Valve and its medium
Let’s learn about the ASTM material specifications for valves. A cast valve body is now manufactured by pouring liquid metals into molds and it is common for valves. A valve body is produced by machining and forging solid steel. This article talks about the medium that is used in the valve industry and why we have to do selective material testing on specific valve material.
Why use different types of material to make valves?
We have different flow control systems and different flow control systems have different situations. Such a flow will have different temperature, different pressure and some flow is also corrosive. We need to choose the correct material while designing a valve. We should also make sure that the system is safe to work.
Valve suitable medium
The medium used in manufacturing of valves are aluminum, copper, bronze, brass, cast iron lining, ductile cast iron, cast iron and special alloy steels.
Aluminum is a nonferrous metal and it is also very light weight. It consists of approximately one third of the steel weight. In valves aluminum is mostly used in the exterior parts such as in the hand wheels and identification tags.
Bronze has good and higher strength than pure copper and it is very easy to cast. It get easily joined by brazing and by soldering. Brass valves are very good for corrosion resistance. Uses of brass valves are for balls, ball valve stem and iron valve stems. The brass is actually used in the commercial valve bodies and for the end pieces.
Mediums used in valve industry
Materials that are listed below are actually used to make valves. These are some of the important materials which are actually used in the valve industry. The selection of material depends on the fluid which helps in flowing through the valve. It depends on the particular service applications like high temperature, fluid property and cryogenic applications etc.
Materials used in valves
For the valve internal components and body such as disc, ball and stem.
1. Carbon steel
An alloy consisting carbon and iron for example A 216 GR WCB a 216 GR WCB
2. Low alloy steel
A steel to which more or one alloying elements other than carbon. For example A 325 GR LCB LCC and many more
3. Stainless steel
It is a family of iron based alloys and it contains the maximum of 11% chromium. It is resistant to corrosion and has low maintenance properties.
Valve contains very different types of nickel such as nickel iron, nickel chromium, nickel copper and nickel molybdenum. Nickel are high corrosive applications and high heat resistance applications. Nickel is a base material for valves rather than an alloying element in stainless steels.
Copper is really used in valve materials and it is with the other alloying elements. Copper nickel aluminum and bronze are much used materials in the valves industry. Copper alloys are high resistance against corrosion and it is very less expensive compared to nickel.