zwei inc hydraulic pump pricelist

We specialize in the wholesale supply of “Made to Order” hydraulic gear pumps and motors. Using our fluid power library and master data base we are able to identify and quote a matching unit and get the customers machine back on the job.

We offer a wide variety of hydraulic gear pumps, motors and service parts, both OEM (Original Equipment Manufacturer) as well as after-market. We stock original Parker and Casappa units and build custom solutions from parts. Additionally, we have established working relations with many distributors and manufacturers enabling us to quickly fill most every pump and motor need.

Permco is a leading manufacturer of high-pressure hydraulic gear pumps and motors, flow dividers, intensifiers, and accessories. Both roller bearing and sleeve bushing series are available in a wide variety of sizes and configurations.

Starting as the Perfection Machining Company in 1964, Permco hydraulic pumps began designing and manufacturing replacement parts for the mining industry. In 1968 the name was officially changed to Permco and the development of replacement hydraulic parts was under way.

In 1974 Permco hydraulic pumps expanded its manufacturing capabilities to include cast iron parts, which enabled us to offer complete units. We later developed our sleeve bushing pumps, which have recently been rounded out with the introduction of the P124 series.

Permco, working with The Torrington Company, developed the patented "controlled stress" roller bearing, which increases pump and motor life by up to 30%. As a result, we recently extended our warranty from one year to two years.

Our commitment is to continue to develop and offer the highest quality product possible to our wide customer base, which includes both OEM"s and distribution. We are also committed to working with our customers to supply them in such a way as to reduce their cost and to make their interface with Permco hydraulic pumps as seamless as possible. We are determined to do business the old fashioned way, while incorporating as much technology as makes sense to keep up with today"s fast pace in business.

At Northern Hydraulics we manufacture your Permco Hydraulic Pump on-site in our full service Machine Shop.Permco products are available in a variety of sizes and configurations to meet your specific needs. Give us a call at 1-800-823-4937, we have the Permco hydraulic components to build you the Permco Hydraulic Pumps or Motors you need.

A hydraulic pump converts mechanical energy into fluid power. It"s used in hydraulic systems to perform work, such as lifting heavy loads in excavators or jacks to being used in hydraulic splitters. This article focuses on how hydraulic pumps operate, different types of hydraulic pumps, and their applications.

A hydraulic pump operates on positive displacement, where a confined fluid is subjected to pressure using a reciprocating or rotary action. The pump"s driving force is supplied by a prime mover, such as an electric motor, internal combustion engine, human labor (Figure 1), or compressed air (Figure 2), which drives the impeller, gear (Figure 3), or vane to create a flow of fluid within the pump"s housing.

A hydraulic pump’s mechanical action creates a vacuum at the pump’s inlet, which allows atmospheric pressure to force fluid into the pump. The drawn in fluid creates a vacuum at the inlet chamber, which allows the fluid to then be forced towards the outlet at a high pressure.

Vane pump:Vanes are pushed outwards by centrifugal force and pushed back into the rotor as they move past the pump inlet and outlet, generating fluid flow and pressure.

Piston pump:A piston is moved back and forth within a cylinder, creating chambers of varying size that draw in and compress fluid, generating fluid flow and pressure.

A hydraulic pump"s performance is determined by the size and shape of the pump"s internal chambers, the speed at which the pump operates, and the power supplied to the pump. Hydraulic pumps use an incompressible fluid, usually petroleum oil or a food-safe alternative, as the working fluid. The fluid must have lubrication properties and be able to operate at high temperatures. The type of fluid used may depend on safety requirements, such as fire resistance or food preparation.

Air hydraulic pump:These pumps have a compact design and do not require an external power source. However, a reliable source of compressed air is necessary and is limited by the supply pressure of compressed air.

Electric hydraulic pump:They have a reliable and efficient power source and can be easily integrated into existing systems. However, these pumps require a constant power source, may be affected by power outages, and require additional electrical safety measures. Also, they have a higher upfront cost than other pump types.

Gas-powered hydraulic pump:Gas-powered pumps are portable hydraulic pumps which are easy to use in outdoor and remote environments. However, they are limited by fuel supply, have higher emissions compared to other hydraulic pumps, and the fuel systems require regular maintenance.

Manual hydraulic pump:They are easy to transport and do not require a power source. However, they are limited by the operator’s physical ability, have a lower flow rate than other hydraulic pump types, and may require extra time to complete tasks.

Hydraulic hand pump:Hydraulic hand pumps are suitable for small-scale, and low-pressure applications and typically cost less than hydraulic foot pumps.

