Cast iron provincial gas blasting test?

Technical conditions for the manufacture and acceptance of cast iron provincial gas WG0101-76 (replacing G0906-61, JT002-76) ------------------------------------------------------------------------------- This technical condition applies to the manufacture and acceptance of cast iron economizer pipes with blades when the boiler medium outlet pressure is ≤2.45MPa (25kgf/cm2). This technical condition must be used together with the "Safety Regulations for Steam Boilers" and JB2639 "Technical Conditions for Pressure-bearing Gray Iron Castings of Boilers". 1． Materials 1.1 The materials used to manufacture the economizer should comply with the provisions of JB2639-81 "Technical Conditions for Boiler Pressure-bearing Gray Iron Castings". 1.2 The raw materials for manufacturing economizer tubes (including cast pig iron and coke) should be inspected and accepted by the inspection department according to the material standards and quality certificates, and can be put into production only after passing the standards. 2. Manufacturing 2.1 The type and size of the economizer pipe shall be as specified in the working drawing. 2.2 The economizer shall be manufactured in accordance with the working drawings, process regulations and other relevant technical documents. 2.3 The economizer tube should be manufactured by mechanical molding (missing mold method), but manual molding can also be used if the equipment is limited. 2.4 The economizer pipe should not have defects such as flash, dust inclusions, shrinkage cavities, and cracks. If there are individual small defects, they can be remedied by grinding, shoveling or welding. If the above defects cannot be eliminated after remediation, they should be scrapped. 2.5 If the lamp-saving tube has the following defects, it is not allowed to be repaired.: 2.5.1 Smooth burrs with a height less than 1.5mm. 2.5.2 There should be no more than 4 gaps in the blades with a width less than 10mm and a depth less than 5mm in every 50 economizer tube blades. 3． Tolerance 3.1 The maximum dimension at both ends shall not exceed 150mm. 3.2 The curvature of the economizer pipe should not be greater than 1mm per meter, and the total length should not exceed 2mm. 3.3 The highest point of the economizer blade shall not be higher than the horizontal line between the two flanges. 3.4 The allowable tolerance of the length of the economizer tube is ±1.5mm. When leaving the factory, those with the same tolerance should be grouped together to facilitate installation. 3.5 The economizer tube wall thickness tolerance is ±0.8mm, and the eccentricity between the square flange groove and the tube centerline is 0.8mm. 3.6 The parallelism between the two planes of the method flange shall not exceed 0.5mm. 3.7 The free tolerances and weight deviations of other non-machined surface dimensions of the economizer tube are in accordance with the provisions of JB2854-80 "Machining allowances, dimensional tolerances and weight deviations of cast iron parts". 4． Test 4.1 The materials used to make the economizer tube should be subjected to mechanical performance testing and chemical composition analysis. The test method, sample size and qualification standards should all comply with the provisions of GB976-67 "Gray Iron Casting Classification and Technical Conditions". 4.2 The economizer tube should undergo a hydraulic test after being cast. The hydraulic test pressure is 2.5 times the boiler operating pressure. There must be no leakage or water seepage during the test. 4.3 The hydraulic pressure test shall be in accordance with the provisions of JB1612-83 "Technical Conditions for Boiler Hydraulic Pressure Test". 5. Acceptance 5.1 The technical inspection department will inspect the materials based on the drawings and the provisions of these technical conditions, and then accept the materials after inspecting them for satisfactory manufacturing quality. 　

I know about the hydraulic test, but what about the blast test?