R983032420 2FRM6B36-2X/32QRV-IN001 Rexroth speed regulating valve

Frequently Asked Questions (FAQ)

Q1: Is this a simple throttle / needle valve?

No. A simple throttle valve (only orifice) lets flow vary with pressure difference. The 2FRM is a pressure-compensated flow control valve​ — the built-in pressure compensator (spool) keeps the set flow rate essentially constantdespite changes in load pressure or supply pressure (within its compensation range ~15–300 bar ΔP across compensator).

Q2: What does "B36 /32QRV" mean?

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

• /32​ = maximum adjustable flow = 32 L/min.

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

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

• V​ = NBR seals (standard).

Q3: How do I set the flow?

Loosen the lock setscrew (if tightened), turn the knurled knob clockwise to increase flow, counterclockwise to decrease. The knob has a scale (1–10 or % reference — not in L/min directly). Use a flow meter to correlate the scale to actual L/min for your application. Retighten the lock setscrew after setting.

Q4: How is it mounted?

As a sandwich (stackable) valve​ between a directional control valve and the NG6 subplate, same as ZDR/Z2FS sandwiches. Uses NG6 DIN 24340 Form C / ISO 6263 bolt pattern (4× M5). Observe the directional arrow on the valve body — A→B = controlled flow.

Q5: 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 you need two 2FRM valves or a 4-way flow control solution.

Q6: Common faults & causes?

• Flow varies with load pressure:​ pressure compensator spool stuck (contamination) — check oil filtration (ISO 4406 18/16/13 or better); or system pressure too low to generate required ΔP across compensator (<~15 bar).

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

• Cannot reach max flow / flow unstable:​ wrong model (smaller Qmax), partially closed, or excessive viscosity (cold start) — allow warm-up.

• Excessive heat:​ some pressure drop is normal; if the valve is set for very low flow but sees high ΔP, energy dissipates as heat — this is normal for flow controls.

Q7: Minimum pressure requirement?

The pressure compensator typically needs min. ~15 bar differential pressure across the compensator​ to properly regulate. System supply pressure must exceed the highest load pressure + ~15–20 bar + line losses for accurate flow control.

Q8: 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. Maintain oil cleanliness per ISO 4406 code 18/16/13 or better.