Double Eccentric Butterfly Valve Factory & Exporters in the Mumbai Market

The primary distinction lies in stem axis positioning. In a concentric (rubber-lined) butterfly valve, the stem passes directly through the disc centerline, maintaining constant interference contact with the rubber seat across the entire 90-degree sweep. This causes steady friction, higher operating torques, and wear.

In contrast, a double eccentric (double offset) valve offsets the stem behind the sealing plane (Offset 1) and laterally from the pipe centerline (Offset 2). This creates a geometric cam action: the disc disengages completely from the seat within 1 to 3 degrees of rotation, virtually eliminating seat rubbing, decreasing operating torque by up to 40%, and vastly extending valve lifespan under higher differential pressures.

For municipal water distribution, potable transmission, and raw water cooling lines (such as MCGM and MIDC municipal pumping schemes), EPDM is the preferred seat material. It provides excellent elasticity, resistance to chlorination, and long service life from -20°C to +120°C with bubble-tight Class VI / ISO 5208 Rate A sealing.

For petrochemical, aromatic hydrocarbon, and chemical processing in areas like Taloja, Virgin PTFE or Glass/Carbon-Reinforced PTFE (R-PTFE) is recommended. PTFE exhibits virtually universal chemical inertness across pH 0–14 and elevated temperature stability up to +200°C. For severe hot oil or fire-safe mandates, secondary metal-to-metal (Stellite/Inconel) fire-safe seats are utilized.

The camming motion is dictated by the secondary shaft offset. When the valve begins its opening stroke, the eccentric pivot forces the disc profile to move along an elliptical path rather than a pure circular arc. The disc lifts cleanly away from the sealing circumference almost instantaneously.

Because there is zero mechanical friction during intermediate modulation between 5 and 85 degrees of opening, the elastomeric or plastomeric seat suffers no compressive shear, tearing, or deformation. Wear occurs only during the brief moment of final shutoff compression.

Yes. High performance double eccentric butterfly valves feature an inherent modified equal-percentage flow characteristic between 20° and 70° disc opening. This makes them highly effective for dynamic flow regulation, balancing, and pressure reduction across water mains and process loops.

When selecting valves for throttling duties, engineers must verify the valve sizing coefficient (Cv/Kv) against the system's cavitation index (σ). Operating below the critical cavitation index may require anti-cavitation trim plates or downstream orifices to prevent localized fluid flashing and vapor bubble implosions.

Our production facilities design, cast, machine, and test double eccentric valves strictly against major global standards: API 609 (Category B) for high-performance industrial valves, AWWA C504 & AWWA C516 for large-bore waterworks infrastructure, BS EN 593 and ISO 10631 for industrial applications, and ASME B16.34 for pressure and temperature boundary integrity.

Face-to-face dimensions comply with ISO 5752 (Series 13, 14, 15, and 16), EN 558, and ASME B16.10, ensuring seamless drop-in field interchangeability without altering existing piping spools.

We routinely accommodate third-party inspection (TPI) protocols specified by EPC contractors and public sector undertakings. Clients frequently commission agencies such as Bureau Veritas (BV), Lloyd's Register (LR), TÜV SÜD, DNV, SGS, and Engineers India Limited (EIL) approved auditors.

These inspectors witness heat-treatment verification, raw casting RT/UT/MPI non-destructive evaluations, PMI spectral analysis, shell hydrostatic strength tests at 1.5x rating, bi-directional bubble-tight seat tests at 1.1x rating, and dry film paint thickness measurements prior to container loading.

For standard configured double eccentric butterfly valves (DN50 to DN600 in WCB or CF8M with manual gearboxes or pneumatic actuators), typical manufacturing lead time ranges from 2 to 4 weeks. Custom engineered large-diameter units (DN700 to DN2400) or special alloys (Duplex/NAB) typically require 4 to 7 weeks.

Ocean freight transit from our coastal shipping terminal directly to Nhava Sheva / JNPT Port takes approximately 14 to 20 sailing days, ensuring fast, predictable delivery for ongoing EPC construction schedules in Maharashtra.

Our double eccentric valves engineered with flanged and full-lug bodies conform strictly to API 609 Category B full rated dead-end service requirements. The seat retaining ring is secured by high-tensile fasteners calculated to safely absorb the full differential hydraulic force without downstream pipe flange support.

The asymmetric pressure-assisted seat geometry provides zero leakage (ISO 5208 Rate A) whether fluid pressure originates from the preferred shaft-upstream direction or reverse shaft-downstream direction, allowing safe isolation for downstream pump maintenance.

Given the aggressive marine humidity and industrial emissions around the Mumbai harbor and coastal belts, external surface preparation begins with automated SA 2.5 blast cleaning to remove all scale and oxidation. Bodies then receive a high-performance coating system:

For water distribution valves, we apply electrostatically deposited, non-toxic Fusion Bonded Epoxy (FBE) coating to a minimum dry film thickness (DFT) of 250 to 300 microns, fully holiday-tested at 1.5 kV. For chemical or coastal offshore skids, a 3-coat marine epoxy/polyurethane system (zinc-rich primer, epoxy intermediate, aliphatic polyurethane topcoat) provides outstanding UV and salt-spray resistance exceeding 1,500 hours ASTM B117 testing.

Yes. Every valve body is manufactured with an integral ISO 5211 direct-mounting top flange and standardized square or keyed drive shaft. This design enables plant technicians to easily remove manual worm gearboxes or hand levers and mount pneumatic quarter-turn actuators, electric multi-turn/quarter-turn motorized units, or electro-hydraulic actuators without disassembling the valve from the line.