Manual Butterfly Valves for Industrial Pipelines

Hard seal or soft seal?
Soft seal butterfly valves use an elastomer seat (typically EPDM or NBR) that provides tight shut-off at low to moderate pressures and temperatures. They are the standard choice for water supply, cooling water, HVAC, and general gas service. Metal hard seal butterfly valves use a metal-to-metal seating arrangement that can withstand higher temperatures and pressures where elastomer seats would degrade. If your application involves steam, high-temperature oil, or natural gas at elevated pressure, a hard seal butterfly valve is the appropriate choice.

Wafer or flanged connection?
Wafer butterfly valves are clamped between two pipeline flanges using through-bolts and are the more compact and cost-effective option. They are well suited for installations where space is limited and the valve does not need to be isolated from the pipeline for maintenance. Flanged butterfly valves have integrated flanges that bolt directly to the pipeline flanges, allowing the valve to be removed independently without disturbing adjacent pipe sections.

Which body material?
WCB carbon steel is the standard choice for general service at moderate temperatures. SS304 (CF8) provides better corrosion resistance for mildly aggressive media and is commonly used in food processing and clean water applications. SS316 (CF8M) offers greater resistance to chlorides and stronger chemicals. For highly corrosive media such as strong acids and alkalis, a PTFE-lined valve body is required. For low-pressure water treatment or chemical dosing systems where weight is a concern, a plastic valve body valve may be the most practical option.

Direct handle or worm gear drive?
For smaller diameter butterfly valves, a direct lever handle provides fast, simple quarter-turn operation. For larger diameters where the torque required to operate the valve exceeds practical hand force, a worm gear drive is used to multiply the operator’s input. VINCER’s hard seal butterfly valve models come with worm gear drives as standard.