W3-spool: hydraulic regeneration extends cylinder quickly. Rod side is blocked by B port.
High pressure on rod end pushes flow over external check valve
– Fast traverse. but rod pressure is high!
– Tonnage reduced!
Extending force = rod area x pressure bore
W9-spool: improved W3 (decel like W8)
W4-spool: 4-position, regen spool
– Full tonnage below 33% (P-to-A and P-to-B, like W1)
– Regen above 33% (P-to-A and B blocked, like W3)
