That’s a counterbalance valve (CBV = counterbalance valve). The check valve lets oil flow freely into the cylinder to lift. Coming down, oil has to push past a relief spring, and the dashed pilot line from the other side helps open it, so the load can’t run away or drop if a hose fails. The arrow across the spring means the setting is adjustable. On a lift table it’s the part that stops the platform falling, so it’s worth showing clearly.
On the drawing: the core symbol set has a check valve in the water network family, it’s in every organisation with the SCADA module. I’d place that, label it « CBV-1 counterbalance » with a text, and you’re honest about what it is. The palette search matches names and common other names, so search « check » rather than the part number.
If you want a proper hydraulic/process valve symbol, the Process library covers pumps and valves and ISA instruments. You can browse it before buying: symbols of a locked library show in the palette with a padlock and a still picture. Just see whether one fits before paying. Details: Symbols and industry packs.
Worth putting your pressure transmitter between the CBV and the cylinder on the drawing too, that’s where a dropping load would show first.