Ball Valves
Ball Valves As the name suggests, ball valves area unit valves that use a ball to manage the flow of drugs from one gap to successive. These valves work by permitting the opening to be open, blocked, or open partly to control the flow of gas/liquid. Ball valves area unit the best alternative for mistreatment with gases as they’re ready to supply higher protection. they’re terribly versatile as they support pressures up to 700 bars and temperatures up to 550°C .. they’re simple to control and repair as they contain an easy structure.
They are designed with special measures that allow solely a 90-degree rotation that is needed for the gap and shutting of ball valves. These valves area unit a notable industrial alternative attributable to their reliable and air-tight protection once within the closed position.
Types
In a floating ball valve, the ball is held in the position by the compression of the two elastomeric seats against the ball. The ball is free to float inside the valve body.
Trunnion mounted valve is a solution to the problem of excessive torque required by a floating type valve in high-pressure service. A short shaft like an extension which is known as a trunnion set in the body. In this design steam and ball work as a single unit. The ball is supported by two floating or spring-loaded seats that remain in constant contact with the ball.
Types of Ball Valves based on Body Construction
Top-Entry Ball Valve
On The Top Entry Ball Valve , removing bonnet cover of top entry valves, allows access to valve internals for assembly, disassembly, repair, or maintenance without removing the valve from the pipeline.
Split-Body Ball Valve
In this design, a valve body is divided into two or three body parts. A ball, seat rings, stem, and other internals set inside the larger body part and held together with smaller parts by bolting.
DIfferent Between Floating and Trunnion Ball Valves
In the floating Ball design, as the name suggests, the Ball does not have a ‘fixed’ position and can change position with the line pressure. The Ball-Shaft connection allows a certain amount of lateral movement during a Quarter Turn.
With the force applied by the flow passing through the line, Ball provides the sealing by applying pressure to the bearing surfaces. With its simple design, reliable sealing performance, it is widely used especially in low pressure and diameters.
However, as the line diameter increases and the pressure increases, the force applied by Ball to the bearings goes beyond the strength limits of the bearing, which is usually made of PTFE -based materials.
In the Trunnion Ball Valve design, the Ball -Shaft is fixed with bearings, the bearings are positioned by the pressure of the flow, there is a kind of Floating Bearing design., Trunnion Ball valves are used safely in high diameters and pressure classes where Floating Ball Valves cannot perform.
Trunnion Ball Valves have lower torque requirements than Floating Ball Valves of the same diameter and pressure class. In this way, they provide economic advantages with much lower actuation costs, especially in cases where automation is required.
Advantages
They contain a compact and low-maintenance style that needs no lubrication
they’re cost-efficient among all of the valves
- They give leak-proof service.
They open and shut quickly.
Ball valves have multi-way style flexibility.
Disadvantages
Ball valves aren’t appropriate for permanent strangulation.
In residual fluids, the particles within the fluid touch the surfaces and persist with them. this might cause discharge, abrasion, and alternative issues.
Applications:
Ball Valves area unit used for flow and pressure management and shut off for corrosive fluids, slurries, traditional liquid and gases.
they’re employed in the oil and gas trade, however conjointly realize an area in several producing sectors, chemical storage, and even residential uses.
- It can be used in different types of fluid services as an on-off stop valve that provides bubble-tight shutoff.
- It can be used in air, gaseous, and vapor services as well as hydrocarbon services.
- Metal seated valves can be used in high-pressure & temperature applications.
- it is widely used with instrument tubing to connect instruments.