When the pump valve parts valve there is a corrosion phenomenon, this time also should take place is to pay attention to the metal surface treatment of valve connection, valve parts for valves in connecting bolts are commonly used galvanized, chrome oxide (blue) treatment can increase air resistance, resistance to corrosion and other fasteners in addition to treatment using the above method, also should be based on the circumstances such as surface treatment with phosphate.
When the pump valve parts valve there is a corrosion phenomenon, if the sealing surface or closure of small diameter, often is the surface nitriding and boronizing process, it also can improve the corrosion resistance and wear resistance of the valve, the 38CrMoAlA production of the nitrided layer is larger than 0.4mm.
When the valve parts of the valve appear corrosion phenomenon, if the valve stem is anticorrosive, the nitriding, boronizing, chrome plating, nickel plating and other surface treatment processes will be widely used, so that it can improve its corrosion resistance, corrosion resistance and abrasion resistance.
After that, we actually also is to pay attention to, when the valve in the valve parts of different surface treatment should be suitable for stem material and working environment is different, in the atmosphere, water vapor medium and asbestos packing contact stem, this time also is should be used in hard chromium plating, gas nitriding process (stainless steel should not be used in ion nitriding in the process of hydrogen sulfide); atmospheric environment the valve will have a high Linnie electroplated coating protective performance better; 38CrMoAlA by ion and gas nitriding can also be corrosion resistant, but not suitable for hard chromium plating.
For the valve when valve fittings for 2Cr13, after quenching and tempering after ammonia corrosion corrosion ability, using gas nitriding of steel is also Ammonia Resistant, and for all the phosphorus nickel plating is not resistant to corrosion by ammonia; gas nitriding 38CrMoAlA materials with corrosion resistance and comprehensive performance is very good, it produced heavy valve accessories the stem is. For small caliber body and handwheel, chromium plating is often used to improve its corrosion resistance and to decorate the valve.http://www.pump-casting.com/