Description
Flow is allowed bi-directionally between 2 and 3, and blocked at 4 until pressure at 1 rises to overcome the spring bias against the spool. When this bias pressure is surpassed, the spool shifts, allowing bi-directional flow between 3 and 4 while blocking 2. The spring chamber is sealed and vented to atmosphere, allowing consistent shifting with only spring bias pressure independent of conditions at 2 or 3.
1) Measured at 200 bar (2900 psi)
