Speicial g surface roughness for OQEP PDO project

We have completed speicial g surface roughness for OQEP PDO project.

This specification defines the minimum requirements of bought-out metallic piping items for design, materials, inspection and testing of pipes, fittings, flanges, spectacle blinds/spacers, bolting and gaskets.

Flanges & Blanks

• All flanges up to and including 24 inch NB and rating up to 900# shall conform to ASME B16.5. Flanges- 26 inch and larger shall conform to ASME B16.47 Series A. Flanges for high pressure rating of API 5000# & API 10000# shall conform to API 6A.
• All flanges are required to meet the definition of hot worked forgings in ASTM A788:
  Flanges shall be hot worked by press, hammer, or ring-mill of sufficient capacity to produce a substantially wrought structure throughout the hub. Flanges must be produced individually, one piece, and not spliced or folded. Flanges must be hot worked as close as practicable to finished dimensions.
• Flanges shall be of a forged type only. Flanges machined from forged bar or billet will not be accepted. Bore of the flange shall match the inner diameter of pipe.
• Chemical analysis must be performed upon each heat (melt), from which flanges are manufactured for all elements specified in the respective standards. The Manufacturer must provide complete certified Mill Test Reports.
• Mechanical testing of representative samples from each test lot is required for acceptance of all flanges. Testing is to be in accordance with the respective standards.
• Orifice flanges shall conform to ASME B16.36. Orifice flanges shall be supplied in pairs, complete with jackscrews and solid steel plugs (1/2inch male NPT), but without bolts, gaskets or orifice plates. Plug material shall be of the same material as flanges.
• Spectacle blinds 24 inch and below shall be in accordance with ASME B16.48.
• Blinds and spacers over 100 kg shall be supplied with lifting lug(s).
• Flange jointing faces shall have the following surface roughness: Class 150 RF – ASME B16.5: Ra 6.3 to 12.5 m; Class 300, 600, and 900 RF – ASME B16.5: Ra 3.2 to 6.3 m
• Ring type joint facings for API Class 5000# & 10000# rated flanges including the sidewalls, shall have a surface roughness less than Ra 1.6 m & 0.8 m respectively.
• RTJ Flange Face hardness shall be 30-40 HB harder than that of RTJ gasket. RTJ rings Gasket material shall have the following maximum hardness values:
  316L stainless steel: 160 HB
  Duplex stainless steel: 200 HB