Is it reasonable for the requirements for steel pipe procurement to exceed those specified in GB?
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In a renovation project, the amount of work is very small. The total quantity of steel pipes to be purchased is less than 100 meters (in various specifications). The system’s design pressure is 150 pounds, the temperature is 100 degrees, and the medium poses a moderate level of hazard with little risk of corrosion. The design unit adopted GB8163; not only is the wall thickness specified using SCH, but the steel grade also exceeds the range specified in GB8163. We believe that steel grade 20 or 16Mn fully meets the requirements. Is it okay to do this? If in accordance with the design requirements, using the wall thickness SCH and the material code specified in the design, it is entirely possible to purchase pipes that comply with other GB standards.
Sure, you can use substitutes; as long as the design is approved, that’s fine.
Based on the design requirements and various calculations, as long as it meets the standards, that should be fine
Does that mean the requirements he proposed are higher or lower than the design requirements? If it is higher than the design requirements, negotiation is possible. If it’s low, it can’t be done
That’s fine then; purchasing something with higher requirements than those specified in the design is acceptable
Why can’t wall thickness SCH be used for 8163?
According to the specifications in GB 8163-2018, the outer diameter and wall thickness specified therein are in accordance with GB 17395, rather than SCH. Of course, if the quantity is large, special customization can be requested.
In practice, GB8163 SCH fittings are also easily available.
GB 17395 is the wall thickness series for products manufactured by steel pipe factories, while Sch is the series for selecting wall thicknesses in pipeline design. The wall thickness range of GB 17395 is wide enough to cover the range specified by Sch; therefore, using GB 17395 for wall thickness selection is not contradictory to Sch.
The standards of GB8163 are somewhat inconsistent with the wall thickness of SCH pipes. However, it is possible to select in accordance with GB8163 and GB6479 standards and provide relevant explanations, while communicating with the design party and the client. It is feasible to use substitutes.