ENERPAC has released a vacuum valving system that drastically improves the retraction times of single-acting heavy lift hydraulic cylinders commonly used throughout Australian industry. It is available from Applied Power Australia .
The new VM3VA valving can be applied to new cylinders or retrofitted to help retract hydraulics more than five times faster than cylinders without the feature. A two minute wait for a 50t, 700 bar cylinder to retract becomes a twelve second wait.
Single-acting high pressure (700 bar, 10,000psi) cylinders are among the simplest and most economical cylinders used by Australian industry. They feature powered extension of cylinder plungers to do the work required of them, then rely on springs and/or gravity to return the plunger to its original position. Unfortunately, this leisurely retraction can substantially increase cycle times and slow down repetitive jobs.
Enerpac's vacuum valving operates in series with manual valving that governs cylinder extension and retraction. It can be fitted to existing VM4 valves and to VSP424 valves with the addition of a relief valve in the retract port.