ASTM A105 vs ASTM A181/1 Flange ASTM A105 vs ASTM A181/1 Flange m.wasif (Mechanical) (OP) 24 May 17 11:36 Can we use Flange of material ASTM A105 instead of ASTM A181/1 flange material at bottom of Vacuum tower? Service temperature = 750 Degree Fahrenheit RE: ASTM A105 vs ASTM A181/1 Flange XL83NL (Mechanical) 24 May 17 14:22 Too little info provided to answer your question. Think of, amonst others, details like Design pressureDesign temperatureCode of constructionServiceSketch or draing of the situationSite conditionsClient standards... RE: ASTM A105 vs ASTM A181/1 Flange BigInch (Petroleum) 24 May 17 19:57 The material spec looks to be nearly the same. A105 has slightly higher Mn content allowed and a higher yield point as well. I would be tempted to make a substitution ... if I had to. Technology is stealing American jobs. Stop H1-Bs for robots. RE: ASTM A105 vs ASTM A181/1 Flange pdiculous963 (Mechanical) 25 May 17 13:24 A181 was replaced with A105 in the ASME Code. Historically, there was a A181-I, A181-II, A105-I and A105-II, with the difference being the tensile strength. Grade I had a minimum tensile of 60 ksi and Grade II had a minimum tensile of 70 ksi for both specifications. My 1968 version of B16.5 has both grades of A181 and both grades of A105, but in my 1973 edition, there is only A105 (no grades, the current specification). My recommendation would be to validate that the A105 meets the pressure temperature ratings of the tower, which it should assuming the tower was designed correctly in the first place. If it does, then the A105 is a perfectly acceptable substitution. RE: ASTM A105 vs ASTM A181/1 Flange BigInch (Petroleum) 25 May 17 14:14 A181 covers the carbon steel forgings used for general-purpose piping. Two classes of material are covered, Classes 60 and 70, and classified according to their mechanical properties. Forging is made at above critical temperature and air cooled. I have always used A105 for low grade CS weld flanges. I can't confirm that A181 has the same fabrication and testing requirements as does A105, which is specifically stated to be compatible for use in pressure systems at ambient and higher-temperature service conditions. A181 is only for "General Purpose Piping". A105 covers standards for forged carbon steel piping components, that is, flanges, fittings, valves, and similar parts, for use in pressure systems at ambient and higher-temperature service conditions. Materials shall be subjected to heat treatment (annealing, normalizing, tempering, or quenching). Material shall conform to carbon, manganese, phosphorus, sulfur, silicon, copper, nickel, chromium, molybdenum and vanadium contents. The forgings shall be subjected to tension, hardness and hydrostatic tests, with the latter applicable when required. Material shall adhere to tensile strength, yield strength, elongation, reduction of area, and hardness requirements. Guidelines for retreatment, repair by welding, and product marking are given. Forging is Normalized. Technology is stealing American jobs. Stop visas for robots. RE: ASTM A105 vs ASTM A181/1 Flange weldstan (Materials) 25 May 17 14:25 A-105 is most often used in your service description. RE: ASTM A105 vs ASTM A181/1 Flange BigInch (Petroleum) 26 May 17 05:37 Exactly! It seems that they should have been using A105 materials, never A181. Technology is stealing American jobs. Stop visas for robots.