FAQ

• 347AP is a brand name owned by Nippon Steel & Sumitomo Metals which has been developed in 1980s for the purpose of preventing sensitization to Polythionic Acid Stress Corrosion Cracking (PTA SCC) in austenitic stainless steel heater tubes.

• 347AP is a proprietary chemical subset of austenitic stainless steel Type 347LN (UNS S34751).

• smiLLe™ is a trade mark owned by Mitsui & Co., Ltd. which covers all 347AP products required to assure Anti-PTA SCC efficacy in hydrocracking units and hydrotreating units.

• smiLLe™ is the only metallurgical solution to prevent PTA SCC, without thermal stabilized heat treatment and without neutralization in hydrocracking and hydrotreating units

• Our business alliance partner Honeywell UOP licenses hydrocracking and hydrotreating technology. Please kindly send your questions to the email address here. (smiLLe-PR-TKZPF@mitsui.com)

• Our business alliance partner Nippon Steel & Sumitomo Metals can address your questions. Please kindly send your questions to the email address here. (smiLLe-PR-TKZPF@mitsui.com)

• The properties of smiLLe™ are such that thermal stabilization heat treatment normally required for stabilized stainless steel, Type 321 and Type 347 after welding, typically consisting of heating the material to 1,650F(900℃) for 4hr, is not required. Therefore shop fabrication time can be shortened and costs for fabrication will be reduced. Field fabrication time will be also reduced, along with expenses for thermal stabilization heat treatment of field welds compared with piping using stabilized Type 321 and Type 347 materials

• smiLLe™ would be used in the fabrication of components requiring austenitic material in hydrocracking and hydrotreating units that could be sensitized leading to PTA SCC, including;

◇Piping

◇Heater tubes

◇Heat Exchanger tubes and components

◇Flanges and Forged components

◇Plate for reactor internals fabrication

◇Weld overlay materials for reactor vessels and exchangers

◇Cast and forged valve and control valve

◇Welding consumables

• The proprietary smiLLe metallurgy is not listed in any standards. For design of smiLLe™ products, you can refer to Type 347LN registered as below. Procedures in place for codes where registration is in progress.

■ ASME Boiler and Pressure Vessel Code

・ASME Code Case 2196-4
・ASME Sec.II

■ Fired Heater

・API560
・API579
・WRC541

■ Piping

■ ASTM products registration

・ASTM A182
・ASTM A193
・ASTM A194
・ASTM A213
・ASTM A240
・ASTM A312
・ASTM A358
・ASTM A351
・ASTM A403
・ASTM A580
・ASTM A965

Registration In Progress

■ Fired Heater

・API530 (expected to be registered by 2018 year-end.)

■ Piping

・ASME B31.3
・ASME B16.5
・ASME B16.47
・ASME B16.34 (expected to be registered by 2019 in mid.)