IW High-Torque Quarter-Turn Gearboxes: up to 500,000 N-m, 18-820x Torque Magnification

source：original date：2026-10-24

When valve size or differential pressure pushes operating torque into the hundreds of thousands of newton-metres, buying a high-torque integrated actuator is the most expensive solution on the menu. The IW series quarter-turn worm gearbox rewrites that math with torque multiplication: output 600–500,000 N·m, magnification 18–820× — a regular 446 N·m actuator on an IW8 yields 20,000 N·m; on an IW14 it reaches 500,000 N·m. Ex stock, at about 1/2–1/3 the price of comparable imported units, fitting electric and pneumatic actuators of all major brands via standard ISO 5210 flanges, with custom sizes on request. Full selection table, the multiplication logic and the pairing method below.

1. IW selection table (base frames IW3–IW14)

Model	Ratio	Output torque N·m	Output torque ft·lbs	Input torque N·m	Magnification
IW3	60	600	442	33	18
IW4	70	1,500	1,107	71	21
IW5	70	3,000	2,214	143	21
IW6	70	6,000	4,428	286	21
IW7	70	10,000	7,380	446	22
IW8	70	20,000	14,760	892	22
IW9	65	35,000	25,830	1,683	21
IW10	64	65,000	47,970	3,175	21
IW12	85	135,000	99,630	4,963	27
IW13	85	250,000	184,500	9,191	27
IW14	85	500,000	369,000	14,706	27

R versions: ratios and magnification multiplied again

Each frame's R version (IW4R–IW14R) extends the ratio ladder — IW8R offers 140/210/280/350/420/490/560/630/700/770/840/910/980 with magnification 45–317×; IW10R tops out at ratio 2564:1, magnification 820×. Practical meaning: with the same actuator torque, choosing a higher-magnification R version scales the output proportionally — one actuator paired with different IW ratios covers a continuous band of output torque, which is exceptional flexibility for procurement and spares.

2. Working the magnification: the three-step pairing method

Size the valve demand: max operating torque × 1.25–1.5 = required output (example: a large butterfly computes to 55,000 N·m);
Pick the gearbox: round up to IW10 (65,000 N·m);
Back out the actuator: 65,000 ÷ 21 (IW10 base magnification) ≈ 3,100 N·m → a regular 3,000–3,500 N·m electric actuator suffices. To downsize the actuator further, use a high-ratio IW10R step (at 820×, roughly 80 N·m input — even a pneumatic actuator can drive it).

The point of this arithmetic: the actuator drops from the "eye-watering" price bracket to the ordinary one, and the gearbox side costs 1/2–1/3 of imported brands. For water utilities, gas networks and pipeline operators buying in quantity, the per-unit saving times units is a serious budget line.

3. Mounting forms

Direct-mount (IW dimension table): input flanges F10–F25, outputs spanning F12–F40, stem bores to 265mm (IW10R);
Bracket-type (IW bracket dimension table): base-bolted with crank-linkage drive for legacy valves without standard flanges; reference weights from ~24kg (IW3) to ~350kg (IW8).

4. Typical applications

Large butterfly/ball valves (DN600–DN1400): IW8–IW10, 20,000–65,000 N·m;
Hydro stations, pumping stations, large gates and flat gates: IW12–IW14, 135,000–500,000 N·m;
Pneumatic actuator upgrades: an existing small pneumatic actuator + a high-ratio IW-R box now drives heavy valves it could never reach — no actuator replacement, just add the gearbox.

Buying tip: the IW series fits electric and pneumatic actuators of all major brands (ISO 5210 flanges F10–F25), in stock, about 1/2–1/3 the price of comparable imported products, custom sizes (special flanges, special ratios) on request.

Summary

Two numbers: output 600–500,000 N·m; magnification 18–820× (R versions to 2564:1);
One method: required output ÷ magnification = actuator torque needed — pulling the actuator down from the premium bracket;
One retrofit idea: existing small actuator + high-ratio IW = heavy-valve drive without replacing the prime mover.

Complete IW selection tables, full magnification charts and dimension drawings (CN/EN PDFs): Gearbox Product Data download. Pairing and quotations — submit an RFQ with your required torque; our engineers return a pairing proposal the same day.