A lock valve holds a cylinder exactly where you left it. When the control valve centres, the lock closes and the load cannot drift, creep or settle — not through the spool, not through anything. When the operator calls for movement, pilot pressure from the opposite line opens it again.

This is what a spool with a "closed centre" cannot do on its own. Every directional valve leaks a little across the spool; on a loaded cylinder that leak is a slow, unstoppable drift.

The VBSL / VBDL series is the compact, higher capacity alternative to the VBS / VBD inline valves. Shorter body, higher flow for the same port size, and a pilot ratio suited to mounting directly on or very close to the cylinder.

Mount it at the cylinder, not at the valve bank. A lock valve is only as good as the hose between it and the cylinder. Put it on the cylinder port and a burst hose cannot drop the load; put it back at the valve bank and it can.

Also available: VBDL38-7:1, a 3/8" double lock valve with a 7:1 pilot ratio for loads that need a lower pilot pressure to release. Ask if you need it.

Manufactured by CBF Hydraulic, Montecchio Maggiore, Italy.