Hydraulic foot pump:Hydraulic foot pumps are suitable for heavy-duty and high-pressure applications and require less effort than hydraulic hand pumps.

Hydraulic pumps can be single-acting or double-acting. Single-acting pumps have a single port that hydraulic fluid enters to extend the pump’s cylinder. Double-acting pumps have two ports, one for extending the cylinder and one for retracting the cylinder.

Single-acting:With single-acting hydraulic pumps, the cylinder extends when hydraulic fluid enters it. The cylinder will retract with a spring, with gravity, or from the load.

Double-acting:With double-acting hydraulic pumps, the cylinder retracts when hydraulic fluid enters the top port. The cylinder goes back to its starting position.

Single-acting:Single-acting hydraulic pumps are suitable for simple applications that only need linear movement in one direction. For example, such as lifting an object or pressing a load.

Double-acting:Double-acting hydraulic pumps are for applications that need precise linear movement in two directions, such as elevators and forklifts.

Pressure:Hydraulic gear pumps and hydraulic vane pumps are suitable for low-pressure applications, and hydraulic piston pumps are suitable for high-pressure applications.

Cost:Gear pumps are the least expensive to purchase and maintain, whereas piston pumps are the most expensive. Vane pumps land somewhere between the other two in cost.

Efficiency:Gear pumps are the least efficient. They typically have 80% efficiency, meaning 10 mechanical horsepower turns into 8 hydraulic horsepower. Vane pumps are more efficient than gear pumps, and piston pumps are the most efficient with up to 95% efficiency.

Automotive industry:In the automotive industry, hydraulic pumps are combined with jacks and engine hoists for lifting vehicles, platforms, heavy loads, and pulling engines.

Process and manufacturing:Heavy-duty hydraulic pumps are used for driving and tapping applications, turning heavy valves, tightening, and expanding applications.

Despite the different pump mechanism types in hydraulic pumps, they are categorized based on size (pressure output) and driving force (manual, air, electric, and fuel-powered). There are several parameters to consider while selecting the right hydraulic pump for an application. The most important parameters are described below:

Speed of operation: If it is a manual hydraulic pump, should it be a single-speed or double-speed? How much volume of fluid per handle stroke? When using a powered hydraulic pump, how much volume per minute? Air, gas, and electric-powered hydraulic pumps are useful for high-volume flows.

Portability: Manual hand hydraulic pumps are usually portable but with lower output, while fuel power has high-output pressure but stationary for remote operations in places without electricity. Electric hydraulic pumps can be both mobile and stationary, as well as air hydraulic pumps. Air hydraulic pumps require compressed air at the operation site.

Operating temperature: The application operating temperature can affect the size of the oil reservoir needed, the type of fluid, and the materials used for the pump components. The oil is the operating fluid but also serves as a cooling liquid in heavy-duty hydraulic pumps.

Operating noise: Consider if the environment has a noise requirement. A hydraulic pump with a fuel engine will generate a higher noise than an electric hydraulic pump of the same size.

Spark-free: Should the hydraulic pump be spark-free due to a possible explosive environment? Remember, most operating fluids are derivatives of petroleum oil, but there are spark-free options.

A hydraulic pump transforms mechanical energy into fluid energy. A relatively low amount of input power can turn into a large amount of output power for lifting heavy loads.

A hydraulic pump works by using mechanical energy to pressurize fluid in a closed system. This pressurized fluid is then used to drive machinery such as excavators, presses, and lifts.

A hydraulic ram pump leverages the energy of falling water to move water to a higher height without the usage of external power. It is made up of a valve, a pressure chamber, and inlet and exit pipes.

A water pump moves water from one area to another, whereas a hydraulic pump"s purpose is to overcome a pressure that is dependent on a load, like a heavy car.

Centrifugal pump design provides good resistance to abrasive solutions and extra flow for agitation. The advantages of the hydraulic pump are mounting versatility, customized performance, and ease of maintenance. They are designed to offer long trouble-free life when matched to a hydraulic power source which will give the correct oil flow and pressure. A wide range of pump outputs can be achieved by simply controlling oil flow and pressure to the hydraulic motor.

We offer a comprehensive range of rugged and dependable products to meet virtually any flow, pressure, material and cost requirement. Tough open and closed center tractor applications challenge any pump’s reliability. Delavan Magnum pumps meet the challenge with superior design, precision engineering and high-quality components.

These hydraulically-driven, cast iron and stainless steel pumps provide fluid flow up to 191 GPM and pressure to 140 PSI, at temperatures up to 140°F. They are available in open and closed hydraulic system configurations.

