C&N Meets OQEP PDO Project Surface Roughness Specs

C&N is pleased to announce the successful completion of special surface roughness requirements for the OQEP PDO project. As a trusted partner in industrial piping solutions, we adhere to the highest international standards to ensure the reliability and performance of metallic piping components. This document outlines the minimum specifications for purchased metallic piping items, covering design, materials, inspection, and testing of pipes, fittings, flanges, spectacle blinds/spacers, bolting, and gaskets.

Flanges & Blanks Standards

Flange Specifications

• Dimensions & Ratings:
  • Flanges up to 24-inch NB (Nominal Bore) with ratings up to 900# comply with ASME B16.5.
  • Larger flanges (26-inch and above) follow ASME B16.47 Series A.
  • High-pressure flanges (API 5000# & 10000#) conform to API 6A, ensuring safety in extreme operating conditions.
• Manufacturing Requirements:
  All flanges must meet ASTM A788 hot-worked forging standards:
  • Produced via press, hammer, or ring-mill to achieve a uniform wrought structure throughout the hub.
  • Single-piece forgings without splicing or folding, hot-worked as close to final dimensions as practical.
  • Forged flanges only; machined products from forged bars or billets are not accepted.
  • Bore dimensions must match the inner diameter of the connected pipe for seamless integration.
• Testing & Certification:
  • Chemical analysis is conducted for each heat (melt) to verify compliance with material standards, supported by certified Mill Test Reports.
  • Mechanical testing of representative samples from each test lot ensures adherence to relevant industry standards.
• Specialized Flanges:
  Orifice flanges (ASME B16.36) are supplied in pairs with jackscrews and solid steel plugs (1/2-inch male NPT), matching flange material. Bolts, gaskets, and orifice plates are excluded for flexible assembly.

Blind & Spacer Requirements

• Spectacle Blinds:
  Blinds up to 24 inches follow ASME B16.48, while units over 100 kg include lifting lugs for safe handling.
• Surface Roughness & Hardness:
  • RF Flanges (ASME B16.5):
    • Class 150: Ra 6.3–12.5 μm
    • Classes 300/600/900: Ra 3.2–6.3 μm
  • RTJ Flanges (API 5000#/10000#):
    • Sidewalls and joint faces feature surface roughness < Ra 1.6 μm (5000#) and < Ra 0.8 μm (10000#).
    • RTJ flange face hardness must exceed gasket hardness by 30–40 HB, with maximum gasket hardness:
      • 316L Stainless Steel: 160 HB
      • Duplex Stainless Steel: 200 HB

C&N’s commitment to precision engineering and compliance with global standards ensures that all piping components for the OQEP PDO project meet rigorous quality benchmarks. Our expertise in material science, manufacturing, and testing delivers solutions that enhance operational safety and efficiency. For more details on our industrial piping services, contact our technical team today.