The most commonly used stainless steel for ball valves is SS 304 and SS 316.
SS 304 is less expensive than SS 316 but is very suitable for non-chemical applications such as: beverages, food stuffs, water & waste, plumbing, irrigation, construction and most manufacturing.
SS 316 has more nickel than SS 304 making it more chemical resistant and generally suitable for all applications that SS 304 is suitable for, as well as the following: general chemicals, most acids, alkaline solutions, fuel & oil, mining and corrosive fluids.
Previously most valves were manufactured from brass and steel as they were much less expensive than stainless steel. However, over recent years the price of stainless steel has reduced and the price of brass has increased making the SS ball valve much more competitive. In actual fact a SS304 ball valve is now about the same price as a brass ball valve.
However, the SS ball valve has many advantages over the brass ball valve including: much stronger, operates at a higher temperature, can sustain higher pressures, is chemical resistant, is inert, is easy to clean, can be used for sanitary and hygienic applications and does not oxidise and affect the taste of the product.
2 Piece Ball Valve
2-piece ball valves are simply constructed, have only 2 main parts, so their major advantage is their relatively low price.
They are available from ½” to 4” and have pressure ratings up to 1,000psi. Because they are inexpensive they are the most commonly used SS ball valve.
3 Piece Ball Valve
3-piece ball valves are manufactured to be easily dis-assembled, cleaned and re-assembled in a very short period of time. This is very important when you are dealing with beverages, food stuffs, pharmaceuticals and hygienic products. If you are not able to clean the valve properly, liquids will remain behind and could oxidise, ferment, collect germs and/or bacteria which is unsafe where the product is consumed. All sanitary and hygienic operations need a 3 piece valve that can easily be dis-assembled and thoroughly cleaned after and before operating.
Home brew Ball valve
This is generally the ½” stainless steel ball valve. Due to the low cost most home brewers use the 2 piece stainless steel ball valve for brewing. They, however, have to thoroughly clean the valve with boiling water before use.
Brewing Ball Valve
This description usually applies to commercial brewers and craft beer brewers. They can still be small brewers but larger that home brewers. They definitely need to use a 3-piece stainless steel ball valve as the conditions have to be sanitary and hygienic.
Tri Clamp Ball Valves
These are also known as tri clover ball valves and are sanitary and hygienic ball valves used by all commercial brewers. They can be easily dis-assembled, cleaned and re-assembled and this is their major advantage over threaded fittings. They are extensive used in the food and beverage industry.
Stainless Steel Ball Valves
By far the major use for SS ball valves is the general industries. These industries include: petro-chemical, chemical, construction, plumbing, irrigation, water and waste, process, manufacturing, fuel & oil, exploration, utilities and mining. Due to cost reasons the 2 piece stainless steel ball valve will generally be used.