This is a method where the liquid form of metal is used to produce valves. Here, the metal is melted in a molten liquid and then poured in various molds. Once the liquid gets cool and turns solid, it is taken out of or ejected out from the mold leaving the valve behind. This method of casting is used to make various types of valve components, such as the body of the cast valve, a valve disc, valve bonnet, valve flange, and different castings of the valve component.
Depending on the material specification and dimension of the casting parts, there are 3 different methods which are used in valve castings India. These are:-
1) Lost Wax Casting:- Through this method, one is able to valve the components of cast steel such as stainless steel, carbon steel, and a few other steel alloys.
2) Lost Foam Casting:- This method is the best fit for creating precision valve parts, that may get a perfect surface finish and different shapes, these net shape or approx net shape would not require any machining or it can be adjusted with little machining allowance.
3) Sand casting:- This method is best fit for both iron and steel castings. Compared to other casting methods, this method is most suitable for making large valve components, in such a normal way, it will require the most machining thus the most machining allowance.
Materials of the casting parts
Various materials are used to make a valve. These are:-
1) Carbon Steel:- WCA, WCB, ZG25, ZG200-350, ASTM A216 WCA/WCB/WCC, G25.
2) Stainless steel:- SS304, SS316, PH17-4 etc
3) Gray Iron:- HT200, HT 250, HT 300, HT 350, GG 20 etc
4) Ductile Iron:- QT400-18, QT500-17, QT600-3, GGG400 etc.
Machinery equipment involved
To supply finish parts, machinery equipment such as NC lathe, CNC along with drilling machine etc are used. To ensure the finished product is workable hydraulic testing is done. For large dimension casting product to prevent the defects of casting, the testing of magnetic particle and ultrasonic is done after casting is completed.
Valve castings India has grown over the years and with its ability to provide a variety of valve components through various casting methods depending on their size, the type of material needed, their properties its provides a good finishing product which could be used in valves. The number of materials used also helps with the fact that each material has its own property which helps greatly in the finished product.