Rickmeier DB9 FL-F-100-P-2-S0 Pressure Relief Valve

Rickmeier DB9 FL-F-100-P-2-S0 Pilot-Operated Pressure Relief Valve

The Rickmeier DB9 FL-F-100-P-2-S0 is a pilot-operated hydraulic pressure relief valve engineered specifically for high-volume lubricating circuits, marine propulsion gear transmissions, and demanding industrial fluid systems. Manufactured in Germany by Rickmeier GmbH, the DB9 series serves as a line-mounted pressure control unit configured to handle nominal throughput volumes up to 1,800 L/min (DN80 / 3″ SAE) with an adjustable operating window reaching up to 100 bar.

Unlike direct-acting spring relief valves that suffer from steep pressure-override curves and chatter at high throughputs, the DB9 series utilizes a balanced two-stage pilot-piston mechanism. The pilot stage senses circuit pressure and accurately meters fluid discharge above the cracking threshold, generating an ultra-flat pressure-override curve across the entire viscosity envelope (10 to 1,000+ mm²/s). The robust spheroidal cast-iron housing (EN-GJS-400-15) and hardened steel internal spool assembly provide continuous resistance against cavitation erosion, fluid shock waves, and pressure pulsations generated by positive displacement gear and screw pumps.

Model Details:

• Manufacturer Part Number (MPN): DB9 FL-F-100-P-2-S0
• Series: DB9 (Nominal Size DN80)
• Mounting / Flange Configuration (FL): In-line flange mounting via standard 4-bolt SAE connection patterns
• Pilot/Spring Execution (F): Standard pilot stage spring cartridge arrangement
• Pressure Rating Code (100): Operating pressure adjustment envelope configured up to 100 bar
• Sealing Material (P): FKM / Viton elastomeric seals for high-temperature and synthetic fluid durability
• Control Porting / Venting (2): Internal pilot oil drain to port B / tank return channel
• Special Modification Index (S0): Manufacturer standard base designator

Applications

• Marine Main Engine Lubrication Systems: Main bearing, crosshead, and camshaft lube oil headers on MAN B&W, WinGD, and Wärtsilä auxiliary and propulsion units.
• Marine Reduction Gearboxes & Clutches: Pressure stabilization circuits on Renk, Reintjes, ZF Marine, and Flender propulsion reduction units.
• Large Positive Displacement Pump Loops: Bypass protection mounted on external supply loops for Rickmeier R45, R65, and R95 gear pumps or IMO/Allweiler triple-screw pumps.
• Hydraulic Deck & Mooring Machinery: Relief bypass for high-capacity power packs supplying anchor windlasses, cargo cranes, and thruster steering gears.
• Industrial Oil Circulation Plants: High-throughput bypass relief loops for mining mills, turbine oil filtration skids, paper machines, and heavy metal roll stands.

Compatible Fluid Power Equipment

• Rickmeier Gear Pump Series: Direct bypass circuit companion to R65/250, R65/315, R65/400, R46, and R95 pump groups.
• Screw Pumps: IMO AB (ACD/ACE/ACG/ACF series), Krauss Maffei, Allweiler (SN/SM series), Leistritz L2/L3 series.
• Marine Gearbox Lubrication Skids: Renk Marine (AUS, HSN, WAV series), Reintjes (WAF, LA, SVA series), ZF Marine (ZF 7000 to ZF 90000 series).

Manufacturer & Part Cross-References

• Rickmeier Type Code: DB9 FL-F-100-P-2-S0
• Alternative Suffix / Standard Equivalents: DB9-B-P100, DB9-R-P100-SAE3, DB9 FL-F-100-2-3
• Interchangeable Frame: Direct physical port footprint replacement for legacy Rickmeier DBV80 and intermediate DN80 flange assemblies.

Frequently Asked Questions

What is the primary difference between the Rickmeier DB9 and direct-acting relief valves?

The DB9 utilizes a two-stage pilot design. A primary direct-acting valve must compress a heavy main spring to open the full port area, creating substantial pressure rise as flow increases. The DB9 uses a small pilot stage to modulate hydraulic balance across a main piston, maintaining a near-constant relief setpoint regardless of whether bypass flow is 100 L/min or 1,800 L/min.

Can the Rickmeier DB9 valve be adjusted during active machinery operation?

Yes. The valve can be adjusted while the system is under pressure. Loosen the hex lock-nut on the adjusting spindle and rotate the threaded screw clockwise to increase cracking pressure, or counter-clockwise to reduce setpoint pressure. Always monitor a calibrated downstream/upstream pressure gauge on the manifold and re-tighten the lock collar firmly once the target setpoint is reached.

Can the DB9 FL-F-100-P-2-S0 handle high-viscosity synthetic gear lubricants?

Yes. The valve is engineered to operate efficiently with fluids up to 1,000 mm²/s in normal service and handles cold start viscosities up to 2,000 mm²/s. The FKM sealing material provides chemical stability against aggressive synthetic ester and polyalphaolefin (PAO) gear oils that degrade ordinary NBR seals.

Is the DB9 certified as a boiler/pressure vessel safety relief valve under DIN 3320?

No. In accordance with industrial valve standards and Rickmeier product classifications, the DB9 series is designated as a hydraulic/lubrication system pressure limiting and regulating control valve. It is designed for continuous operational pressure regulation and bypass duty, rather than single-event ultimate vessel rupture protection.

How do I identify if the internal pilot spool requires servicing?

Common symptoms of pilot circuit fouling include delayed pressure build-up at pump startup, excessive pressure fluctuation (spool hunting) across a steady RPM curve, or fluid weeping past the setting spindle thread. Cleaning the pilot restrictor and replacing the internal FKM O-ring pack restores factory hydraulic responsiveness.