By Josh Cosford, Contributing Editor Hydraulic power units are both the source of hydraulic energy and fluid conditioning. The hydraulic reservoir provides a mounting surface for the hydraulic pump and its prime mover while offering up real estate to mount filters, coolers, valves and accessories. In addition, the reservoir stores the hydraulic fluid, providing a […]
How do you flow test an air compressor?
As compressors age, there can be internal wear or control problems that affect the flow output capacity. Often times, observing the amps of the compressor — and comparing that to the motor nameplate — can show if a compressor has problems. If the amps are low, that usually means the compressor flow capacity is lower […]
Why water-glycol hydraulic fluid maintenance makes all the difference
Keeping equipment working at optimal performance with less downtime and supporting a longer life span are significant factors that make fire-resistant hydraulic fluids a safe and pragmatic choice. As in any hydraulic system, a strong maintenance strategy is vital to reduce component corrosion and thereby avoid the significant costs of replacing parts and unplanned repair […]
Slip rings make continuous rotation possible in hydraulic machinery
Slip rings are small but mighty devices that serve multiple purposes and can be used in various industries. They come in different types, shapes, and sizes and are installed where the stationary part of a machine meets a rotational part. Basic designs include rings that rotate with the rotating part of the machine and static […]
How do air motors work?
By Josh Cosford, Contributing Editor A motor is any device designed to convert one form of energy into rotational mechanical force. For example, an electric motor converts electrical potential into mechanical torque, and a hydraulic motor converts hydraulic energy from pressure and flow into mechanical torque. And an air motor converts compressed air into that […]
What are pneumatic actuators?
By Josh Cosford, Contributing Editor Pneumatic actuators take advantage of compressed air to provide your machine with quick and powerful actuation of nearly infinite possible functions. Pneumatic actuators may take the form of cylinders, motors, slides, grippers and rotary actuators, each of which receives pressurized and compressed air to create linear or rotational force. The […]
What are SAE flanges?
By Josh Cosford, Contributing Editor Permanent plumbing connections, such as those piped or welded, offer the most reliable form of connection for your hydraulic system. But, of course, when the connection is neither flexible (like a hose) nor detachable (like a weld), you have little reason ever to remove the plumbing until you change the […]
How do pneumatics technologies work?
Pneumatics is a fluid power technology similar to hydraulics in that it transmits force through a pressurized medium to create useful work. However, pneumatic technology differs from hydraulics in every critical fashion — compressibility. To be fair, hydraulic oil compresses as well, but only 0.4 percent every thousand psi or so. However, in the simplest […]
What are pneumatic rotary actuators?
By Josh Cosford, Contributing Editor Rotary actuators are devices used to transmit torque through a limited rotational arc. Rather than pneumatic motors, which rotate continuously, pneumatic rotary actuators move a load through a limited range of motion. Some actuators rotate through two discrete positions, while others are capable of positioning at any angle around the […]
What causes hydraulic hose failure?
By Josh Cosford, Contributing Editor Hydraulic hose failures are much like vehicle collisions — they’re not accidents. No longer can you blame weather, road conditions or distractions because it’s always someone’s fault. Unless a meteorite slams into your windshield, causing you to blow through a red light, there is always a cause of collisions. The […]
Pressure makes it go
By Josh Cosford, Contributing Editor Do me a favor — stand up near a wall just out of arm’s length reach. Now raise your arm with your palm facing the wall and very slowly move toward the wall. Without yet touching the wall, tell me where the force comes from to move your body close […]
How do you specify electropneumatic flow controllers and regulators?
Electropneumatic flow controllers and regulators are by nature both electrical and mechanical, thus requiring the designer to develop two sets of specifications for the regulator to function properly. The pneumatic or mechanical portion of the device is the same as a standard flow control valve or regulator. As with many things in fluid power, the […]
What is VSD cooling?
