Legal analysis: Generally, flange elbows can be filled directly, and pipeline accessories can also be filled. Stainless steel pipe fittings's tax classification code:/kloc-0 10802079900000000 Other ferrous metal smelting and rolling products refer to steel except railway steel, large section steel, medium and small section steel, bar, steel bar, wire rod, steel plate, hot rolled sheet, cold rolled sheet, steel strip, strip, seamless steel tube and welded steel tube.

Legal basis: Measures for the Administration of Invoices in People's Republic of China (PRC).

Nineteenth units and individuals that sell goods, provide services and engage in other business activities receive money from foreign operations, and the payee shall issue an invoice to the payer; Under special circumstances, the payer will issue an invoice to the payee.

Article 20 All units and individuals engaged in production and business activities shall ask the payee for invoices when they pay for goods, services and other business activities. When obtaining the invoice, you are not allowed to change the name and amount.