BS1868 Cast Steel API RF Flanged Swing Check Valve

Product Overview

The BS1868 Cast Steel API RF Flanged Swing Check Valve is a robust non-return valve engineered for automatic backflow prevention in industrial pipelines, fully compliant with British Standard BS1868 (specifications for flanged steel swing check valves) and international API/ASME standards (API 6D, ASME B16.34). Constructed from high-quality cast steel (WCB/CF8/CF8M), this valve features API standard raised face (RF) flanged connections (per ASME B16.5), a hinge-mounted swing disc, and bolted bonnet design for easy maintenance. Rated for Class 150-1500 (PN20-PN250) and operating temperatures from -29℃ to 425℃ (-20°F to 800°F), it delivers bubble-tight shutoff (API 598 Class VI), low flow resistance, and exceptional durability in handling water, oil, natural gas, and weakly corrosive media. The RF flange design ensures reliable sealing under cyclic pressure loads, while the swing disc structure opens/closes via medium pressure — minimizing pressure drop and protecting pumps, compressors, and downstream equipment from backflow damage. Widely trusted in oil & gas, petrochemical, power generation, and marine industries worldwide, it balances BS1868’s rigorous quality requirements, API’s global compatibility, and RF flange’s sealing reliability for critical backflow prevention applications.

Key Features & Advantages

1.Dual Standard Compliance for Global Compatibility

Fully adheres to BS1868 — the definitive British standard for flanged steel swing check valves, covering structural design, material specifications, and dimensional tolerances for Class 150-1500. Complies with API 6D (pipeline valves), ASME B16.34 (pressure-temperature ratings), ASME B16.10 (face-to-face dimensions), and ASME B16.5 (flange standards) , ensuring seamless integration into international industrial systems. Meets API 598 inspection and testing requirements (hydrostatic shell/seat tests, air leakage tests) , achieving API 598 Class VI bubble-tight shutoff to prevent media waste and environmental hazards. Marked per MSS SP-25 for clear identification of pressure class, material, and standard compliance — critical for global project procurement.

2.Cast Steel Construction for Durability & Versatility

Available in premium material grades to match diverse operating conditions:

·ASTM A216 WCB Cast Carbon Steel (standard): Tensile strength 485-620 MPa, yield strength ≥250 MPa, operating temperature -29℃~425℃ . Cost-effective, wear-resistant, and suitable for non-corrosive media (water, steam, oil, natural gas) in general industrial service.

·ASTM A351 CF8 (304 Stainless Steel) / CF8M (316L Stainless Steel): Corrosion-resistant, ideal for weakly corrosive media or harsh environments (marine, chemical processing). CF8M grade includes 2-3% molybdenum for enhanced chloride pitting resistance, operating temperature -196℃~550℃ .

Disc and seat surfaces are overlay-welded with 13Cr stainless steel or Stellite 6 hard alloy (HRC 48-62) , ensuring wear resistance, high-temperature stability, and long service life (8+ years in typical industrial applications) .

3.API RF Flanged Connections for Secure Sealing

Equipped with ASME B16.5 raised face (RF) flanges — the most widely used flange type for industrial valves, offering superior sealing performance under cyclic pressure/temperature loads. The RF flange’s serrated surface (per ASME B16.5) paired with stainless steel spiral wound gaskets (graphite filler) creates a tight seal that resists leakage even in high-pressure (Class 1500) applications . Flange sizes range from NPS 2”~48” (DN50~DN1200) , compatible with standard pipeline flanges for easy installation and maintenance. Optional flange faces (RTJ/FF) available for specialized high-pressure (Class 900+) or low-pressure applications, ensuring flexibility for diverse project requirements.

4.Swing Disc Design for Low Resistance & Fast Backflow Prevention

Features a hinge-mounted swing disc with a lightweight yet robust structure — medium flow opens the disc with minimal resistance (pressure drop 30% lower than lift check valves) , optimizing energy efficiency for large-volume fluid transfer . When flow reverses, the disc quickly closes via medium pressure and gravity, achieving API 598 Class VI bubble-tight shutoff to protect downstream equipment (pumps, compressors, reactors) from backflow impact . The disc is equipped with a bronze bushing at the hinge pin for smooth rotation and reduced friction, eliminating jamming risks in high-velocity fluid applications. Suitable for horizontal installation (preferred) or vertical installation with upward medium flow .

5.Bolted Bonnet & Low-Maintenance Design

Bolted bonnet structure enables easy disassembly for internal component maintenance (disc, seat, packing) without removing the valve from the pipeline — reducing downtime and maintenance costs . The midsection sealing gasket (stainless steel spiral wound + graphite filler) ensures reliable sealing under pressure cycling, complying with BS1868 and API 6D leakage requirements. Integral forged hinge pin (ASTM A182 F6a) resists bending and corrosion, while the backseat design allows in-line packing replacement for extended service life . Optional anti-hammer device reduces water hammer effects in high-pressure liquid pipelines, preventing valve damage and operational noise.

