R900424155 DBDS10P1X/100 Rexroth direct acting relief valve

Frequently Asked Questions (FAQ)

Q1: Is DBDS10P1X/100 pilot-operated or direct-acting?

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

Q2: What does "P1X / 100" mean?

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

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

• /100​ = spring pressure stage, maximum settable relief pressure = 100 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 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 to the required system pressure.

Q4: Which subplate is required?

Use a standard NG10 (Size 10) subplate​ per ISO 6264 with P and T ports. The valve mounts via four bolts (typically M10, tightening torque approx. 35–40 N·m — refer to Rexroth mounting drawing). Subplate port threads are commonly G 1/2" BSP or M18×1.5.

Q5: 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.

Q6: Common fault symptoms?

• Pressure won't reach set value / can't be adjusted down to zero:​ wrong spring grade, high T-backpressure, poppet sticking due to contaminated oil, or weak pump.

• Continuous leakage / dribble:​ damaged seating surface, worn 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.

Q7: 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.

Need the Rexroth DBD series datasheet (RE 25402) or NG10 subplate machining dimensions? Just let me know.