Brendan Casey's hydraulics blog

In most hydraulic applications there are essentially two ways to get the required power output: high flow at (relatively) low pressure; and low flow at high pressure. This is because power is a product of flow and pressure; increase pressure and you can reduce flow proportionately but still get the same power output. For example, 100 liters/min at 200 bar equates to the same ...

1. Abrasive wear is the scuffing and scoring of a lubricated surface. It can be further divided into two-body abrasion and three-body abrasion. Two-body abrasion occurs when two lubricated surfaces come into direct contact with each ot...

One of our members wrote me with this question:

“I’d like to hear your opinion about isolation valves on pump intake lines. Within our company there is an ongoing debate over whether we should use a more expensive ball valve or a cheape...

The issues which can arise when switching brand and/or type of hydraulic oil, is a question I get a lot. And the crux of this problem, is:
1. You can never completely drain ALL of the original oil out of the hydraulic system; and therefore:
2. There WILL be some mixing of the original and the new oil, so how do you make sure they are miscible (compatible)?

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