ZECO Valve is API 609 Triple Offset butterfly valve manufacturer in India. We export our products to more than 30+ countries including European countries, Gulf countries, and nearby Indian ocean countries like Bangladesh, Indonesia, Malaysia, Singapore.
What is a Triple Offset Butterfly Valve?
A triple-offset butterfly valve has three separate offsets. Two of these apply to the location of the shaft in respect to the centre line of the bore and the centre line of the disc/seat sealing surfaces. While the third offset is the design in the axis of the seat cone angle.
Triple Offset Technology
Zero Offset: The Disc rotates around the centre axis, allowing for a potential 360 degree rotation. Sealing is achieved by the Disc deforming the soft seal. This results in full friction through the full operating cycle.
Double Offset: To allow displacement of the seat, the shaft is offset from the centre line of the disc seat and body seal (offset one), and the centre line of the bore (offset two). Thus creating a cam action during operation to lift the seat out of the seal. This results in friction during the first 10 degrees of opening and final 10 degrees of closing.
Triple Offset: The third offset is the geometry design of the sealing components. The sealing components are each machined into an offset conical profile resulting in a right-angled cone, which ensures friction-free stroking throughout its operating cycle. Contact is only made at the final point of closure with the 90 degree angle acting as a mechanical stop. This results in no over-travel of the disc seat.
Specifications of Triple Offset Butterfly Valves
| Size Range | NPS 2 to 56 / DN 50 to 1400 Larger sizes available upon request |
| Maximum Allowable Operating Pressure | ASME Class 150, 300, 600, 900 EN 1092 PN 10, 16, 25, 40, 63, 100, 150 |
| Temperature Range | -320°F to 842°F (-196°C to 450°C) Higher temperatures upon request |
| Shutoff Rating | Zero Leakage |
| Body Style | Lug, Wafer, Double Flanged, Gate, Buttweld |
| Design Standard | API 609, ASME B16.34, ASME VIII, API 600 |
| Flange Drilling | ASME B16.5, ASME B16.47, EN 1092, ISO 7005 |
| Testing Standard | ISO 5208, EN12266-1, API 6D, API 598, BS 6755 |
| Face to Face | API 609, ASME B16.10, ISO 5752, EN 558 |
| Fugitive Emissions | ISO 15848-1, API 641, TA Luft |
| Body Materials | Carbon Steel, Stainless Steel Other Materials Upon Request |
| Stem Materials | 17-4PH, 410 Stainless Steel, XM-19 (Nitronic 50) |
| Seat Materials | 316 Stainless Steel Hardened |
| Disc Materials | Carbon Steel, Stainless Steel Other Materials Upon Request |
Benefits of Triple Offset Butterfly Valves
- ‘Cam-action’ and ‘right angled’ conical sealing design ensures that the metal sealing components are never in contact until its final degree of closing – this results in repeatable sealing and a vastly extended valve life.
- Metal-to-Metal sealing ensures bubble tight shut-off, resulting in zero-leakage performance
- Suitability to harsh media – construction of the valve features no elastomers or materials typically affected by corrosion
- Geometric design of sealing components provides friction-free stroking throughout the valve. This extends the valve life and allows a lower torque-actuator to be fitted.
- There are no cavities between sealing components, resulting in no clogging, low maintenance and extended valve life.
Applications of Triple Offset Butterfly Valves
Triple Offset Butterfly Valves are essential in applications where bubble-tight shut off is required. In some applications, bubble-tight shut off cannot be achieved using double offset butterfly valves. Some applications do not lend themselves well to traditional butterfly valves, for example applications involving harsh chemicals or media with small particles prone to clogging valves and pipelines. In such applications, Triple Offset Technology offers superior benefits.
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