R900423730 DBDS6P1X/315 Rexroth overflow valve

Frequently Asked Questions (FAQ)

Q1: Is this a pilot-operated or direct-acting relief valve?

It is a direct-acting seat valve (DBD series), not pilot-operated. The poppet/ball opens directly when system pressure overcomes the spring preload.

Q2: What does "P1X / 315" mean?

• P1​ = adjustment type: hexagon socket with protective cap (Allen key adjustable).

• 1X​ = component series index (proven design, dimensional interchangeability maintained).

• /315​ = spring pressure stage, maximum settable relief pressure = 315 bar.

Q3: How do I adjust the relief pressure?

Depressurize the system, remove the protective cap, turn the internal setscrew with an Allen key — clockwise to increase, counterclockwise to decrease. Reinstall the cap after setting and verify with a pressure gauge.

Q4: Which subplate is required?

Use a standard NG6 (Size 6) subplate​ per ISO 6264 with P and T ports. Port threads on the subplate are typically G 1/4" BSP or M14×1.5. The valve body mounts flush onto the subplate.

Q5: Can backpressure on the T-port affect the set pressure?

Yes. Hydraulic backpressure at the tank (T) port adds 1:1 to the cracking/relief pressure. Keep T-line backpressure minimal or account for it in the setpoint.

Q6: Is the valve pre-set at the factory?

Usually it is set to a mid or minimum value of the spring range. You must adjust it on-site​ to match your system's required relief pressure before operation.

Q7: What are common fault symptoms?

• Pressure will not reach set value → possible contamination in seat, wrong spring grade, excessive pump wear, or high T-port backpressure.

• Continuous leakage / dribble → damaged seating surface or O-ring, contaminated oil causing poppet sticking.