Seamless Steel Tubes for Low and Medium Pressure Boiler GB 3087
Spec:
Material:10# 20# STB33/42 st35.8
Size Range:OD:4-1200mm
WT:0.3-200mm
General Length:4-12.5m
Tolerance:
According to the following tables or customers’ request.
Tolerance of the OD &WT:
OD Tolerance:
| Production Method | OD Tolerance |
| Hot Rolling(Extrusion) | ±1% or ±0.50mm |
| Cold Drawn(Cold Rolled) | ±1% or ±0.30mm |
Tolerance for wall thickness:
1.Wall thickness tolerance of Hot Rolling steel tube:
| Production Method | OD (DN) | WT/OD | Tolerance |
| Extruded tube | ≤102 | / | ±12.5% or ±0.40mm |
| ＞102 | ≤0.05 | ±15% or ±0.40mm |
| ＞0.05-0.10 | ±12.5% or ±0.40mm |
| ＞0.10 | +12.5% -10% |
| Heat expanding steel tube | / | ±15% |
2.Wall thickness tolerance of Cold Drawn(Cold Rolled) steel tube:
| Production Method | WT | Tolerance |
| Cold Drawn(Cold Rolled) steel tube | ≤3 | +15%/-10% or ±0.40mm |
| ＞3 | +12.5% -10% |
Bending tolerance:
WT≤15mm, Bending≤1.5mm/m
WT＞15mm~30mm, Bending≤2.0mm/m
WT＞30mm/OD≥351mm, Bending≤3.0mm/m
Ovality and Wall unevenness:
The ovality and wall unevenness should be no more than 80% of the OD and wall thickness.(Or according to customer`s request)
Test:
- Bending test
- Hardness test
- Impact test
- Squeezing test
- Non-destructive test
Characteristic:
Good concentricity
Good OD and ID tolerance
High Precision
Stable quality
Smooth Roughness
TORICH QUALITY ASSURANCE
Processing:
RAW MATERIAL
↓
INCOMING INSPECTION
↓
STORAGE → CUTTING→HAMMERING → PICKING LUBRICATION → CLEANING → PHOSPHORI CLEAN
↓
ENDS CUTTING←STRAIGHTENING←HEAT TREATMENT↔MIDDLLE CHECK↔ COLD DRAWING ← LUBRICATING
↓
FINAL INSPECTION→BUNDING→STORAGE
Technical Delivery Conditions:Hot rolling with NBK
Widely used in the field of:Boiler pipe
Product Images:
Product Tags:
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Seamless Steel Tubes for Low and Medium Pressure Boiler GB 3087 Images
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