hemos obtenido ISO 9001, ISO 14001, ISO 45001, CE, certificación de calificación crediticia de nivel AAA, etc.
ASTM A178 / A178M Standard Specification for Electric-Resistance-Welded Carbon Steel and Carbon-Manganese Steel Boiler and Superheater Tubes. ASTM A178 standard refers to electric-resistance-welded tubes with minimum-wall-thickness. Materials are carbon steel and carbon-manganese steel, ASTM A178 pipe and tube is to be used in boiler tubes, boiler flues, superheater flues and safe ends.
Outside diameter and Wall thickness tolerance
|
Outside Diameter tolerance |
Wall thickness tolerance |
||
|
OD < 50 |
±0.05mm |
S < 4mm |
±12.5% |
|
OD > 50 |
±1% |
4--20mm |
-120 |
|
|
|
S≧20mm |
±12.5% |
Chemical Requirements
|
Element |
Grade A |
Grade C |
Grade D |
|
% |
Low carbon steel |
Medium Carbon Steel |
Manganess Steel |
|
C |
0.06-0.18 |
0.35 Max |
0.27 Max |
|
Mn |
0.27-0.63 |
0.80 Max |
1.00-1.50 |
|
P |
0.035 |
0.035 |
0.03 |
|
S |
0.035 |
0.035 |
0.015 |
|
Si |
... |
... |
0.10 Min. |
Tensile Requirements
Grade C and D tubes shall conform to the requirements as to tensile properties
|
Data |
GradeC |
GradeD |
|
Tensilestrength,min,ksi[MPa] |
60[415] |
70[485] |
|
Yieldstrength,min,ksi[MPa] |
37[255] |
40[275] |
|
Elongationin2in.or50mm,min,% |
30 |
30 |
|
For longitudinal strip tests a deduction for Each1⁄32-in[0.8mm]decreaseinwallthicknessbelow5⁄16in.[8mm] |
1.50A |
1.50A |
The actual mean wall is defined as the average of the thickest and thinnest wall in that section.
Welded tubes65 %
|
Type |
Over |
Under |
|
Welded Tubes |
0.18 |
0 |
Mechanical Property:
Grade C & Grade D tubes shall conform to the requirements -tensile properties prescribed below:
|
Type |
Over |
Under |
|
Welded Tubes |
0.18 |
0 |
Application Industries
A178 Boiler Pipes & Tubes are used in boiler, superheater, heat-exchanger and pressure equipment in Petrochemical factory, Refinery factory, sugar mill, power plant, power plant, shipbuilding.Used in boiler, superheater, heat-exchanger and pressure equipment in Petrochemical factory, Refinery factory, sugar mill, power plant, power plant, shipbuilding.
