OEM On Off Butterfly Valve Factory & Global Manufacturing Hub

Concentric (zero-offset) butterfly valves position the stem right in the centerline of the disc and seat; the disc is constantly wiping against the resilient elastomer liner throughout rotation, delivering cost-effective zero-leakage shutoff in standard HVAC and water lines. Double eccentric (high-performance) valves displace the stem on two planes, allowing the disc to lift off the seat during the first degrees of opening to reduce friction and seat wear. Triple eccentric valves incorporate an additional conical offset angled geometry with a laminated metal-to-metal seal, completely eliminating rubbing friction during operation and providing bi-directional fire-safe shutoff for high-pressure superheated steam and petrochemical hydrocarbon pipelines.

ZFA Valve engineers versatile body molds designed to match multi-standard international pipeline flange drillings. Our universal wafer and lug patterns accommodate ASME B16.1 Class 125, ASME B16.5 Class 150, EN 1092-2 / DIN 2501 PN10 and PN16, BS 4504, JIS B2220 / B2239 10K, and AS 2129 Table D and Table E. Large diameter flanged bodies comply precisely with ISO 5752 series 13, 14, and EN 558 short and long face-to-face dimensions.

Wafer-type valves are held between two adjacent pipe flanges by long tie-rods; they represent the lightest, most economical design for continuous pipeline runs, but cannot be used for dead-end or tank isolation service because removing downstream piping releases pipe clamping force. Lug-type valves feature individual tapped threaded lugs around the body perimeter; each pipe flange bolts on independently, allowing downstream pipe dismantling while keeping the system pressurized upstream (dead-end isolation). Double-flanged valves provide dedicated integral flanges on both inlet and outlet, delivering the highest structural rigidity for heavy large-diameter municipal distribution mains (DN800 and above).

We utilize proprietary vulcanized elastomer bonding techniques where the EPDM or NBR rubber liner is molded directly onto a rigid phenolic or aluminum backing ring (cartridge design) or cured directly to the cast body shell. This eliminates seat stretching, pinching, and distortion under high differential pressures (up to 16/25 bar). Furthermore, high-polish disc edges (Ra < 0.4μm) and two-piece self-lubricating PTFE/bronze shaft bushings minimize mechanical wear, consistently achieving API 598 and ISO 5208 Rate A bubble-tight isolation across tens of thousands of cycles.

Standard OEM production for common sizes (DN50 to DN600) with custom client cast-in or laser-etched nameplates, bespoke epoxy powder coatings (specified by RAL color numbers), and private labeling typically runs within 15 to 25 calendar days. For custom alloys such as Super Duplex 2507, Hastelloy C, or large-scale project valves exceeding DN1200, lead times range between 30 and 45 days, inclusive of third-party NDT (radiographic/ultrasonic) witness inspection and certification dossiers.