high performing products. Northern Hydraulics replacement pumps also have a cast iron gear housing and are available in flows ranging form 5 GPM to 28 GPM. These Hi-Lo log splitter pumps are ideal for the recreational woodsplitter user, as they are still a quality product, but offered at a much lower price point.

We shall, at our option, repair or replace any items deemed by us to be defective under this warranty. Items returned by the purchaser for warranty adjustment must be handled as stated in our return policy. Proof of, and date of purchase will be required.