20 High Pressure Boiler Tube 
 20 high-pressure boiler tubes are high-quality carbon structural steel (GB/T699-1999), high-quality carbon structural steel is to rely on to adjust carbon (C) the amount to improve the mechanical properties of steel, therefore, according to the level of carbon content, this type of steel can be divided into: 
 Low-carbon steel - generally less than 0.25% carbon content, such as 10, 20 steel; 
 The carbon - carbon content is generally between 0.25 to 0.60%, such as 35,45 steel; 
 High-carbon steel - carbon content is generally greater than 0.60%. Such is generally not used in the manufacture of steel pipe. 
 In fact, they between carbon content and no clear boundaries. 
 Such a large steel production, uses a wider, more general rolling (forging) made of round, square, flat and other profiles, sheets and seamless. Mainly for the manufacture of general structure and mechanical parts and components and structural parts and transmission fluid pipe. According to requirements, and sometimes need to heat treatment (normalizing or quenching and tempering) before use. 
 High-pressure boiler seamless pipe (GB5310-1995) is used to manufacture high-pressure and more pressure water tube boiler heating surface with high-quality carbon steel, alloy steel and heat-resistant stainless steel seamless pipe. 
 High Pressure Boiler Tube 20G 
 Material: 20 # 
 Executive Standard: GB5310-95 national standard, ST45.8-Ⅲ German standard, A106B American Standard 
 Specifications Specifications Specifications Specifications 
 14 × 3 42 × 3 89 × 6 159 × 7 
 14 × 3.5 42 × 3.5 89 × 7 159 × 8 
 14 × 4 42 × 4 89 × 7.5 159 × 9.5 
 16 × 3 42 × 5 89 × 8 159 × 10 
 18 × 2 42 × 6 89 × 9 159 × 12 
 18 × 3 42 × 8 89 × 10 159 × 14 
 18 × 4 45 × 3 89 × 11 159 × 16 
 18 × 5 45 × 4 89 × 12 159 × 18 
 19 × 2 45 × 5 108 × 4.5 159 × 20 
 21 × 4 45 × 6 108 × 5 159 × 28 
 22 × 2.5 45 × 7 108 × 6 168 × 6 
 22 × 3 48 × 4 108 × 7 168 × 7 
 22 × 4 48 × 4.5 108 × 8 168 × 8 
 22 × 5 48 × 5 108 × 9 168 × 9.5 
 25 × 2.5 48 × 6 108 × 10 168 × 10 
 25 × 3 48 × 7 108 × 12 168 × 11 
 25 × 4 48.3 × 12.5 108 × 14 168 × 12 
 25 × 5 51 × 3 108 × 15 168 × 14 
 25 × 5.5 51 × 3.5 108 × 16 168 × 15 
 27 × 3.5 51 × 4 108 × 20 168 × 16 
 27 × 4 51 × 5 114 × 5 168 × 18 
 27 × 5 51 × 6 114 × 6 168 × 20 
 27 × 5.5 57 × 4 114 × 7 168 × 22 
 28 × 5.5 57 × 5 114 × 8 168 × 25 
 28 × 3 57 × 5.5 114 × 8.5 168 × 28 
 28 × 3.5 57 × 6 114 × 9 180 × 10 
 28 × 4 60 × 4 114 × 10 194 × 10 
 30 × 2.5 60 × 4 114 × 11 194 × 12 
 32 × 2.5 60 × 5 114 × 12 194 × 14 
 32 × 3 60 × 6 114 × 13 194 × 16 
 32 × 3.5 60 × 7 114 × 14 194 × 18 
 32 × 4 60 × 8 114 × 16 194 × 20 
 32 × 4.5 60 × 9 114 × 18 194 × 26 
 32 × 5 60 × 10 133 × 5 219 × 6.5 
 34 × 3 76 × 4.5 133 × 6 219 × 7 
 34 × 4 76 × 5 133 × 7 219 × 8 
 34 × 4.5 76 × 6 133 × 8 219 × 9 
 34 × 5 76 × 7 133 × 10 219 × 10 
 34 × 6.5 76 × 8 133 × 12 219 × 12 
 38 × 3 76 × 9 133 × 13 219 × 13 
 38 × 3.5 76 × 10 133 × 14 219 × 14 
 38 × 4 89 × 4 133 × 16 219 × 16 
 38 × 4.5 89 × 4.5 133 × 18 219 × 18 
 38 × 5 89 × 5 159 × 6 219 × 20 
 38 × 5.5 89 × 5.5 159 × 6.5 219 × 22 
 219 × 24 298.5 × 36 377 × 12 426 × 22 
 219 × 25 325 × 8 377 × 14 426 × 30 
 219 × 26 325 × 9 377 × 15 426 × 36 
 219 × 28 325 × 10 377 × 16 426 × 40 
 219 × 30 325 × 11 377 × 18 426 × 50 
 219 × 32 325 × 12 377 × 20 457 × 12 
 219 × 35 325 × 13 377 × 22 457 × 14 
 219 × 38 325 × 14 377 × 25 457 × 16 
 273 × 7 325 × 15 377 × 32 457 × 19 
 273 × 8 325 × 16 377 × 36 457 × 24 
 273 × 9 325 × 17 377 × 40 457 × 65 
 273 × 9.5 325 × 18 377 × 45 508 × 13 
 273 × 10 325 × 20 377 × 50 508 × 16 
 273 × 11 325 × 22 406 × 9.5 508 × 20 
 273 × 12 325 × 23 406 × 11 508 × 22 
 273 × 13 325 × 25 406 × 13 558.8 × 14 
 273 × 15 325 × 28 406 × 17 530 × 13