R983032418 2FRM6B36-2X/25QRV-IN001 Rexroth German made hydraulic lock speed regulating valve

Frequently Asked Questions (FAQ)

Q1: Is this a hydraulic lock / pilot-operated check valve?

No. A hydraulic lock / pilot-operated check valve​ is Rexroth type SV (cartridge) or SL (sandwich dual pilot check). The 2FRM6​ is a pressure-compensated flow control / speed control valve​ — it meters flow in one direction (A→B) and allows free return (B→A). It does not​ hold/lock a cylinder.

Q2: Is this a simple throttle / needle valve?

No. A needle valve lets flow vary with ΔP. The 2FRM is pressure-compensated​ — the built-in compensator spool keeps the set flow essentially constantdespite load or supply pressure changes (provided ≥~15 bar ΔP across compensator).

Q3: What does "B36 /25QRV" mean?

• B36​ = NG6 sandwich, rotary knurled knob with scale (0–max reference) + locking setscrew — adjustable by hand.

• /25​ = maximum adjustable flow = 25 L/min​ (higher-capacity NG6 version; also avail: /1.5, /3, /6, /10, /16, /32).

• Q​ = flow controlled in A→B direction.

• R​ = free reverse flow B→A via check valve.

• V​ = NBR seals (standard).

Q4: How do I set the flow?

Loosen the lock setscrew, turn the knurled knob clockwise to increase flow, counterclockwise to decrease. The knob has a relative scale — use a flow meter to correlate to actual L/min. Retighten the lock setscrew after setting.

Q5: How is it mounted?

As a sandwich (stackable) valve​ between a directional control valve and the NG6 subplate, same bolt pattern as ZDR/Z2FS sandwiches (4× M5). Observe the arrow on the valve body — A→B = controlled/metered flow, B→A = free return.

Q6: Does it work both ways?

No — one direction is pressure-compensated metered flow (A→B), the opposite direction (B→A) is free return through the check valve​ (no flow control, minimal pressure drop ~0.5 bar). For bidirectional flow control use two 2FRM valves.

Q7: Minimum pressure requirement?

The pressure compensator typically needs min. ~15 bar differential pressure across the compensator​ to regulate properly. Supply pressure must exceed the highest load pressure + ~15–20 bar + line losses.

Q8: Common faults & causes?

• Flow varies with load pressure:​ compensator spool stuck (contamination) — check oil filtration (ISO 4406 18/16/13 or better); or insufficient ΔP across compensator.

• No flow / very low at max knob:​ valve installed backwards, or compensator/spool jammed.

• Cannot reach set flow / unstable:​ partially clogged orifice, cold-start high viscosity — flush system.

• Excessive heat:​ normal for flow controls — P_drop × Q = heat; ensure supply pressure isn't unnecessarily high above load requirement.

Q9: Need an actual hydraulic lock (pilot-operated check / overcenter)?

You need Rexroth SV… (cartridge pilot check)​ or SL… (sandwich dual pilot check)​ — not the 2FRM series. Let me know if you need that part number.

Q10: Fluid & seal compatibility?

NBR seals = mineral oil (HL/HLP) & HFC (water-glycol). For HEES/HETG biodegradable oils or HFD phosphate ester → specify FKM (Viton) seal variant.