single stage vs two stage hydraulic pump in stock

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.

The size of the section of pump that goes to high pressure is defined by the engine hp. One stage or two stage it does NOT matter! The small section is defined by the engine hp.

A two stage pump simply adds another section in the same body. When less than maximum psi is needed, the larger gearset adds into the flow. You get way more flow to use the entire engine hp.

BTW, I published in an earlier thread topic here I think, but a two stage pump runs the small one always to the outlet. The larger section either adds to the flow from the small one (say 3 + 8 = 11 gpm out) or it unloads back to the inlet at almost no pressure. Then the outlet is just the small one (3 gpm for instance). The pump does not vary its displacement in any way, just loads and unloads the larger section.

Sure, a single stage pump is constant speed, but the two stage is not "slowing down" from that speed. The single stage pump STAYS on SLOW speed always, as the max size that the engine can pull. The two stage runs at the same speed in low, or speeds up when pressures are low.

Or I could put on a single stage pump and run 7 gpm all day, and use under 10 hp most of the time. SLOW! Or I could put on a 28 gpm single stage pump and a 45 hp engine to turn it….

The only place I would ever consider using a single stage pump is if there was a free, big engine already there running say a processor or elevator, or farm tractor PTO pump package. Then you have more than enough power, so no reason to use a two stage.

A single stage hydraulic pump is a pump that uses a single impeller to generate flow, while a double stage hydraulic pump uses two impellers in series to generate flow. This means that the double stage hydraulic pump has more pressure output than a single stage hydraulic pump of the same size, but it also means that it is typically larger and more expensive. Double stage hydraulic pumps are often used in high pressure applications where a high level of pressure is required to operate the hydraulic system.

A single stage hydraulic pump is typically used in applications where a moderate level of pressure is required, such as in a hydraulic system that is used to operate a lift or a small crane. These pumps are relatively simple in design and are often less expensive than double stage pumps.

Double stage hydraulic pumps, on the other hand, are typically used in applications where a high level of pressure is required, such as in a hydraulic system that is used to operate a large piece of heavy machinery or a hydraulic press. These pumps are more complex in design and are often more expensive than single stage pumps. The increased complexity and cost of double stage pumps is due to the fact that they have two impellers instead of one, which allows them to generate higher pressure.

The main advantage of a double stage hydraulic pump over a single stage pump is its ability to generate higher pressure. This makes it suitable for applications where a high level of pressure is needed to operate the hydraulic system. Additionally, double stage pumps are typically more efficient than single stage pumps, which means they can produce more flow with less input power. This can result in energy savings and can make the hydraulic system more efficient overall.

However, there are also some disadvantages to using a double stage hydraulic pump. As mentioned earlier, these pumps are typically more complex and more expensive than single stage pumps. They are also generally larger and heavier, which can make them more difficult to install and maintain. Additionally, the increased pressure output of a double stage pump can put more stress on the other components of the hydraulic system, which can lead to increased wear and tear and a shorter lifespan for the system overall.

It is difficult for me to provide a comparison of the performance data for single stage and double stage hydraulic pumps without more specific information about the pumps in question. The performance of a hydraulic pump can vary depending on a number of factors, such as the size and design of the pump, the type of fluid it is designed to work with, and the pressure and flow requirements of the hydraulic system it is used in. In general, however, a double stage hydraulic pump will have a higher pressure output than a single stage pump of the same size, but it will also typically have a lower flow rate. This means that a double stage pump is better suited for applications where high pressure is required, but a lower flow rate is acceptable.

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.

Customers often ask, “when do I need a two-stage hand pump versus a single-stage hand pump?” Well, that depends on the type of work you are trying to do inside your hydraulic system. There is a measurable difference between the two of them and both have benefits depending on the application. To explain, let’s look at the new PowerX International line of hand pumps.

First up is the PowerX P43 single-stage 10,000 psi (700 bar) hand pump. The reason why it is called a “single-stage” pump is because the flow of oil produced is the same on each stroke of the handle. For the PowerX P43, the flow is a continuous 0.20 in3 of oil per stroke. The pumps flow rate remains constant, whether it is simply raising a single acting cylinder with no weight on it, or pushing 10 tons at 10,000 psi. A single-stage pump is great if your hydraulic ram does not have to travel far before it starts to lift or push the load. But if the ram needs to travel any significant distance to meet the load, there would be a lot of excessive pumping by the operator before they actually started to do any work. This would get tiresome very quickly!

Enter the PowerX P37 “two-stage” 10,000 psi (700 bar) hand pump. Two stage hydraulic hand pumps give the operator higher flow rates up until the cylinder or ram starts to do work. In the case of the PowerX P37 hand pump, the first stage has a flow of 0.79 inches3 of oil per stroke (almost 4 times more than the P43) before making contact with the work load where the pressure builds. Once the ram makes contact with the load, and the pressure inside the system raises above 200 psi, the second stage kicks in at 0.17 in3 of oil volume. This two-stage pump allows the operator to do less work (or hand pumping) before coming into contact with the load. Your operators will thank you!

Both the PowerX P43 and the PowerX P37 are built with rugged steel construction and both have internal pressure relief valves to protect against overload. To learn more about the PowerX line of 10,000 psi (700 bar) hand pumps, click here.

Hydraulic pumps convert mechanical energy into fluid power energy. All hydraulic pumps are positive displacement which means the outlet flow is sealed from the inlet flow. A small amount of fluid is designed to leak internally to lubricate and cool the internal components of the pump. The only function of the pump is to produce flow in a system. Bailey International, LLC provides a wide range of pumps and accessories including clutch pumps, dump, gear, jaw couplers, mounting brackets, pistons, PTO, vane and two stage pumps.