Technical Specifications

Applications

•Oil & Gas Industry: Oil/gas gathering pipelines, natural gas transmission lines, LNG terminals, wellhead manifolds, refineries .

•Petrochemical Industry: Refining units, chemical reactors, distillation columns, high-temperature/high-pressure process pipelines .

•Power Generation: Thermal power plant steam/feedwater systems, nuclear power auxiliary pipelines, waste heat recovery systems .

•Marine & Offshore: Shipboard ballast water systems, offshore platform oil/gas transfer lines, seawater desalination plants .

•Industrial General-Purpose: Water treatment plants, heating networks, compressed air systems, industrial refrigeration equipment, metallurgical process lines .

Why Choose Our BS1868 API RF Flanged Swing Check Valve?

✅ Dual Standard Compliance: BS1868 + API 6D/ASME, ideal for international projects and global industrial systems .

✅ Durable Cast Steel/Stainless Steel Construction: Resists corrosion, high temperature, and pressure cycling for long service life .

✅ Low Resistance & Fast Backflow Prevention: Swing disc design minimizes pressure drop, protects downstream equipment from backflow damage .

✅ RF Flange Sealing Reliability: ASME B16.5 RF flanges ensure tight sealing, easy installation, and maintenance .

✅ Full Pressure/Size Coverage: Class 150-1500, DN50-DN1200, meets diverse industrial requirements .

✅ Proven Global Performance: Trusted in oil & gas, petrochemical, and power projects worldwide (over 10,000 units installed) .

Order Information

•Minimum Order Quantity (MOQ): 1 Unit

•Lead Time: 20~35 Working Days (Standard Sizes/Materials); 35~50 Working Days (Customized Stainless Steel/High-Pressure Sizes)

•Payment Terms: T/T (30% Advance + 70% Against B/L Copy), L/C, Western Union

•Shipping Method: Sea Freight (FCL/LCL), Air Freight (Urgent Orders)

•Packaging: Anti-Corrosion Coating + Wooden Case + Steel Frame + Export Labeling (Compliant with International Shipping Standards)

•After-Sales Service: 18-Month Warranty, Technical Support, Spare Parts Supply, On-Site Installation Guidance

•Certifications Provided: Material Test Certificate (EN 10204 3.1), API 598 Test Report, ISO 9001 Certificate, API 6D Compliance Certificate, BS1868 Conformity Document

Contact Our Valve Experts for customized quotes, 2D/3D drawings (per BS1868/API 6D), material certificates, or technical consultations. We specialize in standard-compliant check valves for global industrial applications — let us tailor a solution for your backflow prevention needs.

What Is a Cast Steel API Flanged Swing Check Valve

A Cast Steel API Flanged Swing Check Valve is an automatic non return valve designed to prevent reverse flow in industrial pipeline systems. It uses a hinged disc that swings open when fluid moves forward and closes automatically when flow reverses. The body is manufactured from cast steel for high strength and durability. API design standards ensure dependable construction and performance, while flanged ends provide secure installation and convenient maintenance in industrial applications.

Why the Cast Steel API Flanged Swing Check Valve Matters

This valve is important because it protects pumps, compressors, and process equipment from damage caused by backflow and pressure surges. The swing disc design allows smooth fluid movement with minimal restriction. Cast steel construction withstands demanding pressure and temperature conditions. API compliant manufacturing ensures consistent quality and reliable sealing, helping maintain safe and stable operation in oil, gas, power generation, water treatment, and chemical processing systems.

Common Product Types by Cast Steel API Flanged Swing Check Valve

Common product types include bolted bonnet swing check valves, pressure seal swing check valves, and tilting disc check valves. Standard swing check valves are widely used in horizontal pipelines carrying clean fluids. Dampened disc and non slam designs are selected for applications requiring reduced water hammer effects. Different trim materials, seat facings, and flange standards are available to match corrosive, abrasive, or high temperature service conditions.

Key Advantages of Cast Steel API Flanged Swing Check Valve

The valve offers reliable backflow prevention, automatic operation, and low pressure drop during normal flow. Cast steel construction provides excellent mechanical strength and long service life. The swing disc mechanism reduces turbulence and improves flow efficiency. Flanged ends simplify installation and maintenance. API compliant design ensures dependable sealing performance and compatibility with demanding industrial process systems.

Cast Steel API Flanged Swing Check Valve Machine Structure and Core Stations

Manufacturing begins with casting the body, bonnet, disc, and hinge components from cast steel materials. Core stations include heat treatment, CNC machining of flange faces, seat surfaces, hinge bores, and internal flow passages. Assembly stations install the disc, hinge arm, pin, gasket, and bonnet. Final operations include seat lapping, pressure testing, coating, marking, and packaging to ensure dimensional accuracy, sealing integrity, and reliable valve operation.