The GS series quarter-turn worm gearbox is the workhorse of valve automation: the electric actuator's 90° rotation passes through the worm train and comes out multiplied, driving butterfly valves, ball valves, plug valves and dampers. Our GS line spans 11 frame sizes covering 250–300,000 N·m, with input flanges F07–F30, output flanges F07–F60 (ISO 5210), and two-stage R versions reaching ratio 2040:1 — ex stock, at roughly 1/2–1/3 the price of comparable imported worm gearboxes, custom sizes on request. The companion GF series offers a bracket-type (base-and-crank) mounting for installations without a standard flange face. Full selection tables and sizing guidance below.
| Model | Ratio | Max. stem bore | Input flange | Output flange (std/opt) | Max. output torque N·m | Weight kg |
|---|---|---|---|---|---|---|
| GS50.3 | 51 | 28(8×7) | F07 | F10 / F07 | 250 | 7 |
| GS63.3 | 51 | 45(14×9) | F10 | F12 / F10 | 1,000 | 13 |
| GS80.3 | 53 | 60(18×11) | F10 | F14 / F12 | 2,250 | 18 |
| GS100.3 | 60/74 | 80(22×14) | F14 | F16 / F14 | 4,500 | 47 |
| GS125.3 | 60 | 90(25×14) | F14 | F25 / F16 | 9,000 | 66 |
| GS160.3 | 60 | 100(28×16) | F14 | F30 / F25 | 16,000 | 121 |
| GS200.3 | 55 | 125(32×18) | F25 | F35 / F30·F25 | 30,000 | 196 |
| GS250.3 | 55 | 160(40×22) | F25 | F40 / F35·F30 | 45,000 | 288 |
| GS315 | 65 | 200(45×25) | F30 | F40 / F48·F35 | 80,000 | 622 |
| GS400 | 70 | 220(50×28) | F30 | F40 / F48 | 160,000 | 863 |
| GS500 | 85 | 250(56×32) | F30 | F48 / F60 | 300,000 | 1,508 |
Every frame has an R version (e.g. GS100.3R) adding a second reduction stage and extending the ratio range several-fold: GS100.3R offers 104/120/150/180/255/312/384:1, and GS500R reaches 2040:1. R versions serve two duties: valves requiring slower stroking (large water gates, sludge-discharge valves), and small actuators requiring greater torque multiplication. Flange interfaces are identical to the base frames; mounting dimensions are in the product data PDF.
Where the valve has no standard ISO 5210 flange face (legacy valves, non-standard equipment) or direct mounting won't fit, the GF bracket-type quarter-turn worm gearbox is the answer: a mounting base under the housing drives the valve through a base bolted + crank-linkage arrangement. Models GF50.3–GF250.3 correspond to the GS frames; base dimensions (B/G/H/K/L), input/output interface parameters are all documented (GF dimension tables in the product PDF). R two-stage versions are available from GF100.3R to GF250.3R.
Typical pairings: DN100–DN300 butterfly valves with GS63.3–GS100.3 (1,000–4,500 N·m); DN400–DN600 ball/butterfly valves with GS160.3–GS250.3 (16,000–45,000 N·m); hydro-station and pumping-station large gates with GS315–GS500 (80,000–300,000 N·m). The economics: a 30,000 N·m imported integrated actuator delivers what a 3,000 N·m actuator plus a GS200.3 gearbox delivers together — and the pair typically costs 1/2–1/3 of the integrated unit, with the all-mechanical gearbox running long maintenance-free intervals. For engineering firms buying in volume (water, power, chemical), that per-unit difference multiplied by quantities is real budget.
Buying tip: these gearboxes fit electric actuators of all major brands (Rotork, AUMA, Limitorque, Bernard — direct ISO 5210 mating). In stock, about 1/2–1/3 the price of comparable imported products, custom sizes on request.
Complete GS/GF selection tables, dimension drawings and flange standards (CN/EN PDFs): Gearbox Product Data download. Sizing, quotes, customization — submit an RFQ, same-day reply.
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