GB3087-2008 is applicable to the seamless steel tubes that are made of quality carbon structural steels and used for manufacturing various low and medium pressure boilers.
This standard specifies the dimensions, shape, weight, technical requirements, test methods, inspection rules, packaging, marking and quality specifications of seamless steel tubes for low and medium pressure boilers.
This standard is applicable to the manufacture of high-quality carbon structural steel hot-rolled (extruded, expanded) and cold drawn (rolled) seamless steel tubes for various structural low-pressure and medium-pressure boilers and locomotive boilers.
2 Reference standard
The provisions contained in the following standards constitute provisions of this standard by reference in this standard. At the time of publication, the editions indicated were valid. All standards will be revised and parties using this standard should explore the possibility of using the latest version of the following standards.
- GB/T222—1984 Sample sampling method for chemical analysis of steel and chemical composition tolerance of finished products
- GB/T223.5-1997 Methods for chemical analysis of steels and alloys – Determination of acid-soluble silicon content by molybdate spectrophotometry
- GB/T 223.12—1991 Methods for chemical analysis of steels and alloys – Sodium carbonate – Diphenylcarbonyl hydrazide photometric method
- GB/T 223.19—1989 Chemical analysis methods for steel and alloys Xinyatongling-trichloromethane extraction
- GB/T 223.23—1994 Methods for chemical analysis of steels and alloys – Determination of nickel content by succinimide spectrophotometry
- GB/T 223.62—1988 Methods for chemical analysis of steels and alloys – Determination of phosphorus content by butyl acetate extraction spectrophotometry
- GB/T 223.63—1988 Methods for chemical analysis of steels and alloys – Determination of manganese content by sodium periodate (potassium) photometric method
- GB/T 223.69—1997 Method for chemical analysis of steel and alloys. Determination of carbon content by gas volume method after combustion in tubular boilers
- GB/T 223.72—1991 Methods for chemical analysis of steels and alloys – Aluminium chromatographic separation – Barium sulfate gravimetric method
- GB/T 226—1991 Low-fold structure of steel and defect acid etching test
- GB/T 228—1987 Metal tensile test method
- GB/T 241—1990 Metal pipe hydraulic test method
- GB/T 242—1997 Metal pipe flaring test method
- GB/T 244—1997 Metal tube bending test method
- GB/T 245—1997 Metal tube crimping test method
- GB/T 246—1997 Metal tube flattening test method
- GB/T 699—1999 high quality carbon structural steel
- GB/T 2102—1988 Acceptance, packaging, marking and quality instructions for steel pipes
- GB/T 5777-1996 Ultrasonic flaw detection test method for seamless steel tubes
- GB/T 7735-1995 Steel pipe eddy current testing method
- GB/T 12606—1999 Steel pipe leakage magnetic flaw detection method
- GB/T 17395—1998 Seamless steel pipe size, shape, weight and tolerance
- YB/T 5222-1993 high quality carbon round billet
3 size, shape, weight
3.1 Outer diameter and wall thickness
3.1.1 The outer diameter, wall thickness and theoretical weight of the steel pipe shall comply with the provisions of Table 1 of GB/T 17395-1998.
Steel pipes of different specifications as specified in Table 1 of GB/T 17395-1998 may be supplied through negotiation between the supplier and the buyer.
3.1.2 The allowable deviation of the outer diameter and wall thickness shall comply with the requirements of Table 1.
When the purchaser requests to supply according to advanced precision, it should be indicated in the contract.
After consultation between the supplier and the buyer, and in the contract, it can produce steel pipes with deviations from those specified in Table 1.
Table 1 Allowable deviation of outer diameter and wall thickness
| Type of steel pipe | Outer diameter(mm) | Tolerance | ||
| ordinary | advanced | |||
| Hot rolled tube | OD | ≤159 | ±10%（min±0.50mm） | ±0.75%(min±0.40mm) |
| ＞159 | ±1.0% | ±0.90% | ||
| WT | ≤20 | ＋15.0%(min＋0.45mm) | ±10%（min±0.30mm) | |
| －12.5% －0.35mm) | ||||
| ＞20 | ±12.5% | ±10% | ||
| OD≥351 | ±15% | ±15% | ||
| Cold drawn tube | OD | 10-30 | ±0.40mm | ±0.20mm |
| ＞30-50 | ±0.45mm | ±0.25mm | ||
| ＞50 | ±1.0% | ±0.75% | ||
| WT | 1.5-3.0 | 15% | ±10% | |
| -10% | ||||
| ＞3.0 | 12.50% | ±10% | ||
| -10% | ||||
Chemical Composition(%)
| Steel Grade | C | Si | Mn | S | P | Cr |
| 10 | 0.07-0.13 | 0.17-0.37 | 0.35-0.65 | 0.02 | 0.025 | ≤0.15 |
| 20 | 0.17-0.23 | 0.17-0.37 | 0.35-0.65 | 0.02 | 0.025 | ≤0.25 |
Application
It Is Mainly Used To Make High-Quality Carbon Structural Steel, Low Pressure Medium Pressure Boiler Pipe, Super Heated Steam Seamless Carbon Steel Pipe
Main Grade: 10#,20#
Test Requirement
Flattening Test
Steel Tubes With An Outer Diameter Greater Than 22 Mm And Up To 400 Mm, And Wall Thickness Greater Than 10 Mm Should Undergo The Flattening Test. After The Samples Are Flattened
Bending Test
Steel Tubes With An Outer Diameter Not Greater Than 22 Mm Should Undergo The Bending Test. The Bending Angle Is 90o . The Bending Radius Is 6 Times The Outer Diameter Of The Steel Tube.After Bending The Sample, No Fissures Or Cracks Are Permitted To Appear On The Sample.
Macroscopic Examination
For Steel Tubes Directly Made By Continuously Cast Billets Or Steel Ingots, The Supplying Party Should Guarantee That There Are No White Spots, Impurities, Sub-Surface Air Bubbles, Skull Patches Or Layering On The Cross-Sectional Acid Pickled Macroscopic Tissue Of The Billet Or Steel Tube.
Non-Destructive Inspection
According To The Demanding Party’s Request, Which Is Then Negotiated Between The Supplying And Demanding Parties And Indicated In The Agreement, Ultrasonic Flaw Detection May Be Individually Performed For Steel Tubes. The Longitudinal Manual Defect Of The Reference Sample Tube Should Meet The Requirements For Post-Inspection Acceptance Grade C8 Specified In GB/T 5777-1996.
