Basics about ball valves

1. Ball Valves
Presented by: Daniyal Ahmed

2. Introduction
 A valve is a device to control the flow of a fluid.
 Types of Valves:
1) Isolation valve (Globe Valve, Gate Valve, Ball Valve etc.)
2) Control Valve
3) Pressure Reducing Valve
4) Pressure Safety Valve
 Ball Valve is a type of isolation valves.
 Ball valves are rotary motion actuated valves.
 A ball valve is an on-off or a shut-off valve.
 A ball valve is a quarter turn valve and is used where quick and frequent
operation is essential.

3. Working:
 A ball with a hole through the middle is installed within the body. If the hole is
in-line with the flow, the valve is said to be in the open position and there is
little resistance to flow. If the hole is rotated 90 degrees and is perpendicular to
the flow direction, the valve said to be in the closed position and there is no
flow.
 The valve handle is often used to indicate the position of the valve. If the valve
handle is in-line (parallel) with the piping, the valve is in the open position. If
the valve handle is not in-line (perpendicular) with the piping, the valve is in
the closed position.

4. Materials
 PVC
 Brass (67% copper and 33% zinc.)
 Bronze (88% copper and 12% tin)
 Cast Iron (alloy of Iron and carbon)
 Ductile or SG Iron (Type of Cast Iron)*
 Carbon Steel
 Stainless Steel
*SG iron has spherical shaped graphitic carbon whereas CI has flat graphitic
flakes making SG iron much more stronger than cast iron.

5. End Connections
 Threaded or Screwed
 Flanged
 Welded

6. Internals of Ball Valve

7. Types of Ball Valves:
There are four general types of ball valves: full port, standard port, reduced port, and v port.
 A full port ball valve has an oversized ball so that the hole in the ball is the same size as the
pipeline resulting in lower friction loss. Flow is unrestricted, but the valve is larger.
 A standard port ball valve is usually less expensive, but has a smaller ball and a
correspondingly smaller port. Flow through this valve is one pipe size smaller than the
valve's pipe size resulting in slightly restricted flow.

8. Types of Ball Valves:
There are four general types of ball valves: full port, standard port, reduced port, and v port.
 A v port ball valve has a 'v' shaped ball. This allows the orifice to be opened and closed in a
more controlled manner with a closer to linear flow characteristic. When the valve is in the
closed position and opening is commenced the small end of the 'v' is opened first allowing
stable flow control during this stage. This type of design requires a generally more robust
construction due to higher velocities of the fluids, which would quickly damage a standard
valve.
 A trunnion ball valve has a mechanical means of anchoring the ball at the top and the
bottom, this design is usually applied on larger and higher pressure valves(say 4 inch and
above 600 psi)
Trunnion Ball Valve
V Port Ball Valve

9. Uses of Ball Valves:
 Ball Valves are used for flow and pressure control and shut off for corrosive
fluids, slurries, normal liquid and gases. They are used in the oil and natural
gas industry, but also find a place in many manufacturing sectors, chemical
storage, and even residential uses.
 Depending on what they are made of, ball valves can hold up to 10,000
pounds per square inch.
 They are not recommended for use in pharmaceutical, bio processing and
food or beverage applications because they cannot be cleaned easily.

10. Advantages and Disadvantages:
 Advantages:
 This type of valve is considered fast acting as it can move from the fully open
to fully closed position by rotating the valve stem only one quarter of a turn
(90 degrees).
 Ball valves allow flow in either direction and have a very low pressure drop.
 Ball valves are well suited for direct local manual operation, although they
can be remotely actuated using a motor and planetary gearbox arrangement.
 Ball valves are usually the cheapest of all the common valve types and
maintenance costs are also low.

11.  Disadvantages:
 Ball valves are not suitable where flow control (throttling) is required as the
flow rate cannot be accurately controlled.
 Ball valves should not be used in any flowing mediums with a high abrasive
particle count. Abrasive particles could easily damage the valve seat and
prevent the valve seating correctly.
Advantages and Disadvantages:

12.  One of the most common types of ball valve failures involves a buildup of dirt
and sediment within the valve, making it difficult to open and close.
 Media leakage: Damaged seals or loose nuts and bolts can cause media to
leak out of the valve.
Solution: Verify that your valve’s seat components are compatible with the
system media. Check whether the elastomer components need to be replaced or
if any hardware needs to be tightened.
Three-piece ball valves allow replacement of these components without
removing or replacing the entire valve.
Failure Cases:

13.  Production downtime: A failed valve reduce production, which results in lost
revenue and wasted time.
 Repair costs: Periodic equipment repairs are expected in any industrial
setting, but repairs that result from valve failures can end up costing you
more than you budgeted for.
Effects of Failures:

14. Thank You!