ANSI DN150 PN16 Diaphragm Cast Iron Non-return Spring Dual Plate Wafer Check Valve

Specification

TIANYU Diaphragm-Type Ductile Iron Spring Double-Disc Wafer Check Valve: Efficient Industrial Backflow Prevention Solution

I. Product Overview

TIANYU diaphragm-type ductile iron spring double-disc wafer check valves are designed to API 594 and DIN EN 1092 standards, constructed from QT450-10 ductile iron. The dual-disc linkage with spring-loading ensures automatic backflow prevention, covering DN40-DN800 (1.5″-32″) with PN10-PN16 (1.0-1.6MPa) pressure ratings and -10℃~120℃ operating temperatures. Suitable for water, sewage, steam, and oil, they excel in municipal water supply, building networks, and industrial circulating water systems.

II. Core Technical Parameters

Specifications & Operating Range
- Nominal Diameter: DN40/50/80/100/150/200/250/300/400/500/600/800 (1.5″-32″)
- Pressure Class: PN10 (1.0MPa), PN16 (1.6MPa)
- Temperature Range: -10℃~120℃ (standard), -40℃~150℃ (special seal option)
- Media Compatibility: Water, sewage, seawater, steam, non-corrosive oils
Materials & Sealing System
- Body/Disc: QT450-10 ductile iron (tensile strength ≥450MPa, elongation ≥10%)
- Sealing Pair: NBR rubber diaphragm (standard), EPDM (temperature-resistant), Viton (oil-resistant), leakage rate ≤0.1% (API 598)
- Spring/Pin: 304 stainless steel (HRC28-32), corrosion-fatigue resistant
- Connection: Wafer Type (fits DIN PN10/16, ANSI 150# flanges)
Mechanical Performance
- Opening Pressure: ≤0.02MPa (forward flow resistance)
- Closure Response Time: ≤0.3s (triggered by backflow)
- Water Hammer Protection: Withstands 1000 impact tests without damage (ISO 16780)

Product Overview

III. Structural Design & Technical Features

Dual-Disc Spring Linkage Mechanism
- Symmetric dual-disc design disperses medium impact; spring-loading ensures rapid reset under low pressure, closing 35% faster than single-disc valves to eliminate water hammer.
- Disc opening angle ≤40° with streamlined flow path, DN100 pressure loss ≤0.06MPa (25% lower than traditional lift checks).
Diaphragm Seal Optimization
- Embedded rubber diaphragm forms elastic extrusion seal with seat, specific pressure ≥10MPa for bidirectional bubble-tight performance, suitable for media with particles (diameter ≤1mm).
- Chrome-plated pin (thickness ≥15μm) with PTFE bearings reduces friction, enabling >80,000 operation cycles.
Compact Lightweight Design
- Wafer structure shortens length by 45% and reduces weight by 35% vs. flanged types, saving installation space and transport costs.
- Precision-cast body with surface roughness Ra≤12.5μm minimizes medium deposition and corrosion risk.

IV. Manufacturing Processes & Quality Control

Precision Casting Flow
- Lost foam casting process, blank dimension tolerance ≤±0.8mm, 100% ultrasonic testing (UT) for internal defects.
- Ductile iron parts annealed at 920℃, graphite morphology controlled to GB/T 1348 Grade Ⅱ+, fatigue resistance 30% higher.
Assembly & Testing System
- Disc-seat lapping with contact rate ≥80% (red lead test), spring load deviation ≤±5%.
- Hydrostatic test: 1.5x pressure (2.4MPa for PN16) held 30min, 1.1x sealing pressure—zero leakage.
- Life test: 80,000 cycles at 1.6MPa without sealing degradation (GB/T 13932).
Certifications & Compliance
- CE-PED 2014/68/EU, ISO 9001:2015 certified; compliant with WRAS (UK drinking water), ACS (French sanitary standard).
- Provides Material Test Reports (MTR), pressure test certificates, and third-party inspection.

Valve Details

V. Core Product Advantages

Multi-Scenario Backflow Protection
- Municipal water supply: DN300 PN16 valve at pump station prevents backflow, 5-year leak-free operation, WRAS certified.
- Building fire protection: DN100 PN16 valve in sprinkler systems, diaphragm resists fire water corrosion, response time ≤0.5s.
- Food processing: FDA-certified NBR diaphragm for DN50 valve in clean steam, condensate meets USP purified water standards.
Full-Life Cycle Cost Optimization
- Replaceable diaphragm design shortens on-site maintenance to 1.5 hours/operation, reducing costs by 50%.
- Maintenance-free cycle reaches 6 years or 80,000 operations, 40% longer than cast iron valves.
Installation & Maintenance Convenience
- Disc and spring assembly replaceable without pipeline disassembly; supports horizontal/vertical installation (vertical flow upward).
- Provides installation videos and torque guides, bolts torqued diagonally in three steps (DIN EN 1514-3).

Application

VI. Application Fields & Cases

Urban wastewater treatment plant: DN600 PN16 valve in aeration tank inlet reduces sludge backflow, water hammer protection decreases pipeline vibration by 50%.
Commercial complex: DN150 PN10 valve in 70℃ hot water system, EPDM diaphragm annual leakage ≤0.3m³, ACS compliant.
Industrial circulating water station: DN200 PN16 valve controls chloride-containing (1500ppm) cooling water, ductile iron body corrosion life >7 years.

VII. Installation & Maintenance Guide

Installation Notes
- Center valve between flanges, align flow with body arrow; bolt torque graded as DN100≤75N·m, DN200≤150N·m.
- DN≥300 valves require supports to avoid pipeline stress affecting seals.
Routine Maintenance
- Check disc mobility quarterly; replace pin grease annually for high temp (silicone-based, 150℃ resistance).
- Seal leakage repairable by diaphragm replacement or seat lapping, no full valve replacement needed.