I. Model Breakdown Explanation (D633-317B)

D633: D633 series direct-acting servo valve (DDV), NG6 (03) mounting surface, Moog Inc.

317:

3: Flow code → 40 L/min (Δp = 35 bar)

1: Electronic / Frequency Response → Standard frequency response (60–90 Hz), analog input, position closed-loop, Moog Inc.

7: Y Port / Seal → No Y Port (T Port low pressure ≤ 50 bar), NBR seal, -20 to +80°C, Moog Inc.

B: Standard type, no special coating, standard voltage version

One sentence: D633-317B = NG6 + 40 L/min@35 bar + 350 bar (P/A/B) + Direct actuation without pilot valve + 60–90 Hz standard frequency response + No Y Port (T Port low pressure) + NBR seal

II. Core Parameters (Δp = 35 bar)

Rated Flow: 40 L/min (Main flow in D633 series)

Maximum Pressure:

P/A/B: 350 bar Moog Inc.

T Port: ≤ 50 bar (No Y Port) Moog Inc.

Hysteresis: <0.2%

Resolution: <0.1%

Frequency Response (±100%): 60–90 Hz (Standard mode) Moog Inc.

Step Response: ≈ 12 ms Moog Inc.

Zero Position Leakage: ≈ 0.5 L/min (210 bar)

Seal / Temperature: NBR (-20 to +80°C)

Drive: 24VDC, ±10V or 4–20mA

Filter: ISO 4406 15/12

Features: No pilot hole, extremely anti-pollution, independent of dynamic and pressure, power-off spring centering, no Y Port low-pressure return oil, the most commonly used standard dynamic model of D633 series at 40 L/min

III. Comparison of D633-317B with 312B/313B/315B (Key Differences) Table

Project D633-312B D633-313B D633-315B D633-317B

Flow rate 75 L/min 75 L/min 75 L/min 40 L/min

Frequency response 60–90 Hz 120–150 Hz 120–150 Hz 60–90 Hz

Y port Yes (350bar) Yes (350bar) No (T≤50bar) No (T≤50bar)

Sealing NBR 80℃ NBR 80℃ NBR 80℃ NBR 80℃

Positioning Large flow standard dynamic Large flow high-frequency dynamic Large flow high-frequency + low-pressure return oil Middle flow standard dynamic + low-pressure return oil

Sentence: 317B = the medium-flow version of 312B, with the same frequency response / sealing / return oil, half the flow rate, suitable for regular 40L/min systems

Four. Application scenarios

NG6 small installation surface, 40L/min medium flow + 350bar (P/A/B) + 60–90Hz standard frequency response + standard temperature (≤80℃)

T port low-pressure return oil (≤50bar), no need for Y port leakage from Moog Inc.

General precision control: ordinary presses, bending machines, injection molding machines, metal rolling gap, fatigue test machines (non-high-frequency)

Installation space limited, 40L/min flow rate sufficient, regular dynamic response, low-pressure return oil high-pressure system