The VPR 34100 CF Pneumatic Control Butterfly Valve (Part Number / Model: VPR 34100 CF - Fail Open) engineered and manufactured by premier French industrial valve maker Automatic Valve Réalisation (AUTOMATIC VALVE S.A.S. - France) seamlessly pairs the proven 34 100 / 34 102 wafer butterfly valve with a heavy-duty rolling diaphragm pneumatic actuator configured for Fail-Open (Air Failure Opened / Air-to-Close) operation.

PRODUCT OVERVIEW & SPECIFICATIONS (VPR 34100 CF):
- Model Designation: VPR 34100 CF (Vanne Papillon Régulatrice - Commande Fermante / Air to Close).
- Manufacturer: Automatic Valve Réalisation (France).
- Fail-Safe Operating Logic: Air-to-Close / Spring-to-Open. In the event of control air failure or pressure loss, heavy-duty internal return springs instantly drive the butterfly disc to the fully open position, providing emergency pressure venting or draft relief to prevent catastrophic duct overpressurization.
- Nominal Diameter Spectrum: Available from DN65 (2-1/2") up to DN1300 (52"), suitable for major industrial air handling and high-volume flue gas ducts.
- Rolling Diaphragm Actuation: Employs a long-stroke reinforced elastomeric rolling diaphragm that completely eliminates sliding piston friction, ensuring zero hysteresis, exceptional control precision, and maintenance-free service exceeding 1,000,000 cycles.

KEY ADVANTAGES:
- Intrinsic Emergency Fail-Open Protection: Guarantees full path clearance during power blackouts or instrument air failure.
- Extreme Thermal Resilience: Operates continuously and reliably in severe hot gas environments from -50°C up to +900°C without binding.
- Live-Loaded Stem Sealing: Features a graphite stuffing box energized by Belleville spring washers, delivering constant seal tightness and eliminating fugitive emissions.

• Manufacturer: Automatic Valve Réalisation (AUTOMATIC VALVE S.A.S.)
• Origin: France
• Valve Series: VPR 34100 CF (Belonging to 34100 / 34102 SERIES)
• Valve Type: Pneumatic Control Butterfly Valve - Fail-Open Configuration
• Failure Action: Air Failure Opened (Normally Open / Air-to-Close)
• Nominal Diameters: DN65 to DN1300 (ND65 - ND1300 mm / 2-1/2" to 52")
• Mounting Style: Wafer-type design for clamping between flanges (PN6, PN10, PN16, PN20, or ANSI 150 lbs)
• Control Characteristic: Approximately Equal Percentage
• Seat Leakage Class: Class II (34100) or Class III (34102 with metal stops) per ANSI/FCI 70-2
• Thermal Operating Range: -50°C to +900°C
• Pneumatic Actuator: High-performance rolling diaphragm actuator (VPR Series)
• Instrument Air Supply: 2.0 to 6.0 bar
• Control Input Signals: 4-20 mA / 0.2-1.0 bar (with optional electro-pneumatic positioner)
• Body & Disc Materials: Carbon steel, high-temperature alloy steel, or stainless steel grades
• Stem Packing: High-temperature graphite with live-loaded Belleville spring compensation
• Actuator Interface: Standardized ISO 5211 mounting pad
• Typical Applications: Emergency boiler exhaust bypass dampers, metallurgical furnace pressure relief, cement kiln cooling lines, and industrial thermal oxidizer air supplies.