These valves are single or dual check units. Dual check units have identical check elements located in the “A” and “B” cylinder port lines. The check valve poppets are moved into the open position by a central pilot control spool which moves toward one check or the other, depending on which port is pressurized.
The check valve located in the return circuit is opened by the operating pressure in the primary circuit. When the pressure in the pilot line is vented, the check valve will remain closed.
The pilot spool area to valve seat ratio is 3:1 on standard models, and 20:1 on models with the decompression feature.
Check valve cracking (opening) pressures of 1 bar (15 psi), 2,5 bar (36 psi) and 5 bar (73 psi) are available. Please note that back pressure on the downstream or free-flow side of the pilot check valve may prevent the valve from opening in certain situations. (Back pressure opposes pilot pressure trying to open the valve.)
Maximum flow: 120 l/min (32 USgpm)
Maximum operating pressure: 315 bar (4500 psi)
Leakage @ 50°C (120°F) Poppet @ 35 bar (500 psi)
Standard models: 0.3 ml/min.
“D” models: 1.0 ml/min.
Piston @315 bar (4500 psi): 20°C to 50°C (70 to 120°F)
Operating temperature: 20°C to 50°C (70° to 120°F)
Weights: 2,9 kg (6.4 lbs)