Butterfly Valves

Butterfly valves rotate a disc 90° inside the flow path to open or close—the simplest quarter-turn mechanism in industrial valve design. That simplicity is the reason butterfly valves dominate water, HVAC, and general process isolation: one moving part, one 90° stroke, one sealing interface, minimal space envelope, lowest cost per diameter inch of any shutoff valve type. FLOWKS manufactures eight butterfly valve configurations spanning three sealing philosophies and three body connection formats. Concentric (centerline) designs align the shaft, disc, and body on the same axis—the disc slides across the seat surface during rotation, simple and cheap but limited in pressure rating and cycle life. Double eccentric (high-performance) designs offset the shaft in two planes so the disc cam-lifts off the seat during opening, reducing rubbing and extending elastomer seat life by 3-5x. Triple eccentric designs offset the shaft in three planes so the disc only contacts the seat at the final 2-3° of closing—frictionless travel that enables metal-to-metal seating for high-temperature and fire-safe service. Seat types range from resilient elastomer liners (EPDM, NBR, Viton—bubble-tight, low-cost, temperature-limited) through metal seats (Stellite 6 overlay—fire-safe, high-temperature, slight ambient leakage) to multi-layer composite seats (metal base ring + flexible graphite layer—bubble-tight at ambient AND fire-safe under fire conditions). Body connections include wafer (sandwich between flanges, slimmest, cheapest), lug (threaded ears, one-side isolation capability), and butt-weld (permanent welded-in installation, zero external leak paths). Pneumatic, electric, hydraulic, and manual actuation options cover the full range of process automation requirements.

FLOWKS butterfly valves provide quarter-turn shutoff across the widest range of process conditions—from HVAC water isolation at Class 150 to petrochemical high-pressure high-temperature service at Class 900. Concentric centerline butterfly valves with resilient elastomer liners deliver cost-effective bidirectional sealing for water, wastewater, and light-process applications. Double eccentric high-performance butterfly valves reduce seat friction through cam-action disc rotation, extending elastomer cycle life and enabling Class 150-300 service with tighter shutoff. Triple eccentric butterfly valves with metal-to-metal Stellite seats eliminate elastomer entirely—rated for 350°C+ continuous temperature, fire-safe per API 607, ISO 15848 low-leakage fugitive emission compliant. Multi-layer composite seats combine bubble-tight ambient sealing with fire-safe metal backup for petrochemical installations that demand both capabilities. Wafer bodies offer the slimmest installation footprint between pipeline flanges. Lug bodies enable dead-end service and one-side isolation through independent threaded flange ears. Butt-welded ends eliminate flange gaskets entirely for permanent high-pressure and buried installations. Forged body construction provides casting-free pressure boundary integrity for severe service at small sizes. Pneumatic, electric, hydraulic, and manual gear actuation available across all configurations.