By Josh Cosford, Contributing Editor A clutch is a mechanical device that disconnects a driveshaft from its input shaft, pausing output torque. Clutches — hydraulic or otherwise — often use friction to engage the input and output ends of the assembly. The friction material is not unlike the compound employed by vehicles for their brake […]
Engineering Basics
What type of pressure valve do I need?
Pressure valves use a poppet, ball or (rarely) a spool pushed offset by a spring, and that description you’ll find accurate for nearly every pressure valve ever made. This is because a pressure valve simply resists hydraulic pressure until the force to overcome its spring rises above the value of that spring — common sense. […]
How do you select hydraulic pumps?
By Josh Cosford, Contributing Editor Hydraulic pumps convert mechanical energy into hydraulic energy, and it goes without saying every hydraulic system requires such a device to transmit controlled force to the actuators of your hydraulic machine. How you select a pump comes down to many factors but working through this guide will help you select […]
How do directional seated valves operate?
In the most traditional sense, a directional control valve simply dictates the direction of hydraulic flow in some regard. The inline check valve is generally regarded as the most basic version of a directional valve, and simply allows flow in one direction while blocking flow in the opposing direction. Their advantage lies in their simple, […]
When can you use manual hydraulic valves?
By Josh Cosford, Contributing Editor Although many valves have a manual adjustment, as the knob on a flow control or the hex screw on a relief valve, we generally consider a manual valve to be a directional valve operated by a lever, button or knob. Many hydraulic systems run exclusively with manual valves, like your […]
How are ball valves used to ensure hydraulic safety?
By Josh Cosford, Contributing Editor In fluid power, safety is always a concern. Everyone understands the force capacity of hydraulic actuators (which explains why some YouTube hydraulic press channels have millions of subscribers). Indeed, a high-powered hydraulic press can make nearly any material appear no stronger than modelling clay. It’s wise to respect the power […]
When should you use check valves?
By Josh Cosford, Contributing Editor Check valves are the most basic form of directional valve. In their simplest form, a check valve has the singular task of allowing flow in one direction while blocking flow from returning in the opposite direction. These valves are not only simple in their operation but also simple in their […]
When should you use cartridge valves?
By Josh Cosford, Contributing Editor Cartridge valves are a type of compact hydraulic valve that slips or screws into the machined cavity of a ported manifold or block. Unlike other valves, such as monoblock lever valves or stackable industrial valves, the manufacturer leaves the porting for you to decide. Cartridge valves still use poppets or […]
How do linear transducers work?
By Josh Coford, Contributing Editor Temperature, pressure, and displacement are typical transducer offerings. A linear displacement transducer measures linear position or distance, especially when high accuracy is needed. Linear transducers work using a principle called magnetostriction. A typical transducer uses three major components; the sensor assembly, a waveguide and a permanent magnet. The sensor assembly […]
What are the differences between proportional and servovalves?
By Josh Cosford, Contributing Editor The line that separates the performance of servo and proportional valves has blurred in recent years. Some may consider a servovalve to be any valve capable of accurately positioning your actuator with closed-loop control. However, in everyday hydraulic circles, many industry professionals describe a servovalve as a valve with a […]
