Ball Valves


Ball valves are given their name by the nature in which they operate, where an internal ball with a bored through center is rotated to either allow or prevent flow through the valve. Ball Valves are part of the quarter-turn valve family, which means they open or close with a 90 degree turn of the handle. Intended for open and close use only, throttling or controlling the flow of media with a ball valve is not recommended and will damage the ball valve itself.

MSI is a full-line ball valve distributor with a large portfolio of: carbon steel ball valves, stainless steel ball valves, and exotic alloy ball valves. End connections include flanged, threaded, and socket weld. With sizes ranging from 1/4” to 36" ball valves, MSI can meet the needs of virtually any project.

Ball Valve, Gate Valve, Check Valve, Globe Valve, Butterfly Valve

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Size Range: 1/4" - 36" Diameter
Body: 2PC, 3PC, 1PC
Floating: Ball is floating and will drift with the flow of media
Trunnion:  Mechanical anchoring of the ball at the top and bottom at the valve, for use in higher pressure situations
Types: Quarter Turn: (Ball, Butterfly, Plug), Gate, Globe, Check, and Relief Valves
End Connection: Flanged (RF, FF, and RTJ), Threaded, Socketweld, Buttweld
Materials: Alloy 20, Aluminum Bronze, Bronze, Carbon Steel (WCB, A105), Cast Iron, Ductile Iron, F5, F9, F11, F22, F91, Hastelloy C, Monel/Inconel, LF2, LCB, LCC, Stainless Steel (316, 304, 304H, 347), WC6, WC9, C5, C12, C12A, FORGED BRASS (B283, C37700)
Pressure Class:  (FLANGED) 150# 300# 600# 900# 1500# 2500#...(THREADED, SOCKET WELD) 800# 1000@ 1500# 2000# 2500# 3000# 6000#...
Ball & Stem:  Carbon Steel, Carbon Steel and Electroless Nickel Plating, Stainless Steel, Monel, etc
Soft Goods (Seats, Seals and Stem Seal):  Teflon, Reinforced Teflon, Graphite Filled, Peek, Metal, etc
Port: Full or reduced: Full has oversized ball same size as pipeline, reduced is smaller than the pipeline
Actuation: Most valves can have an actuator installed to make opening and closing easier.

Manufacturers/Brands of Ball Valves:



Body Ball Valve Configurations (Style of Ball Valves)

You can get ball valves generally in five different styles: single body ball valve, two-piece body ball valves, three-piece body ball valves, top entry ball valves and welded ball valves. The most common are one, two and three piece. The differences are the configuration related to the bore of the ball mechanism itself, but functionality remains the same. Ball valves are also broken down into two main types (Trunnion and Floating), which we will go into further details below.

One piece Ball Valve

One piece ball valves are almost always reduced bore and are generally low cost and referred to as a “throw away ball valve”. Their body ball valve is one whole piece.

Two piece Ball Valve

Two piece ball valves are usually reduced or standard bore and can either be thrown out or repaired

Three piece Ball Valve

Three piece ball valves allow for the center part of the ball valve, containing the ball, to be easily removed and replaced or repaired. This function of the ball valves allows for easy access and repair of the ball valves without having to replace.

Top Entry Ball Valve

The difference is based on how the pieces of the ball valves are manufactured and assembled, but the ball valve operation is the same in each type. Each design has its benefits. 

Trunnion Ball Valves

Trunnion ball valves have additional anchoring at the top and bottom of the ball valve to secure the ball from moving. This makes these ball valves more suitable for larger sizes and higher pressure applications. 

Trunnion Ball Valve Cutaway Diagram

Floating Ball Valves

Floating ball valves are constructed to where the ball floats freely in the body ball valve of the ball valve. As the flow moves through the ball valve the ball will shift slightly downstream against the seat of the ball valve creating a secure seal. These ball valves are typically cheaper than their trunnion counterpart.

