BS 1868 Check Valve

1. Valve Types‌

• Valve Types: Covers swing check, lift check, tilting disc, and ball check valves.
• Applications: Hydrocarbon, chemical, and utility services in refineries, pipelines, and process plants.

‌2. Key Features‌

• ‌Body & Bonnet‌: Bolted cover construction
• ‌Disc‌: Hinged or guided to ensure tight shutoff against reverse flow.
• ‌Seat‌: Metal-to-metal for tight sealing.
• ‌Face-to-Face Dimensions‌: Complies with ASME B16.10

‌3. Material Specifications‌

• ‌Body/Bonnet Materials‌: Carbon steel (e.g., ASTM A216 WCB), stainless steel (e.g., ASTM A351 CF8M), or alloy steel (e.g., ASTM A217 WC6).
• ‌Trim (Disc, Seat, Hinge Pin)**‌: Stainless steel (316/304), stellite, or hard-faced alloys for wear/corrosion resistance.
• ‌Bolting‌: High-strength materials (e.g., ASTM A193 B7/B8 for high-pressure/temperature).
• ‌Gaskets‌: Spiral-wound (stainless steel + graphite) or ring-joint type (RJT).

‌4. Pressure & Temperature Ratings‌

• ‌Pressure Classes‌: ASME B16.34 (e.g., Class 150, 300, 600, 900, 1500, 2500).
• ‌Temperature Range‌:
  • ‌Standard‌: -29°C to 593°C (-20°F to 1100°F), depending on material.
  • ‌Cryogenic/High-Temp‌: Extended ranges with special materials (e.g., ASTM A352 LCB for low temps).

‌5. Testing Requirements‌

• ‌Hydrostatic Shell Test‌: 1.5x rated pressure to check body/bonnet integrity.
• ‌Seat Leakage Test‌: 1.1x working pressure to verify sealing; leakage rates align with ISO 5208 classes (e.g., Class A for zero leakage).
• ‌Fire-Safe Testing‌: Optional compliance with API 607/6FA if required.

‌6. End Connections‌

• ‌Flanged Ends‌: ASME B16.5 (up to Class 2500) or B16.47 (large diameters).
• ‌Butt-Weld Ends‌: ASME B16.25 beveled ends for pipeline integration.

‌7. Marking & Identification‌

• ‌Body Markings‌:
  • BS 1868 standard, material class, pressure rating, size, flow direction arrow.
  • Manufacturer’s name/trademark, heat number, and casting marks.

‌8. Certification & Documentation‌

• ‌**Material Test Reports (MTRs)**‌: Traceability for all components.
• ‌Inspection Certificates‌: Third-party verification (e.g., Lloyds, DNV).

‌9. Optional Features‌

• ‌Lever & Weight‌: For swing check valves to control closing speed.
• ‌Bolted Bonnet‌: For easier maintenance.
• ‌Extended Body‌: For low temperature service or insulation.