Arflu - Ball Valves
Ball valves are used in opening or closing position, not recommended for intermediate positions. Unlike Gate valves, Ball valves are quarter-turn valves whose closing element rotates very quickly from the fully open to fully closed position.
Main design parameters in ball valves are the parallelism, and perpendicularity of the turning axe and the pipeline, and the spherical of the ball. Taking care of these two facts operating torque will be smooth and the valve will have a long tight life, as not foreseen stresses on the seat will be avoided.
The main advantages of the ball valve are low cost, high capacity, bidirectional cut, circulation in straight line, few leaks and it cleans itself.
Ball valves are recommended for:
- For driving and cutting duty, no strangulation
- When quick opening is required
- For moderate temperatures
- When minimal resistance to circulation is needed
- Low maintenance
- It does not require lubrication
- Compact Size
- Tight shut off with low torque
BODY AND ENDS
The body is made of cast steel or forged steel, depending on the customers’ requirements. All our ball valves are bidirectional and can be installed both in vertical and horizontal position. The spherical sections are designed to reduce tension under the most severe working conditions.
FIRE SAFE DESIGN
All our valves incorporate fire protection design, complying with international standards such as API-607, API-6FA, BS-6755. To guarantee this design we use fire resistant gaskets and packings namely graphite for the packings and metal with graphite for the gaskets.
SECONDARY INJECTION SYSTEM
System normally used for gas valves. A sealant may be injected both in the body and in the stem to repair loss of airtightness. For 6” valves and greater, the body injectors are positioned on the two seats, while for 4” and greater the injectors are placed directly on the body.
DESIGN OF TRUNNION BALL VALVES WITH SOFT METAL SEATS
In this design the ball is guided by the up and down stems. In this case the only possible movement for the ball is to rotate on its stem. To close the valve, the springs push the seat rings against the ball making a perfect close. The springs are used for providing uniform pressure and guided movement.
