Description
Flow is allowed from 3 to 4 and blocked at 2 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 2 and 3 while blocking 4. The spring chamber is drained to 4, thus any pressure at 4 is additive to the spring bias and pilot pressure required for shifting.
1) Measured at 200 bar (2900 psi)
