Resilient Seated Butterfly Valve – Series 31H, Lug Type, Bi-Directional Shutoff

The Resilient Seated Butterfly Valve – Series 31H is engineered for reliable isolation and control in fluid systems requiring tight shutoff and durable construction. This lug-style butterfly valve features a ductile iron or cast iron body, resilient elastomer liner, and a 316 stainless steel disc for corrosion resistance and extended performance life. The fully supported stem and precision-machined disc edge ensure low operating torque and bubble-tight shutoff in either flow direction.

With mounting provisions per ISO 5211, this valve supports various actuation options including manual handles, gear operators, electric actuators, and pneumatic actuators. The internal stem bushing, shaft seal, and top/bottom trunnion support offer superior alignment and protection against leakage and wear. Designed to ANSI Class 150, the valve is available in sizes from 2" to 48" and meets AWWA, API, and EN standards for industrial valve integrity.

The Series 31H is ideal for potable water, wastewater, HVAC systems, fire protection networks, chemical processing, and general utility pipelines. Its concentric design and soft-seat construction enable it to operate efficiently in both high-cycle and static service conditions.

Specifications:

– Valve Type: Resilient seated butterfly valve
– Body Design: Lug style (bi-directional shutoff)
– Size Range: 2” to 48”
– Pressure Rating: ANSI Class 150 / PN10 / PN16
– Temperature Range: -20°C to +120°C (varies by liner material)
– Body Material: Ductile Iron ASTM A536 / Cast Iron ASTM A126
– Disc Material: 316 Stainless Steel, Aluminum-Bronze, Ductile Iron with Nylon/EPDM coating
– Shaft Material: 316 Stainless Steel
– Liner/Seat Material: EPDM, NBR, PTFE, Viton (optional)
– Shaft Design: One-piece through shaft with upper and lower trunnion support
– Stem Bushing: Self-lubricating PTFE or bronze
– Stem Seal: O-rings / packing system
– Face-to-Face: ASME B16.10 compliant
– Flange Compatibility: ASME B16.5 / EN 1092 / JIS / BS
– Testing Standards: API 598 / EN 12266-1
– Operation Modes: Lever, gear operator, pneumatic actuator, electric actuator
– Mounting Flange: ISO 5211 top flange for actuator mounting
– Applications: Water treatment, chemical processing, HVAC, fire protection, oil & gas utilities

For further specifications or to inquire about this equipment and ReflowX's logistics services, Please contact ReflowX at info@reflowx.com