Q. Process of Alloy Materials Sampling?
The following alloy-materials require a minimum of 10% per lot representative PMI sampling. If any incorrect material is found in representative sample basis testing, 100% PMI verification shall be required.
• Tubular products used in the fabrication of equipment, such as heat exchangers and boilers, provided that traceable mill certification is available.
• Fired heater, heat exchanger, and boiler internals example: tube hangers, tube supports, and tube-sheets. Internals which are part of the supports in fired heaters and boilers are also included in the PMI program.
• All alloy steel bolting, fasteners and nuts.
• Ring joint flange and clamp type (e.g., Grayloc) connector flange gaskets.
• Internal non-pressure-containing parts. Metallic alloy components for refractory linings (e.g., refractory anchors and hex mesh) shall be covered under this requirement.