Insane Hydraulics
Bold and audacious blog about fluid power
PAGE 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21,
I realize that people who are used to Eaton orbital steering valves will find no news in this article, but folks like me, who deal exclusively with classic Danfoss units may find it surprising that Two Steering Valves With Equal Displacements Can Produce Very Different Steering Speeds.
Strange Behavior of Danfoss 155G4074 PVEH Electro-Hydraulic Actuator
Today's post is a rant from a person who spent the last eight days replacing old hoses with new hoses and old HPUs with new HPUs - Random Advice for Aspiring Hydraulic Technicians.
Well... I must confess that a week underground doing double shifts does take its toll... Yet I still somehow managed to finish my interactive nomogram - and now it has three flow ranges, the possibility to switch between gallons US and UK, and the recommended flow velocity highlights. Due to how much modern browsers (especially mobile) like caching, you may need to go to the options, and clear the browsing history to visualize correctly the updated page - Interactive Nomogram for Sizing Hydraulic Hoses.
Several days ago, when I was in the field, I needed to quickly ballpark the correct size for a hydraulic line, and I pulled out my phone and opened a page that I created a long time ago for this very purpose. The page was supposed to have an interactive monogram, where one would push about a virtual ruler, and get the necessary figures on the spot (yes, I do have a soft spot for monograms, slide rules, and other types of mechanical calculators). I immediately saw that the page does not work well with mobile devices (especially phones, and especially in vertical orientation), and so I decided to do a major upgrade: instead of using a static image and a piece of code for moving a line, I wrote a program that draws the nomogram parametrically (in other words creates the lines in the code), which turns it into a very precise tool, and allows you to change the scale, or the annotations of axes dynamically - for example, change the flow range from 3...400 l/min to, say, 400...1000 l/min, or replace the US gallons with UK gallons. Now, I haven't implemented the range/units feature yet - because the annual maintenance stop in the mine has been taking up pretty much all of my free time - but I should be able to finish it this week (if I survive through it...). I did manage to write a boilerplate that works within the flow range of the old nonogram (400 l/min). What makes it even cooler is the fact that the numbers that are displayed above the ranges are actually the "geometric" numbers - i.e. derived from the coordinates of points where the ruler line crosses the range lines, but the speed figures at the bottom of the nomogram are calculated - and you can see they are spot on! So, please, check it out, and, if possible, see if it works well on your mobile devices (if you already use this page, you'll need to refresh it to get the latest version) - any feedback will be greatly appreciated: Interactive Nomogram for Sizing Hydraulic Hoses.
A Test Bench - The Best Place to Learn Pump Troubleshooting.
Today's blog is a heads-up to all pressure filter users - I am talking about not one - but two high-pressure filter failures, one of which I've seen many times, and the other one only once - it turned up last week and, frankly speaking, puzzled me so bad that I feel I must document it - Strangest Failure of a Pressure Filter Element.
This was supposed to be a short post, but as is always the case, I got "carried away" and a three-paragraph article turned into a multiple-page rant... - Let's Talk About Hydropneumatic Accumulators (Part 3) - Getting Real
Let's Talk About Hydropneumatic Accumulators (Part 2)
My (Latest) Thoughts on Aftermarket Spares for Hydraulic Pumps and Motors.
Exploring the Design of a Low-Cost 100-bar Digital Pressure Gauge.
Testing Another Cheap Digital Pressure Gauge Kit.
This week I opened yet another 15000 hour+ PV180 (impaired by unscheduled "hydraulic fluid enhancement" with generous amounts of water), and I, once again, found a "sneaky" failure that I've seen before (on this and other pump series). I feel I need to address it again in Something You Should Know Before Overhauling a Parker PVplus Pump.
The Most Embarrassing Mistake of My Career as a Hydraulic Technician.
Not so long ago I described how I had to set the neutral of several large closed-loop pumps, and I mentioned a "secret technique" that I used on the pumps and said that I would reveal it one day. Well - today is the day, and I present to you an "alternative centering technique" in Setting Hydraulic Pumps With Lasers
Some details of The Analog Front End of the Cheapest Digital Pressure Gauge.
Adding another myth to the collection - Bigger Motor Displacement Automatically Guarantees Bigger Torque.
A Simple Way of Protecting DIY Steel Parts From Rust.
Testing the Cheapest Digital Pressure Gauge I Could Find
You know me - I like taking stuff apart, and naturally, when we got several of these "extremely economical" digital pressure gauges, I immediately decided to break into one - The Cheapest Digital Pressure Gauge I Could Find. And, of course, a Happy New Year to All!!!
Merry Christmas to all and thank you for being there for this blog! And also - a short video today in When Valves Sing. (Unfortunately, YouTube's video compression made the digital pressure gauge reading somewhat blurry, and I didn't make a close-up shot of the gauge's screen, but, hopefully, it still conveys the message. I'll make sure to make a better one the next time I catch one of these).
I kind of screwed up... again... And I am glad I did because fixing my blunder armed me with another piece of useful practical knowledge, and now I can pass the "weaponry" on to you in Something to Bear in Mind When You Assemble Multi-Section Load Sensing DCVs.
About the O-ring Patent and More....