Wholesale Double Non Return Valve Suppliers & Supplier

Engineered Dual-Plate Backflow Prevention Systems with In-House Elastomer Molding & Certified Zero-Leakage Performance for Global Fluid Networks

Direct Pipeline Portfolio

Featured Industrial & Dual Non-Return Valve Assemblies

Engineered for high-integrity reverse flow containment, municipal delivery, and industrial process engineering under severe hydraulic pressures.

Dual Plate Wafer Check Valve

High-Quality High - Performance Dual Plate Wafer Check Valve for High - Flow Pipeline Systems

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Buried Elastic Seat Gate Valve

High-Quality Buried Elastic Seat Gate Valve for Reliable Flow Control

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Electrical Butterfly Valve

High-Quality High-Performance Electrical Butterfly Valve for Seamless Control

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Pneumatic Butterfly Valve

High-Quality Pneumatic Butterfly Valve - Efficient Flow Control Solution

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Single Flange Butterfly Valve

Wholesale Single Flange Butterfly Valve - Durable & Efficient Flow Control

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Flanged Butterfly Valve Lever

CE Certification Flanged Butterfly Valve with Lever Actuator - Durable & Reliable

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Metal Seal Hard Seal Butterfly Valve

Wholesale CE/ISO/DIN/BS High Pressure Metal Seal Hard Seal Butterfly Valve

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WRAS Approved Butterfly Valve

High-Quality WRAS Approved Butterfly Valve - High Performance & Durability 4020L

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Global Engineering Landscape

Industrial Evolution of Double Non Return Valves (DNRV)

Modern fluid handling networks demand dual-layered backflow prevention to eliminate water hammer shockwaves, safeguard cross-connection zones, and prevent fluid contamination.

Critical Redundancy Architecture

Unlike conventional single-disc swing valves, double non-return valves utilize dual independent spring-loaded check assemblies in series. This provides fail-safe backflow prevention even if one disc becomes obstructed by suspended solids or mineral scaling.

Hydraulic Surge Mitigation

Equipped with torsional springs calibrated to line kinetics, the dual plates begin closing before reverse flow velocity reaches its destructive peak. This swift, non-slam response minimizes catastrophic water hammer pressure transients across pumping stations.

Compact Wafer Topology

Compared to massive traditional flanged check bodies, our wafer DNRV profiles reduce face-to-face envelope requirements by up to 80% and overall weight by 70%, dramatically reducing piping stress and installation crane operations.

Manufacturing Precision

Full Vertical Integration: From In-House Foundry to Hydrostatic Rig

Decades of operational mastery allow us to bridge the gap between competitive mass-scale manufacturing and zero-compromise mechanical integrity.

Casting & Chemistry Assurance

Direct operation of dedicated foundries (heritage since 1996) eliminates subcontracting variance. We verify Ductile Iron (GGG40/50), WCB, CF8M, and Aluminum Bronze alloy structures via optical emission spectrometry prior to mold pouring.

Proprietary Rubber Compounding

Operating Tianjin Dongfang Rubber Factory since 1987, our internal formulation of WRAS-compliant EPDM, NBR, and Viton prevents seat degradation, guaranteeing optimal elasticity under continuous cyclical load.

CNC Machining & 100% Inspection

Multi-axis CNC centers guarantee pin-to-seat coaxial concentricity within 0.02mm. Every valve undergoes hydrostatic body (1.5x PN) and pneumatic low/high-pressure seat tests before automated laser marking and packaging.

23,000 m² Integrated Production Hub
100% Pressure Tested (ISO 5208)
50+ Export Nations Worldwide
30+ Yrs Foundry & Rubber R&D
Application Matrix

Localized Deployment Scenarios

Optimized fluid dynamics engineered to fit regional installation codes, whether horizontal risers, vertical distribution shafts, or marine containment chambers.

Potable Distribution

WRAS/CE compliant EPDM internal liners safeguard municipal water mains from chemical back-siphonage and biological cross-contamination at junction nodes.

HVAC Cooling Loops

Compact installation between chiller outlet manifolds and cooling tower return loops to eliminate pump impeller backward rotation upon system shutdown.

Marine & Desalination

Dual-phase Nickel Aluminum Bronze (C95800) and Duplex Steel trims resist pitting and chloride stress corrosion in aggressive seawater ballast systems.

Industrial Fire Sprinklers

Quick-reacting torsion springs withstand continuous high standby static head pressures, opening instantly upon fire booster pump cycling.

