Carbon steel is a common material for industrial ball valves but it lacks the image of silver chrome that has made stainless steel so well-known. On the other hand, carbon steel ball valves have a fine translucent texture that looks more like cast iron. Carbon steel ball valves are intended for use in fully open or closed positions. Depending on the implementation circumstance, adjusting a carbon steel ball valve may result in premature seal failure and/or inability to push the valve handle. In the ASTM A105 standard, carbon steel for A105 valves refers to forged steel. Plastic deformation may be used to enhance the internal framework, mechanical properties, and grain size of an A105 valve.
Types of Carbon Steel Valve
Low Carbon Steel Valve-
- Plain carbon steel- It has a very low content of alloying elements and a small amount of Mn.
- Does not lend itself to heat treatment; Cold work is required to build endurance.
- Good weldability and machinability.
- High strength low alloy steel (HSLA) elements (such as Cu, V, Ni, and Mo) up to 10% by weight have higher strength and can be heat treated.
Medium Steel Valve-
- Carbon Content in the range of 0.3-0.6%
- Medium Carbon steels have low hardenability.
- Heat-treated alloys are stronger but have less ductility.
- Typical application- Railway wheels and tracks gears crankshafts.
High Carbon Steel Valve-
- High Carbon Steel – Carbon Content 0.6 – 1.4 %.
- High Carbon Content provides high hardness and strength.
- Hardest and Least Ductile.
- Used in hardened and tempered condition.
Super-High Carbon Steel Valve
- Approxmately `1.25% – 2.0 % carbon content.
- Steels that can be tempered to great hardness.
- It is used for special purposes such as knives, shafts, or punching holes (non-industrial).
- Most steels with more than 2.5% carbon content are made using powder metallurgy.
The main components of carbon steel gate valve include:
- Seat: These are either provided together with the valves or come in a type of connection that is a seat ring construction. This construction puts a pressed or threaded seat into position then welded into the valve’s body.
- Body: It is connected to other parts of the carbon gate valve through flanged, welded, or screwed connections.
- Stem: It ensures that the disk positions properly and is well connected to the handwheel. Stems are typically connected and forged to the disk using threaded technique or any other available technique.
- Actuator: They open and close the carbon steel gate valve in response to either manual or automatic manipulation.
- Bonnet: It possesses moving parts of the carbon gate valve. It is fixed to the body of the carbon gate valve by a bolt to make maintenance easy.
