There is a savings opportunity many valve-automation buyers overlook: you don't have to buy a "large" actuator — add a gearbox and multiply a smaller one instead. The price of an imported high-torque integrated actuator typically covers a regular-torque actuator plus a quality gearbox — with money left over. Our eight gearbox series (GS/GF/IW/GK/BST/GZ/LE/QJ) are built for exactly that strategy: quarter-turn output from 250 to 500,000 N·m, multi-turn from 600 to 20,000 N·m, and linear thrust up to 217 kN; every interface uses standard ISO 5210 flanges (F07–F60) mating directly with electric and pneumatic actuators of all major brands; in stock, at roughly 1/2–1/3 the price of comparable imported products, with custom sizes on request. Full product documentation (selection tables + dimension drawings + flange standards) is downloadable in both Chinese and English. This page is the entry point to the line: meet the families first, then size in three steps.
Take a large butterfly valve (DN600+): direct drive usually demands a 50,000 N·m-class integrated actuator — at an imported price to match. The alternative: a regular 2,000 N·m electric actuator plus an IW-series quarter-turn gearbox (torque magnification 18–820×) delivers well beyond 50,000 N·m — and the two together cost about 1/2–1/3 of the imported integrated unit. The split architecture has operational upsides too:
This is the route European and American engineering companies have taken for decades. The difference today: Chinese-made gearboxes deliver the same quality at 1/2–1/3 the price — ex stock.
| Series | Type | Output | Ratios | Typical use | Details |
|---|---|---|---|---|---|
| GS | Quarter-turn worm gearbox (direct-mount) | 250–300,000 N·m | 51–2040 | Butterfly/ball/plug valves, dampers | GS/GF |
| GF | Quarter-turn worm gearbox (bracket-type) | GF50.3–GF250.3 | — | Base-and-crank installations | GS/GF |
| IW | Quarter-turn worm gearbox (high torque) | 600–500,000 N·m | 60–2564 | Large heavy valves; torque multiplying | IW |
| GK | Multi-turn bevel gearbox | 600–15,000 N·m | 3–36 | Gate/globe multi-turn valves | GK/BST/GZ |
| BST | Multi-turn spur gearbox | 1,500–20,000 N·m | 2–8 | Multi-turn valves, low-speed direct drive | GK/BST/GZ |
| GZ | Quarter-turn gearbox (low ratios) | 300–15,000 N·m | 2–36 | Applications needing low ratios | GK/BST/GZ |
| LE | Linear-stroke thrust unit | Thrust 11.5–217 kN | Stroke 50–500mm | Globe/gate linear valves | LE |
| QJ | Ball-hinge mechanism | 100–20,000 N·m | — | Linkage connections | QJ |
Buying tip: these gearboxes fit electric actuators of all major brands via standard ISO 5210 flanges (F07–F60). In stock for fast delivery, about 1/2–1/3 the price of comparable imported brands, and custom sizes are made to order — special flanges, special ratios and special mounting dimensions are all negotiable.
Required torque = valve break torque (usually the maximum) × safety factor 1.25–1.5. See Torque on Valves: Breaking, Operating and Seating Torque for how torque builds up — or simply send us the valve data (size, ΔP, medium) via the RFQ form and our engineers will do the math.
Input side matches the actuator's output flange (F07–F40); output side matches the valve flange (F10–F60). Every flange code's full dimensions (ød1/ød2/ød3/bolt holes) are in the ISO 5210 flange standard table — F03 through F60 in one view.
Full documentation (Chinese/English PDFs with selection tables, dimension drawings and flange standards): Gearbox Product Data download. For sizing, quotations or customization — submit an RFQ; our engineers reply the same day.
An industry resource for electric & pneumatic actuators, dampers and heaters: brand manuals, sizing guides and maintenance know-how. Global brands in, China manufacturing out.
