ASME B16.5 A182 F22 CL3 Alloy Flange Package for Singapore Sour Service Piping

Haihao Group has finished forging, heat treatment and full material property validation for a complete set of ASME B16.5 A182 F22 CL3 alloy flanges and spectacle blind, now packed and ready for delivery to our Singapore petrochemical client. This batch combines weld neck, slip-on and blind flanges alongside a figure-8 isolation blank, all Class 600 and built strictly to NACE MR0175 / MR0103 sour service requirements.

ASME B16.5 A182 F22 CL3 Class 600 alloy flange set including WN, SO, blind flange and spectacle blind NACE MR0175, Haihao Group shipment to Singapore

Product Specification Summary

This ASME B16.5 A182 F22 CL3 flange package is produced from 2.25Cr-1Mo low alloy steel, a grade selected for its stable performance at elevated temperature while resisting sulphide stress cracking in H₂S-containing streams. The client set tight chemical limits: sulfur controlled below 0.01% and phosphorus below 0.015%, far stricter than the base ASTM A182 specification, to reduce harmful non-metallic inclusions. Every ASME B16.5 A182 F22 CL3 flange undergoes dedicated heat treatment to lock in the mechanical properties required for Class 3 acceptance, before 100% material performance examination carried out in-house by our Haihao inspection team.

The shipment includes multiple flange types to fit different joint functions. Weld neck RF flanges in 1″, 1-1/2″, 4″ and 6″ sizes all follow S80 / XS wall matching the adjoining pipe schedule. A 1-1/2″ hub-style slip-on flange and two blind flanges for 1″ and 4″ closures complete the ASME B16.5 scope. The 6″ FF spectacle blind, manufactured to ASME B16.48, serves as a positive isolation point for maintenance shutdowns, sharing the same A182 F22 CL3 alloy and NACE compliance as the rest of the flange set. All sealing faces are raised face (RF) except the flat face spectacle blind, aligned with the client’s P&ID and flange mating details.

Sour service alloy flange sourcing carries little room for shortcuts. Many suppliers can supply standard F22 flanges, but consistent control over traceability, heat treatment cycle and low impurity chemistry adds extra layers of QA that refinery projects in Singapore demand. Each component carries its unique item number and material heat number, linking dimensional reports, hardness records and chemical certificates into one traceable package. This lets the site QC and third-party inspectors cross-verify compliance before spool fabrication starts.

Haihao Group supplies ASME B16.5 A182 F22 CL3 flanges, spectacle blinds and matching alloy fittings for Singapore and Southeast Asia refinery, gas processing and offshore associated piping. We support custom impurity caps, full MPE inspection, NACE sour service qualification and project-specific documentation packages for Cr-Mo alloy grades. If you require alloy flange assemblies for high-temperature or sour hydrocarbon service, send your size, class and inspection matrix for a detailed quotation.