苏丹采购需求：不锈钢焊条、不锈钢管、平焊法兰、镀锌管、聚氨酯防水涂层、不锈钢板

I'm looking to purchase API 5L black steel pipes for an upcoming project. Please provide your specifications, including dimensions, wall thickness options, and available lengths. It's important for us to know the material grades you offer as well. Additionally, it would be great if you could share your pricing structure, lead times, and any minimum order quantities. We're keen to establish a long-term partnership, so information on your quality control processes and certifications would also be appreciated. Look forward to hearing from you soon!