Description
Straight-Through Diaphragm Valve Technical Datasheet
(Non-Weir, Reduced-Bore Design)
Compliance: BS5156 ∙ Materials: Ductile Iron + Full EPDM Lining
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Component
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Material & Specification
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Key Properties
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1. Valve Body
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Ductile Iron (EN-GJS-400-18/GGG40) • Full Internal Lining: EPDM (3 mm min. thickness)
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• Pressure Rating: PN10/PN16 • Lining Adhesion: ≥ 5 MPa (ISO 4624) • Corrosion Protection: Full EPDM barrier
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2. Disc
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Ductile Iron (GGG40) • EPDM-Encapsulated
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• Reduced-Bore Design: 85–90% of pipe ID • Abrasion-Resistant Surface
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3. Stem
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AISI 316L Stainless Steel • Mechanically Polished (Ra ≤ 1.6 μm)
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• SSC-Resistant (NACE MR0175) • Hardness: 140–180 HB
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4. Diaphragm
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Hypalon • Polyester Fabric Core
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• Temp Range: -20°C to +130°C • Cycle Life: ≥ 50,000 cycles
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5. Bonnet
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Ductile Iron + Full EPDM Lining
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• Bolted Design (EPDM-Coated Bolts)
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6. Seals
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EPDM O-Rings/Gaskets
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• Bubble-Tight Shutoff (ISO 5208 Rate A)
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Critical Technical Data
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Parameter
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Specification
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Flow Path Design
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Straight-Through (Non-Weir) ∙ Bore: 85–90% of nominal pipe ID
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Size Range
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DN50 to DN200 (2″ to 8″)
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End Connections
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• Flanged (EN 1092-1 Type A) ∙ ANSI Class 150 • Optional: Lug/Wafer
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Flow Coefficient
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DN100 (4″): Cv ≈ 120 (vs. 180 for full-bore)
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Pressure Drop
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ΔP ≈ 0.3–0.8 bar (water, 2 m/s flow)
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Actuation
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Manual Handwheel ∙ Pneumatic (Spring-Return) ∙ Electric (On/Off)
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Certifications
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PED 2014/68/EU (Cat. II) ∙ ISO 9001 ∙ EN 10204 3.1
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Straight-Through vs. Full Bore: Key Differences
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Feature
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Straight-Through Valve
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Full-Bore Valve
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Bore Diameter
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85–95% of pipe ID
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100% of pipe ID
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Flow Efficiency
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Moderate (Cv ≈ 65% of full-bore)
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Maximum (No restriction)
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Slurry Handling
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Good (Less clogging than weir-type)
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Excellent (Zero clogging risk)
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Mechanical Strength
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Higher (Thicker walls due to reduced bore)
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Lower (Thinner walls to match pipe ID)
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Cost
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Lower (Less material)
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Higher
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Design Advantages of Straight-Through Configuration
- Optimized for Slurries & Viscous Fluids
- Smooth, obstruction-free flow path prevents particle buildup (e.g., wastewater sludge, pulp).
- Robust Pressure Containment
- Thicker ductile iron walls (enabled by reduced bore) withstand surge pressures up to 1.5×PN.
- Simplified Maintenance
- Top-entry diaphragm replacement (no pipe disassembly).
- Cost-Effective Corrosion Protection
- Full EPDM lining isolates ductile iron from corrosive media (pH 3–12).
Limitations & Design Notes
- Not Pigable: Reduced bore prevents pipeline pigging.
- Chemical Limits: EPDM incompatible with oils, aromatics, concentrated acids (>20% H₂SO₄).
- Temperature: Max. 130°C (EPDM) – derate pressure above 80°C.
- Actuator Sizing: Higher torque required vs. weir-type due to larger diaphragm area.
GUATANTEE:
SAVVY VALVES is committed to delivering exceptional product quality and worry-free after-sales service. Our valves are guaranteed to provide a minimum service life of 12 months, during which we will supply all necessary spare parts and detailed maintenance instructions free of charge. Within the warranty period, if any non-human-induced damage occurs, we will replace components at no cost and provide professional technical support. After the warranty expires, customers only need to pay for the cost of spare parts, while still benefiting from discounted maintenance services. Our goal is to help clients reduce operational costs and enhance production efficiency through reliable quality and comprehensive after-sales support. Whether for technical inquiries or maintenance needs, our expert team will respond promptly to ensure your valve system maintains optimal performance at all times.