Forged Steel A105 Flange Swing Check Valve With PN16 Single-disc Swing Check Valve

Specification

TIANYU Flanged Swing Check Valve: Industrial Pipeline Backflow Prevention Solution

I. Product Overview

TIANYU flanged swing check valves are crafted from A105 forged carbon steel, adhering to API 594 and ASME B16.34 standards. Featuring a single-disc swing mechanism, these valves automatically prevent backflow in industrial pipelines. With nominal diameters ranging from DN50 to DN600 (2″ to 24″) and pressure classes from Class 150 to Class 600 (PN20 to PN100), they operate reliably across temperatures from -29°C to 425°C. Ideal for water, steam, oil, and other industrial media, these valves are widely used in petroleum, chemical, power, and municipal applications.

II. Core Technical Parameters

Specifications & Operating Range
- Nominal Diameter: DN50/80/100/150/200/250/300/400/500/600 (2″/3″/4″/6″/8″/10″/12″/16″/20″/24″)
- Pressure Class: Class 150 (PN20), Class 300 (PN50), Class 600 (PN100)
- Temperature Range: -29°C to 425°C (standard), -46°C to 538°C (high-temperature alloy option)
- Media Compatibility: Water, steam, oil (non-corrosive), air
Materials & Sealing System
- Body/Bonnet: A105 forged carbon steel (tensile strength ≥485MPa, yield strength ≥250MPa)
- Disc: A105 with NBR rubber seal (standard), 316 stainless steel (corrosion-resistant)
- Pin Shaft: 316 stainless steel (HRC30-35), chrome-plated (thickness ≥25μm)
- Gasket: Flexible graphite + 304 stainless steel spiral wound (resistant to 650°C)
Mechanical Performance
- Opening Pressure: ≤0.03MPa (forward flow resistance)
- Closure Response Time: ≤0.5s (triggered by backflow)
- Fatigue Life: ≥50,000 cycles (API 594 standard)

Product Overview

III. Structural Design & Technical Features

Swing-Type Single Disc Design
- The disc rotates around a pin shaft with a streamlined flow path, achieving a resistance coefficient ≤2.5 (DN200), 30% lower than lift check valves.
- Maximum opening angle ≥70°, ensuring smooth flow and minimizing energy loss.
Flanged Connection Advantages
- Complies with ASME B16.5 flange standards for easy installation and maintenance.
- Optional lap joint flanges accommodate pipeline alignment errors, simplifying installation.
Sealing Optimization Technology
- Beveled sealing surfaces on the disc and seat ensure a sealing specific pressure ≥15MPa for bidirectional reliability.
- Vulcanized rubber seals offer bonding strength ≥8MPa with the metal substrate, enhancing tear resistance by 20%.

IV. Manufacturing Processes & Quality Control

Precision Forging
- Valve bodies forged with a ratio ≥3:1, inspected via ultrasonic testing (UT) per ASTM A388.
- Forged blanks normalized at 920°C and tempered at 650°C to eliminate stress, hardness controlled at HB170-220.
Surface Treatment
- Carbon steel components hot-dip galvanized (coating thickness ≥85μm), passing 1000-hour salt spray test (ASTM B117).
- Sealing surfaces ground to ≤0.005mm flatness, surface roughness Ra≤0.4μm, contact rate ≥90% per red lead test.
Comprehensive Testing
- Hydrostatic Test: 1.5x pressure (7.6MPa for Class 300) for 30 minutes, 1.1x sealing pressure—zero leakage.
- Water Hammer Test: Simulates 10m/s flow changes without damage, maintaining Class IV sealing performance.
- Fire Test: API 607 certified, post-fire leakage ≤0.1kg/h.

Valve Details

V. Core Product Advantages

Efficient Backflow Prevention
- Petrochemical Industry: DN300 valves in a refinery atmospheric-vacuum unit control high-temperature oil and gas (350°C), preventing equipment damage from backflow.
- Municipal Water Supply: DN600 valves at pump outlets reduce water hammer pressure peaks by 40%, extending pipeline life.
Corrosion Resistance & Longevity
- Seawater Systems: 316 stainless steel discs in 20,000ppm Cl⁻ environments exhibit corrosion rates ≤0.05mm/year, lifespan exceeding 8 years.
- Steam Systems: High-temperature alloy pins maintain flexibility in 450°C steam, resisting creep.
Low Maintenance Cost
- In-line seal replacement without valve disassembly reduces maintenance time by 70%.
- Self-lubricating bearings on pin shafts minimize friction, extending service life.

Application

VI. Application Fields & Case Studies

Offshore Platform: DN200 Class 600 valves in seawater injection systems operate for 5 years without failure in H₂S (500ppm) environments.
Thermal Power Plant: DN150 valves control high-temperature, high-pressure steam (400°C, 4.0MPa) with stable sealing and annual leakage ≤0.1m³.
Wastewater Treatment Plant: DN400 valves in aeration tank return lines resist sludge erosion, serving over 6 years.

VII. Installation & Maintenance Guide

Installation Guidelines
- Install horizontally with flow direction matching the arrow on the valve body.
- Tighten flange bolts diagonally in three steps, following ASME PCC-1 torque values (e.g., ~750N·m for Class 300 DN200).
Routine Maintenance
- Inspect disc mobility quarterly and clean sealing surfaces.
- Replace pin shaft grease annually (high-temperature applications), monitor disc thickness (replace if wear >1mm).
Troubleshooting
- Minor leaks: Tighten flange bolts. For severe leaks, replace seals.
- Disc jamming: Check pin shaft wear; clean or replace shaft and bearings.