Q
What outer diameter sizes are available according to this specification table?
A
The specification table covers outer diameters ranging from 200 mm to 1000 mm, including sizes: 200, 250, 300, 350, 400, 450, 500, 600, 700, 800, 900, and 1000 mm.
Q
How does wall thickness relate to outer diameter in these specifications?
A
Wall thickness generally increases as the outer diameter increases. For example, a 200 mm OD pipe has a standard wall thickness of 6–12 mm, while a 1000 mm OD pipe requires 25–45 mm wall thickness, ensuring structural integrity at larger sizes.
Q
Why does the standard length decrease for larger diameter pipes?
A
Larger diameter pipes (700 mm and above) have reduced standard lengths (1000–1800 mm or 1000–1500 mm) due to their increased weight and the practical limitations of handling, transportation, and installation. Smaller diameters can be produced up to 2000 mm in length.
Q
What do the outer diameter tolerances indicate, and why do they increase with size?
A
Outer diameter tolerances define the acceptable deviation from the nominal diameter during manufacturing. They increase proportionally with diameter because larger pipes are more difficult to manufacture to tight absolute tolerances. For instance, a 200 mm pipe has ±2.0～±3.0 mm tolerance, while a 1000 mm pipe allows ±12.0～±15.0 mm.
Q
Can custom wall thickness or lengths be ordered outside of the standard specifications?
A
Yes, in most cases custom wall thicknesses and lengths can be accommodated upon request. The table reflects standard production ranges; however, specific project requirements may allow for variations within the stated tolerance limits or through special manufacturing orders.
Q
How are wall thickness tolerances applied in quality control?
A
Wall thickness tolerances are used during inspection to verify that the manufactured pipe wall does not deviate beyond the specified range. For example, a 500 mm OD pipe with 12–25 mm wall thickness must fall within ±1.5～±2.5 mm of its nominal wall thickness at any measured point to be accepted as a conforming product.