Additional features include a corrosion-resistant nylon impeller and Viton/ceramic seals, as standard. A polypropylene impeller and Viton/silicon carbide seals are available. A standard selection of hydraulic motors offers simple off-the-shelf replacement and covers all applications, and types of tractors. Optimum hydraulic performance is achieved with an optimally matched pump and motor, which provides cooler running temperatures for less heat and longer life.

For hydraulic systems that place high demands on control engineering, servo pumps are the perfect solution. The basic version of these pump systems also consists of three main components:Servo inverter

Servo pumps control the pressure or the volume flow. They precisely convert electrical energy into the hydraulic energy that is currently needed in the system. The classic use of valves for control can be either completely or partially omitted. This considerably simplifies every hydraulic system.

Gear Pump Manufacturing (GPM) manufactures a complete range of internationally interchangeable commercial components for Bearing gear pumps, Bushing gear pumps, Motors and Flow Dividers.

At Transcat, you can rent hydraulic pumps with the rugged durability and consistent performance you need for your torque and tension applications. Transcat offers flexible weekly and monthly terms on our hydraulic pump rentals that meet a range of tightening applications. When you need hydraulics to exert torque and properly tighten or loosen a connection, look at the top pumps available through our

Check that the pump shaft is rotating. Even though coupling guards and C-face mounts can make this difficult to confirm, it is important to establish if your pump shaft is rotating. If it isn’t, this could be an indication of a more severe issue, and this should be investigated immediately.

Check the oil level. This one tends to be the more obvious check, as it is often one of the only factors inspected before the pump is changed. The oil level should be three inches above the pump suction. Otherwise, a vortex can form in the reservoir, allowing air into the pump.

What does the pump sound like when it is operating normally? Vane pumps generally are quieter than piston and gear pumps. If the pump has a high-pitched whining sound, it most likely is cavitating. If it has a knocking sound, like marbles rattling around, then aeration is the likely cause.

Cavitation is the formation and collapse of air cavities in the liquid. When the pump cannot get the total volume of oil it needs, cavitation occurs. Hydraulic oil contains approximately nine percent dissolved air. When the pump does not receive adequate oil volume at its suction port, high vacuum pressure occurs.

This dissolved air is pulled out of the oil on the suction side and then collapses or implodes on the pressure side. The implosions produce a very steady, high-pitched sound. As the air bubbles collapse, the inside of the pump is damaged.

While cavitation is a devastating development, with proper preventative maintenance practices and a quality monitoring system, early detection and deterrence remain attainable goals. UE System’s UltraTrak 850S CD pump cavitation sensor is a Smart Analog Sensor designed and optimized to detect cavitation on pumps earlier by measuring the ultrasound produced as cavitation starts to develop early-onset bubbles in the pump. By continuously monitoring the impact caused by cavitation, the system provides a simple, single value to trend and alert when cavitation is occurring.

The oil viscosity is too high. Low oil temperature increases the oil viscosity, making it harder for the oil to reach the pump. Most hydraulic systems should not be started with the oil any colder than 40°F and should not be put under load until the oil is at least 70°F.

Many reservoirs do not have heaters, particularly in the South. Even when heaters are available, they are often disconnected. While the damage may not be immediate, if a pump is continually started up when the oil is too cold, the pump will fail prematurely.

The suction filter or strainer is contaminated. A strainer is typically 74 or 149 microns in size and is used to keep “large” particles out of the pump. The strainer may be located inside or outside the reservoir. Strainers located inside the reservoir are out of sight and out of mind. Many times, maintenance personnel are not even aware that there is a strainer in the reservoir.

The suction strainer should be removed from the line or reservoir and cleaned a minimum of once a year. Years ago, a plant sought out help to troubleshoot a system that had already had five pumps changed within a single week. Upon closer inspection, it was discovered that the breather cap was missing, allowing dirty air to flow directly into the reservoir.

A check of the hydraulic schematic showed a strainer in the suction line inside the tank. When the strainer was removed, a shop rag was found wrapped around the screen mesh. Apparently, someone had used the rag to plug the breather cap opening, and it had then fallen into the tank. Contamination can come from a variety of different sources, so it pays to be vigilant and responsible with our practices and reliability measures.

The electric motor is driving the hydraulic pump at a speed that is higher than the pump’s rating. All pumps have a recommended maximum drive speed. If the speed is too high, a higher volume of oil will be needed at the suction port.

Due to the size of the suction port, adequate oil cannot fill the suction cavity in the pump, resulting in cavitation. Although this rarely happens, some pumps are rated at a maximum drive speed of 1,200 revolutions per minute (RPM), while others have a maximum speed of 3,600 RPM. The drive speed should be checked any time a pump is replaced with a different brand or model.

