蒙古采购需求：工业管道、管件、工业管道解决方案、管道制造、中心通管

I'm looking to purchase several piping and fitting products for an upcoming project. Specifically, I need seamless pipes with insulation in various sizes, including 20 inches, 24 inches, and 16 inches, all with a wall thickness of 9.53 mm. The lengths required for the 16-inch pipes are 6 meters, while the 20-inch and 24-inch pipes don't have specified lengths. In addition to the pipes, I also need a few fittings, including 90-degree and 45-degree elbows, with insulation for the 20-inch size. I require the elbows in seamless construction as well, maintaining consistent wall thickness. Please provide your best lead times and pricing for these items, as I'm eager to finalize this order soon.