Portable hydraulic tools are taking over more tasks that would otherwise require dangerous and strenuous human labour. These time and back-saving devices make significantly lighter work of a plethora of plant maintenance chores such as lifting equipment, tightening and loosening bolts, spreading flanges, and cutting corroded nuts. As powerful as these tools are, using the right pump is crucial to ensuring safety and efficiency on the job.
Global hydraulics industry leader Enerpac advises that because of the vast spectrum of capabilities and functions of portable hydraulic tools, several factors should be taken into account when determining the appropriate power source. Hydraulic tool users can choose from three primary power sources: hand, electric, or air. Each method offers unique benefits relative to a wide range of situations.
Hand Pumps
A hydraulic hand-powered pump is usually the simplest and most economical type of pump to use. It is ideal for sporadic use of small or medium-sized hydraulic tools and is especially suitable for use in remote locations where other reliable power sources cannot be secured. In some potentially hazardous cases, a manually powered pump could be the only viable option as it does not require a source of power that could ignite.
Hand-operated pumps are available in sizes ranging from smaller single-speed devices weighing under 5 kg to larger metal two-speed models weighing almost 45 kg. These pumps can come with oil capacities of up to eight litres and valving for either single or double-acting tools. The proper hand pump will meet requirements for system oil capacity, fluid compatibility, and valving type. Duty cycle is not a major issue because a hand pump is normally used for short one-time tasks.
The primary drawback with hand-powered pumps is its reliance on manual effort: its use is limited to the physical ability of its operator. Additionally, since one hand must be used to work the pump, the operator must sacrifice convenience and efficiency. Although hand-powered pumps are quite portable, they may not be operative in cramped locations, such as on ladders or catwalks, where operators may not be able to generate enough power. Further, these types of pumps require a flat surface for operating.
Enerpac’s new ULTIMA line of hand hydraulic pumps is constructed for greater ease, safety, and longer life. These pumps work especially well for applications where durability matters most. The ULTIMA series’ design lessens handle effort by as much as 20 percent without sacrificing performance or speed. The ULTIMA series’ bypass system also diminishes loads commonly created by two-stage hand pumps. Their cutting-edge Power Push construction distributes loads more efficiently to minimise operator fatigue.
Electric Pumps
Electric pumps are the most common high-pressure pumps used after hand-powered pumps. Electric units come with versatile options of motor types, heat exchangers, valves and actuators, and operating voltages. The abundance of variations makes it challenging to choose the correct pump in this category.
While the major factors in selecting a pump are size, voltage, reservoir capacity, and valving, the additional aspects of electric motor and the necessary duty cycle are critical in choosing the best electric pump. Duty cycle is the time frame in which the pump will run at a particular percentage of full load. Most high-pressure pumps are not suitable for higher duty cycles. Tasks that necessitate pressures over 5,000 psi for over an hour require pumps with coolers to regulate oil temperatures at a safe level of 65C (150F) or less. Electric motors are either induction or universal. The application determines the proper selection of either.
Induction motors operate for longer periods of time with greater durability. They perform at reduced noise levels, which is a significant benefit for jobs in restricted spaces. Induction motors are usually heavier, which explains why they are more commonly used in areas where a stationary, high-production pump is needed. An induction motor requires a highly stable electrical power source. A reduction in line voltage — even as small as 10 percent — could cause extensive damage to the motor. Using this kind of pump is not advisable for settings where electricity is sourced by a generator with an extension cord.
A universal motor pump may be ideal for situations that require the performance and speed of an electric pump and flexibility with portability and power sources. These motors are lighter than induction motors, provide more power in proportion to weight, and can function with less stable electrical power. If necessary, universal motors can run full torque on half of terminal rated voltage.
Enerpac’s ZU4 line of hydraulic pumps features portability with a strong 1.25kW universal motor. A brand new pump element construction facilitates smoother oil flow with fewer moving components and reduced friction. Select models can be adjusted for special tasks such as bolting.
