BS1868 Cast Steel API Flanged Swing Check Valve

Product Overview

The BS1868 Cast Steel API Flanged Swing Check Valve is a critical anti-backflow valve engineered for industrial pipelines, designed to automatically prevent medium reversal and protect downstream equipment (pumps, compressors, reactors). Fully compliant with British Standard BS1868 (specifications for flanged steel swing check valves) and international API/ASME standards (API 6D, ASME B16.34), this valve features a cast steel (WCB/stainless steel) body, API standard flanged connections, and a swing disc design that opens/closes via medium pressure. Rated for Class 150~2500 (PN16~PN420) and operating temperatures from -29℃ to 425℃ (-20°F to 800°F), it delivers tight shutoff (API 598 Bubble Tight Class), low flow resistance, and long-term durability in handling water, oil, natural gas, and weakly corrosive media. Widely trusted in oil & gas, petrochemical, power generation, marine, and industrial general-purpose systems worldwide, it balances BS1868 compliance, API flange compatibility, and swing check functionality for reliable backflow prevention.

Key Features & Advantages

1.Dual Standard Compliance for Global Applications

Fully adheres to BS1868 (British standard for flanged steel swing check valves) — covering structural design, material requirements, and dimensional tolerances for Class 150-2500. Complies with API 6D (pipeline valves), ASME B16.34 (pressure-temperature ratings), ASME B16.10 (face-to-face dimensions), and ASME B16.5 (flanges ≤24”) / ASME B16.47 (flanges ＞24”) standards. Meets API 598 inspection and testing requirements (hydrostatic shell/seat tests, bubble tight sealing), ensuring global interchangeability and compliance with oil & gas/petrochemical industry safety regulations. Marked per MSS SP-25 for clear identification of pressure class, material, and standard compliance.

2.High-Quality Cast Steel Construction for Durability

Available in premium body materials to match diverse operating conditions:

·ASTM A216 WCB Cast Steel (standard): Cost-effective, excellent toughness (tensile strength 485-655 MPa, yield strength ≥275 MPa), and temperature resistance up to 425℃. Ideal 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, suitable for weakly corrosive media or harsh environments (marine, chemical processing). CF8M offers enhanced chloride pitting resistance with 2-3% molybdenum, temperature range -196℃ to 550℃.

Disc and seat surfaces are overlay-welded with 13Cr stainless steel or Stellite hard alloy (HRC 48-62), ensuring wear resistance, high-temperature stability, and reliable sealing for extended service life.

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

Features a hinged swing disc with a lightweight yet robust structure — medium flow opens the disc with minimal resistance (low pressure drop), optimizing energy efficiency for large-volume fluid transfer. When flow reverses, the disc quickly closes via medium pressure and gravity, achieving bubble-tight shutoff (API 598 Class VI) to prevent backflow damage to pumps/compressors. Designed with a stainless steel hinge pin and bronze bushing for smooth rotation and reduced friction. Suitable for horizontal installation (preferred) or vertical installation with upward medium flow.

4.API Flanged Connections for Secure Sealing & Easy Installation

Equipped with API/ASME standard flanges (RF/Raised Face, RTJ/Ring Type Joint, FF/Flat Face options) to match different pressure and sealing requirements:

·RF Face: For Class 150-600, paired with flexible graphite or spiral wound gaskets for reliable sealing under cyclic pressure/temperature.

·RTJ Face: For Class 900-2500 (high pressure), compatible with metal ring gaskets to ensure leak-proof performance in HTHP applications.

·FF Face: For low-pressure systems or flat-faced flange mating.

Flanged design enables easy assembly, disassembly, and maintenance — critical for industrial pipelines requiring periodic inspection.

5.Bolted/Pressure Seal Bonnet for Reliable Midsection Sealing

·Bolted Bonnet (Class 150-600): Easy to disassemble for internal component maintenance (disc, seat, packing), with a graphite spiral wound gasket ensuring midsection sealing.

·Pressure Seal Bonnet (Class 900-2500): Self-sealing design — system pressure enhances bonnet sealing, eliminating leakage risks in high-pressure/high-temperature (HTHP) service. Ideal for Class 900+ applications such as power plant steam lines or oil refinery process pipelines.

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 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.

✅ API Flanged Reliability: Multiple flange face options ensure secure sealing, easy installation, and maintenance.

✅ Full Pressure/Size Coverage: Class 150-2500, DN50-DN1200, meets diverse industrial requirements.

✅ Proven Global Performance: Trusted in oil & gas, petrochemical, and power projects worldwide.

Order Information

•Minimum Order Quantity (MOQ): 1 Unit

•Lead Time: 20~35 Working Days (Standard Sizes/Materials); 35~50 Working Days (Customized/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 Flanged Swing Check Valve

A Cast Steel Flanged Swing Check Valve is an automatic non return valve designed to allow fluid flow in one direction while preventing reverse flow in industrial pipelines. The valve uses a hinged disc that swings open with forward flow and closes when flow reverses. Cast steel construction provides high mechanical strength and durability under demanding conditions. Flanged ends allow secure pipeline connections and convenient maintenance in oil, gas, water, steam, and chemical systems.

Why the Cast Steel Flanged Swing Check Valve Matters

This valve is important because it protects pumps, compressors, and piping systems from damage caused by backflow and pressure surges. The swing disc design allows smooth operation with low flow resistance. Cast steel construction withstands pressure, temperature changes, and mechanical stress in industrial environments. Flanged connections improve installation reliability and simplify inspection or replacement, helping maintain safe and efficient process operation.

Common Product Types by Cast Steel 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 with clean media. Dual plate and dampened disc versions are selected for systems requiring faster closure or reduced water hammer effects. Different trim materials and seat designs are available for corrosive, abrasive, or high temperature applications.

Key Advantages of Cast Steel Flanged Swing Check Valve

The valve offers reliable backflow prevention, low pressure drop, and automatic operation without external power. Cast steel construction provides strong structural integrity and long service life. The swing disc mechanism reduces turbulence and supports efficient flow. Flanged ends allow easy installation and maintenance. With proper material selection, the valve performs effectively in high pressure, high temperature, and corrosive service conditions.

Cast Steel 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 flow passages. Assembly stations install the disc, hinge arm, pin, gasket, and bonnet. Final operations include seat lapping, pressure testing, surface coating, marking, and packaging to ensure sealing integrity, dimensional accuracy, and dependable valve performance.