# Hydraulic diagrams you can't do without

Marian Tumarkin, my co-author of Hydraulics Made Easy and Advanced Hydraulic Control, sent me an interesting article published in the BBC's News Magazine, called: Diagrams that Changed the World.

One of the examples the article's author Marcus Sautoy cites, involves Florence Nightingale. As Sautoy explains:

"Although better known for her contributions to nursing, her greatest achievements were mathematical. She was the first to use the idea of a pie chart to represent data. She had discovered that the majority of deaths in the Crimean War were due to poor sanitation rather than casualties in battle. She wanted to persuade government of the need for better hygiene in hospitals but realised that just looking at the numbers was unlikely to impress ministers. But once those numbers were translated into a picture - her 'Diagram of the Causes of Mortality in the Army in the East' - the message could not be ignored."

A good diagram is indeed worth a thousand words (or numbers in Nightingale's case). It can also be worth a lot of nickel. Consider the four main types of hydraulic diagrams in common use -- and the consequences of having to manage without them:

Block Diagrams show the components of a hydraulic circuit as blocks joined by lines, which indicate connections and/or interactions.

Cutaway Diagrams show the internal construction of hydraulic components and their flow paths. Because these diagrams typically use colors, shades or patterns in the lines and passages, they are very effective at illustrating different flow and pressure conditions.

Pictorial Diagrams show a hydraulic circuit's components and piping arrangement. The hydraulic components are seen externally and are usually in a close reproduction of their actual shapes in scaled sizes. This aids in hydraulic component recognition and identification.

Graphical Diagrams are the shorthand system of the fluid power hydraulics industry. They comprise simple, geometric symbols, drawn to ANSI or ISO standards that represent the hydraulic components, their controls and connections.

To a hydraulic technician skilled in reading and interpreting them, a graphical circuit diagram or schematic is a valuable aid in identifying possible causes of a problem. And this can save a lot of time and money in a hydraulic troubleshooting situation.

If a hydraulic schematic diagram is not available, the technician must manually trace the actual, physical circuit and identify its components in order to isolate possible causes of the problem. This can be a time-consuming process, depending on the complexity of the hydraulic system.

Worse still, if the hydraulic circuit contains a valve manifold, the manifold may have to be removed and dismantled - just to establish what it's supposed to do. Because if the function of a component within a hydraulic system is not known, it can be difficult to discount it as a possible cause of the problem.

Schematic diagrams eliminate the need to reverse engineer the hydraulic system. A picture may be worth a thousand words, but THIS one can be worth thousands of dollars!

#### Related articles:

If you enjoyed this article, you'll love Brendan Casey's Inside Hydraulics newsletter. It gives you real-life, how-to-do-it, nuts-and-bolts, hydraulics know-how -- information you can use today. Here's what a few members have said about it:

Can't Put It Down
I get e-mails like this all the time. I never find time to read them. I decided to read Issue #30 and I couldn't put it down. I'll make time from now on.

Richard A. Shade, CFPS, Project Engineer (Hydraulic Design), JLG Industries Inc.

So Valuable It Earned Me A Raise
The knowledge I've gained from this newsletter has been so valuable it has earned me a raise!

Jack Bergstrom, Heavy Equipment Mechanic, Sharpe Equipment Inc.

Love It - Keep Them Coming
I just love this newsletter. As a Hydraulics Instructor for Eaton, I make copies and distribute them to my students as I address various topics. Please keep 'em coming.

Michael S Lawrence, Hydraulics Instructor, Eaton Hydraulics Inc.

To get your FREE subscription (\$149 value), simply type your first name and primary email address into the form below and hit 'SUBSCRIBE NOW!'

First Name *
Email *

This is a private mailing list that will NEVER be shared for any reason.
You can also unsubscribe at anytime.