Flanged Floating Ball Valve with Cutaway Diagram

Body Ball Valve Material: Cast and Forged Material Specifications

Most ball valves are going to be cast steel or forged steel. The main difference with forged steel is that they are going to be for high-pressure applications.  In addition to the materials below, many other grades of stainless and exotic alloys are also available.

A216 WCB Ball Valves

A216 WCB is the specification that covers the castings for carbon steel ball valves for high-temperature service and the quality assurance required for assembly. The “WC” stands for wrought carbon and specifies that the product is made through “casting”, which is a manufacturing process where liquid material is poured into a mold and allowed to harden. A216 is suitable for fusion welding and high temperate services.

A105 Ball Valves

A105 specification covers forged carbon steel components for ambient and higher-temperature service in pressure systems. The application of thermal and mechanical energy changes the shape of the material without melting it down. This is better for the structural integrity because it never is melted.

A351 Ball Valves

ASTM A351 GR CF8M (SS 316SS) is the specification that covers cast stainless steel ball valves. F8M is a molybdenum bearing modification of CF8 alloy and is the cast equivalent of wrought AISI 316 stainless steel. The presence of molybdenum increases the general corrosion resistance and the resistance to pitting by chlorides. The alloy is used in mildly acidic and alkaline conditions and for handling citric, oxalic and phosphoric acids.

End Connections:

Ball valves will come in a few variations of end connections; this will usually give you an idea of the range of pressure classes you should choose from for your ball valve. Cast and forged ball valves will share the same end connections, but you should specify which type of end connections you will need for your project.  Ball valves are “Bi-Directional” meaning material can go either way through the ball valve and you will not have to worry about installing the ball valve a certain way on the pipeline.  

  • Threaded – A very common end connection, this will normally come in female national pipe thread (FNPT). The ball valve will be screwed or threaded on to the pipeline.
  • Socket weld – the end connection is counter bored and the pipe will be inserted and butted up to the inner lip of the end connection then fillet welded around.
  • ThreadX SocketWeld – Since ball valves are bi-directional you can have thread x socket weld, but do not need to specify which end is which.
  • Flanged – Will have flanges installed on the ball valves to be installed directly into the pipeline.
Floating Ball Valve with Socket Weld End Connections Valve End Connections Floating Ball Valve with Threaded Connections

Full Port vs. Reduced Port Ball Valves

  • Full port will have an oversized ball so that when fully opened the hole of the ball will be the same size of the pipeline. The main advantage is that flow will be unrestricted. The pipeline will also be piggable (a process to clean or clear the pipeline).
  • Reduced Port is where the flow of the ball valve is one size smaller than the pipe size. The flow discharge will remain constant, but the velocity will increase as the size gets smaller
Full Port vs. Reduced Port Ball Valves


Manual operators, such as gears, are relatively inexpensive and require little peripheral planning beyond the installation and orientation of operators in the process line. Gears are simple machines that utilize a series of mechanical parts to increase efficiency – the mechanical advantage that the user gains.

Torque is a function of force and distance – the required force (rim pull) required to open or close the ball valve can be decreased by increasing the length of the lever or diameter of the handwheel mounted on the ball valve. The industry defines specifications for the highest values personnel should exert on levers or handwheels to operate a ball valve. Current API specifications limit pull to 360 Newtons (80 pounds-force). The maximum lever length or handwheel diameter also is limited by industry specifications.

  • Lever Handle – usually ¼” turn, as it states you operate the ball with a lever by hand. The lever will turn the ball in either a floating or trunnion ball valve, letting the opening allow media to flow through or be stopped.
  • Handwheel -  the hand wheel operates the ball by physical force and turns the ball open or closed.
  • Gear Operator – uses gears to reduce the amount of force required to open and close the ball on the ball valve.
  • Actuator – Takes the physical component of operating the ball valve out of the equations and will operate the ball valve automatically, usually by switches (Hydraulic, Electrometer, and Pneumatic)