One Day In the Life of a Hydraulics Go-To-Guy

The hydraulics Go-To GuyBack in 1991, the hydraulics company I was working for had supplied conversion kits to change the hydraulic piston pump on an ROV (remotely operated [submersible] vehicle) from an obsolete brand to Linde.

The kits had been supplied as an in-field replacement, so that the changeover could be done when necessary. In other words, when the existing hydraulic pump failed. … Read more

Why Direction Control Valve Solenoids Fail

Hydraulic Solenoid Valve (Bosch Rexroth)

In the case of AC electric coils, the resistance or impedance of the coil is lowest when the solenoid is open, i.e. when the plunger is out. Impedance increases as the plunger is pulled into the closed position. As a result, the current draw of an AC solenoid is highest when the solenoid is open (plunger out) and lowest when … Read more

The Correct Way to Calculate the Efficiency of a Hydraulic Pump

Rexroth A2VSL1000 hydraulic pumpThe hydraulic pump is the hardest working component of a hydraulic system. And as the pump wears in service, internal leakage increases and therefore the percentage of output flow available to do useful work (volumetric efficiency) decreases. If volumetric efficiency falls below a level considered acceptable for the application, the pump will need to be changed-out. In a condition-based maintenance … Read more