Engineering Basics

By Josh Cosford, Contributing Editor Pascal’s Law, a fundamental principle of fluid power, explains how pressure in an enclosed fluid is uniformly transmitted to move and support loads. Sometimes, we fluid power professionals can’t see the forest for the trees. We take for granted the first-day education we experienced in college or university that provided…

By Josh Cosford, Contributing Editor There are three ways to plumb a hydraulic system — rigid systems, flexible systems or a combination of the two. Rigid systems include pipe and various forms of tube, while flexible systems are assembled using only hydraulic hose. Most machines today are created using a combination of fixed plumbing, where […]

By Josh Cosford, Contributing Editor From selecting the right fluid to keeping machines clear of snow, regular cold weather hydraulic preparation and maintenance will ensure smooth and consistent machine operation from start-up. As I sit here writing this article about cold weather hydraulic maintenance, the temperature in my Canadian city hovers around 77°F (25°C). Usually,…

By Josh Cosford, Contributing Editor Although a hydraulic machine could run off highly crude forms of hydrocarbons, without a complement of additives, the performance and longevity of your hydraulic machine would suffer. Welcome to Part Seven of the Hydraulic Oil Analysis series, where we dig deep into the various additives that are always or usually […]

By Josh Cosford, Contributing Editor When I sat in my first fluid power class 18 years ago, I remember learning about built-in contamination and how the reservoir was the biggest offender. The welds and their slag were the biggest problems, the teacher stated, but a close second was the debris from pipe threading machines. Looking […]

I never thought I’d be writing this article, even if you asked me a year ago. Mobile hydraulic machines are often high-powered beasts with insatiable power demands that traditionally disqualified battery power. However, the proliferation of electric passenger vehicles has funnelled investment dollars into battery technology, which has trickled down into other industries. By removing […]

By Donald Krause, Industry Consultant, Ohio Fabricators Company Exploring the basics of spin-on filters: design and functionality Spin-on filters have cemented their position as a cornerstone of liquid filtration and tank breather applications, thanks to their unique design and operational efficiencies. These filters consist of a self-contained housing and filter element assembly, which facilitates straightforward […]

In this blog post, we will discuss the fifth of five industrial compressor capacity control modes. A very efficient method of controlling a compressor at part load using variable speed mode. With this type of compressor, an electronic drive is fitted to a specially designed compressor with air end components matched to the intended speed […]

By Josh Cosford, Contributing Editor During everyone’s basic training in fluid power, we talk about “spring-centered” this and “spring-retract” that. Springs are used in nearly every component in hydraulics; valves, pumps and cylinders. So prolific in hydraulic components that it’s clear we’re taking springs for granted. Ground compression springs are used in most pressure valves…

In this blog post, we will discuss the third of five industrial compressor capacity control modes. A moderately efficient method of controlling a compressor at part load uses load/unload mode with adequately sized storage receiver capacity. With this mode, a pressure switch, or electronic control, is used to provide load and unload signals to the […]

In this blog post, we will discuss the second of five industrial compressor capacity control modes. The least efficient method of controlling a compressor at part load is using modulating mode by way of pneumatically controlled inlet valve control. With this mode, a pneumatic system detects the compressor discharge pressure and compares it to a […]

In this blog post, we will discuss the first of five industrial compressor capacity control modes. The simplest method of controlling a compressor is Start/Stop mode using pressure switch control. This control simply turns on the compressor to run at full load when the pressure hits a lower pressure level — and turns off the […]

By Josh Cosford, Contributing Editor This is part 6 in this series on hydraulic oil analysis, and if you’ve missed any of the previous issues, you can find them here — part 1, part 2, part 3, part 4, and part 5. I’ve covered everything from viscosity to water saturation already, and we’re not done […]

By Josh Cosford, Contributing Editor One of the few disadvantages of hydraulics is the mass added to components capable of withstanding thousands of pounds of pressure. Of course, the raison d’ệtre of hydraulics is the transfer of pressurized fluid to achieve work. But do high-pressure components have to be high mass, especially on mobile machines? […]

By Josh Cosford, Contributing Editor In part 5 of this series covering hydraulic oil analysis, we move on to discuss acidity. As it pertains to hydraulic oil, we need to know the total amount of acidic substances found within the sample. Most commonly referred to as the Total Acid Number, or TAN for short, the […]

By Josh Cosford, Contributing Editor If your hydraulic cylinder is moving slowly and you’re reading this article, your cause is not likely a lazy operator. Your situation is obviously one where an expected performance isn’t being met, or there was a sudden and dramatic slowdown of your cylinder velocity. Diagnosing the cause of a cylinder…

By Josh Cosford, Contributing Editor Hydraulic hoses come in many sizes and designs, and the expression of each design is a result of the purpose of that hose. Generally, there are three common locations where a hose is used in a hydraulic system: suction lines, working lines and return lines. Each location has its own […]

Contributed by Enrique Busquets  •  Director of Engineering Systems and Components, Bosch Rexroth Fueled by unceasing innovation, electric motors have solidified their position as a catalyst for change, reducing countries’ greenhouse gas emissions (ghg) and lowering total cost of ownership for heavy- and medium-duty vehicles and machinery. The accelerated adoption of electric motors has been […]

It is common to see the air in a complete plant dried by a desiccant dryer only to service one small end-use that is subject to freezing temperatures. The purge from a large desiccant dryer is much more costly than that of a small point-of-use dryer, which can be placed on the outdoor feed. The […]

By Josh Cosford, Contributing Editor In the bustling battlefield of pneumatic systems’ hose and tubing, two contenders stand ready for combat: polyethylene and nylon tubing. Armed with unique strengths and weaknesses, they prepare to face off in the high-pressure war, so let’s dive into this skirmish and see who emerges victorious. Round 1: The Durability […]

Understanding the intricacies of aircraft hydraulic systems provides insight into the engineering marvels that keep aircraft flying safely through varying conditions. By Josh Cosford, Contributing Editor Aircraft hydraulic systems are a special breed of essential components in modern aviation, providing the power and control necessary for various functions that provide the safe and efficient flights…

In linear motion applications, pneumatics, servo pneumatics, and controlled pneumatics each deliver unique motion and force capabilities. Contributed by By Frank Langro, Director of Product Market Management, Pneumatic Automation, Festo Pneumatic linear actuators are fundamental for automation because of their low cost, ease of installation and operation, high yet compliant force, speed, compactness, safety in hazardous areas, […]

Contributed by Gary Molton • BSc, Owner, Engineering Adventures Poor assembly or using the wrong type of fluid power fitting has been shown to increase risk of fluid leakage and industrial injury. Fitting designs have changed considerably over the last 30 years to reduce these risks but this has resulted in a myriad of assembly […]

By Josh Cosford, Contributing Editor Comparing electrical with hydraulics is one of my favorite topics to write about. When you study both fields, you quickly realize how much the concepts, mathematics and symbology coincide. However, not all readers share my same enthusiasm for the analogy. Many years ago, one LinkedIn member commented that I was […]

By Josh Cosford, Contributing Editor If you’re not terribly familiar with hydraulic fittings, you may think BSPT is a typo. Is it supposed to be BSPP (British Standard Pipe Parallel) or perhaps NPT (National Pipe Thread)? No, it’s not a typo – we’re actually talking about British Standard Pipe Taper, which is the version of […]