Knowledge related to Globe Valve material selection

From the perspective of metallography, except for austenitic steel, copper, aluminum, etc. with face-centered cubic lattice, general steel materials will exhibit low-temperature brittleness at low temperatures, thus reducing the strength and service life of the Universal Valve. When selecting the main body material, you must first choose materials suitable for working at low temperatures. Aluminum does not exhibit low-temperature brittleness at low temperatures. However, because the hardness of aluminum and aluminum alloys is not high, and the wear resistance and scratch resistance of the aluminum sealing surface are poor, there are certain restrictions on its use in Globe Valve. It is only used in low pressure and small applications. caliber Universal Valve.

Materials working at low temperatures must ensure the low-temperature performance of the Globe Valve, mainly ensuring its cold impact strength. The internal parts of the Globe Valve must be correctly selected to have sufficient cold impact strength to prevent breakage. C and Cr alloy steels quickly lose impact strength below -20°C, so the use temperatures are limited to -30°C and -50°C respectively. Nickel steel with a Ni content of 3.5% can be used up to -100°C, and nickel steel with a Ni content of 9% can be used up to -192°C. Austenitic stainless steel, nickel, Monel, Hastelloy, titanium, aluminum alloy and bronze can be used at lower temperatures (-273°C).
In addition, the following factors should also be considered when selecting materials for Globe Valve:
(1) The minimum operating temperature of the Universal Valve;
(2) The mechanical properties required for metal materials to maintain working conditions at low temperatures, especially impact toughness, relative elongation and structural stability;
(3) It has good wear resistance at low temperature and without oil lubrication;
(4) Has good corrosion resistance.