Smooth deceleration and acceleration of hydraulic movements

A common problem in hydraulics is abrupt starts and hard stops, which cause shocks, jerks, increased wear on the hydraulic system, and leakage.

This is often caused by large flows and/or high pressure differences in combination with directional valves where the opening or closing time is very short. The normal switching time for a solenoid valve is up to 50 milliseconds.

Electro-hydraulic soft start and soft stop with solenoid valve and controller

A very effective way to avoid pressure spikes is to use solenoid valves in combination with a controller, such as the SUN Hydraulics XMD.

This allows ramp and switching times to be set for the best balance between response time and pressure spikes. A proportional valve offers a wide range of possibilities, from long ramp times to stepwise or accelerating operation.

The XMD controller is available under the controller section.

Solenoid valves with hydraulic damping – SoftShift soft opening

SUN Hydraulics’ SoftShift solenoid valve series features an orifice in the solenoid tube that dampens abrupt pressure spikes during opening. This does not affect the flow capacity.

This results in an extended response time from when the solenoid valve is energized until it has shifted and opened – between 150 and 200 milliseconds. In this soft-shifting series, 2-, 3-, 4-, and 6-way valves are available.

They can be used as main valves (up to approx. 30 l/min) or as pilot valves in combination with a main stage, such as a pressure relief valve.

Pressure relief valve against shock

At high flows, the opening of a pressure relief valve can cause shocks in the hydraulic system. This results in jerky movements, loud bangs, and increased wear on components.

SUN Hydraulics’ RPT and RVT pressure relief valves feature soft opening to reduce these shocks. The ramp-up time for these valves is 200–400 milliseconds.

To increase the service life of pumps and electric motors in hydraulic power units, this anti-shock valve can advantageously be used. It also provides a smoother startup. These valves use the same cavities as SUN’s standard range of pressure relief valves.

SUN Hydraulics also offers several other valves for reducing pressure spikes in different functions. Please contact us for more information!

You will find antichock pressure relief valve RP*T here

You will find antichock pressure relief valve RV*T here