characteristics of the Ball
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.
COMPETITIVE ADVANTAGES
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
DESIGN FEATURES
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.
TECHNICAL INFORMATION
ARFLU MANUFACTURING RANGE
SIZE
construction
ends
asme class
international standards
INTERNATIONAL DESIGN STANDARDS
Our ball valves are designed and manufactured according to the following international standards:
DESIGN AND MANUFACTURING:
API 6D: Pipeline Valves. Pressure Test Specification.
ASME B 16.34: Valves-Flanged, Threaded, and Welding End.
BS 5351 (substituída por ISO 17292)
API 608: Metal ball valves – Flanged, Threaded, and Welding End
ISO 17292: Metal ball valves for petroleum, petrochemical and allied industries
ISO 14313 Petroleum and natural gas industries, pipeline transportation systems, pipeline valves
INSPECTION AND TEST:
API 6D: Pipeline Valves. Pressure Test Specification.
API 598: Valve Inspection and Testing.
API-607: Fire Test for Soft-seated Quarter-turn Valves
ISO 15848: Industrial Valves – Measurement, test and qualification procedures for fugitive emissions.
API RP 6FA: Specification for Fire Test for Valves
FLANGE DIMENSION:
ASME B 16.5: Pipe Flanges and Flanged Fittings.
ASME B16.47: large diameter steel flanges: nps 26 through nps 60
MSS SP 44: Steel pipeline flanges
WELDED OR THREADED ENDS:
ASME B16.25: Buttwelding ends
ASMEB16.11: Forged fittings, socket-welding and threaded
ASME B1.20.1: Pipe threads general purpose
FACE TO FACE AND END TO END:
ASME B 16.10: Face-to-Face and End-to-End Dimensions of Valves.
API 6D: Pipeline Valves. Pressure Test Specification
* Other standards/materials on request
