BDC - Double counterbalance valve, for closed center
BDC counterbalance valves (SAE/NPTF thread) are used to keep a load locked , the built-in relief valve protects the system from overpressure in the cylinder by draining the oil.
Overcenter valves are particularly used on all cylinders that hold suspended loads. They are manufactured in various sizes with SAE (from SAE6 up to SAE10) and NPTF (from 3/8 NPTF up to 1/2 NPTF) threads.
The hardened and ground obturator and sealing seat guarantee the perfect sealing of the valve, the manifold in which they slide is made of high quality steel with zinc treatment. Normally they are set at 1.3 times the maximum pressure induced on the load.