Butterfly valves are selected for on/off isolation and flow regulation service in pipeline systems where compact face-to-face dimensions, low weight, and fast quarter-turn operation are required. The rotating disc design provides full closure in a 90° turn, making butterfly valves the preferred choice for large-diameter, low-to-medium pressure applications in water treatment, HVAC, cooling water, fire protection, and general process industries. Triple offset butterfly valves extend this range into high-pressure, high-temperature, and demanding process applications — the three-dimensional offset geometry between the stem axis, disc axis, and cone axis generates a cam-action seating movement that eliminates contact friction during opening and closing, producing a bubble-tight metal-to-metal seal suitable for Class 150 through Class 600 service.

Triple offset construction removes the limitation of conventional rubber-seated designs: there is no seat contact friction during rotation, no elastomer degradation under elevated temperature, and no deformation of soft seating materials under high differential pressure. The metal seat — typically Stellite-overlaid or SS316 hard-faced — provides shutoff integrity at temperatures from cryogenic to 600°C and enables bidirectional zero-leakage sealing to ASME Class VI requirements. This makes triple offset butterfly valves the standard selection for steam isolation, cryogenic LNG service, offshore hydrocarbon isolation, and high-cycle industrial process applications where conventional butterfly valves or gate valves are either unsuitable or disproportionately heavy.

Body materials in bronze (C95800), cast steel (WCB, CF8M), duplex stainless steel (F51), and nickel alloys cover the full range of corrosive and high-pressure applications. Gear operators are standard for DN200 and above, where manual handwheel torque becomes impractical under full differential pressure; electric, pneumatic, and hydraulic actuators are available for automated or remote-controlled service. HD Flowtech triple offset butterfly valves are manufactured to API 609 Category B, with shell and seat testing per API 598, and are available in wafer, lug, and double-flanged end configurations to ASME B16.5 and EN 1092-1.