Inspection and testing: API598

Product structure characteristics
1. Forged steel valves are suitable for medium to high temperature and medium to high pressure valves with nominal pressures of PN2.5, 4.0, 10.0, 14.0, 25.0Mpa, and nominal diameters of DN10-50mm. Applicable media include water, mixed gas of nitrogen and hydrogen, urea, and methylamine solution.
2. The valve stem and valve stem nut are driven by trapezoidal threads, and the threads comply with the provisions of GB5796. The valve stem head is designed with a conical upper sealing surface, which tightly matches the upper sealing seat of the valve cover when the valve is fully open, without external leakage.
3. The pressure bearing parts such as the valve body and valve cover are integrally forged (tire model forging), and the valve body flange can also be welded. The connection forms of valves include flange connection, socket welding connection, and internal thread connection.
4. The connection between the valve seat and the valve body includes threaded connection, welding, overlaying alloy layer on the valve body, or directly processing stainless steel valves on the valve body. The thickness of the surfacing layer is greater than or equal to 2mm.
5. For forged steel valves with a nominal pressure greater than 15.0Mpa, a pressure self tightening sealing structure is adopted, and the packing box and gate plate are all integrally forged to ensure compressive strength.