Industry Intelligence

Market Evolution & Strategic Global Sourcing Criteria

Analyzing regulatory shifts, life-cycle expenditures, and supply chain rationalization parameters for Tier-1 infrastructure procurement specialists.

Total Cost of Ownership (TCO)

Engineering firms are moving away from cast iron swing valves due to frequent seat leakage and mechanical hinge wear. Dual-plate non-return designs minimize hydraulic drag, lowering lifetime pumping energy costs while extending maintenance intervals past 150,000 cycles.

Smart Monitoring Integration

With smart water grid digitalization, procurement demands flow valves with integrated non-intrusive acoustic emission sensing and differential pressure tapping ports to pinpoint localized leakage or mechanical pin blockage in real time.

Rigorous Traceability Protocols

Global EPCs require EN 10204 3.1 material test certificates, vulcanization lot testing for elastomers, and 100% radiographic weld/cast inspection records. Our integrated facility documents the entire metallurgical path from ingot melt to sea container loading.

Technical Clarifications

Frequently Asked Engineering & Procurement Questions

Direct answers from our senior engineering team regarding flange standards, hydraulic performance, material selection, and logistics.

What are the key technical differences between a dual-plate wafer check valve and a dual non-return valve (DNRV)?
A standard dual-plate wafer check valve uses two semicircular plates hinged on a central pin within a single valve body to mitigate backflow quickly and prevent water hammer. A dual non-return valve (DNRV) typically refers to an assembly of two independent check mechanisms arranged in series with intermediate testing or relief capabilities to prevent cross-contamination in potable water lines. We supply both designs depending on whether your priority is surge suppression or backflow protection.
Which international flange dimensions and pressure classes can your factory machine?
Our valves can be machined to meet EN 1092-2 (PN6, PN10, PN16, PN25), ASME/ANSI B16.5 (Class 125, Class 150, Class 300), BS 10 (Table D/E), and JIS B2239 (10K, 16K). Wafer and lug bodies feature universal alignment bolt holes to simplify warehouse stocking across multi-market distribution operations.
How does in-house elastomer vulcanization benefit valve service longevity?
Through our group company, Tianjin Dongfang Rubber Factory (operating since 1987), we control the entire polymer compounding process. This ensures strict control over virgin elastomer content, carbon black dispersal, and vulcanization duration. Our resilient seats deliver consistent shore hardness and low compression set, preventing swelling, hardening, or dislodging during high-velocity line surges.
Can dual non-return valves be installed in vertical flow runs?
Yes, our dual-plate non-return designs can be positioned in vertical pipelines, provided the flow direction is upwards. The dual springs ensure the plates close immediately when flow ceases, eliminating reliance on gravitational back-pressure and providing non-slam shut-off in vertical riser applications.
What documentation and quality certificates accompany wholesale export consignments?
Every export shipment includes EN 10204 3.1 Material Test Reports (MTRs), hydrostatic and pneumatic test inspection sheets, coating thickness reports, and CE/ISO 9001 compliance declarations. WRAS material declarations are supplied for models with certified drinking-water ratings. Third-party inspections (SGS, BV, TÜV) are welcomed and regularly conducted on site.
What lead times and logistical workflows are standard for wholesale OEM container orders?
Standard production runs for full 20ft/40ft FCL orders range between 25 to 35 days. Located in Wuxia Industrial Park, Dongli District, Tianjin, our plant is located near Tianjin Port (Xingang), allowing direct container drayage with minimum inland transit delays.
Complete Pipeline Series

Complementary Valves for System Isolation & Flow Throttling

Integrate our certified double non-return valves with matched gate, globe, and resilient butterfly valves for end-to-end fluid performance.

Low-Torque Flange Type Butterfly Valve

Wholesale Low - Torque Flange Type Butterfly Valve

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Water Seal Globe Valve

High-Quality Water Seal Globe Valve with Quick - Closing Feature

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WRAS Approved Lug Type Butterfly Valve

Wholesale WRAS Approved Lug Type Butterfly Valve 4325G

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Low Pressure Wafer Butterfly Valve

Wholesale Low - Pressure Wafer Type Butterfly Valve

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Three Way Flange Ball Valve

CE Certification Quick - Opening Three - Way Flange Ball Valve for Emergency Fluid Diversion

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PTFE Lined Cast Body Butterfly Valve

Wholesale PTFE Lined Cast Body Butterfly Valve

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Gate Valve Flow Control

Wholesale High-Quality Gate Valve for Reliable Flow Control

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Dual Plate Check Valve Device

CE Certification Dual Plate Check Valve, Reliable Backflow Prevention Device

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