The Laux Valve wafer type butterfly valve with chain wheel gearbox is specifically designed for pipelines installed at elevated positions where manual handwheel operation is impossible or unsafe. The chain wheel gearbox allows the operator to open, close, and modulate the valve from ground level by simply pulling the chain, eliminating the need for ladders, platforms, or aerial work platforms.
This combination of a compact wafer butterfly valve and a self-locking worm gearbox with chain wheel drive is widely used in water treatment plants, pumping stations, HVAC systems, and industrial facilities where valves are mounted 2-8 meters above the floor. The chain is available in two material options: cost-effective galvanized steel (standard) or corrosion-resistant SS304 stainless steel (premium) for marine, coastal, chemical, and food-grade applications.
✔ Key Advantage
Chain wheel operation converts a 90-degree valve turn into a simple pulling motion at ground level. The worm gear's self-locking design holds the valve position automatically — no chain lock or additional braking device required. Safe, economical, and maintenance-free operation for overhead valves.
The chain wheel gearbox is mounted on the valve's ISO 5211 standard mounting pad. A continuous loop chain hangs from the chain wheel down to an accessible height (typically 1-2 meters above floor level). Pulling one side of the chain rotates the worm shaft, which drives the worm gear and opens the valve. Pulling the opposite side closes it. Chain length is customized to the actual installation height.
| Galvanized Steel Chain | SS304 Stainless Steel Chain | |
| Material | Carbon steel, hot-dip zinc galvanized | Austenitic stainless steel 304 (A2) |
| Standard | EN 818-4 / DIN 5687-2 | EN 818-4 / DIN 5687-2 |
| Corrosion Resistance | Good (indoor/dry) | Excellent (outdoor/marine/chemical) |
| Typical Service | Water, HVAC, indoor plants | Coastal, offshore, food, pharma, chemical |
| Parameter | Specification |
| Valve Type | Concentric Wafer Butterfly Valve |
| Size Range | DN50 – DN600 (2" – 24") |
| Pressure Rating | PN10 / PN16 / Class 150 |
| Body Material | Ductile Iron ASTM A536 65-45-12 (standard); CF8/CF8M SS (optional) |
| Disc Material | Ductile Iron + Epoxy/Nylon Coating; CF8M SS (optional) |
| Stem Material | 416 SS / 420 SS / 316 SS (optional) |
| Seat Material | EPDM (standard) / NBR / Hypalon |
| Face-to-Face | EN 558 Series 20 / API 609 Short Pattern |
| Flange Drilling | EN 1092-2 PN10/PN16 / ASME B16.5 Class 150 |
| Gearbox Type | Worm gearbox with chain wheel drive |
| Gearbox Ratio | 1:24 / 1:32 / 1:40 (by valve size) |
| Gearbox Housing | Ductile iron / aluminum, epoxy coated |
| Chain Wheel | Cast iron / steel, zinc plated |
| Chain Material | Galvanized Steel (standard) / SS304 (option) |
| Chain Standard | EN 818-4 / DIN 5687-2 |
| Chain Length | 3m / 5m / 8m / 10m / custom |
| Mounting Interface | ISO 5211 standard mounting pad |
| Temperature Range | EPDM: -20°C to +90°C; NBR: -10°C to +70°C |
| Leakage Rate | Bubble-tight (ISO 5208 Rate A) |
| Test Standard | API 598 / EN 12266-1 |
| Design Standard | API 609 Category A / EN 593 |
A: Measure the vertical distance from the floor to the chain wheel center, then add 1.0-1.5 meters of free-hanging chain for comfortable reach. Example: valve center at 4m above floor, order 5m chain. If unsure, send us the installation drawing and we will calculate the correct length.
A: For a butterfly valve (90-degree rotation) with a gearbox ratio of 1:24, the chain wheel must make 6 complete rotations (24 x 90° / 360°). With a typical chain wheel of 250mm pitch circle, each full rotation requires approximately 0.8m of chain travel, so a DN300 valve takes roughly 5m of chain pulling to fully open. This takes about 30-45 seconds of continuous pulling.
A: Galvanized steel chain has a zinc coating that protects the steel core and is ideal for indoor, dry, or general outdoor use. SS304 stainless steel chain is inherently corrosion-resistant (no coating to wear off), making it the right choice for marine, coastal, chemical, food, and pharmaceutical environments where salt or chemicals would eventually attack the zinc coating.
A: Yes. The worm gear drive is inherently self-locking — the valve holds its position automatically, even under flow-induced torque and vibration. No chain locking device is required, though an optional padlockable chain stop is available for lockout/tagout safety procedures.
A: Yes. The valve is fitted with an ISO 5211 standard mounting pad. The chain wheel gearbox can be removed and replaced with a pneumatic or electric actuator at any time, using the same mounting interface. No pipe modification needed.
A: Chain wheel operation works reliably for installation heights up to 8 meters. For heights beyond 8m, a chain guide tube is recommended to prevent chain sway, or an electric actuator should be considered.
A: Minimal. For galvanized chains in dry indoor service, periodic light oiling (once per year) is sufficient. For SS304 chains, no lubrication is required in most services. Inspect the chain annually for link wear or deformation.
To order, please specify: size, pressure rating, seat material, chain material (galvanized or SS304), chain length, and installation height. Our sales team will confirm the gearbox size and provide a complete quotation.
Email: james@lauxvalve.com | Tel / WhatsApp: +86 18920833829
Laux Valve — Professional Butterfly Valve OEM Manufacturer Since 2011 | ISO 9001 & CE Certified | Factory Direct Pricing
From raw material inspection to final delivery, every butterfly valve undergoes a comprehensive quality inspection to ensure reliable performance and compliance with international standards.
