Two different jobs, often confused:

Main relief sits in the inlet and caps pressure for the whole valve. Every DCV has one. Change it to re-rate the machine or because it has drifted.

Port relief sits in an individual A or B port and protects that one function at a lower pressure than the rest. This is how you stop one cylinder being over-pressured while everything else runs at full system pressure — and how you protect against shock from an external load pushing back on a closed port.

Anti-cavitation versions also let oil in. When a load with inertia is stopped suddenly, the actuator keeps moving and tries to draw a vacuum behind itself; the anti-cav valve opens and feeds it from tank instead of pulling air past the seals.

Set the port relief below the main relief, or it will never open and you have wasted the part.

DCV spares are model specific. A DCV40 kit will not fit a DCV60, even where the part looks identical. Check the model plate on the valve before ordering.

Technicians Advice

Match the kit to the spool code stamped on your section - spools are matched to their bore in production, so a kit fixes seals and springs, not a scored bore. Reseal on the bench, not on the machine: clean the cavity, oil every seal before assembly, and never drive a seal home dry. If a spool is scored or the bore shows wear lines, replace the section - new seals will not save it.

Fits These Valves

DCV60A - 60 L/minDCV100 - 100 L/minDCV150 - 150 L/minDCV200 - 200 L/min