R900424742 DBDS10G1X/315 Rexroth Germany overflow valve

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

It is a direct-acting seat valve (DBD series)​ — no pilot stage. The spring-loaded poppet/ball opens immediately when system pressure overcomes the spring preload.

Q2: What does "G1X / 315" mean?

• G​ = screw-in cartridge version with threaded port connection (G 1/2" ISO 228-1 on the cavity), for installation in a manifold block.

• 1X​ = component series index (dimensionally interchangeable within series 1X).

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

Q3: How is this different from the DBDS10P1X/315?

The P-version​ mounts on a NG10 subplate (sandwich style, bolted). The G-version​ (this item) screws into a machined manifold block cavity with G 1/2" threaded port — no subplate required. Function and spring stage are the same.

Q4: How do I install this valve?

Screw the cartridge into the prepared manifold block cavity (G 1/2" threaded bore per Rexroth drawing). Ensure P-port in the block aligns with system pressure and T-port connects to tank. Typical tightening torque approx. 80–90 N·m — refer to the official Rexroth cavity drawing. Use appropriate O-ring sealing on the cartridge shoulder.

Q5: 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 and verify with a pressure gauge at the P-port. Factory preset is typically near the low end of the spring range; always adjust on-site.

Q6: Does T-port backpressure affect the set pressure?

Yes. The spring chamber drains internally to the T-port, so any backpressure at T adds 1:1 to the relief/cracking pressure. Keep T-line backpressure minimal or compensate in the setpoint.

Q7: Common fault symptoms?

• Pressure won't reach set value:​ wrong spring grade, high T-backpressure, poppet sticking due to contaminated oil, damaged seating.

• Continuous dribble / leak:​ damaged seating surface, aged O-ring, or contamination trapped in the seat — clean or replace.

• Chatter / noise:​ air in the system, flow exceeding ~120 L/min, or line resonance — bleed air and confirm flow rating.

Q8: Fluid & seal compatibility?

Standard NBR seals suit mineral oil (HL/HLP) and HFC (water-glycol). For HEES/HETG biodegradable oils or HFD phosphate ester, FKM (Viton) seals are required — order the "V" seal variant if needed.