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.

This 2-Stage pump fits a wide variety of log splitters and outdoor power equipment and works in both horizontal and vertical orientations. The inlet (suction) port is 1" NPT and the minimum suction hose inner diameter (ID) is 1-1/4". The inlet barbed fitting is not included but is available separately. Use a 1-1/4 ID Suction Hose and 3/4" ID high-pressure hose.

Be sure to use AW-32 10-Weight (ISO 32) or AW-46 20-Weight (ISO 46) light hydraulic 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. The hydraulic fluid reservoir should have a capacity of at least 12 gallons to allow sufficient cooling. 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 15hp engine to maintain 3,600 RPM under load.

This versatile 1-stage hydraulic pump can be used across a wide range of equipment applications including mining, farming, machine tooling, compaction, and hauling.

If you’re looking for information on what is a two stage hydraulic pump, you’ve come to the right place. A two-stage hydraulic pump is a positive displacement pump that uses two pistons to move fluid through a chamber. The first piston, called the “suction” piston, draws fluid into the chamber from the inlet port. The second piston, called the “discharge” piston, pushes fluid out of the chamber through the outlet port.

The suction piston is the first piston in a two-stage hydraulic pump. It is responsible for drawing fluid into the chamber from the inlet port. The suction piston typically has a larger diameter than the discharge piston and may also have a different number of slots or windows cut into it.

The discharge piston is the second piston in atwo-stage hydraulic pump. It is responsible for pushing fluid out of the chamber through the outlet port. The discharge piston typically has a smaller diameter than the suction piston and may also have a different number of slots or windows cut into it.

Two-stage hydraulic pumps are often used when high pressure is required, such as in construction equipment or heavy machinery. They are also sometimes used in automotive applications, such as power steering or brakes. Depending on the application, two-stage hydraulic pumps can either air or water-cooled.

Two-stage hydraulic pumps offer some benefits over other types of positive displacement pumps. They can generate higher pressures than single-stage pumps, making them ideal for use in applications where high pressure is required. Two-stage hydraulic pumps are also more efficient than single-stage pumps, which can move more fluid per cycle while using less energy.

Additionally, two-stage hydraulic pumps are less likely to cavitate than single-stage pumps, making them less likely to damage the pump or cause disruptions in fluid flow.

A two-stage hydraulic pump is a device that uses two pistons to move fluid through a cylinder. The first piston, the low-pressure stage, draws the fluid from the reservoir and moves it into the second stage. The second piston, called the high-pressure stage, forces the fluid through the outlet port at high pressure.

Two-stage hydraulic pumps are used in various applications requiring high volume and pressure. For example, they are commonly used in construction equipment, agricultural machinery, and manufacturing machinery.

Gear pumps and vane pumps. Gear pumps are the most common type of two-stage hydraulic pump. They use gears to move fluid through the pump and are typically used in applications where high pressures are required. Vane pumps use vanes to move fluid through the pump and are typically used in applications with high volumes.

Gear pumps typically have a pressure rating of 3000 psi or more. They are also very efficient, with some models achieving efficiencies as high as 99%.

Always check the pressure relief valve to make sure it is functioning correctly. The pressure relief valve protects the pump from damage if the pressure gets too high.

If the pump is not working correctly, check the inlet and outlet ports to ensure they are clear. Sometimes debris can build up in these ports and block fluid flow.

One-stage hydraulic pumps are less efficient than 2 stage hydraulic pumps. Additionally, 1-stage hydraulic pumps are more likely to cavitate than 2-stage hydraulic pumps, making them less reliable. 2-stage hydraulic pumps are more expensive than 1-stage ones, but they offer superior performance and reliability.

One-stage hydraulic pumps are less efficient than 2 stage hydraulic pumps. This is because they have to pump the fluid twice to reach the high pressure required for most applications.

2 stage hydraulic pumps are more expensive than 1 stage hydraulic pumps. Still, they offer superior performance and reliability. 2 stage hydraulic pumps are more efficient than 1 stage hydraulic pumps because they only have to pump the fluid once. Additionally, 2-stage hydraulic pumps are less likely to cavitate than 1-stage hydraulic pumps, making them more reliable.

Gear pumps and vane pumps. Gear pumps are the most common type of two-stage hydraulic pump. They use gears to move fluid through the pump and are typically used in applications where high pressures are required. Vane pumps use vanes to move fluid through the pump and are typically used in applications with high volumes.

Always check the oil level in the pump before starting it. The pump will not work correctly if the oil level is too low. Always check the pressure relief valve to make sure it is functioning correctly. The pressure relief valve protects the pump from damage if the pressure gets too high. If the pump is not working correctly, check the inlet and outlet ports to ensure they are clear. Sometimes debris can build up in these ports and block fluid flow. If the pump is still not working correctly, check the piston seals. These seals can wear out over time and need to be replaced. Always consult the owner’s manual for your specific model of the two-stage hydraulic pump before performing any maintenance or repairs. By following these tips, you can help ensure that your two-stage hydraulic pump will work correctly and last many years. We hope this guide has helped teach you what is a two-stage hydraulic pump.

Hydraulic pumps come in a wide range of styles and designs, and Flowfit Hydraulic two stage hi-lo gear pumps are amongst the most efficient available. These models can give you much faster cycle times and provide a higher maximum pressure, whilst only utilising a small engine. Typically, two-stage hi-lo gear pumps are excellent for use on log-splitters and hydraulic press applications.

Running at 85% efficiency, our range of hydraulic pumps are amongst the most effective in compactly designed hydraulic components available in the UK. With various designs, all available with a range of GPM specifications, you will be able to find the ideal model for your systems requirements amongst our extensive range.