Due to a very large flow passage DAFRAM control ball valves can grant high flow coefficients compared to other valve types. Thanks to their operating principle, quarter-turn ball valves are able to control fluid flow at very small openings and to open at high differential pressure. They are also able to maintain low fluid velocity thus lower noise and vibration to the pipeline. In addition, control ball valves allow tight and fast shut-off in case of emergency.
DAFRAM control ball valves assure excellent flow characteristic and provide accurate, reliable control in a wide range of applications, such as chemical, power and oil, both on gas and liquid service.
DAFRAM multi-stage ball valves are equipped with an internal cage that splits the pressure drop into several stages. Each stage is made up of a drilled plate placed in the ball hole. The number and configuration of internal stages are defined to meet the working conditions specified by the customer, in order to ensure the best flow control capability.
Multi-stage ball valves are designed to operate against high pressure drops providing excellent control capability and noise attenuation during a long service life. Furthermore, thanks to DAFRAM proven experience, tight shut-off and zero external leakage are a fixed point.
Both design and testing are performed by Dafram qualified engineers using dedicated software and hardware tools. Finite Element Analysis and Computational Fluid Dynamics for both structural and fluid dynamic design validation. Advanced calculation software and hardware allow to predict the valves flow characteristics in terms of pressure drop, flow velocity and risk of cavitation.
CFD analysis is the primary instrument for the design optimization: pressure and velocity fields are clearly defined at every opening angle, allowing cavitation and noise level numerical prediction.
Once known the working conditions, the single valve can be designed to perfectly meet the plant requests.
Read more: CFD analysis, flow calculation & testing facilities
High quality measurement equipment allows DAFRAM to collect reliable test data, that ensure a predictable behaviour of the valve in every working condition. Once known the customers’ specification in terms of fluid characteristic, expected flow temperatures, pressure levels and mass flow rates DAFRAM can develop a control valve that perfectly meets the process configuration.
Both benches ensure DAFRAM a complete design validation of control valves and an extremely accurate connection between tests and calculation results.
MODEL | DESIGN | SIZES | RATINGS | APPLICATION & DESIGN |
---|---|---|---|---|
LIGHT SERVICE | ||||
Reduced Flow Ball (RFB) | Trunnion mounted, reduced bore | Up to 48” | ANSI 150 to 4500 API 2000 to 20000 |
Basic control capability Tight shut-off Suitable for low differential pressures |
Hemisphere-molded Ball (HMB) | Segmented ball, trunnion mounted | Up to 20” | ANSI 150 to 2500 API 2000 to 10000 |
Light control capability Tight shut-off Suitable for low differential pressures Unidirectional |
MODEL | DESIGN | SIZES | RATINGS | APPLICATION & DESIGN |
---|---|---|---|---|
MEDIUM SERVICE | ||||
V-Shaper Ball (VSB) | V-port seat, trunnion mounted | Up to 48” | ANSI 150 to 4500 API 2000 to 20000 |
Good control capability (V shape designed to meet process conditions) Tight shut-off Fair cavitation resistance Unidirectional |
Disk Controller Ball (DCB) | Trunnion mounted with drilled disk | Up to 20” | ANSI 150 to 4500 API 2000 to 20000 |
Good control capability (Drilled disk designed to meet process conditions) Tight shut-off Moderate cavitation resistance Light noise reduction Unidirectional Vibration control Suitable for gas application |
MODEL | DESIGN | SIZES | RATINGS | APPLICATION & DESIGN |
---|---|---|---|---|
SEVERE SERVICE | ||||
Stream Tuner Ball (STB) | Multistage ball, trunnion mounted | Up to 48” | ANSI 150 to 2500 API 2000 to 10000 |
Multistage ball (stage number, hole configuration and general trim design are chosen to meet process conditions; the design is carried out by means of CFD analysis and validated by laboratory measurement) Tight shut-off Good control capability Vibration control Good cavitation resistance High differential pressure for gas service Noise reduction |
Noiseless Ball (NLB) | Special multistage ball, trunnion mounted | Up to 20” | ANSI 150 to 2500 API 2000 to 10000 |
Multistage ball (stage number, hole configuration and general trim design are chosen to meet process conditions; the design is carried out by means of CFD analysis and validated by laboratory measurement) Tight shut-off Good control capability Vibration control Excellent cavitation resistance High differential pressure for gas service Noise reduction |
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Because of the constant technical review of our products, we reserve the right to modify those products within the specified Standards criteria... Read more...