Enerpac’s ZE line of electric hydraulic pumps is designed for saving power and increasing durability with fewer moving parts as well, thereby reducing friction and oil flow turbulence. The ZU and ZE electric pumps are constructed for increased efficiency to allow for high bypass pressure and oil flow, cooler operating, and significantly less current draw than similar pumps. Enerpac also offers special purpose torque wrench pumps that can provide superior, reliable productivity with easier operation and maintenance.
The TQ-700E Classic bar electric pump includes a brushless motor for continuous operating and convenient maintenance in high-cycle situations and rugged environments. This pump is designed for use with turbine erections, gearbox installations, wind farms, pressure vessel and pipeline maintenance, tower foundation bolting, and myriad applications in demanding industries such as construction, gas and oil, and mining and energy. The TQ-700E Classic is lightweight and runs well with generators. It is suitable for remote environments such as mobile plant workshops on mining sites or field maintenance for heavy plant, shovel, and dragline repair.
Enerpac’s XC line of cordless pumps marks a breakthrough in pumping technology. These pumps perform like electric or air-powered pumps with the convenience and portability of hand-powered pumps. This brand new offering of cordless hydraulic pumps is an economically sound solution for challenging locations, providing the power, speed, and durability expected of a corded pump.
Enerpac’s cordless hydraulic pumps feature a bladder reservoir that eradicates venting and allows for flexible, leakage-free operation. They are ergonomically designed for maximum portability and easy handling. Constructed for extensive wear and hard-to-reach areas, XC pumps feature lightweight materials, a sturdy motor, and a Lithium-Ion battery.
Air Pumps
Like a hand-powered pump, an air pump is relatively easy to use, portable and lightweight. Air pumps are available in many different sizes. They offer greater performance capabilities relative to hand-operated pumps. Another advantage is that they can be safely used in a location where an electrical current could be hazardous, provided that the pump is positioned at a sufficient distance from a compressor.
Reciprocating pumps are more popular than other air pumps, offering greater performance at lower cost. Usually, they are single-speed models that provide high flows at lower pressure since it can operate faster under diminished loads. However, a dual reciprocating air-powered pump is available for situations where high flow is necessary. With this design, the high-flow unit can stall at high pressure without an unloading valve.
A rotary air pump is ideal for higher performance needs. This type of pumps utilizes a rotary air motor which drives an ordinary hydraulic pump. However, rotary air pumps are typically noiser, heavier, and need more air than reciprocating pumps.
Sufficient air supply is the most critical factor to consider when choosing either air pump style. All air-powered pumps require a certain air flow rate to perform at their maximum level. If the airflow rate cannot be determined beforehand, a common standard is that each horsepower at the compressor will supply five scfm (approximately 142 litres).
Air pumps are suitable for operation in environments where pneumatic lines have been installed and are easily accessible. However, air pumps are typically more costly to use relative to electric pumps as compressed air tends to power tools less efficiently.
The XVARI XA air-over-hydraulic foot pump by Enerpac offers significantly quicker, safer and more refined control of jobs than traditional pumps. Its rotating dual-stage pump element and air motor provide two times the oil flow of most air-powered pumps. This innovative technology is paired with ergonomic control functions for safe, efficient hands-free operating with greater stability and reduced fatigue.
Guidelines for Pump Selection
- Determine proper ratings for maximum operating pressure, oil capacity, flow rate, cycle frequency and duration, and valving.
- Analyze cost factors including impact on productivity and manpower.
- Research ergonomic and safety features. Weight, dimensions and portability must be considered to help determine the level of dexterity and strength the operator will need. Noise levels should be as low as possible.
- Know the power source requirements. The power that is safely available often determines what pump is best to use.
- Ensure that tool speed matches pump size needed. Power requirements increase exponentially with pump size. The ideal pump matches the necessary speed without superseding it.