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Posi-flate Butterfly Valve Seat Guide

SEAT TYPEPRESSURE RANGE PSIG (BARG)TEMPERATURE
RANGE
°F (°C)
SERIES 435,
436, 485, 486,
487 & 488
SERIES
483 & 484
SERIES
585 & 586
Min.Max.Min.Max.Min.Max.Min.Max.
Black EPDM60 (4.1)115 (7.9)60 (4.1)70 (4.8)60 (4.1)130 (9.0)-20° (-29°)150° (65°)
FDA White EPDM60 (4.1)80 (5.5)60 (4.1)70 (4.8)60 (4.1)100 (6.8)20° (-7°)125° (52°)
Black Buna-N60 (4.1)115 (7.9)60 (4.1)70 (4.8)60 (4.1)130 (9.0)-10° (-23°)125° (52°)
FDA White Buna-N60 (4.1)80 (5.5)60 (4.1)70 (4.8)60 (4.1)100 (6.8)20° (-7°)125° (52°)
Black Polyurethane60 (4.1)115 (7.9)60 (4.1)70 (4.8)60 (4.1)130 (9.0)32° (0°)150° (65°)
White Polyurethane70 (4.8)115 (7.9)70 (4.8)70 (4.8)80 (5.5)130 (9.0)32° (0°)150° (65°)
FDA White Silicone HS60 (4.1)115 (7.9)60 (4.1)70 (4.8)60 (4.1)130 (9.0)-40° (-40°)350° (175°)
Black Fluoroelastomer60 (4.1)70 (4.8)60 (4.1)70 (4.8)60 (4.1)90 (6.2)50° (10°)300° (149°)

If operating outside of these constraints, please consult factory.

FDA Materials: Seats constructed of FDA approved materials.

Temperature Range: Operating temperature range.

Maximum Pressure: Maximum seat inflation pressure.

Minimum Pressure**: Minimum seat inflation pressure to ensure seal.

**Seat inflation should be regulated to a minimum of 15 psig (1 barg) above material process pressure. Seat inflation should never be set below 40 psig (2.8 barg) for 430 and 480 Series valves. Seat inflation should never be below 60 psig (4.0 barg) for 580 Series valves.