In the compressed air world, the hottest thing in the market lately has been the introduction of variable speed drive controlled compressors. Being hot (as in popular) is good — but being hot as in temperature is not so great. These units, if installed appropriately, can stabilize the air pressure, and save significant amounts of […]
Hydraulic hose routing considerations
By Josh Cosford, Contributing Editor Hydraulic hose enjoys the title of go-to fluid conveyance of choice for many hydraulic machines. Although steel tube is also popular and provides a tidy, permanent solution to plumbing, it is less easily serviced and replaced. Hydraulic hose, when properly manufactured, routed and installed, offers a tidy and permanent solution […]
Designing optimum pneumatic systems for food & beverage packaging
These tips not only adhere to food safety guidelines, but also serve to improve machine utilization and performance. By Steve Bain, Food and Beverage Industry Segment Manager, Festo Before describing the four pneumatic automation design tips for food and beverage packaging applications, it is a good idea to answer a fundamental question: Why apply pneumatic […]
Dealing with filter gauge issues
Air filters very often have differential gauges installed on them to help compressed air system operators detect when the element needs changing. It is very important for maintenance personnel to change the element when it is required. Having high pressure differential causes the air compressor energy input to increase by about 1% every 2 psi […]
The difference between automotive and industrial shock absorbers
By Josh Cosford, Contributing Editor Your first thought upon hearing the term shock absorber leads your mind to the cylindrical tubes mounted to the four corners of your vehicle’s suspension system. Other than the misnomer (“shocks”), your correct thinking applies to the term. Even the term “shock absorber” is a bit misleading, and industry professionals…
What to consider when using TPU for fluid power seals
Contributed by Chuck White, Director of Sales & Marketing, Hallite Thermoplastic Polyurethane (TPU) is widely used in fluid power seal applications and is a family of polymers formed using a combination of isocyanate and polyol crosslinked to create a homogeneous compound polymer. There are many different combinations of these chemicals that may be used to […]
Can electropneumatic regulators be used in hazardous locations?
When thinking of hazardous locations, one’s mind conjures an oil/gas drilling rig, refinery, or underground coal mine — all these locations have in the past utilized traditional pneumatics as risk reduction because they do not have a spark risk, which a solenoid’s electrical actuation requires and creates. Expanding our view of hazardous locations, we should […]
Why is flow meter contamination important?
Thermal mass flow meters are excellent devices to use when measuring compressed air flow. These devices use a hot wire anemometer method of measuring the velocity of the compressed air in the pipe. Two probes are used, one heated and the other not, and are inserted into the compressed air pipe. The flow of air […]
Hydraulic hose tube – it’s the inside that counts
By Josh Cosford, Contributing Editor We’re all taught from a young age to place focus and worth on what’s inside, and the more thought you put into this concept, the more it rings true. For example, would an orange taste any less sweet if, on the outside, it looked like dragon fruit? And, of course, […]
When should you use desiccant breathers?
Hydraulic systems are susceptible to many forms of contamination – particles, heat and water. When each of these contaminants is kept in check, there is no reason your hydraulic oil cannot last indefinitely, all the while providing conditions for a reliable hydraulic system. Water is an especially interesting contaminant because it works its evil in […]
What are accumulator safety blocks?
By Josh Cosford, Contributing Editor Hydropneumatic accumulators combine the power density of hydraulics with the compressibility (and expandability) of air. The accumulator itself uses either bladders, diaphragms or pistons to separate the gas side from the hydraulic side. The air side is pre-charged with nitrogen gas to a pressure appropriate for the application. Nitrogen is…
Avoid this one piston pump mistake
Hydraulic pumps are primarily designed to convert incoming prime mover energy into hydraulic energy, manifested as pressure and flow. The term hydrostatic refers to a state of pressure equilibrium, especially in a confined space. All traditional hydraulic applications are hydrostatic, and in most cases, if you shut down the pump, physical loads should hold fast […]
Understanding proportional valve designs and uses
By Josh Cosford, Contributing Editor The lever-operated directional valves used to control the fore and aft movement of cylinders, or motors’ rotation, offer a performance advantage well above electric solenoid valves. Although inexpensive options are typical for either option, lever valves tend to flow more than their solenoid counterparts. In addition, because pressure and flow…