Seamless stainless steel tubes for boiler and heat exchanger
Seamless Stainless Steel tubes For Boiler and Heat Exchanger, made according to the Chinese National Standard GB13296-91.
GB13296-91 is a standard applicable for Seamless Stainless Steel pipes which is used for boiler and heat exchanger.
GB13296-1991 Seamless Stainless Steel Tubes for Boiler, Heat Exchangers
0Cr18Ni9 1Cr18Ni9Ti 0Cr18Ni12Mo2Ti
Standard: GB13296-91
Tolerance for seamless stainless boiler tube:
| Production Method |
Size(mm) |
Tolerance |
| Hot Rolling(Extrusion) |
OD |
≤140 |
±1.25% |
| ＞140 |
±1.0% |
| WT |
≤10 |
±12.5% |
| ＞10 |
±15% |
| Cold Drawn(Cold Rolled) |
OD |
8~30 |
±0.20mm |
| ＞30~50 |
±0.30mm |
| ＞50 |
±0.8% |
| WT |
1.0~3 |
+12%
-10%
|
| ＞3.0 |
±10% |
Length:
The length or general steel tube:
Hot Rolling(Extrusion) tube: 3~12 m
Cold Drawn(Cold Rolled) tube: 3~8 m
The length for water pipe & boiler steel pipe:
Hot Rolling(Extrusion) tube: 4~12 m
Cold Drawn(Cold Rolled) tube: 4~8 m
Bending tolerance:
WT≤15mm, Bending≤1.5mm/m
WT＞15mm, Bending≤2.0mm/m
End shape:
Both ends of the pipe should be cut at right angles, and remove burrs
mechanical property
Heat treatment of longitudinal mechanical properties of steel pipe shall according to the standard.
| Material |
Tensile strength MPa
≥
|
Yield Strength MPa
≥
|
Elongation
%
≥
|
| 0Cr18Ni9 |
520 |
205 |
35 |
| 1Cr19Ni9 |
520 |
205 |
35 |
| 0Cr19Ni10 |
480 |
175 |
35 |
| 1Cr18Ni9Ti |
550 |
205 |
40 |
| 0Cr18Ni12Mo2Ti |
530 |
205 |
35 |
| 0Cr26Ni5Mo2 |
590 |
390 |
18 |
| 1Cr17 |
410 |
245 |
20 |
| 00Cr27Mo |
410 |
245 |
20 |
| 1Cr25Ti |
440 |
245 |
17 |
Hardness:
For the tubes which W.T. ≥2 mm, Rockwell hardness tests should be taken.
Tests of the seamless boiler tubes:
1.Bending Test:
The tubes should take the bending test when OD ≤22mm. The bending angle is 90 degrees, and the bending radius is 6 times the outer diameter of the steel tube.
2. Hydraulic test;
Eddy current testing, ultrasonic testing can be used instead of hydraulic tests. When eddy current testing, GB/T 7735-1995 Gr. A should be followed; when ultrasonic testing, GB/T 5777-1996 Gr. C8 should be followed.
3. Flattening test
4. Flanging test
5. Expand test