Every one of these devastating causes of cavitation threatens to cause major, irreversible damage to your equipment. Therefore, it’s not only critical to have proper, proactive practices in place, but also a monitoring system that can continuously protect your valuable assets, such as UE System’s UltraTrak 850S CD pump cavitation senor. These sensors regularly monitor the health of your pumps and alert you immediately if cavitation symptoms are present, allowing you to take corrective action before it’s too late.

Aeration is sometimes known as pseudo cavitation because air is entering the pump suction cavity. However, the causes of aeration are entirely different than that of cavitation. While cavitation pulls air out of the oil, aeration is the result of outside air entering the pump’s suction line.

Several factors can cause aeration, including an air leak in the suction line. This could be in the form of a loose connection, a cracked line, or an improper fitting seal. One method of finding the leak is to squirt oil around the suction line fittings. The fluid will be momentarily drawn into the suction line, and the knocking sound inside the pump will stop for a short period of time once the airflow path is found.

A bad shaft seal can also cause aeration if the system is supplied by one or more fixed displacement pumps. Oil that bypasses inside a fixed displacement pump is ported back to the suction port. If the shaft seal is worn or damaged, air can flow through the seal and into the pump’s suction cavity.

As mentioned previously, if the oil level is too low, oil can enter the suction line and flow into the pump. Therefore, always check the oil level with all cylinders in the retracted position.

If a new pump is installed and pressure will not build, the shaft may be rotating in the wrong direction. Some gear pumps can be rotated in either direction, but most have an arrow on the housing indicating the direction of rotation, as depicted in Figure 2.

Pump rotation should always be viewed from the shaft end. If the pump is rotated in the wrong direction, adequate fluid will not fill the suction port due to the pump’s internal design.

A fixed displacement pump delivers a constant volume of oil for a given shaft speed. A relief valve must be included downstream of the pump to limit the maximum pressure in the system.

After the visual and sound checks are made, the next step is to determine whether you have a volume or pressure problem. If the pressure will not build to the desired level, isolate the pump and relief valve from the system. This can be done by closing a valve, plugging the line downstream, or blocking the relief valve. If the pressure builds when this is done, there is a component downstream of the isolation point that is bypassing. If the pressure does not build up, the pump or relief valve is bad.

If the system is operating at a slower speed, a volume problem exists. Pumps wear over time, which results in less oil being delivered. While a flow meter can be installed in the pump’s outlet line, this is not always practical, as the proper fittings and adapters may not be available. To determine if the pump is badly worn and bypassing, first check the current to the electric motor. If possible, this test should be made when the pump is new to establish a reference. Electric motor horsepower is relative to the hydraulic horsepower required by the system.

For example, if a 50-GPM pump is used and the maximum pressure is 1,500 psi, a 50-hp motor will be required. If the pump is delivering less oil than when it was new, the current to drive the pump will drop. A 230-volt, 50-hp motor has an average full load rating of 130 amps. If the amperage is considerably lower, the pump is most likely bypassing and should be changed.

Figure 4.To isolate a fixed displacement pump and relief valve from the system, close a valve or plug the line downstream (left). If pressure builds, a component downstream of the isolation point is bypassing (right).

The most common type of variable displacement pump is the pressure-compensating design. The compensator setting limits the maximum pressure at the pump’s outlet port. The pump should be isolated as described for the fixed displacement pump.

If pressure does not build up, the relief valve or pump compensator may be bad. Prior to checking either component, perform the necessary lockout procedures and verify that the pressure at the outlet port is zero psi. The relief valve and compensator can then be taken apart and checked for contamination, wear, and broken springs.

Install a flow meter in the case drain line and check the flow rate. Most variable displacement pumps bypass one to three percent of the maximum pump volume through the case drain line. If the flow rate reaches 10 percent, the pump should be changed. Permanently installing a flow meter in the case drain line is an excellent reliability and troubleshooting tool.

Ensure the compensator is 200 psi above the maximum load pressure. If set too low, the compensator spool will shift and start reducing the pump volume when the system is calling for maximum volume.

Performing these recommended tests should help you make good decisions about the condition of your pumps or the cause of pump failures. If you change a pump, have a reason for changing it. Don’t just do it because you have a spare one in stock.

Conduct a reliability assessment on each of your hydraulic systems so when an issue occurs, you will have current pressure and temperature readings to consult.

Al Smiley is the president of GPM Hydraulic Consulting Inc., located in Monroe, Georgia. Since 1994, GPM has provided hydraulic training, consulting and reliability assessments to companies in t...