Q1: Why is ASTM A179 used for heat exchangers?
A: Its low carbon content (C≤0.06%) minimizes scaling and allows efficient heat transfer.
Q2: Which grade is standard for oil & gas downhole tubing?
A: API 5CT L80 Type 1 (yield strength 80,000 psi) with controlled hardness for sour service.
Q3: What makes ASTM A519 4130 popular in aerospace hydraulic lines?
A: High strength-to-weight ratio and good weldability after normalizing.
Q4: Why are ASTM A268 TP444 ferritic stainless tubes used in condensers?
A: High chromium (18%) and molybdenum (2%) provide pitting resistance in brackish water.
Q5: Which grade is specified for urea synthesis reactor tubes?
A: UNS S31050 (25-22-2) austenitic stainless steel resists ammonia and carbamate corrosion.
