Flanged Duckbill Check Valve
Industry-leading flanged duckbill check valve with patented design. Engineered for superior backflow prevention in mission-critical industrial applications.
Unmatched Professional Excellence
As China's pioneer in duckbill valve technology since 1989, we deliver superior engineering solutions trusted by major corporations across 46+ countries worldwide.
Patented Innovation Leader
First company in China to introduce duckbill valve technology. Holder of multiple R&D patents including revolutionary curved-bill designs and advanced manufacturing processes.
Advanced Manufacturing
Small Diameter: Precision mold technology for consistent quality.
Large Diameter: Spool-type hand-wrapping method for optimal performance up to DN3000.
Unmatched Global Scale
Maximum diameter capability up to DN3000 - the largest in the industry. Proven export experience across Australia, New Zealand, Europe, North America, Middle East, and Asia.
Premium Material Selection
Elastomer Body: EPDM, Neoprene, Nitrile, NR, VITON rubber
Flanges: SS316, SS304, Carbon Steel
Standards: ANSI, AS, BS, JIS compliance
Complete Customization
Flexible customization for different lengths, rubber body shapes, flange standards, and customer logos. Extensive mold reserves enable rapid custom solutions.
Proven Long-Term Reliability
Exceptional product quality stability with long-term partnerships spanning over 10 years with major corporations. Consistent performance in critical applications.
Engineering Excellence
Size Range
DN50 - DN3000
Industry's widest range
Elastomer Materials
EPDM, Neoprene, NBR, NR, VITON
Premium grade compounds
Flange Materials
SS316, SS304, Carbon Steel
Corrosion resistant
Flange Standards
ANSI, AS, BS, JIS
International compliance
Superior Performance Features
Mission-Critical Applications
Primary Industries Served
Wastewater & Stormwater Management
Treatment plants, discharge systems, outfall protection
Marine & Coastal Protection
Seawall drainage, tidal barriers, marina applications
Thermal Power Plants
Cooling tower systems, condenser drainage, process water
Industrial Process Systems
Chemical plants, manufacturing facilities, HVAC systems
Municipal Water Systems
Distribution networks, flood control, infrastructure protection
Working Principle
The flanged duckbill check valve operates as a sophisticated one-way flow control device with its patented elastomeric "bill" design. Under forward flow conditions, internal pressure forces the bill to open smoothly, allowing unrestricted flow passage with minimal head loss.
When reverse flow attempts to occur, external pressure combined with the valve's inherent elasticity causes the bill to close tightly, creating an effective hermetic seal that prevents backflow while maintaining zero leakage performance throughout its service life.
Installation Guide & Critical Precautions
Proper installation ensures optimal performance, maximum service life, and warranty coverage for your flanged duckbill check valve investment.
Step-by-Step Installation
Pre-Installation Inspection
Verify valve size matches pipe diameter, check flange rating compatibility, and inspect elastomer material suitability for your application. Examine for any shipping damage or manufacturing defects.
Pipe End Preparation
Ensure pipe ends are perfectly clean, smooth, and properly aligned. Remove all burrs, sharp edges, or debris that could damage the elastomer body during operation.
Critical Flow Direction Check
Position valve with duckbill opening facing downstream (flow direction). Align bolt holes precisely and ensure proper gasket placement according to flange standard.
Precision Bolt Tightening
Tighten bolts in star pattern to manufacturer's specified torque values. Avoid over-tightening which may damage rubber body or create stress concentrations.
System Commissioning & Testing
Gradually pressurize system to operating pressure. Test for proper valve operation, leak-free performance, and verify backflow prevention functionality.
Critical Safety Precautions
CRITICAL: Flow Direction
NEVER reverse install! The duckbill opening must always face downstream. Reverse installation will cause immediate valve failure, system damage, and void warranty coverage.
Temperature Operating Limits
Strictly observe material temperature ratings: EPDM: -40°C to +120°C, Neoprene: -35°C to +100°C, NBR: -30°C to +80°C. Exceeding limits causes rapid elastomer degradation.
Chemical Compatibility Verification
Verify complete elastomer compatibility with all process media, including trace chemicals and cleaning agents. Contact our technical team for comprehensive chemical resistance data and compatibility charts.
Handling & Storage Requirements
Handle elastomer body with extreme care. Avoid contact with sharp objects, petroleum products, ozone, or prolonged UV exposure during storage. Store in cool, dry conditions away from direct sunlight.
Professional Installation Strongly Recommended
For critical applications, large diameter valves (>DN600), or high-pressure systems, professional installation by certified technicians is strongly recommended to ensure optimal performance, safety compliance, and full warranty coverage.
Contact our technical support team for installation guidance: +86 18703845698
Engineering Excellence in Detail
Explore the superior craftsmanship and precision engineering of our flanged duckbill check valves
Flanged Duckbill Valve - Front View
Complete assembly view
Installation Detail
Proper mounting configuration
Material Cross-Section
Internal structure detail
Flange Connection
SS316 flange assembly
Size Comparison
DN50 to DN3000 range
Quality Testing
ISO9001 verification process
Partner with the Industry Pioneer
Join major corporations in 46+ countries who trust GYLDT's patented flanged duckbill check valves for their most critical applications. Get your custom engineered solution today.